Going Green

Ecopower Thermal Dispatch

2010-01-22T07:00:00.000-08:00

How much does the micro-CHP contribute to satisfying the thermal load of our house, and what would be needed to put the entire thermal load onto a co-generator? That is the question that this post tries to answer.

The above plot shows the amount of electric power generated over a 24-hour average versus the average daily temperature. The temperature reading is from the Hartford, CT airport, but has been adjusted upwards by 2 degrees Fahrenheit, for that appears to be the average temperature difference between the thermometer at our house and at the airport. It is important to note that the y-axis is the electric power and not the thermal output. To get the thermal output in KWH, multiply the y-axis value by 2.6 (the long-term average of the Ecopower's thermal/electric ratio). To get to BTUs/hr, multiply the thermal output by 3412.

Let's go through all the different things on the plot. The blue points are ones from the past year where the Ecopower was run as the primary heating source for the house. The purple dots are from the period where the Ecopower was used as hot water and second-stage heat. Recent analyses suggest to me that this 2nd stage usage is almost entirely hot water and not space heating, and maybe with time I can get a post out on that.

The black dots are from an empirical linear fit to the non-space heating data. What is interesting about it is that the points colder than 50 F are not needed to get the slope. In other words, there is a slight temperature dependence to the amount of fuel needed to heat the hot water, and extending that dependence to lower temperatures lines up with the actual data at lower temperatures. Generally, people speak of base load and heating load where base load is found by taking the fuel consumption in the absence of the space heating. The small base load temperature dependence is usually ignored (well, it is small). I found the temperature dependence somewhat surprising, but of course, now it is obvious that there should be such a dependence at some level. Don't take the exact match at the temperatures below 40 degrees to mean that hot water load is totally responsible, but it almost certainly is most of it.

The red dots are from a (loose) fit to and extrapolation of the space heating data, and they have the same range in temperature as the black dots. They span the entire daily data set for Hartford from 1948 up to the present. The light blue dots show the Ecopower's maximum output stuck at 4.7 KW. Indeed, you can see that the actual data (the blue dots) do turn over just under the power cap. The blue "sagging" points are from days where either we were away or where we used the geothermal for part or all of the space heat.

The blue vertical dashed line at zero degrees F represents the so-called "Manual-J" esitmate as filed with the local building department when our original heating oil boiler was installed in early 2006. The heating unit is supposed to be sized to keep the house at 70 degrees Fahrenheit at the minimum expected temperature for our geographic location, which for our location, just happens to be 0F. The expected heating load is 99,111 BTU/hour, or, about 29 KW which corresponds to just more than 11 KW electric output from a co-generator with the Ecopower efficiency and thermal to electric output ratio.

Recall that the red line is the extrapolation of the actual load experience through the expected temperature range. The light dashed green line is just the line from the Manual-J level to 65F, the place where traditionally the heating load starts. You can certainly quibble that the red-linear fit isn't exactly right, and I won't argue too much, but it seems pretty clear that our heating load is lower than that estimated by the person who installed the oil burner--a burner that was rated at 125,000 BTU/hr, a full 34% higher than the Manual-J calculation.

The real irony here is that the person who installed the geothermal called me up after I had sent him that previously filed load calculation and told me that that calculation had under-estimated the house's true load, and he estimated the load to be about 25% higher, and he sized the geothermal system based upon his calculation. With that, I decided at the time to try to do the load calculation myself, and from some web surfing, I found www.hvaccomputer.com, where for $49, you can get a 2-month use of software that does the Manual-J calculation. It takes some time to input all the data, but once I did, I got somewhere around 80,000 BTU/hr as the proper heating load, a value that would be equivalent to about 9KW electric output for an Ecopower type system. After arguing in vain with the geothermal guy that we didn't need such a big system, I finally caved in and got the geothermal--primarily because I really really wanted to get off of oil as much as I could. This was in late 2006.

Anyone who has made a Manual-J calculation will tell you that there are more than a few places to vary the inputs to get some different outputs. It appears that the installers tend to be a little loosey-goosey. There are two good reasons. The first is that they probably have an arrangement with the equipment provider to get a cut of the sale, and that would bias folks to a larger system. I want to stress here that I haven't any proof that that happened in this case and am not accusing anyone of any thing. The second reason I think may be more plausible, and that is that with a slightly larger size, the HVAC installer knows there won't be a problem with heating or cooling due to insufficient capacity, and so they would naturally want to oversize by a little to provide for some room for growth and to insure they don't have to come back any time soon. At any rate, it looks to me that my calculation was probably the most accurate, but frankly, why not just take people's actual data and use that?

At any rate, to get back to my question asked at the beginning, a 10KW system would probably be sufficient to meet the entire heating load for our house as we use it. The Manual would say we'd want 12KW at least, and the local installer, if he had a choice, would probably recommend 15KW. There are all sorts of questions that this answer raises, namely what about the economics, etc? Presently, to recover the capital costs involved with the systems, you really need to be running the devices at 80-100% of capacity, and we are at about half of that. It is interesting to note that most of the present systems seem to match a clear load, namely water heating.

My question next is to go in the opposite direction, namely, are there things I could do to have the current system be sufficient for total heating load? And a related question really is whether or not one would want only an engine heating the house. That second question is a trade-off of economics versus security as I see it, and today I don't have a satisfactory answer as to how to make the appropriate size, and it isn't clear to me that anybody else has the answer to that either, but I could be wrong there.

One last thing on the plot is the blue dashed line on the right-hand side. This doesn't really belong on this plot at all, and it is misleading to put it on the plot, but I did anyway. The value there corresponds to the cooling load of 58,447 BTU/hr as filed with the Building Dept here. The geothermal guy was of course higher, and our geothermal system is rated at 6.5 tons or 78,000 BTU/hr (an 8.8KW machine), roughly, it seems, to match our heating load and not our cooling load! I think the hot water/2nd stage heating only data support that notion.

Our Latest Power Bill

2010-01-16T06:45:00.000-08:00

Due to the recent cold spell, we sold back more KWH than we purchased over the last month. We have banked 202 KWH to work against future consumption. Bill is $16 which is the monthly service fee. Click on the figure for a better view.

A Temperature Measurement Issue

2009-12-22T08:53:00.001-08:00

One of the major issues in the climate change discussions is the reliability of the historical temperature records. The sceptics pounce on this one, and frankly, I have to give them some credit, because I've spent a good deal of time looking into the temperature data, and understanding some of the nuances isn't necessarily easy. In fact, I'm not convinced that the scientific community at large understands this as well as they need to. This is not to say that I think the carbon issue is a non-issue, but I would not be surprised if a significant part of the measured warmth is not due to greenhouse gases but to other things with the measurement problem being one of a myriad of outstanding analysis wrinkles.

The graph above is a rather extreme case in point. This is a plot of the outside temperature data as measured at our house and nearby. The light blue line is the temperature measurement from the thermometer associated with my generator, and a reading is taken every 15 minutes. The outside temperature is measured mainly to make sure the fuel balance is correct. I'm using the data to help understand the expected heating load.

The data are from 31-Mar-2009. Last spring I was outside and remember seeing that the sun was shining directly on the box that is attached to the back of my house and which contains the temperature reader. Most of the year this side gets shaded by three trees, but in the spring, prior to the leaves coming, the sun will peek through to the back side of the house in the late afternoon. When that happens, the process of radiative heating warms up the box beyond the ambient air temperature. I remember at the time thinking I needed to check the data for this, and well, I guess the effect is pretty big.

The other data are from the Weather Underground site. There are data from literally thousands of personal weather stations available there now, and I picked the closest stations to my house that had data on the appropriate date. There are two green-colored datasets, one of which is missing most of the data (and is the straight line across the plot). The second one is closer to the beach, and that is the primary reason it is lower in temperature. The others are further from the shore and more representative of our experience--except for the late afternoon when the sun hits our thermometer.

Alas, another thing that needs to be checked and corrected.

Just for the record, no I don't think all the NOAA (and other scientifically oriented) thermometers drift by as much as 20 degrees F, but I would not completely rule out issues at 1/20th that size, and this comment is based on not this particular graph but on my own experience dealing with NOAA data as well as other International data. Yes, there is a whole sub-industry involved in this academically, and yes they do good work, but I don't think the issue is as closed as many believe it is.

Power Source--Relative Contributions

2009-12-10T11:15:00.000-08:00

As an addendum to the last post, the figure above shows the relative fraction of the different power sources. Solar varies between 10 and 15 percent of our power that we use. The big shift is when the Ecopower was installed. We now co-generate locally between 25 and 85 percent of our own power depending upon the heating needs with the largest local generation naturally being in the winter. Combined with the solar, during the swing heating months we generate virtually all of our power locally.

For completeness, the two vertical lines show important operation changes. The first is when the solar panel upgrade occurred (can you tell the difference?! It sure is hard!). The second is when we switched the Ecopower from 2nd stage heating to first stage heating. The plan is to keep it that way at least through this coming winter with no other changes.

Household Energy Use

2009-12-04T13:11:00.000-08:00

With the digitization of the propane data as described in the last post, the total household energy use can now be analyzed. This kind of analysis seems to be growing in popularity. Witness the rise of Google Power and Microsoft Hohm. The latest one I've been introduced to is www.mygreenquest.com. I've looked at the last one and may migrate some material there, but for now, I'll use my own clunky analysis program as there are only so many hours in a day.

The following figure shows the fuel use for our house since late 2000. The dark blue is heating oil, the light blue is propane, and the big purple vertical rectangle is the period where we gutted the house and expanded it from 2600 to 4200 square feet. The size addition, I think, now files inside the "what were we thinking" folder, but we do love our home. Below the fuel figure is a figure detailing the electricity use and generation.

In the household fuel use figure, the different rectangular boxes represent one delivery by the distributor(s). The use clearly spikes in the winter and deliveries are more frequent then, so the rectangles are narrower. The base load is easy to estimate at 1.9 gal/day for heating oil--independent of time amazingly--and the propane use is 3.9 gal/day. The difference between those two numbers is discussed in the post prior to this. (That post is unfortunately a little technical and its significance is probably only appreciated by the makers of the Ecopower and maybe a few other pointy-headed geeks such as myself.)

The electricity figure is a little busy but full of information. The upper black line is the total amount of electricity consumed with the blue infill being the amount pulled from the grid. The yellow infill is solar generation, and the green infill is the Ecopower co-generation.

The number of different operation modes is beginning to become a problem in analyzing the data. Here are some of the details. Prior to the renovation, the situation was the standard old New England drafty house, poorly insulated, heat came from heating oil with supplemental electric heaters, and power all came from the grid. Just after the renovation, the solar panels were installed (2.5 KW) and they were upgraded in Sep '08 to 3KW. The Ecopower co-generator went live in Apr '08. In the fall of '06, after the renovation and after the hot summer, the geothermal (ground source heat pumps) were installed. Needless to say, this is a very non-standard situation here. One further complication is that prior to 2009, the system was run with the geothermal as first stage heat and the Ecopower as second stage heat when the geothermal couldn't quite keep up with the heating load. Since Jan, 2009, the situation is reversed with the Ecopower as first stage and the geothermal brought on only when the Ecopower can't keep up with the heating load. Very non-standard indeed.

The above figure shows the data from 2006 and is an attempt to better see the detail. The co-generation contribution is encouraging, but it comes at a cost of more fuel consumption. It seems like we are in a game of whack-a-mole here. We put in geothermal in an effort to reduce heating oil dependence only to see the power consumption go up. We put in solar, and while it helps, it sure seems less than stellar (I guess that pun was intended). Co-gen works at reducing electricity from the grid, but now we burn more fuel.

The question now in my mind is whether or not the move to propane and local generation was what I wanted, for it means more fuel consumption, or at least it seems that way. A primary aim is to reduce foreign energy dependence and increase our energy security, and given that as the goal, is burning propane, which has some foreign sourcing, better than burning natural gas at a power station and running geothermal off the power which is almost all domestic in origin? I think I've resolved how to think about that issue beyond (1) the efficiency argument that the grid structure is enormously inefficient, and (2) local power capability represents an improvement in energy security (even if it has yet to be enabled for backup power mode). These issues and more will be the subject of a later post.

When analyzing the last figure, there are two things worth mentioning. The first was alluded to earlier, and that is prior to 2009, the Ecopower ran in second-stage heat mode with geothermal as first stage. The drop-off in grid power since 2009 is substantial and installations would reflect a drop, but remember that the drop is in part from a reduction in heating with geothermal. The second item regards the small spike in heating oil use in Mar, Apr, 2008. Seeing that brought back some memories.

Throughout the winter of '07-'08, the exact Ecopower installation time was somewhat uncertain. As a result, I was ordering heating oil in 100 gallon units from a local distributor, the minimum amount they would deliver, for I didn't want to be stuck with extra oil. Timing wasn't always good, and we ran out a couple of times. With geothermal available, we had house heat but not water heat, sometimes for as long as 24 hours, much to the consternation of an increasingly impatient family. The experience was valuable for it taught us that having hot water is an enormous contributor to one's self-esteem and without it, life can appear less than dignified.

In early '08, as the Ecopower launch was getting closer, the heat was switched to heating oil as first stage heat to insure we wouldn't get stuck with any extra oil, and the spike in heating oil use is with the house just on heating oil. That period of 2 fills provides us with a powerful comparison between the old house and the new one, and the new house on heating oil still used less than the old house on heating oil, degree-for-degree, even though the house is now considerably larger.

At the tail end of the heating oil period, with the heating season over, we only needed hot water heat, and it made no sense then to buy 100 gallons from the distributor. It was funny interacting with them. Prices were soaring during that period, and I think they thought I wasn't able to afford too much oil, which was the case for many people, because we were only buying to 100 gallon increments instead of filling our tank. They knew I was in the process of getting off heating oil, and when heating oil went above $4/gal, the drivers started asking me about how the geothermal was working. It was an interesting turn of events that the people whose income depended upon a system of fossil fuels was beginning to question the value of it.

The last little heating oil fill is actually me filling it 5 gallons at a time with diesel from the gas station. We still have about 5 gallons of heating oil (diesel really) in our tanks. Some day we'll remove all vestiges of the heating oil system. Whenever we get around to it, that will be a good day.

Propane Use and the Power Conversion Number

2009-11-25T06:24:00.000-08:00

In the prior co-generation posts an important number I've used to calculate the propane to power factor via the Ecopower. That number is 5.82 KWH/gallon of propane (plus about twice that amount in heat produced which is also used). That number comes from the Ecopower spec-sheet that has the rate of 4.7KW with a fuel rate of 3.42 lbs/hr, and using 4.24 lbs/gal, the weight of propane, you get the 5.82 number above.

I've been putting off the analysis of trying to check the power conversion number, mainly because it meant aggregating my propane bills and importing the numbers into a spreadsheet. Well I did that finally and this post goes through the estimation.

Our propane tank has a 500 gallon capacity, and about once a month the propane truck shows up and fills the tank to some level near the top. Exactly where it gets filled to, I don't know, but I know it isn't to full capacity. They always leave a little room for vapor expansion and such, so there is potentially some jitter there on a month-to-month basis. I will make the assumption that the tank is filled to the same level each time, and the amount of power generated from fill-to-fill is related to the amount put into the tank.

Another complicating factor is that we also use propane for cooking, and the amount of cooking isn't necessarily a constant, so if we just take the amount of propane used and divide that into the amount of KWH generated, the result will be an under-estimate of the conversion efficiency, and there will be a fill-to-fill variation depending upon how much stove top usage there is. The only way to get a more accurate number would be to put a flow meter on the co-generator fuel line, and I may request that, but the soonest that would be done is January, 2010.

The useful data is comprised of 16 periods starting with a fill on July 22, 2008 to the latest fill on November 9, 2009. The following figure shows the daily propane usage for the periods where each box represents one fill.

The red line in the figure is an estimate of the baseline propane use, and at just under 4 gallons per day. I'm going to call it 3.9 gallons/day baseline which is where the line is drawn. That sure is a lot of fuel just to heat hot water. When we were using heating oil, we used about 1.9 gallons per day for hot water use which is still quite a lot, and it continues to bother me.

At any rate, how do the numbers compare? For starters, we have to compare with similar heat content. A gallon of heating oil, if burned, releases 139,000 BTUs of heat while a gallon of propane releases 91,333 BTUs, so heating oil has 1.52 times more energy than propane, gallon for gallon, which means that if magically we could run the Ecopower on heating oil (or diesel for that matter), we would be using 2.56 gallons of heating oil--still above the 1.9 gal/day old use.

Well, we are close to our heating oil use, but we have one more adjustment before a proper comparison. Because we are co-generating electricity, we using 27% more than we would normally use in heat production, and if we divide 2.56 by 1.27, we get 2.02 gallons per day of heating oil boiler equivalent--close to our old baseline rate, so that's good on a consistency basis. It is a little bit high, though, and that could in part be explained by the cooking use. Let's keep that in mind as we continue on our goal, the propane-to-power conversion number.

The other great thing about the Ecopower is that it keeps track of how much power has been generated, and I've been logging that information too. The next figure shows the KWH generated per gallon of propane for the 16 periods. The blue points are the raw numbers without any adjustment. The x-axis has the number of days between fills, partly as a way to separate the estimates, and partly to look for a bias that would show the cooking use. The red line is the advertised value from Marathon Engine, 5.82 KWH/gal.

Looking at the data scatter, one can argue that there is an average daily use, and it works out to about 0.28-0.29 Gal/day cooking use. This number is determined iteratively. Frankly, I haven't thought much about cooking use, so I don't know how to interpret that value, but that value would give an agreement with the old baseline heating oil use of about 1.9 gal/day (in fact, it overcorrects!). The blue line shows the least-squares fit to the data, and it intercepts out at 5.62 KWH/gal which is the number that should be compared to the advertised value. The error estimate on that is 0.1 KWH/gal (from a bootstrap technique for any geeks reading this).

One has to be careful over-interpreting these data. The two points out near 80 days between fills were early on. After those points were taken, a leak in the system was found. Was the leak present during those points, and later use has less of an effect? Also, the laggards at 20 days and near or below 5 KWH/gal can be selected out, because my in-laws were in town, and my mother-in-law loves to cook. Could she have been using 4 times as much propane per day we normally use in cooking? Seems easy to believe, and it can't be ruled out at the moment. If you discard those two laggards, you get to the 5.82 value, and it would raise the daily cooking use to about 0.4 gal/day. All sorts of data adjustments are possible. I'll leave the values as I found them for now which is the appropriate thing to do.

This post has tried to test the Ecopower propane-to-power conversion number advertised by Marathon Engine. The value I get using the number of gallons reported to me by the propane delivery company and the number of KWH reported by the Ecopower is 5.62 KWH/gal plus or minus 0.1 KWH/gal, and I estimate we are using 0.29 gal/day of propane in stove top cooking (our oven is electric). The measured propane to KWH number is lower than advertised by about 3%, but it is within the statistical error range and probably within the possible systematic errors, the bulk of which would bias our estimate to be too low.

Note: The daily cooking rate number was originally calculated incorrectly, and I have corrected that from an earlier version of this post and adjusted the text appropriately.

Co-generation Operation Cost vs. Fuel Cost

2009-11-21T06:23:00.000-08:00

In an extension of previous posts, I've looked at the Ecopower operating costs versus fuel costs for propane and natural gas. The above figure shows the cost of power production for these two fuels. There are three different lines drawn. The blue lines show the cost of production assuming that no "waste" heat is used, and clearly the costs are rather high.

The red lines (and next lines down from the tops) show the generation cost in co-generation mode. The main assumption is that the extra fuel requirements are 30% over a traditional boiler or furnace.

The lower purple lines in both graphs in the figure is the equivalent market generation cost in the case of a $0.05/KWH delivery cost. Currently here in CT, the delivery cost is $0.0545/KWH. The purple lines show what the market competition is (coal!). What is notable is that with a propane price of less than $1.5/gal or a natural gas price of less than $15/mcf (retail price), it makes sense always to generate the power locally in co-generation mode if there is a net metering arrangement in place, because it costs more to deliver the power than it does to co-generate the power locally.

Current costs this year in CT is about $2/gal for propane and $20/mcf for natural gas. This is the retail price, and for natural gas it is rather high as wholesale natural gas for delivery next month is currently under $5/mcf. There is always a retail mark-up due to the extra delivery costs and, in the case of natural gas which is regulated, there is probably an additional cost from prior hedging with gas procured for delivery earlier in the year or last year when prices were significantly higher. The retail power cost including generation and delivery is in the range of $0.15/KWH to $0.18/KWH depending upon the retail provider (we have choices here in CT).

The conclusion is that co-generation wins hands down, and the primary reasons are (1) close to 70% of the fuel energy is lost as waste heat up the smoke stack and in transmission, and (2) there is a delivery cost for distributing the power, and these extra costs are larger than the extra retail fuel cost over wholesale fuel cost.

I would love someone to check these numbers. The methodology is described in prior posts on the co-generation costs.

Time of Use Power Pricing

2009-11-12T11:36:00.000-08:00

The current power rate structures that exist provide very little options for power users. One of the reasons is that historically power meters have to be read on-site and are usually done so only once a month. The only real option that users have had are either a single rate structure where power costs the same regardless of when you use it (what most everybody does), or a time of use structure where you pay less for off-peak usage and more for on-peak usage. Here in CT, peak time is between Noon and 8:00 PM local time weekdays.

Here in Southern CT, the peak/off-peak option doesn't get one much if anything. We are somewhat deregulated here, so there are a few companies vying for retail power business. The main supplier is Connecticut Light and Power, but there are other ones now, and most of them offer rates that beat the peak/off-peak CL&P rate, so if one is interested in saving something, it seems best to just switch providers and take their single rate structure--which is what all of them only seem to offer.

The one new difference now is that CL&P offers something called Variable Peak Pricing or VPP. The VPP option involves a fixed off-peak rate and a peak rate that varies daily. The VPP option has been available for about a year. I decided to look into VPP just to see if it offered any advantage, and here is the result.

The first question was if the pricing could be reproduced. The off-peak price is just the same as the standard Time-of-use option, and it is presently about 11.5 cents/kwh which is more expensive than some of the competitors' single rate cost. For standard TOU service, the peak price is about 14.5 cents generation rate. To get the billing price, you have to add $.0545/KWH, the transmission and taxes portion of the price.

The VPP history is posted on the CL&P website, and it is shown below. Included is my attempt to model the price, and I can get the variation, but there is also an offset of between 2 and 5 cents that seems to reset every quarter or so. Exactly how this offset is determined, I don't know, and I have a call into CLP and hopefully will get an explanation. At any rate, to within an offset, I can reproduce how they get their price just by taking the Day-ahead New England price and averaging over the peak demand hours (Noon-8:00 PM).

The first item of note is that the peak price is in fact lower than the set off-peak price and has been for about a year now. At present, then, it makes sense to shift load to peak times as opposed to off-peak times! That is a characteristic of how CLP currently structures their program as well as lower natural gas prices this year as compared to past years and frankly doesn't make any sense. I'm guessing it is a result of CLP hedging their off-peak price when power prices were higher.

Given the historical day-ahead pricing data from the New England ISO, we can now estimate how the price would have varied back to 2003 and that is in the above figure in blue. I've assumed an average additional $.035/KWH as the average offset fixed over the period. In the more distant past, it is possible that that figure is too high, but it is probably reasonable going forward. The black line is the actual single-rate price from our electric power bill. Only the generation rate is shown, and transmission, taxes, etc would have to be added to get the true cost. The off-peak price would probably be at a discount to the single-rate price, probably on the order of a penny or so.

The question still remains as to whether or not to shift to VPP. It seems that it makes sense in a market where the power prices are falling, and to stay with fixed pricing when power prices are rising, which is the standard result of hedging--it works in rising markets, but you pay for it in falling markets.

For most people, I think it would make sense just to shift to a different provider for now to save money. However, with some load shifting capability (and with generation capability), VPP may even make sense. One needs historical off-peak prices to answer that question, and I have that call into CL&P for that too.

I was also hoping VPP offered the ability to do daily-net metering. With generation capacity (both solar and co-gen), there are time where I could crank up the amount going back to the grid. Unfortunately, net metering occurs only over the course of the year, and so there is no advantage to generating more than would be used on a daily basis. For instance, in early January, 2004, the price was over $.4/KWH. This cost is large enough that I could run the Ecopower at full throttle and still make money if CL&P was in fact paying $0.4/KWH for power sold back. However, under the VPP program, the most economical thing I could do would be to run enough to offset any purchases made that day so that the net grid power purchase was in fact zero.

The question of whether or not it is advantageous to switch to VPP remains and to better answer it, I need a daily load model for our house. With some data I've collected, it is possible to generate that, but it is going to take more work.

Co-Generation Return on Investment

2009-07-17T06:09:00.000-07:00

In the last post, our Ecopower operating costs were estimated at $.08/KWH using $2 per gallon propane cost when running in combined heat and power mode (as opposed to just straight generation where the operating costs are $.34/KWH for the same fuel price). How does this savings translate into a return on the investment? The answer to that question depends upon how often (and at what level) the Ecopower is run as well as the power company power cost.

The present power cost here in Southern CT is $0.18/KWH, so for each Kilowatt-hour generated, our present savings is ten cents. This cost difference is variable and is at the high end of the historical range due in part to the lower propane costs relative to the cost of fuel last year when the power costs were set for the year. Next year the power costs will probably come down to $.12/KWH, or, at least they should, so the cost difference will shrink. However, the fuel costs will also probably continue to decline, so it will still be cheaper to generate locally.

Let's now assume that we have an application where the Ecopower can be constantly run. With net power production at 4.7 KW maximum power and using 8760 hours per year, we get a potential of 41,172 KWH generation annually which translates to an annual savings of $4117.2.

Our cost to install the Ecopower was about $28,000. This, frankly, is high. Looking at the technology, I can't see why this unit couldn't sell for $15,000 or less. Unit production would have to be much higher and parts would have to be manufactured locally instead of the current reliance on some European parts for this cost to be realized, but $15K should be within reach. At any rate, for full generation capacity at current margin and our installation cost, the return on investment is 14.7%.

How did we do? That is a loaded question, because we have a lot going on here with many tests of the Ecopower versus the geothermal, start up issues, & etc. A quick estimate is that if we had run the Ecopower when we called for heat (as opposed to sometimes calling our geothermal units first), then we would have generated close to 20,000 KWH over the year, so the return would have been close to 7%. Instead, from Jul 1, 2008 to Jun 30, 2009, we generated 13,112 KWH giving us a return of 4.7%. Not a great return, but it sure beat the stock market over the past year in addition to the other benefits (less reliance on the grid, less fuel burned in power plants, etc.). Notice that our unit's capacity utilization was only 31%. In other words, we only used the Ecopower 30% of the time.

Which number to quote? It depends upon how much heating needs you have. Our house is (roughly) 4200 square feet, and our heating needs are only hot water year-round and space heating in the cold season for a family of four. In this situation, the 7% return is probably a typical number with the possibility it could be double that with a lower capital cost. If we had a swimming pool or a hot tub or other large heating load, our generation would go up with potential 15% return at present installation cost, or double that with large scale capital costs. These numbers tell me that this technology should become ubiquitous.

More on Cogeneration Operating Costs

2009-05-10T05:28:00.000-07:00

The last post showed that running cogeneration saves about 20-25% in operating costs when combining heating and electricity. These numbers are based upon the current retail fuel and retail electric prices and assume the standard single rate price for electricity. What would the economics be in the case of a varying electricity price? When would it make sense to run the Ecopower if the electric price wasn't fixed but varied as the wholesale price does on a real-time basis?

On the high power price side, it is easy to calculate. At $2/gallon propane cost, if power costs exceed $.34 per KWH, then it makes sense to run the Ecopower at full capacity. Under present conditions here in the Northeast, this can occur probably for a few hours during the heart of the cooling season in July or August, but the current regulatory inefficiencies in power pricing restrict this potential capability. We could sure use a smart grid with smart pricing.

On the lower power price side, what is the limitation? The economic-based decision that justifies cogeneration in the first place is that the cogenerator runs when heat and power are required, and when it does run, then the combined heat and power costs are lower than heating locally and buying power externally. We turn the problem around from the last post and ask what would the power cost need to be to break even by using the cogeneration versus the standard historical setup of purchasing all the power from the grid?

To get the same amount of heat from a co-generator, 1.3 gallons must be burned for every 1 gallon in a standard boiler. When we burn that extra 0.3 gallons, we need to make up enough money to pay for the power costs. The answer I get (after some algebra) for $2/gal propane cost is $.079/KWH.

Let's check that. In the traditional arrangement, we burn 1 gallon of propane and buy 5.82 KWH from the grid. At $.079/KWH, the total cost is $2.46 for heat and power. In the cogeneration case, we burn 1.3 gallons of fuel and generate 7.56 KWH for a total fuel cost of $2.6 minus a credit of $.14 for the extra power beyond what we would traditionally buy, giving a total cost of $2.46. Good, we got the right number.

Now let's vary the propane cost. At $1/gallon, the break-even power cost is $.04/KWH, at $3/gallon, the break-even power cost is $.12/KWH, and etc. The numbers are even better with a cheaper fuel like natural gas. Hopefully all these numbers aren't too eye-glazing. There is a more important point here, which we now finally get to.

The break-even power costs calculated are for the total power cost. In CT, the bill is divided into generation cost, delivery cost(s), and monthly service fee ($16/month). In the single rate bill, the generation cost last month was $.12217/KWH and delivery costs (including taxes, etc) totaled $.0574/KWH. So, at $1/gal propane cost, it would be cheaper to make the power in cogeneration mode than it would be to deliver it, let alone generate it. At current propane prices of around $2/gallon, with a delivery cost of $0.0574/KWH, we would need to get to a generation cost of $0.032/KWH (currently about 25% of the current single-rate power cost) in order for cogeneration NOT to make sense. Does this ever happen? Yes.

The wholesale generation power costs can be found at the ISO-NE website (www.iso-ne.com). In 2009 through April, the average generation price has been just under $0.05/KWH and about 14% of the time the cost has been under $0.032/KWH. In fact, on 25-Apr-2009 in the early morning, wholesale prices went to zero! They were literally giving it away (as seen in the following figure).

The irony is that during part of this time, we were generating power (see above figure), and given that it was early Saturday morning, we were almost certainly selling back to the grid--and we were saving money, because our average cost to purchase from the grid is $0.18/KWH and break-even generation cost is around $0.08/KWH. If during that time we had purchased the power from the grid ($0/KWH for the generation(!) plus $.0574/KWH for the delivery services), would could have heated the hot water cheaply via electric heat. On the other hand, if we had just delayed the hot water heat for a few hours, system costs would have been close to break-even with the wholesale price close to the break-even generation price. As a third alternative, if we were able to store more of the heat from 12 hours earlier during the prior day's peak price time, we could have saved some money and helped deliver power when prices were higher during the afternoon of 24-Apr.

The inefficiencies in the power grid system can be pretty glaring at times. What this note has tried to show is that with the single-rate power structure that most people use, cogeneration has a cheaper operation cost. Further, other system inefficiencies could be eliminated if real-time pricing were available and utilized by the consumer.

Co-generation Operating Costs

2009-04-11T08:10:00.000-07:00

The generator in the basement provides for a good deal of local flexibility, at least in principle, with respect to our energy choices. In the present setup, the generator runs when heat is needed, either space heat or water or both. The plan or goal is to optimize this with our geothermal units, but that is a big project, and it will take a while. For the rest of this year's heating season, we will be running only the generator when we need heat--unless we get some anomalous cold wave, but given the lateness of the season, that is rather unlikely.

The question I've been thinking about is how to best reduce operating costs, and this is a first look at those issues. First up is the question of what are the co-generation operating costs? One would think this would be an easy question. For now, I will try to make it easy, but it could be complicated.

The State Legislature in Connecticut has been fairly progressive with respect to energy issues. In the recent past, they have opened up the electric grid to competitive pricing where companies can compete for customers, so some competition has come in. The Legislature has also required net metering, so any kilowatt hours sent back from solar or generators etc., will net against those that are pulled from the grid. One of the recent mandates coming from Hartford is that residential customers must have a variable pricing option. This is to encourage consumers to reduce demand during the peak hours. We haven't explored this option too far. An initial inquiry with our supplier, Connecticut Light & Power, was discouraging, for they didn't believe people with generation capabilities were allowed to use variable pricing. I've just looked at the CL&P website, and it appears that we are. This is definitely something to look into.

For now, let's use the KISS principle and keep it simple. Our current rate is the standard single rate residential rate that is a constant charge per kilowatt hour (KWH) used (plus a monthly fee that seems to ever be creeping up in price and is currently $16/month). This power rate has also been going up and is currently $.18/KWH. The propane costs are currently around $2/gallon. This has come way down from last summer, but it is still historically high.

So what does it cost? Per gallon of propane, the Ecopower makes 5.82 KWH/gallon. That number is derived from the data on the Ecopower spec sheet, and I'm suspicious of the accuracy of that last decimal place, but okay. At $2/gal, the price then is $.34/KWH, or almost twice the amount we are paying. Hmm....what's wrong? That's easy! We are also using the heat. If we were using the generator to make electricity only, the cost would be too high. So let's look at it from a heating perspective.

We (currently) use the Ecopower only when heat is needed, and because we are also generating electricity, we have to use more fuel than we would if we were only heating. The question is how much more? A typical new boiler is about 85% efficient. Some of the older ones are a lot worse, but let's compare to new equipment. The Ecopower, from a heating perspective, is 65% efficient (and 27% efficient for power generation). Let's assume then we use one gallon in a standard boiler. In the Ecopower, we need to use 1.3 gallons for the same heating needs. The advantage is that we'd also generate 7.56 KWH of electricity along with that heat. Let's compare costs.

In a standard residential setting here in CT, the heating and power costs would be $2 for the propane plus (7.56 KWH * $.18/KWH = ) $1.36 for the power costs or $3.36. With the Ecopower, we are charged the cost of 1.3 gallons of propane which in this example would be $2.60, and the power generated comes as a free by-product. Per the heating requirements for a traditional boiler using a gallon of propane, we are saving $0.76 or 23% in combined heat and power operation costs.

For this comparison to work, there are a few assumptions, namely that one also uses power, that the power can be sold back at the same rate it is generated (net-metering laws), that the amount of power used is more than what is produced with the co-generation. There are also issues with the relative pricing of power versus heating. For instance, in New England, our power prices are driven mainly by natural gas prices, so co-generation works well here. In the Midwest, power is driven mainly by coal prices, so one would have to compare local power prices with heating fuel prices.

These assumptions are important and drive the applicability of co-generation. For instance, it only makes sense to keep part of the local needs as co-generation. You don't want more power generation capacity than you use, and one must have good heating requirements to even consider the idea (so it may not be a good fit in the Southern USA unless it can be sized primarily for hot water needs, and even that may not make sense, because solar heating would be much better in the South).

For our needs here in CT, the 5 KW Ecopower is a good sizing fit, but we could have settled for something a little smaller if one had been available. For smaller houses with smaller demands, a smaller unit (1-2 KW in size) would be preferable. For larger demands, say small businesses, etc., a larger unit would be better.

In this simple comparison, it is clear the co-generation has lower operation costs. There is the question of whether or not it is worth the machine cost, and I defer that question to another post. It is also important to know that there are other advantages coming from the co-generation. Less energy is lost in the generation and transmission of the power with the typical energy losses as high as 70% in standard power generation. The vast majority of those losses are saved with co-generation. Further, the co-generation requires less transmission grid capacity which will be a big deal going forward. Getting more power lines up in the current environment will neither be easy nor cheap. Needless to say, I'm a big fan of co-generation. It has just come 20 years too late.

First Look at Ecopower Operation

2009-04-05T07:16:00.000-07:00

It has almost been a year now since the generator was installed in the basement, and there are more data points to analyze than there is time to do it. The photo shows the engine from the side view. First let's review the motivation for buying this thing and then see how it has performed.

The decision to purchase the co-gen unit goes back to late 2006 shortly after the geothermal was installed. Geothermal is a great heating device, but the power usage is high. In New England, geothermal peak power is in the winter, and if everyone went to geothermal for cooling, the power peak would be in the winter instead of in the summer as it is now. That is pretty much true across the USA, although it gets hard to use geothermal for cooling in the deep south due to the high ground temperature. I'm digressing.

The concern was the large power requirements and dependence upon the grid for heating needs. Given a choice, I'd choose the domestic power grid over heating oil supplied by foreign providers who don't seem to care for us, which is why we went to geothermal in the first place. The geothermal unit sizing still required second-stage heating, and moving from heating oil to propane (natural gas is not available at our house still) was a better choice, and with a co generation unit, I'd get both heat and power and a fuel source that is about 70% domestic instead of about 70% foreign.

So, why not more solar. Definitely, more solar would be better, but the largest problem with solar, aside from the cost which is becoming less and less of an issue, is its intermittent nature. Solar power has a fixed generation schedule with frequent interruptions. These interruptions are difficult to forecast as the behavior of clouds is rather hard to predict. The other difficult problem is that these solar outages can extend for a couple of days, so there is some need for something other than solar (or lots of power and heat storage) to help smooth out the rather jagged production.

The other reason is the gross inefficiency of the electric grid. With close to 70% of the energy lost as waste heat, there is good reason to be generating power close to where heat is required, and residential heat is a large fossil fuel consumer, so generating power at the residential level has the potential of recapturing the heat lost in power production. In terms of cost, it is a trade-off between building a small number of large-scale power plants that are 30-50% efficient versus a larger number of small-scale generators that are 95%+ efficient. Historically, the large-scale system has dominated for a variety of reasons, not all of them rational, but with the semiconductor revolution of the 1980s, it is my opinion that the micro-generation paradigm is more efficient, potentially cost-advantageous, and definitely better in terms of energy security.

The following figure shows the amount of generated daily power from June, 2008 through March, 2009. The big gap in October is due to a computer outage, so daily Ecopower files that are normally available were not saved.

Notice in the figure there are three main periods. When the system was started, it was put in a maximum power generation mode. The amount of power generated was limited by how fast the heat could be dissipated. No system was installed to dissipate excess heat other than losses from the water tank, because it was not really cost-effective to do so (I may be changing my mind on that). Starting in late July, in an effort to reduce operating costs, we switched it to water heating and second-stage space heating mode only, so the Ecopower only ran when hot water (or second-stage house heat) was needed, and the average daily power was reduced as a result. It ran in this mode until the end of 2008.

At the beginning of 2009, the unit was switched to first-stage heat. The problem with this mode is that the generator is not sized to the heating needs of the house. It comes at a maximum 5KW power generation capability, and to meet the standard design criteria for house heating needs, it would have to be 2-3 times larger than it is. When thinking about the size of generator I wanted, 5KW seemed to be about the right size to match up the with geothermal needs and about what I'd want for backup power in case it was necessary. An important point is that with a co-generation unit, one still wants a second stage heating source for the very cold days. Otherwise, the unit required will be way too large for the local power needs.

Two points after 2009 are worth mentioning. The drop shortly after the New Year was a result of a discovered propane leak, so we shut off the Ecopower until it was fixed. The second one at the end of February was over a vacation and the house heating needs were dramatically reduced. The rest of the variability is mainly explained by changing temperatures and the required heating needs.

Currently, I think 5KW is too much given our plans and our current other equipment, but for now, it is still too little to heat the house by itself. We found this out shortly after switching to the cogen unit running by itself with no geothermal heating, for it was not enough to keep up with the heating load, and the house slowly became colder. For the colder days, I've come up with a compromise which is to put part of the house onto geothermal and part on co generation. This happens when the average daily outside temperature is near freezing or colder as seen in the next graph.

In this graph, we plot the average daily power generation versus outside temperature (which is recorded every 15 minutes by a thermometer outside the house and read by the Ecopower computer). Each dot represents one day. Remember that zero degrees Celsius is 32 degrees Fahrenheit. Only the days from August, 2008 are included. The important features are (1) the lower boundary where the Ecopower is used for hot water and 2nd stage heating needs, (2) the upper boundary where the limit is the 4.7KW power capability, and (3) the sloping boundary on the upper right where the Ecopower is used as first-stage heating. Above 15C (60 degrees Fahrenheit), there is no space heating need and the Ecopower is used only to make hot water. For the points in between the 3 boundaries, the heating was a combination of Ecopower and geothermal.

There have been a few issues with operation, but that will have to be discussed in another post. Bottom line is that most of the issues have been resolved, and the Ecopower is now running well and represents yet another step down for us in terms of fossil fuel usage and another step in the direction of energy security.

The next question is how best to operate the generator by itself and/or with the geothermal. This is not an easy question to answer, and it is one of the problems I'm working on now.

Solar Power Update

2009-03-21T07:16:00.000-07:00

While the most interesting thing here is still the new generator in the basement (I'll get to it, I promise!), here is an update on the solar panels. We are coming up on the 3rd year in May, 2009, and there are enough data to get a good sense of how the system is performing.

The above graph shows the solar generation results. This energy issue has many moving parts, and the figure attempts to document the main changes associated with the solar panels. The black line is the actual amount of kilowatt-hours generated for each month from May, 2006 to Feb, 2009. The yellow filled area shows the expected amount of power production as calculated by the installers, Sunlight Solar in Milford, CT. The first month's value is low because the system wasn't put in until the first week or so had passed, but otherwise, the first year's worth of data fit the expectation pretty well. The differences between the expected and the actual can be from two reasons: (1) weather, and (2) model errors such as estimating the amount of shading from trees each month.

Continuing chronologically, there is a vertical red line in May, 2007 that marks the point where we cut down a tree in the front yard on the Eastern side and relatively close to the house. Notice how the amount of power generated increased after doing so. This fits with the notion that shading is a really big issue. Also note that the increase in power seems to be dominated by the summer months (May-Sep). The tree that was taken down affected the morning light when the sun was at higher angles. The Oct-Apr time was not affected (probably) because there are other trees that still shade the roof in the morning during those months.

Next up is the replacement of the older panels and the addition of 2 more panels in September, 2008 (as told in a prior blog entry). The light blue filled in area is the expected power using the original advertised expected generation multiplied by 1.24. The 24% increase is a quick estimate that comes from the addition of 2 panels plus the increase in panel efficiency. Also of note is the new power inverter that takes the direct current from the panels and converts it to the alternating current in sync with the power from the power company. I'm guessing that the actual generated power will exceed this expectation, but by how much we will have to wait and see.

There are a couple of other things worth noting. Even with the new panels, it appears that the array under performs in the winter months. This is probably a consequence of the shading model underestimating the amount of shade in the winter months. The winter is when the sun angle is lowest, and its light spends more time in the neighbor's trees then. This segues well to the next obvious point which is that more power is generated in the summer than winter. Actual power demand also peaks in the summer, and solar fits this pattern well. Solar power is peak power!

There are important economic consequences of the peak power fact, because peak power is much more expensive than base-line power. Power use increases during the hot summer months, primarily because of air conditioning. Solar power can meet a significant part of that demand while wind almost certainly won't. Wind is erratic and peaks in the Fall and Spring when the wind is the strongest. Wind will do nothing for you on those hot still summer days. Solar, however, will.

In terms of return on capital, the solar panels have saved over $1600 so far from a cost base of $10,878 (net cost after the CT 50% rebate but not including the federal tax credit, because we used that money to cut down another tree!). On an annualized basis, the panels have returned 5.4% (that is an after-tax equivalent number), and the rate of return is growing because of the newer efficient panels, the increased exposure due to the removed tree, and the increased power cost. Last year's return was an even 6%, and this year should be better, because power prices are still a high $0.18/KWH here in Southern CT. Sure has beaten the stock market over the last 3years!

New Solar Panels

2008-12-13T09:01:00.000-08:00

Way behind on updates. Most interesting thing happening here is probably the co generation installation and operation. There are many items related to that which will take some time to write up. Until that can get updated, here is an update on the solar panels.

As mentioned in a previous post, the older Sunpower panels had a defect associated with them as one can see in the following photo. Apparently an outer coating was coming off of the surface.

Here is a picture of the Sunlight Solar employees (Milford, CT) taking down the old panels. They did this in mid September, 2008--shortly after they took delivery of the replacement panels from Sunpower.

Here is a picture of one of the new panels. These are the newer 220W panels. The older panels were rated at 215W peak power. The difference is the technological improvement over the last 2 years (about 1% improvement per year).

Finally, here is a recent shot of the new installed array. Before there were 12 panels, and now there are 14.

There are other upgrades with the new system besides the 2 additional panels. The improved efficiency has already been mentioned. The other improvement is the inverter that takes the direct current out of the panels and converts it to alternating current in sync with the electric grid. The earlier inverter was rated at 2 Kilowatts (KW) while the old panels had 2.5 KW peak output, so there was some loss when the old inverter maxed out in its capacity to convert DC to AC power. In fact, the old peak power I ever saw during operation of the old system was 1.948 KW, and during good sunny days, the system would stay just under 2KW in output for about an hour. The new inverter maxes out at 3 KW which is just under the peak power rate. I haven't measured the new actual peak rate yet....a good thing to put on the list of things to do. Given the inverter and transmission (from the roof to the basement where the inverter is located) losses, there should be some spare inverter capacity, so there should be not maxing out of the actual power output now with the new array versus the old array.

Before, the old array consisted of 12 panels with peak output of 2.5 KW with an inverter limit of 1.95KW. Now, there are 14 panels with peak output of 3 KW. This peak output has yet to be verified, but I have seen output above 2KW. In the spring when the peak output is expected, I'll make sure this is correct.

The new system represents approximately a 30% increase in actual output. While only a small step, it is nonetheless a positive one in the right direction.

Co-Gen Unit Installed--Finally!

2008-06-01T06:01:00.000-07:00

After 14 months, finally, the Ecopower combined heat and power unit (CHP) is installed. It has been running now for about 3 weeks, and after some initial debugging, it seems to be working well. Above is a picture of the unit in our basement. The Ecopower is clearly in the foreground. The silvery thing behind and to the right is a new water storage tank that is in addition to my normal hot water tank (to the left and behind the copper pipes), and this new tank acts as a heat storage unit.

According to the installer, this unit is indeed the first residential co-gen unit installed in Connecticut.

The unit is very quiet. We never hear it upstairs while it is running. This surely beats having a noisey back-up generator in the back yard. Our CHP is presently grid-tied which means that it is not set up for backup power. In the case of a power failure, the CHP will also go down. This will change once the "island mode" electronics become available. Current target date for that is December, 2008, but given the amount of time it took for this thing to become installed, I'm not so optimistic that it will be ready then. We'll see.

I've been monitoring the power this generates (5 KW max power) on a daily basis and will post some graphs in due time. It seems to be generating about 40% of our monthly baseload power while satisfying our hot water usage (I can't say "hot water needs" because we definitely use more than we need!). The heating season is over, so we won't know about the winter power generation until it gets cold enough again in the late fall.

This past winter provided some opportunities to determine our (past) heating oil use vs. our geothermal heat pump power use, and I want to post that data first for comparison to our new system.

Funny thing about this co-gen unit. We agreed to purchase it in February, 2007. Since then, the oil situation has changed for the worse. While I'm still glad we got this thing, it seems our next goal will be to make the ecopower less critical to the daily house operation. This CHP technology is a great improvement efficiency-wise, but I can't help but wonder if it isn't coming 20 years too late.

Discoloration of Solar Panels

2008-05-18T13:05:00.000-07:00

One problem I've seen with our Sunpower solar panels was that about half of them have air-pockets in them. You can see this in the above picture as the light green areas on the panels.

I've let this problem fester for some time, but while at the Earthday celebration (where our efforts were acknowledged), the company who installed the panels had a booth, and I told them about the problem. They said that this was a known defect, and that Sunpower will replace the panels.

After a few days letting the wheels turn on this, Sunpower has decided to replace all of my panels, because replacing only half of them would not work out well. Apparently, my panels are now obsolete (after 2 years!). So far, they have worked as advertised, despite the defects.

Bottom line: We get a new solar panel array sometime near Labor Day this year. Will update on that when appropriate. Until then, there is plenty to write about.

Work Honored By Local Group

2008-05-18T12:52:00.000-07:00

So someone is noticing anyway.

We were honored by the Westport Green Energy Task Force for our "green" residential efforts. The awards ceremony was on the Saturday after Earthday at the local nature center (Earthplace). Westport's First Selectman (essentially the Mayor of Westport) gave out the awards. Some of the local press showed up too and had small blurbs about the event.

A fun time was had by all. The kids loved the sea-life exhibit for the Earthday celebration. They had live shellfish from the Long Island Sound for the kids to touch and look at.

The Best Oil Interview I've Seen in a Long Time

2008-02-21T10:42:00.000-08:00

Usually, I have my TV set to the CNBC business channel during the day while working, but 99% of the time, the sound is muted. The best expression I've heard for this station is "bubblevision," and it is a good description of the cheerleading that goes on during most programs.

There are a few people for which I have an exception to the mute rule, and one of those is Texas oil and gas man T. Boone Pickens. You can see find some of the interview in the video at www.cnbc.com. As I was typing up this note, I decided to review the video, and what is interesting is that they cut the first half off, and it was the better half! The second half is still good and worth viewing. He mentioned that with the present oil price, the USA is now sending over half a trillion dollars a year overseas to purchase oil, and that we are pretty much heading for a disaster in this country if we don't change our energy policy, and further, that none of the presidential candidates seem to be clued into the problem.

Boone Pickens is a man who understands the issues that set me off on my treck to "go green." With time more and more seem to be coming around to this view. The question in my mind is will we reach critical mass soon enough to prevent a pending disaster?

Local Green Energy Task Force Cited in NY Times

2008-01-21T07:10:00.000-08:00

On Thursday, 17-Jan-2008, there was a local showing of the environmental movie "Everything's Cool." The event was picked up by the New York Times (click on the link to go to the article). I attended this event with my son, but we had to leave early, for it was a school night, and we missed the bulk of the discussion afterward. Information on the film is found at its website.

It was a good movie about the global warming movement. What was missing, I think, is what is missing a lot in these discussions, namely a discussion about our energy security.

The green energy movement is indeed growing in Westport. The Green Energy Task Force has recently published a report on the local greenhouse gas emissions, and it can be found here. Already, the town has installed solar panels on the Firehouse roof. There is a lot of work to do still, but, as the euphemism says, the train has left the station.

Micro Combined Heat and Power

2008-01-13T05:19:00.000-08:00

About a year ago, I read an article about small-scale or micro combined heat and power (CHP) units. In the traditional situation, you burn fuel locally for water and space heating, and you get electricity from the grid. That electricity comes from a power plant that is producing an enormous amount of excess heat. Wouldn't it be good to be able to capture that heat for use in water and space heating? Alternatively, how about putting the power plant locally, so you can use the excess heat? That is what the micro-CHP is all about: local power generation combined with heat capture.

Immediately, I contacted the company that was offering CHP generators for commercial and residential applications. I signed a contract for a unit last February, and I've been waiting ever since for the installation. Part of the problem was that the engine was not UL rated, and apparently they spent some time getting the unit through all the tests. We are currently waiting for Connecticut Light and Power to grant approval to connect this to the power grid. There shouldn't be any problem, for the solar panels have already been approved for grid-tie. In pushing the envelope in this area, I've noticed you have to spend a lot of time waiting for things to get done.

In my mind, this co-generation technology will be revolutionizing power generation. We are about to the break the utility monopoly paradigm, and it will be economical, because, as shown in the last post, an enormous amount of energy is wasted in the traditional power generation scheme. With local production, you can gain back the lost heat for local uses, and the savings will offset the so-called economies of scale that larger power plants offer. It isn't clear if this is available everywhere, but in the State of Connecticut, they are committed to introducing cleaner power technologies, and CHP certainly qualifies.

Distributed or local generation offers other advantages as well. First among them is that the need for power lines is reduced, and so are the losses associated with them. Distributed generation also allows for (but does not guarantee) a more stable grid structure. This is a big deal locally, where the power company is running new underground high voltage lines in an effort to increase the grid robustness (and more than likely, to increase the amount of power they can sell into Long Island). If the distributed generation takes off, we will not be needing to do much more of that--ever.

Information on combined heat and power units is given at the Marathon Engine website. Here is a diagram of a typical layout. (Click on the figure for a larger image.)

I will be posting more information on our actual configuration at a later date. This technology presently is not economical for the average residence (although with some changes, I think it could be), but because we have geothermal heat pumps, we use about twice as much power (with a corresponding reducton in fuel use for heating) as the average residence, and this helps make our installation economical. I'm hoping on synergies between the the CHP and the geothermal that will then make the geothermal even more economical, but for now, I'm just waiting for this to get installed to actually measure how much we will be saving with the CHP.

Lots of Wasted Energy

2007-11-24T08:50:00.000-08:00

If you spend any time looking at the national energy complex, one eye-catching part is the amount of energy that is lost to waste heat in the electric and transportation systems. In the following flowchart from the Lawrence Livermore National Laboratory, the energy flow in the USA energy system in 2002 is shown.

EIA has similar flowcharts similar to this on their website for all parts of the energy system. To see this flowchart effectively, you may have to open it up in a new window by right-clicking on it. While a little out of date, the numbers are still fairly close to what is used today in 2007 (we use over 100 Quads now), and the ratios are very close. In case you have forgotten, one Quad represents one quadrillion BTUs or British Thermal Units--a unit of energy that is so arcane that even the British no longer use it, but we Americans seem bound to it forever. For completeness, a BTU is the amount of heat required to raise the temperature of one pound of water from 60 degrees Fahrenheit to 61 degrees. Arcane, indeed, but we need not go there.

The numbers are staggering. In the electric system, close to 70% of the energy is lost to waste heat. In the transportation system, which dominated by petroleum, the loss is closer to 80%. The size of the numbers makes sense if you think about it. Most of the energy used by your car goes away in heat from the engine, and only about 20% is converted into making the car and its contents move. (Critics like Amory Lovins go even further and point out that most of that useful power is used to move the car and not the people in the car, and so the amount lost is 90-99%.) In the electric system, about 60-63% is lost to waste heat, and the bulk of the remainder (7-10%) is lost in transmission.

There are ways to capture most of this wasted energy. It is hard to use it to make more power, for you are fighting the 2nd Law of Thermodynamics (entropy). However, if what you want is the heat instead of the power, then you are in business.

If you look at how we use fossil fuels, a large fraction goes to heat: space heat, water heat, dryer heat, oven heat, etc. The way we traditionally do it, however, doesn't make a lot of sense (or, at least not any more). We burn coal at the power plant to make electricity, and the excess heat goes up the stack or into the cooling pond. We then take that power off the grid and start up the oven or the dryer. Further, we burn heating oil or natural gas in the furnace or boiler to heat the water or the house.

What if we were to take to power plant and put it in the basement? That is the idea of combined heat and power or cogen units. Instead of one big electric plant powering hundreds of sites, we distribute the generation out to the places where it is used. The excess heat is also used locally in other processes instead of being dispersed into the atmosphere, streams, lakes and oceans. We are about to do just that in our house. More details to follow as the cogen unit gets installed.

So What Exactly What Are We Burning?

2007-11-16T11:26:00.001-08:00

This post comes from a question on the geothermal analysis. We are burning less heating oil now, but we are using more electricity. What, then is used to generate the electricity that runs the heat pumps? The answer to that question depends upon where you live and what the marginal fuel is in that area. Here I look at Connecticut, because that is where I live.

The data used in the post can be found at the ISO-New England website.(www.iso-ne.com). In particular, I used the hourly demand data and the capacity data from the 2007 CELT report. CELT stands for a Forecast Report on "Capacity Energy Loads and Transmission", and the report is published annually.

The figure below shows both the electric generation capacity in Connecticut and the demand. To see this plot and some of the details described, you may need to open the figure in a new window (right click and select "Open in New Window").

The capacity is stacked upon each other in a general manner of cheapest to most expensive. It is the nameplate Winter Capacity which is a little higher than the Summer Capacity. There are a few caveats to the generation capacity data. For instance, on any given day, the available capacity is usually less than the total capacity depending upon which units are down for maintenance or for other reasons. There is also the issue of fuel cost. The stacking assumes all of the natural gas plants can run cheaper than all of the petro-based plants. That isn't necessarily true and it depends upon the plant efficiency as well as the current fuel cost. Also, I've put the waste and bio-fuel plants just above the natural gas. It isn't clear if they should go above or below natural gas. What is not apparent, but is present in the plot, is a small sliver of wind and baseline hydro capacity operating below the nuclear block.

Superimposed on top of the generation stack is the historical hourly demand. The data show the minimum and peak demand over a 7-day window. This time period was chosen only to make the graph easier to see. I've also added the bulk of the hydro at the top of the demand data, because most hydro is peak-capacity power. Solar capacity is also included in the peak hydro part (you can't see it on this scale because solar power capacity is presently minuscule).

From the graph, one can see that the peak power demand is in summer, usually in early August in the late afternoon. When this happens, the marginal power is usually petroleum based. Minimum demand occurs in the early morning during the spring and fall--times when there is less heating, cooling, and lighting needs. Only during this period is there any encroachment into the coal capacity. Otherwise, coal is run pretty much continuously. The vast majority of the time, the marginal fuel is natural gas.

Yet another caveat is that CT is connected to other areas, namely all of New England, and the New England electric system has connections to New York and to Canada. The interconnections can mean that New England can bring in up to 2000 MW of power from other areas, the equivalent of CT's nuclear base. Not all of this is used by CT but is shared by all of New England, and some even passes through to New York, but when we are importing from Canada, we do get a larger hydro component than is shown here. That potentially reduces the coal use in spring/fall, but in the winter and summer, the marginal fuel is still natural gas.

The answer seems clear. For the winter heating, we are using more natural gas in place of the heating oil through the increased power use. In the summer, compared to a traditional air conditioning unit, we are using less petroleum yet again, due to the better efficiency (and cooler ground temperature) with the heat pumps.

Net-net, for heating efficiency purposes, we are more efficient, because on average, the natural gas plants, which are very efficient electricity producers, have efficiencies in the range of 30-50%, while the heat pump performance is about 3.5 to 1. In other words, for every unit of electric energy used, we get 3.5 times that in thermal heating. That amount is lost, however, as a result of the natural gas (or other fossil fuel plant) efficiency. There are also transmission losses from the plant to our house. Let's assume we have an efficient natural gas plant at 50%, our heat pumps have a coefficient of performance of 3.5, the transmission losses are 8%, and the efficiency of the boiler that is no longer running is 85%. Net-net, our gain is 3.5*0.5*.92/.85 = 1.9 (or 90% increase in efficiency). Even assuming a power plant running at 30% efficiency, the net gain is 1.14 (or 14% increase in efficiency). It isn't clear if these numbers will sink in (or even if they are correct!). Suffice it to say that the heat pumps mean we are now burning natural gas, and in addition, we are using the fossil fuels more efficiently. That is something I can live with, but can we do better? I think that we can...

Coming Out

2007-11-10T06:54:00.000-08:00

When I decided to start a blog, I chose to stay anonymous. There was no really good reason for this. Perhaps I was worried of blow back of some sort, but anyone who wanted to figure out who I was could probably piece together the information from the posts. Such an act would be diabolical, but nonetheless possible, I suppose.

Last week (Tuesday, November 6, 2007 to be exact), I was elected to local government. Because I was not well known in my hometown, Westport, CT, I gave people my blog address, so they could get a sense of my style and thought processes and to see what I've been up to with respect to moving towards energy sustainability. Some visited the blog, and I've heard some feedback, mainly that I need to update it more. That, I cannot argue with. At any rate, there is no reason to be anonymous any more, and hence the title of this post.

Since the start, we've worked on moving to a more sustainable energy use with modest success. The approach is different and less intense (although more capital intensive) than what you can find elsewhere on the web. Many people are a lot more hard-core than we are. An example of really hard-core is No Impact Man, a NYC resident trying to make no net impact on the environment. Another approach can be found at the blog of Sharon Astyk. Sharon is a New York state Jewish farmer working towards sustainability. Her primary motivations are peak oil and global warming, and her style is a bit more palatable than No Impact Man's, even though she's advocating, among other things, a 90% reduction in carbon emissions.

Locally, here in Westport, there are efforts going on. The Green Energy Task Force was initiated by Gordon Joseloff, our local First Selectman (basically, our Mayor), and under the leadership of Carl Leaman, they have estimated the town's carbon footprint and are working on recommendations on how to reduce that. The goal is nowhere near a 90% reduction, and if you are to believe the climate models, something near 90% will be needed. The Task Force's start is a reasonable one, and with time, I could easily see that it could get to advocating more drastic reductions.

As for me, I am still of the opinion that the most important problem is the geopolitics of oil: who has it, who doesn't, and the consequences of this relationship. We are working first to lessen our exposure to foreign energy sources in a way that is (hopefully) environmentally friendlier and that is more economical than what we have been doing traditionally. I've been working on this every since Hurricane Katrina, for that really opened up my eyes on the possibility and consequences of a major supply shock.

Listening to the news chatter, some seem convinced that the run-up in oil prices is a result of those pesky speculators. My response to that is that the speculators go to where the action is, and they wouldn't be in oil if there wasn't a supply/demand mismatch problem, and there is definitely a supply/demand mismatch problem, and it looks like it won't get better any time soon. We are talking years for it to work out at best, and if the peak oil people are right, it will never work out.

We've heard the refrain before, and so one has to ask what is different this time. The answer is that in the 1970s, we imported roughly 20% of our oil whereas now we generate 20% and import 80%. In addition, our position as a country has moved from being the world's largest creditor nation to the world's largest debtor nation. With our trade imbalance and our declining dollar, we may not have seen the last of the oil price rises. To stop that we will need to experience a global slowdown and not just one that is national. The increased demand from China and India is real and is the primary driver of increased oil use. Any reduction from US demand can be quickly replaced by increased consumption elsewhere.

At any rate, I'll be advocating locally for efforts to reduce our oil use first and foremost and doing it in a way that helps the environment, reduces our carbon footprint, and saves us money in the long run. That is the goal, but the energy complex is complicated. We'll see if we can get there. I'll also be commenting more on energy use in CT and in Westport and Fairfield County in particular. At least that is the goal I have. Can I get to 1 post a week? I'll certainly try.

Our personal efforts are not yet complete. Once you start on this project, you get quickly overwhelmed by the numbers involved, and we have a long, long way to go to get to where we feel comfortable with our personal vulnerability to energy risk.

Finally, a thank you to all those who voted for me. Town Representatives are elected at 4 per district, and there were 7 vying for 4 places in our District. The town turnout was 35.3% of the electorate and 37.8% in District 9. In District 9, 43.8% of the voters voted for me. It was enough to get me the 4th slot, but it only represents 16.6% of the electorate.

Kevin D. Green
Westport Town Representative-Elect
District 9

Geothermal Analysis: How's it Working (Part 2)?

2007-10-06T07:48:00.000-07:00

From the last two posts, we know we have saved on the amount of heating oil we use with geothermal heat pump installation, but we are using a lot more electricity. One lingering question is "Are we saving any money by switching to the heat pumps or did we just change energy sources?"

Before starting with the calculation, it is important to remember the goal, namely, we wish to reduce dependence on foreign energy sources (particularly oil, but also natural gas), and to do it in a manner that helps (or is at least neutral) environmentally. In a world with uncertain oil geopolitics, it is important to consider that a big part of this process is buying insurance, and traditionally, insurance costs more than it is worth (otherwise, insurance companies wouldn't be in existence).

In our particular case, it turns out we aren't saving much money by moving to geothermal from heating oil, so it is win-win-draw: our dependence is reduced, the environment is bettered, but little savings have accrued (or, at least not yet). There are many reasons for this, and if planned properly, I don't think that this has to be the case.

This post has some technical details in it, and they are included for clarity (hopefully) and for helping others make similar calculations. There is a lot of uncertainty in some of the crucial numbers, so the actual numbers may be different. If you spot any errors, please let me know, for I'm more interested in getting to the truth than I am in advocating a position.

Let's recall two graphs from the last two posts: (1) the heating oil use, and (2) the electric use. Also, to beat a dead horse, the house was renovated from late 2005 to mid-2006. There are a lot of moving parts in all of this, and that introduces more uncertainty than one would like.

System Cost

The total cost to install the 3 wells and the heat pumps was $44,800. To break this down, it was $32,410 for the heat pumps and new air handler, $15,390 for the 3 wells, and we received a $3000 rebate from CL&P. However, we did not install air conditioners, which I estimate would have cost $15,000 for high efficiency condensers. The incremental cost is then $29,800. This cost could be bettered if one plans for geothermal initially instead of making a decision half-way through the process of renovation, but okay, enough self-flagellation.

The Quick Guestimate

It helps to have a so-called back-of-the-envelope number that is easy to calculate. Here is my version of that. In the older house, for the winter months (Nov-Mar), we'd use between 1500 and 2000 gallons of heating oil. With 2 gallons/day for water heating (I'm still amazed it is that much and am kicking myself for not making sure the de-superheater came with the geothermal unit), and adjusting for the number of days, we can roughly say between 1200 and 1800 gallons were used to heat the house. Last year we used 700, with about 280 for water heating (from 11/17/06 to 4/9/07), and so we used 420 gallons to space-heat. In this simple comparison, we saved between 780 and 1380 gallons of heating oil, or about $1850-$3300. (Heating oil last year was $2.39/gallon).

For power, we used to use between 50-60 KWH per day and we now use around 120 KWH per day in the winter months. In the old house, we used fewer lights, but we used more electric space heating. Let's say net-net the effects cancel, and we are using about 60 KWH per day heating, or about 8600 KWH in the same period we used the 700 heating oil gallons last winter. At $.18/KWH (one of the highest rates in the Continental USA), that cost us $1548, so it is about $300 - $1700 saved from the geothermal, so according to this quick calculation, we made somewhere between 1-6% return on investment. Can we better the estimate? Let's try.

A More Detailed Estimate

To make some the conversions below, I used the EIA kid's page
(http://www.eia.doe.gov/kids/energyfacts/science/energy_calculator.html#unitsexplained).

A more detailed review of the electricity usage makes me conclude that over the period of 11/17/2006 to 4/9/2007 (the period in which we used 480 gallons of heating oil for space heat), we used between 8360 and 9430 KWH for operating the heat pumps These numbers are still suspect and requires some subjective guessing, which I won't get into right now. With some effort, I think I can separate out the heating from the other electric use, but that will take a lot of work.

Let's calculate the amount of oil saved not by looking at past years, but by looking at how the heat pumps work. The heat pumps have a coefficient of performance of 3.5-3.6. That means that for every unit of energy used to run the heat pumps, we get about 3.5 units of thermal energy out. So, our 8360 KWH turns into 25,080 KWH thermal energy, and converting that to BTUs, we get (using 3412 BTU/KWH) 100 million BTUs. One gallon of heating oil contains, roughly, 139,000 BTUs of energy, and let's assume our boiler is 85% efficient as advertised.

Combining all this together, I get between 845 and 953 gallons of heating oil saved, or between $2020 and $2280 last year. At an electricity cost of between $1548 and $1697, we only saved between $470 and $583, or 2% of our installation cost. At that rate, we are looking at 50 years for this to pay for itself in its present state.

Here enters yet another uncertainty in the calculation. How much did we save in cooling costs? The geothermal is very efficient and would be better than the air conditioners that we would have installed--even very efficient ones. How much savings would that translate into? The hard-core green people would say none, because we are using more electricity cooling the house now than we did before. For the moment, I'll assume no savings.

This coming heating season, the savings look a little better. Heating oil now costs about $2.70/gallon, and electricity has come down to $.17/KWH. If these values stay the same, then we are looking at savings of $850-$950, and that would make the return a not much better 3%. I think we'll do better, but that is because of other things we are doing (details in a later post).

Where would geothermal work best? It seems to me that the Northeast is not the best spot, primarily due to the electricity cost. Note that if the power cost was down to $.10-.12 per KWH, then our return would climb to 4% at the same heating oil cost, and given current interest rates, that makes it a decent-enough long term investment (the 4% is an after-tax equivalent on a long-term investment). In essence, our geothermal is a bet on the heating oil/electricity spread. If electricity costs are cheap and heating costs are high, geothermal makes more sense. This could happen if indeed the dollar keeps plummeting. The bulk of our oil is imported, but the bulk of our electricity is domestic and is based on nuclear and coal and not oil.

Conclusions

I'm a little ambivalent about our move to geothermal. On the one hand, I'm glad we did it, for we are using two-thirds less heating oil, but on the other, I wish we had planned a little better, for better planning would have saved us a little more money, and I also don't like what happened to our electricity usage. It did buy us some insurance though, for we are now less dependent upon foreign sources for our survival (and heat is necessary for survival!), and it did make the world a little greener and one step closer to something we could call sustainable. Perhaps that's worth the extra cost (and probably better than sending the Sierra Club a check for $10,000), but if geothermal or something similar is to become widespread, it will have to be a little more cost-effective.

Our Electricity Use Over the Years

2007-10-05T12:02:00.001-07:00

In order to assess both how the solar panels and the geothermal heating and cooling have impacted our energy usage, we need to understand our electricity use. The first step in doing so is finding out how much we have used historically. The recent past data can be obtained from the power company. Connecticut Light & Power keeps the last 2 years' data online for easy access, but we have more.

While digging through old boxes full of bills looking for heating oil invoices, I also collected the electricity bills and cross-checked them with old check registers. As a result, a history of our usage from the time we moved into our house until present has been compiled, and it is given in the first figure.

The red line shows, according to Connecticut Light and Power, how much energy we pulled from the grid, and the blue line shows how much we have used. The difference is the amount we generated from our solar panels since May, 2006. The amount generated doesn't look like much, and compared to what we now use, it isn't, but the details deserve its own discussion, and now is not the time.

There is a lot of structure in this plot that needs to be explained. The big drop in usage from late 2006 to May, 2006 is the renovation phase. We moved out of the house in this period, and the amount shown is what was used during the reconstruction.

Again, we have to divide the house into two periods: (1) the old house (2000-2005), and the newly renovated house (May, 2006 to present). Let's look at the old house first.

Interestingly, our electric usage peaks in the winter and not in the summer as the national and regional power does. The reasons for this are many, namely we didn't have central air, we had one room that was fully electric heat, and we used a couple of small space heaters in some of our draftier rooms. Although the summer usage was lower, a small summer peak is present in the data, and it got bigger from 2001 to 2005, because over that time we purchased more window air conditioner units. 2005 was also a particularly hot summer (next figure).

The big spike in our electricity use starts in November, 2006 with the turning on of the geothermal heat pumps. Clearly our electric use has gone up significantly, but as the last post showed, our heating oil demand decreased significantly. So which one has won out? The newer system is more efficient, but by how much, we still have to estimate. I'll get into the details in the next post, but before that, this part cannot end without showing the energy use versus the average temperature, and that is given in the next figure.

There are four main groups in this plot. The lower purple circles are during the construction phase and can thus be ignored. The blue dots are prior to the renovation, and the red dots are after. The four red dots falling below and to the right of the others are from the brief period where we had a new house, but the central air wasn't in, for we were awaiting the completion of the geothermal system. We had our four window air conditioners going full blast during this period, and interestingly enough, the data match up pretty well with the old house in the 2005 period (the dots hotter than 60 degrees closest to the lower four red dots). The house was not at all comfortable in this period, and needless to say, the final completion of the geothermal was welcome indeed, even though it came too late for the 2006 cooling season.

There is a lot of scatter in the blue data, and there are a couple of reasons for that. The first is that electricity demand is a combination of heating and lighting, and it is when the days are shorter that they are generally also colder. Part of the demand is for lighting, and de-tangling the two effects may not be possible. Other contributing factors are guests and vacations, and these effects have not been taken out. A final factor adding to the scatter is that in the earlier data, some of the data are estimates and not actual readings. This was prior to the time that CL&P had electronic meters, and reading the meter was much more variable. I've noticed that the newer readings are all "ACTUAL" readings and not estimates. On the warmer side, as previously noted, the amount of cooling capacity increased over time, and that and vacations explain a good deal of the scatter during the warmer periods.

Finally, I just want to say that while January, 2005 represented our peak heating oil use, January, 2007 represents the high water mark for us in our electric usage, or at least I believe it will be. We are working on reducing that peak value, and hopefully the new changes will be in before the winter comes...and the changes aren't the switching to fluorescent light bulbs, which, I'm somewhat embarrassed to say, we still haven't done as yet.

Geothermal Analysis: How's It Working (Part 1)?

2007-10-03T11:37:00.000-07:00

Now that it has been about a year since we have converted to geothermal for our cooling and our first-stage heating needs, it is time to check the results. It hasn't been easy to do this analysis. A lot of time was spent digging out old bills and check registers to find out how much heating oil we actually used, how much we are now using, and whether or not the conversion was worthwhile. The short answer is yes, it has been worthwhile, but there are a few side-effects and mis-steps we made along the way.

Locating our old heating oil bills wasn't easy. With having to move our for our renovations in 2005, we boxed everything, and of course, the process wasn't as efficient as one would have hoped. We are packrats to a large extent, so most of the bills were located, and the information was cross-checked with the checking account records and verified by the weather data. I think the analysis is as complete as it can get here, and the results pass some simple consistency checks.

The first figure below shows the amount of heating oil we have used on a daily basis since late 2000. The gap starting in the Spring, 2005 is because of the renovations, and the start of the geothermal period starts in late-2006. We had hot water starting May, 2006, but I've left that period out due to complications of how much heating was used in the renovation period.

The amount of heating oil used are given by the blue bars and are in daily amounts. The use of daily amounts is because the deliveries are not on a periodic schedule and vary depending upon how cold it has been. For instance, the very first bar represents 386 gallons used over 65 days. The very next bar is 278.3 gallons but is was used in only 24 days, and so on. Conversion to daily rates makes the analysis easier.

There are many parts to this first graph that deserve comment. One issue is shown by the red dashed line, and it represents the baseline heating oil use. The line is drawn at 2 gallons per day, and interestingly enough, it is the same for all years--both before and after the renovations. I'm assuming that this 2 gal/day is predominantly the amount we use for water heating. Here is one area where we blew it. The geothermal units can come with a water heater attachment (the desuperheater) that effectively gives you free hot water during periods of high geothermal heating and cooling, and we didn't get it. I think that was a big mistake.

The most interesting item is the major reduction in the amount of heating oil used since the installation of the geothermal. The total rate for last season was about 4.2 gallons/day, and about half of that was for heating water! So, yes, the geothermal heating has significantly cut into our heating oil use! However, it has come at a cost, namely more electricity, and that discussion is taken up in part 2.

Most remarkable about the reduction is that the renovated house is 60% larger than the older house. We are now at 4200 square feet instead of 2600 square feet. Countering that, though, is the fact that the present house is insulated and thermally wrapped whereas before, there was very little insulation, and the house was drafty. Nonetheless, the data suggest we went from roughly 2000 gallons of heating oil per heating season to about 700--a reduction of 65%. This reduction estimate is a little too high, as we will see below.

There is another complication, and that is that each year is a little different in terms of how cold it gets, and that factor needs to be taken into account. The way this is done is with something called the Heating Degree Days (HDD). A heating degree-day is a measure of how cold it is, and the amount you need to heat increases as the number of HDDs increases. The exact definition is that the number of HDDs is the total number of degrees the daily average temperature (in fahrenheit) is below 65 degrees. For instance, if the high and low temperatures for the day are 78 and 50, the number of HDDs for the day is 1 degree day [65-(78+50)/2]. For average temperatures over 65, the number of HDDs is zero. For a cold day where the average is 30 degrees, the number of HDDs would be then be 35. The next figure shows the number of HDDs for the same periods shown in the first figure.

From looking at the HDDs, the proper year to compare the new data to is the 2001-2002 season, because it was a similar winter in terms of overall heating. Taking out the water heating, we went from 6 gallons/day for heating to about 2.3 gal/day. The reduction is still 60% in our heating oil use.

The next figure shows the relationship between the amount of heating oil used and the number of heating degree days.

In the figure, I've noted 2 blue data points that are below the trend in the old house, and that is because we were on vacation during these two periods, so our demand was indeed down, but not for weather-related reasons. The red points are from the renovated house with geothermal heating. The red line shows a simple linear model for the new period, but it is not correct. The way the heating works is that the first stage is always geothermal. If the geothermal cannot keep up with the needed heating, the second stage heating (heating oil) comes on-line. The non-linear dashed line is probably closer to the current set-up in how our heating needs use heating oil.

Our biggest goal is to reduce our foreign oil dependence, and the switch to geothermal heating as first-stage heating has surely done that. In this manner, the new units have been successful. But at what cost? To answer that, the electricity data need to be analyzed, and that will be a subject of a later post.

Hybrid Vehicles: One Year Update

2007-09-11T14:24:00.000-07:00

We've had our hybrid vehicles for over a year now, and it is worth discussing our experience with them.

We purchased our 2006 Toyota Highlander Hybrid at the end of April, 2006, and our 2007 Toyota Camry Hybrid at the end of July, 2006. Some of the results are good, but some were a little surprising.

It is difficult to compare our new vehicles directly to our old. The things that stand out as being good are the GPS, the better feel of a new car, and the better gas mileage than the vehicles they replaced. Those are the good things. I wanted to compare actual mileage and fuel used, but I can't find the records for our older cars (probably in a box somewhere in storage), so an actual usage comparison is tough, but we really haven't altered our driving habits, or, at least I don't think we have. In particular, we haven't purposely driven less to save energy. I'm seriously rethinking this conservation aspect due primarily to lack of alternatives. More on that in later posts.

One obvious reason the SUV is used more is that it is easier to travel with kids in the Highlander. There is definitely more room for us when we do travel in it (in fact, I don't think we have once all gone together in the Camry). Personally, I definitely enjoy the Highlander more than the Camry and usually take it to run errands, and in addtion, our babysitters use the Highlander to shuttle the kids around (they used to use their own vehicles until the gas cost started soaring).

The one thing that isn't so good, but is definitely understandable, is that we used the Highlander SUV more than the Camry. In fact it looks like we use it about twice as much! In the Highlander's first year, we drove 11,600 miles and used just under 493 gallons of gasoline for a fuel economy of 23.5 MPG. Not bad for an SUV. In the Camry's first year, we drove it approximately 5250 miles and used about 188 gallons for a fuel economy of 27.9 MPG. One amazing thing with the Camry is that we filled it only 15 times in the first year, about once every 3 1/2 weeks. That compares to the Highlander's 40 fillings in the first year.

From what I have read, to break even on the hybrid cost, fuel costs have to be over $3 per gallon. When we purchased the vehicles, the gasoline price was $3, but it fell to as low as $2.30 a gallong here in lower Fairfield County, CT. Since then, it has climbed back up closer to break-even. My own personal opinion is that the extra cost will indeed pay for itself, meaning that I'm expecting gas prices to be above $3 a gallon going forward for some time.

Our distance traveled is notable. At 16,850 miles in a year, that's only 4212 miles per family member. Nationally, on a per capita basis, the average mileage is about 12,000 miles annually per person. We have only 2 registered drivers, but I can assure you, most of the driving is for the kids and not for the parents. It helps that I work out of the house, and my wife works part time about 10 miles away. Our commutes are significantly less than the average commuter. Some of that is compensated in our higher than average residential energy usage.

At a combined 681 gallons in their first year, our gasoline usage is probably down about 20%. That's not bad, I suppose. If everyone in the nation could magically reduce their total oil usage (and not just gasoline) by 20%, we'd be down to 16 million barrels of oil per day instead of the 20-21 million barrels per day we use in the USA. With oil imports presently comprising 80% (roughly) of our usage, we'd only reduce our dependence on foreign oil by 5% (from 16 imported + 4 domestic million barrels per day to 12 million imported + 4 million domestic), and that assumes all the reduction would be in imports and not less production at home. Clearly, as a nation we need something more drastic.

A 20% demand reduction would have one major benefit. The cost of gasoline would definitely come down if magically demand were to fall by that amount. Instead of $80/barrel for crude, we'd probably be down to half of that. Gasoline stocks are very low at the moment, and that in and of itself adds a risk premium to the price. Refineries are old and straining to keep up their production. If the demand were to fall, stocks would build, and, more than anything else, larger stocks would bring down the fuel price.

To get the fuel reduction, however, one doesn't need a hybrid. One only needs a car with better fuel economy. In fact, this is my biggest criticism of the hybrid to date. In the current models, the vehicles need gasoline to run, and they cannot run without it. The battery technology is only used to save energy during braking. If instead we could plug in the batteries and charge it with other means, then the gasoline consumption could go down dramatically. We need the ability to plug them in. Until then, I don't see how we cannot be dependent upon foreign sources for our transportation sector.

Toyota sent me a survey form to evaluate the Highlander. In the comments section I wrote words to the effect that our next vehicles will be plug-in hybrids, and that if they wanted us to buy another Toyota, then they would have to offer one.

Solar PV Array: One Year Update

2007-08-27T10:36:00.001-07:00

The question I most frequently get is "How are those solar panels working for you?" My response is usually "Just as advertised." With the panels being up and running for a year, it is worthwhile to look back and see how things have gone.

The expected amount of power to be generated monthly by the 2.5 KW system was included with the proposed installation. The calculation included corrections for the observed shading and average expected sunshine, but, of course, it couldn't put in the actual amount of clouds. Some differences are to be expected.

How has it done so far? In the figure below, the actual and predicted amount of energy is shown from June, 2006 through July, 2007. (Click to enlarge.)

The system was installed in May, 2006, so this month will be taken out of the following numbers. In the year 6/2006-5/2007, a total of 2471 KWh were generated with 2423 KWh expected. The worst month was Apr-07, down by 20% from average. This was also a record-breaking month in terms of the amount of rain.

In early May, 2007, we removed another one of our trees that was partially shading the solar panels in the morning hours. So far, the tree removal appears to have increased our output by 10-15%. The trend of enhanced power over epectation should continue going forward.

In terms of dollar amounts, we have saved $563.46 over the 6/2006-5/2007 period from the power costs (now $.17/KWh here in Fairfield County, CT!). This includes a 6 cents per KWh green-tag credit paid to us by MassEnergy. Return on investment appears to be over 5%.

The one difference from the proposal is that the power is less as a percentage of our usage as was guestimated in early 2006. We were still in renovation mode, and the amount of power we would use wasn't clear. Our use is significanly more than we were expecting, but that is mainly because of the geothermal heating and cooling. More on that in a later post.

One other interesting comment is that the spring/summer generation is about double that of the winter generation. That is a big swing. For most of the nation, peak power consumption is in the summer. Our peak power usage, however, has shifted to the winter season, again due to the geothermal heating.

In summary, then, the panels are indeed working as advertised.

Geothermal Heat pumps: Installation

2007-04-05T14:42:00.000-07:00

Here are some pictures of my geothermal heat pump installation. These are big files (2-3 meg/picture). First up is the well drilling done by Connecticut Wells. They were very professional, and they got the truck into the back yard, despite the warnings of a certain skeptic. The wells hit bedrock at about 25 feet, water around 250-275 feet (3 wells total), and each went to a depth of 350 feet.

Here are the pipes coming from the 3 wells and running to the house.

Finally, here are the Climatemaster units for the 3 air-handlers in the house.

Geothermal Heat Pumps: Adventures in Contracting

2007-02-12T08:53:00.000-08:00

Getting our geothermal heat pumps was, to say the least, an adventure. The first problem was that neither our builder nor our architect were very familiar with heat pumps. While both very competent individuals, they were always hesitant whenever we brought up ideas with which they were not familiar. If there was something different that we wanted, they always provided the advice that there were cheaper ways or other ways to do what we wanted, and they always deferred to their contacts that they had used. This is a natural reaction for anyone, namely you go with what you know or who you trust. We would get our way only if we kept pressing the matter. On most things, their advice was well-given, but on others, in particular when it came to the heating and cooling systems, their advice was more appropriate for the 1980s and not the coming decades.

With respect to installing the heat pumps, we were on our own and had to take over the contractor's role. I wasn't quite ready for that, and it resulted in some inconvenient delays. The installation in our renovation project had been done to code and standard practices (of course, given how many things go, that is actually a good thing!). What had been installed was a standard heating oil boiler and three air handlers with appropriate duct work. Two of the air handlers were dual zone, so we have five separate zones in our house. The air conditioning wasn't installed as yet, but they would hook right into the air handlers.

We located dealers for both WaterFurnace and Climatemaster from the dealer locator buttons on their website. (As mentioned, we didn't know about the Trane units.) The Climatemaster dealer came out, looked at the house and said no problem. He took a set of house plans and sized a system and then told us that the guy who had sized the original system had shorted us a bit. Looking around the house, he located a good place for the vertical wells in the back, and said we could get in a system. He sent us a quote and said we would need to swap out one of the air handlers for a bigger one to meet the cooling load and that the guy who sized the original system undersized it.

So, now I have two different people giving me two different answers for what the house needs. Being technically inclined, I decided to look into the calculations a bit to see what I came up with. The method for sizing the heating/cooling systems is known as a Manual J calculation. I found software for this at HVAC Computer Systems Ltd. The software for a residential calculation is $49, and given the drawings of the house, the estimate took about one hour including time to change some of the parameters to get an idea of the sensitivity to different assumptions. It was very user-friendly. You can download a demo that gives you an idea of how the software works. If you end up purchasing the software, please let them know where you heard about it.

What I found disagreed with the first two estimates. By my estimate, the original heating/cooling load calculations were high by about 20%, and the new quote I got were about 20% higher than that. After performing the calculation myself, there were clearly many things in this calculation where judgement came in. If the world is ever going to improve its energy efficiency or turn to greener methods, a new look at the Manual J assumptions will probably have to be done. Let's put that firmly on the back-burner and plow forward.

Given the discrepancies, I thought I'd ask the Climatemaster dealer about it. Some of the differences were due to things like the use of shading. In the calculation, you can deduct some of the cooling load if the house is shaded by bushes or trees. Well, we have two trees on our neighbor's property that shade a good portion of the house in the summer afternoons. As mentioned in a prior post, they annoyingly cut into our solar power output. The dealer said that he "never puts shading into the calculation." Hmm... Eventually it dawned on me why he would never put in shading. With houses turning over every 7 years or so, and with people not very literate when it comes to HVAC, making the most conservative assumptions is a good idea. This way you sell a system slightly larger than the code would suggest, and any future changes were bound to be covered pretty well. If a new owner came in a chopped down the tree, the system would still work, and the HVAC company wouldn't have to be bothered in that situation.

The other thing I noticed in the calculation that I'll quickly mention is that putting glass doors on the fireplace are a rather good way to reduce the heating load. Funny how nobody seemed to mention that one or mention about the present insulation in the house. Hmm...

After thinking about it for a couple of days I figured I'd get the opinion from the other dealer. What could it hurt? A second quote is a good idea (and 3 is even better), and I wanted more information.

The WaterFurnace guy came out and gave us a completely different story. He said we'd be wasting our money, we'd never get the well driller in the back yard where we needed to put in the well, and we should have called him at the beginning of the project. He was Mister Negative. I still haven't figured that one out. He clearly didn't want the job. I told him we were still interested in a quote and were very serious about putting in geothermal and weren't just tire kickers. He said to send us the plans and he'd work on it. We did and never heard back from him.

So we didn't get the other Manual J calculation from the Climatemaster dealer, but doubt was put into my mind regarding whether or not the well drilling truck could get into the back yard. After thinking about it for a week, I decided that the best thing to do was to call the drillers and ask them directly. Their guy said "no problem." That taken care of, it was time to make a decision.

As you could probably guess, we chose the Climatemaster system; not because we thought it was particularly better than the WaterFurnace technology, but because the representative for Climatemaster took our project more seriously. With regards to the sizing issue, my reasoning was this. The system was sized for the cooling load, and secondary heating was going to be required anyway. Given our Yankee location, heating needs are about double the cooling needs, so if the heat pumps are sized for the cooling loads and under still under my estimate for the heating loads, then it would probably be okay. I might pay up more in the initial cost but would probably make out in the future. We were also running up against time limits due to issues with the house reconstruction, and a decision had to get done quickly.

The story of our installation has some lessons too. Again, we didn't find a one-stop shop for this. I lined up the well drillers, the heat-pump guys, and I also had to hire the backhoe operator. Not knowing the timing of each or knowing what all needed to get done at the beginning, it took longer just due to scheduling constraints.

Well, the heat pumps have been in use since October, 2006. They've worked well (despite some quibbles with the electronics....maybe another time) and have definitely saved money. When the numbers are all in, I'll post on how they've performed.

Geothermal Heat Pumps: How it Works

2007-02-12T07:56:00.000-08:00

With heating oil our primary heating source, it was clear an alternative was needed, and for better or worse, we got geothermal heat pumps. There are a few on the market now, and the technology is getting better. At the time of purchase, I knew of two companies: Water Furnace and Climatemaster. Since then, I've learned that Trane also makes heat pumps, but they are listed under their commercial section and not the residential section of their website.

How Geothermal Works

There are good write-ups on how heat pumps work on both the Climatemaster and the WaterFurnace websites. From Climatemaster:

The earth absorbs almost 50% of all solar energy and remains a nearly constant temperature of 50°F to 70°F depending on geographic location. Working with an underground loop system, a ClimateMaster geothermal unit utilizes this constant temperature to exchange energy between your home and the earth as needed for heating and cooling.

In winter, water circulating inside a sealed loop absorbs heat from the earth and carries it to the unit. Here it is compressed to a higher temperature and sent as warm air to your indoor system for distribution throughout your home.

In the summer, the system reverses and expels heat from your home to the cooler earth via the loop system. This heat exchange process is not only natural, but is a truly ingenious and highly efficient way to create a comfortable climate in your house.

Another more detailed explanation can be found on the WaterFurnace page here.

Getting Quotes

At the company's websites, there are dealer locator links, and we used those to get quotes from local installers. There is a story there and some lessons (next post).

Counsel on Foreign Relations Weighs In

2007-01-19T09:44:00.000-08:00

"America is addicted to oil," said President George W. Bush in the State of the Union Address on 31-Jan-2006. You sure wouldn't know it from any actions by either the Executive or Legislative Branch. At least, that is, until the new Congress convened. Since then, both the House and Senate have been busy, but we are a long ways from anything concrete as yet, and the direction isn't necessarily good.

One bright spot is that we seem to be getting past the recognition stage that there is indeed a problem, although there is still some disagreement at exactly what the problem is, but at least the House and Senate are working on the issue.

On the recognition front, an interesting development occurred in October, 2006, before the election, when the Council on Foreign Relations (CFR), a prominent "nonpartisan resource for information and analysis" issued a report entitled National Security Consequences of U.S. Oil Dependency. This report is interesting, I think, primarily because it is not an outside group that is calling attention to the dependency issue. The CFR is an insider organization if ever there was one. What follows is a synopsis of the report. (This is more for my own edification than anything. I highly recommend downloading the pdf (it is free) and reading it yourself.)

Out of the gate, the report states that "The lack of sustained attention to energy issues is undercutting U.S. foreign policy and U.S. national security." Noting that energy supplying states are beginning to flex their muscles, we (the United States) find ourselves less influential because of it. It recommends five types of actions.

It is "unanimous in recommending the adoption of incentives to slow and eventually reverse the growth in consumption of petroleum products, especially transportation fuels such as motor gasoline."
It "recommend[s] that the United States take several initiatives to encourage the efficient, transparent, and fair operation of world oil and gas markets."
"The United States must work more closely with major oil suppliers...to detect and deter attacks on their infrastructure...and...[g]reater efforts are needed to harden the energy infrastructure against both attacks and natural disasters."
"There are too many examples of countries that exploit their oil and natural gas resources while failing to manage the revenues in a way that improves the social and economic prospects of their people...The U.S. should play a more active role...working to convince others, such as the governments in China and India, of the importance of...measures [to improve economically the people in exporting countries]."
"The U.S. government is not well organized to address the threats to national security created by energy dependence. There is a need to mobilize...in a manner that better ensures continuity of attention and integration of the different perspectives needed for energy policy making." However, it says specifically that it "cautions that it would be neither practical nor wise to insist that energy security be the central foreign policy priority of the U.S."

There are two main findings that influence the recommendations for action above. They can be easily summed up as (1) the U.S. is dependent on foreign energy imports, and (2) this influences how we conduct foreign policy. In the recommendations sections, it discusses specific ways to address these two issues. The findings are worth describing in more detail.

Imports of Oil and natural gas supply 63 percent of our energy needs. Coal is abundant domestically, and the remaining sources are nuclear, biomass, hydroelectric, and then the other renewable sources. Oil fuels 96 percent of the transportation needs and is thus critical to the transportation sector. Because of this dependence on a single source, the Task Force believes that the U.S. cannot be energy independent for "at least several decades", barring, that is, any "draconian" measures. It also states that a cut in imports won't help, due to tight production, and the private companies cannot be controlling the price of oil due to their small size relative to the large national companies. Further, there is little hope in lower prices any time soon, for "the world has used [its] low-cost oil."

Natural gas has more end-uses, namely electricity, heating, and industrial feedstock. Presently most imports come from Canada, but 2 percent comes as liquefied natural gas (LNG), and LNG is expected to increase for "there is well-founded concern about the availability of adequate supplies of natural gas to the North American market." In other words, we are past peak production in North America in natural gas as well as oil! This dependence upon imports will cause a fundamental shift and raises the issue of the security of gas supplies going forward.

Turning to the issue of foreign policy, the panel identifies five major reasons why this dependence matters and mentions a sixth, the relationship of the military and oil dependence.

The control over enormous oil revenues gives exporting countries the flexibility to adopt policies that oppose U.S. interests and values.
Oil dependence causes political realignments that constrain the ability of the U.S. to form partnerships to achieve common objectives.
High prices and seemingly scarce supplies create fears that the current system of open markets is unable to ensure secure supply.
Revenues from oil and gas exports can undermine local governance.
A significant interruption in oil supply will have adverse political and economic consequences in the U.S. and in other importing countries.
Some observers see a direct relationship between the dependence of the U.S. on oil and the size of the U.S. defense budget.

Given these set of problems, the Task Force recommends some policy objectives for both domestic and foreign policy. Domestically, the need to reduce oil imports, we should:

Increase efficiency of oil and gas use
Switch from oil-derived products to alternatives
Encourage supply of oil from sources outside the Persian Gulf
Make oil and gas infrastructure more efficient and secure
Increase investment in new energy technologies

Each of these are then elaborated. Policies increasing efficiency are encouraged. In terms of alternatives, co generation (heat and power), biomass and plug-in hybrid vehicles are recommended. However, a switch to electricity could cause a switch from imported oil to imported natural gas, unless other electricity production (wind, nuclear) is also available. The Task Force cautions that increased renewable and nuclear alone will not quickly reduce dependence on oil and gas, although improvements in hybrid and electric cars could change that in the future. Possible measures to increase efficiency include implementing a "substantial federal excise tax on gasoline," tighten the Corporate Average Fuel Economy (CAFE) rules, capping gasoline consumption by adopting a system of tradable vouchers. They also strongly recommend removing the $.54 per gallon tariff on imported ethanol and making greater use of nuclear power.

In terms of supplies from outside the Persian Gulf, they give the specific example of Canadian tar sands. However, they also recommend opening up ANWR in Alaska as well as off-shore areas for drilling. Further on, they recommend increasing the ability to import LNG.

On the security issue, they recommend increasing oil stockpiles to 1 billion barrels (up from 700 million), making the oil and natural gas infrastructure less vulnerable to disruption (natural or terrorist), and in the event of a disruption, stay away from price and allocation controls similar to those imposed in the 1970s. They also recommend streamlining the regulations for the U.S. refinery industry to better upgrade their capacity for heavy crude refining. The Task Force also recommends increasing R&D in a variety of manners with goals of improving automobile mileage, development of hybrids, production of ethanol and synthetic fuels, and advanced research in fission and fusion energy.

Finally, there is the section on foreign policy recommendations. The Task Force states the the U.S. government has failed to pay sufficient attention to energy in its foreign policy conduct and recommends making energy an integral part of policy. It recommends the U.S. seek stability in the Persian Gulf and try to expand sources of oil and gas production. It recommends encouraging efficiency in all markets and in other countries as well as encouraging proper functioning and integrated energy markets. In this latter regard, it recommends U.S. foreign policy "encourage a regulatory process that allows the timely construction of cross-border infrastructures", encourage "accurate historical data and objective projections" of energy data, and recognize that National Oil Companies (NOCs) are now a dominant force in the world oil and gas markets and must find ways to work with these enterprises.

There's more on the foreign policy front. The U.S. should "revitalize international institutions and collective international efforts." To do this it should "work with other countries to prepare the world market for oil to better withstand price shocks...encourage countries to devote greater attention to energy infrastructure protection...and do more to promote better management of oil revenues because good management serves the long-term U.S. interest in encouraging increased oil production." Finally, it gives recommendations on how to integrate energy issues into the foreign policy apparatus.

There is a lot of information in this report, and I've only touched the surface. It is clear from the recent Congressional hearings that Congress is listening. It will be interesting to see what the Executive branch comes up with in this year's State of the Union Address.

NYT Article on Solar Power in California

2007-01-04T06:22:00.000-08:00

In today's New York Times is an article entitled Plugging into the Sun on the wave of solar power systems being installed in California. It contains the following testimonials:

WILLIAM LEININGER is not your typical environmental zealot. A Navy commander who works as a doctor at the Naval Medical Center San Diego, he is a Republican and lives in one of California’s most conservative counties, in a development of neat lawns and Spanish-style houses....
As a member of the military who has been deployed to the Persian Gulf three times, Dr. Leininger has been affected by the nation’s foreign oil habits more than most. “The need for stable oil supplies is the big reason that we spend so much time in the Persian Gulf,” he said. “Decreasing our national energy consumption is in my self-interest.”

Another guy they interviewed also has similar motives:

Mr. Felton, 67, said that a solar system did not make sense when he built his house in 2000, but that the rebate, as well as rising electricity prices, persuaded him to install the system last year. His pragmatic concerns were also informed by broader issues. “I’m not a hippie greenie,” he said, pointing out that with a background in nuclear engineering, he strongly supports nuclear power. “But solar is certainly a way to get off foreign oil.”

Sounds a bit like my story, although I'm not in the military or a big nuclear advocate, I'm also not a severe critic of either (but the present administration's policies, however, that is another matter).
It is interesting that people worried about foreign supplies go first to solar power like I did. I applaud all attempts to going solar and to increase green energy sources. The data point to transportation as the biggest sector using foreign oil, however, and we really need to fix that. Plug-in hybrids anyone?

Heating and Cooling Our House: Needs and Wants

2007-01-02T09:58:00.001-08:00

With respect to energy security, it seems to me that heating is the most important energy need. Yes, you need private transportation, but in a crunch, other less convenient modes (walking anyone?) will do. However, proper climate is essential for life. With prices high these last couple of years, I've heard anecdotes of people on fixed income who have to decide between heating or eating. They generally choose heating and go to food kitchens for eating. I am determined that my family and I will not have to face this dilemma.

This need for proper climate puts us all in a precarious situation. It doesn't presently ring many bells for most of us, but if a sudden disruption in oil occurred similar to Hurricane Katrina except on a larger scale (e.g. Saudi Arabia exports are shut down by terrorists), we'd all be affected, whether we used natural gas or heating oil for our main heating source. If you are limited financially in what you can do, I'd make sure, more than anything else, you can keep warm when it gets cold.

As we would put our survival first, I think the way a major shortfall in oil and/or natural gas would play out is that people would pay whatever it took to heat the house and worry about the consequences later. This would squeeze many people financially, but any human being would choose higher debt or even bankruptcy to dying from freezing.

A similar issue arises in health care, namely what are we willing to spend for life extension? In the case of health care, the problem is rather open-ended, and it makes it rather difficult to conceive of a health care policy that is prudent, for there is nothing that seems prudent about dying when the technology exists to let you live a little longer. But, I digress.

Maybe to keep the heat on the only requirement is to have a large woodpile for the fireplace. That gets you through one cold winter, but if the peak-oilers are even remotely right, it won't get you through many more. In his second book on peak-oil, Beyond Oil, Ken Deffeyes mentioned that one of his colleagues purchased an acre of land to insure a continuous supply. If the Middle East shuts down, as the North American natural gas production falls off (it is beyond peak production already), it seems deforestation becomes a possibility here. It seems unlikely now, but wood is presently the backup fuel of choice. As one precaution, I've been taking down the evergreens on our property and am replacing them with hardwoods, namely oak and maple indigenous to the area. This is simple enough to do, but we don't have an acre of land, and I definitely do not want to have wood replacing heating oil as the primary source of heating. Also, it's going to take 10-15 years before the home-grown supply will be useful to us. Let's call this tree selection as our insurance on our insurance.

What about cooling? Do we need cooling? That's easy. From a survival standpoint, almost certainly not, even in the tropical climates. With respect to cooling, especially in the higher latitudes, cooling is more a want than a need.

Back to heating. What do we need? In truth, just a small well-insulated seal-off room with a fireplace and a stack of wood. But it isn't really about what we need. It is more about what we want, and what we want is a stable, secure, low-maintenance climate system for our entire house. Wood is getting rejected because it is high-maintenance, and we don't have to long-term supply secured (i.e. we don't own an acre of forest). I'm rejecting our present use of heating oil, because of future supply reasons--even with a newer efficient boiler. Natural gas was not available to us at our house, and after looking into the future of natural gas, I'm glad about that. It gives me the excuse not to go that way. Propane is available, and we presently use it for cooking, but its supply also is subject to all the issues that natural gas is. The so-called green technologies are all that remain. Solar heating is an option, but we also want efficient cooling, and solar needs backup for those cloudy wintry days, and so we went with a geothermal heat-pump.

Heat pumps have come a long way, and the ground-loop ones are an excellent green technology. They aren't all that cheap to install, and (as we are finding) the electricity needed to run them is a factor one has to consider. In short, the ground-loop heat pump is giving us what we need and virtually everything we want.

The next couple of posts will describe how they work, what we purchased, and describe their installation and our initial experience with them. I'd have to say, overall, it has worked great.

Here's a Great Idea I Haven't Implemented....Yet

2006-12-26T09:58:00.000-08:00

Our largest use of fossil fuels was for home heating. The legacy system in our house when we bought it, was oil. With no insulation in the house, we went through a lot of oil! When we moved to our present house in 2000, the price was just over $1/gallon. Last year it was $3.50.

When deciding what to do going forward, we had already purchased a new efficient boiler. This was done by our builder in the early part of our renovation to our house, and when it happened, I was not thinking hard about long-term energy use and the best way to go about it. Some thoughts had crossed my mind regarding solar heating, but with solar, you still need a backup source, for the sun isn't shining all the time, and given the efficiency boost, I was thinking more about the great improvement the new system was going to give instead of dumping the entire technology. With time, we could then implement solar systems to reduce our use of oil. That was plan anyway.

That all changed earlier this year when the decision was made to try to get off of the oil entirely, and in a later post, I'll explain why we went with a geothermal heatpump, but here I want to discuss something we haven't done as yet: the solar wall. Check out this website: www.solarwall.com

The solar wall is brilliant. In its simplest description, it is a black piece of metal, put on a sun-facing side of the building, and it has holes in it to suck in the air heated near the surface of the metal, for the surface becomes hot by exposure to the sun's rays. If you are looking for an inexpensive method of seriously reducing you heating bills, it is worth looking into purchasing a solar wall system.

A really ingenious system is the PV/solarwall "co-gen" unit. Here you put a solar wall in tandem with photovoltaics, so you get power and heat at the same time. The combination is especially powerful, for the PVs are less efficient the hotter they get, and the solar wall can help with that problem by taking the heat away from the PVs, and as the PVs are dark, they are already the right color and produce a lot of heat by themselves. According to the website, payback times can be cut by as much as two-thirds by having the combined unit. I believe this, although it should be pointed out that the main cost of the combined system would be the PV part, and you'd probably get a better return dollar for dollar by just installing the solar wall.

A great critique of solar power is the book The Solar Fraud: Why Solar Energy Won't Run the World by Howard C. Hayden. You can get a copy of this book on Amazon.com. I don't buy all of his arguments, and he definitely has a nuclear bias, but the book is well argued and worth reading.

One of his criticisms of solar-generated electricity is that the efficiency of the solar cells is low (20% or less), and that it isn't likely to increase, due to the inherent physics of converting sunlight into electricity via the photoelectric effect. Technically, Hayden is correct, for there are good physical limits, and so far, all panels that get great efficiency, say 30% or better, all use elements that will probably remain expensive, and none get the 50% or more efficiency one would like.

But this criticism of power conversion is true of most methods of producing electricity or any kind of work (the internal combustion engine is one of the worst!). The problem is that it is easy to convert work to heat, but harder to convert heat back to work. The work-around for all efficient power units is to use the heat for other processes. For example you can use the heat to boil water to make steam that then gets turned into work by turning turbines. The most efficient power plants do that. The solarwall with the PV tie does something similar. It uses both the heat and power, and it is a great piece of engineering.

If your budget is limited, and you really want to do something to reduce your reliance on fossil fuels, definitely check out the solar wall. A properly planned system will save you money and significantly reduce your use of either heating oil or natural gas.

Energy and the Middle East

2006-12-20T06:10:00.000-08:00

While campaigning for Republican Senatorial and House candidates during the last elections, George W. Bush made a couple of references to the problem of the United States' dependence on foreign oil. For instance, at the Springfield Exposition Center in Springfield, Mo on Nov 3, 2006, he said the following with regards to his waging of the war on terror (http://www.whitehouse.gov/news/releases/2006/11/20061103-1.html):

The consequences of retreat would be felt for generations. I see a lot of young
folks here today. (Applause.) My job is to think not only how to protect you
today, but how to create the conditions for peace in the long run. Retreating
from the Middle East because of the unspeakable violence that the enemy inflicts
on others, as well as their own troops, would create a dangerous world for you
to grow up in. You see, the enemy has made it clear that they expect us to lose
our nerve. They have made it clear that they don't believe America has what it
takes to defend ourselves. They want to topple moderate governments. They want
to be able to use energy as a tool to blackmail the United States.
Imagine the radicals and extremists taking over a country, and they were able to pull millions of barrels of oil off the market, driving the price up to $300 or $400
a barrel, whatever it would be, and saying, okay, we'll reduce the price, all
you've got to do is surrender. All you've got to do is abandon your alliance
with Israel, and we'll lower the price. All you've got to do is retreat. And
couple that with a country which doesn't like us, with a nuclear weapon, and a
generation of Americans will say, what happened to them in 2006? How come they
couldn't see the impending danger? What was it that clouded their vision?

Some pundits have jumped on President Bush's comments as an admission that we went to Iraq because of oil. At the time of the invasion, there were plenty of denials that oil was the reason for the campaign. I specifically remember Former Defense Secretary Rumsfeld's comments that oil had absolutely nothing to do with the invasion of Iraq. For what it is worth, I didn't believe him then, and I don't believe it now. Sure, you could justify going in for other reasons, but it is now clear the neoconservative agenda of stabilizing the Middle East appears the primary reason, and for what other reason would we do it besides oil? Israel perhaps, but if we were interested in world stability, we'd go into places in Africa first. Anyway, that's an old and tired debate.

I've been thinking about Bush's admission since it hit the news cycle in early November, 2006, and the general reaction of "gotcha" by his critics. What shouldn't be lost in all this is that Bush is in essence right. We cannot find ourselves held hostage because of our oil addiction, I couldn't agree more. But I find myself differing in the approach of the solution. The best way to fix our problem, in my opinion, is to make the Middle East irrelevant, and that means going off oil with sooner being better than later. Nothing will change the attitude towards America better than our statement that we don't want what they have anymore. I think that would do more for our foreign policy state than anything else.

Our Toyota Hybrids

2006-12-10T10:55:00.000-08:00

Hearing about the 2007 Toyota Camry back in April, 2006, I decided to pay a visit to the local Toyota dealership to check it out. The reason for the interest is that the Camry was the first full-sized car that was rated at 40 mpg of which I had heard. They didn't have any then, for the production didn't start until May, 2006. As I was there, they suggested I try the Highlander Hybrid, so I did, and of course, we liked it enough that we decided to buy it.

The salesman wanted me to put my name on the waiting list for the Camry for a $500 deposit. I told him to call me when he had one that fit my desires. I didn't want to reserve a car I had never driven before. He called on their second hybrid Camry they got. Apparently the gentlemen who reserved it didn't have the credit, and so the car was available. I drove it, my wife drove it, we bought it.

Prior to the new vehicles, we owned a 1996 Nissan Maxima and a 2002 Subaru Legacy Outback. I usually tracked the Maxima mileage, and it tended to get between 19 and 21 mpg. This is from a car that the EPA rated at 21 city , 28 highway, and 23 combined. Checking with http://www.fueleconomy.gov/, from 6 drivers who registered, they got between 21 and 25 mpg--much better than we averaged. This government site is really good for people interested in comparing the fuel economy of different vehicles. Especially good are the actual mileage rates from actual drivers. (It is on my list of things to do to upload the mileage from our hybrids.)

The Subaru was also in the same range, 22 city and 27 highway with the combined at 24 mpg. We generally got a little better mileage with this car, probably around 23 mpg. This is from memory, for it wasn't tracked as often.

Before replacing the cars, I figured we'd get the Camry to replace the Maxima. After driving the Highlander, I concluded we could replace the Subaru too, although that perhaps wasn't so pressing. Just as an aside, I didn't even consider the Prius. Don't know why exactly. I think it is because I'm looking for the same or improving driving experience and didn't want to down-shift to a smaller car unless it is absolutely necessary.

Driving our new cars has four pleasant advantages over the previous cars. The first is the GPS. This is probably one of the best additions to cars in years, and I highly recommend it, even though it doesn't help with the fuel economy. The second one is the regenerative breaking, i.e. the hybrid nature to the car. You feel good pushing on the brakes on these cars, for you know you are saving energy by doing so.

The third improvement is the pick-up. The best-kept secret of these cars is that they accelerate fast. This is a true advantage of an electric drive, and it represents a real improvement over just internal combustion. The gas only Highlander has 215 horsepower, but the hybrid has a combined value of 268 horsepower, and it gets better gas mileage. The gas-only is rated at 19 city, 25 highway. The hybrid is rated at 31 city, 27 highway. Same for the Camry. The combined output (V-4 plus electric) is higher than the V-6 Camry. These things have great pick-up. There is no contest.

Finally, the best part is that we go farther between fill-ups. Gas mileage is rated at 40 mpg for the Camry. Our mileage, while better than our previous cars, appears to be less than the people who have uploaded their data to http://www.fueleconomy.gov/. Most Camry hybrid drivers are getting between 32 and 42 mpg. We are getting just over 30 mpg. For the Highlander, we are getting just under 25 mpg, while the average on the website is 25.2 and a range of 21-31 mpg. I think the primary reason we aren't doing as well is that our trips are short (under 10 miles most of them), and generally speaking, one gets better mileage on longer commutes, because the mileage improves as the engine heats up. That's my guess. Frankly, I don't really know.

We can estimate what we are saving by a quick gas mileage comparison. The Camry replaced the Maxima, and the Highlander replaced the Subaru. The Camry represents a 50% improvement in mileage [(30 - 20)/20 = 0.5] over the Maxima, but the Highlander represents only a 10% improvement over the Subaru. It wins more in larger space and newer equipment (including the GPS). The third row in the Hylander is a major plus.

Replacing the Maxima was a great idea, but frankly, I like the Highlander better. We are driving the Highlander more than the Camry, but we drove the Subaru more than the Maxima. On average, we are probably using 25% less gas than before, or about 180 gallons a year savings.

No bad? Frankly, I think it is inadequate. We need to use 80% less or even less than that. If only we could plug these vehicles in and use solar, wind, or even nuclear power for that matter. Any would be better than sending the money to people who don't seem to like us.

You Can Pry My Car From My Dead Cold Hands

2006-12-10T08:04:00.000-08:00

Is the automobile a bad thing or is it just the fuel? My answer to this question is "yes."

Environmentalists can give you a litany of issues brought on by the automobile from pristine land degradation to air polution to global warming. I'm not going to get into that debate here really, except to say that I do believe it has done a lot of damage as well as facilitated a lot of good. More importantly for the moment, it is unlikely the personal automobile is going to go away soon, and to repeat my personal situation, we aren't giving ours up any time soon.

Sure, we could have more public transportation, and that would probably be a good thing. But, the automobile is too convenient to just go away without a serious world change. Perhaps Peak Oil and all its problems will do it, but I don't think so. Personally, I think the automobile is here as long as humans are.

As I wrote in the last blog, even before the automobile, people of means had wagons or carriages, and some even had rail cars. The truly amazing thing is that in the USA, virtually everybody who wants a car can get one. That's empowerment if ever there was such a thing.

The more pressing problem, in my mind, is the fuel source for the auto, namely gasoline. And what are the problems with that? Well, ok there again is the environmental side which is an issue for another discussion. The bigger problem is where the fuel comes from, and that is not here.

The accompanying graph shows the amount of petroleum supplied since 1949 (light-blue line). These data from from the EIA site at DOE and were from the last Annual Energy Review.

Post WWII, the USA pumped most of its own oil (dark blue). However since the mid-to-late 1980s, our dependence on foreign sources has been steadily increasing (yellow line).

This graph tells many things. It shows the peak in the domestic USA oil production in 1970 (as predicted in the late 1950s by M.King Hubbert), and the peak in Alaskan oil in 1988 (purple line). It has been downhill for domestic production ever since, and despite what the news may tell you, the deepwater Gulf of Mexico oil won't get us back. It could replace Alaskan oil, maybe, but that appears to be about it. Exactly where this foreign oil is coming from and where it is expected to come in the future is an interesting story in itself, and I'll try to post that too.

Another interesting part of this graph are the peaks in consumption in 1973 (the Arab Oil Embargo), in 1978 (the Iranian crisis), and what may be another peak in 2004. The 2005 data are preliminary, but it looks like 2005 and 2006 have less usage than prior years. We can call this the Hurricane Katrina shortage, although that is a bit of a simplification.

A significant fraction of the decline in petroleum supplied post-1978 were demand destruction caused by the federally mandated fuel economy (CAFE) standards and also a significant reduction in the use of oil for electricity production. My take on that aspect is that yes, conservation worked, for it bought us some time, but it hasn't fixed the problem, and we are now more vulnerable to a foreign source disruption (or Peak-Oil for that matter) than ever before.

What we need is a new fuel source for personal transportation needs. There is a new book called Internal Combustion by Edwin Black, and I recommend it for anyone interested in how we got tied to gasoline. It is an interesting story.

In the meantime, I'm in the camp looking for a different fuel source, and I have become convinced that it resides in electricity or a plug-in hybrid. Ethanol has problems (in the USA), and hydrogen isn't here yet (if it ever gets here), but we could get plug-in hybrids today, for the technology exists and is available. By going that route, we would have a chance in becoming self-sufficient again and help the environment at the same time.

Unfortunately, no large automaker is building plug-in hybrids at the moment. Feeling we needed to do something, we bought Toyota Hybrids. My thoughts on those are coming up.

Our Transportation: What Do We Need?

2006-12-05T06:07:00.000-08:00

It is interesting to reflect upon what the automobile means to us. For my family and I, it is probably 99% convenience and at most 1% necessity. Could we do without it? Yes, I believe so. Will we? Probably not unless we absolutely have to.

Why is this so? Why don't we need it? The primary reason is that we live on the Eastern Seaboard where public transport is pretty good. There are local buses that service the train to NYC (or New Haven if we need to go that way). I work out of the house, and my wife works about 12 miles from the house. The public transportation, while incredibly inconvenient, would suffice for commuting if it came to that.

Of course the Eastern Seaboard isn't the only place with good public transportation. Many places have it, but the culture clearly in the USA is automobile focused, and that is true also on the East Coast. I'm also guessing that most Americans (i.e. over half) are in a similar situation where the automobile represents an incredible time saver and convenient mode of transportation.

What about needed trips, say to the grocery store and such? The closest store to us is about a mile away. We could do that by bike, although dealing with the traffic is a major deterrent. Our daily habits would have to change considerably if for some reason gasoline became scarce, but it is clear we could cut our consumption by 1/2 and still have a decent lifestyle, but it would be, to borrow a word from our former Vice President, inconvenient.

So there is the contradiction. We use the auto because we can. We burn the gasoline, originating primarily from foreign sources, because it makes live easier. We would like to reduce or eliminate this connection, but, frankly, it isn't going to be easy. Sure, we could go "cold turkey", I'd rather spend time and effort figuring out a different way.

Many vocal critics of the US energy policy attack the automobile, saying it makes sense to invest in public transportation. I don't disagree with a good public transportation system. If I need to go into Manhattan, I take the train probably 90% of the time. That is because it is more convenient to do so. If it is Queens, though, I drive. The extra hour each way for the public transportation is just too much to take--especially with kids.

Yeah, we could give up the cars, but we won't. Looking back to times before the automobile, there also was public and private transportation. You could take the stage coach or you could ride your horse or your personal carriage or wagon. Take away gasoline, and I'm willing to bet you would still see the remnants of what we see now: some public, some private modes of transportation. It has always been that way. Why should it change now?

Power Prices Going Up...Again!

2006-11-29T13:26:00.000-08:00

According to the Connecticut Post (www.connpost.com), November 16, 2006, Connecticut Light & Power has applied for another rate increase. This one will be 8.3% for residents and will amount to about $.015 more per kilowatt hour. According to the article, the request was made because the generation costs have increased. In CT, generation is just a pass-through charge, and CL&P enters into contracts annually to secure these costs. These are usually approved without much discussion.

Interestingly, the increase is actually lower than expected, because the federally mandated congestion charges will be going down, due I believe in part to a new underground power line in the area. However, according to the article, all of the 2007 power contracts are apparently not fixed as yet, and another proposal for an additional rate increase is to be expected for the 2nd half of 2007.

This 8.3% rate increase further improves the economics of the solar panels. Assuming no further increases come, the new rate cuts the payoff time by 4 years. Assuming 8.3% is the new inflation rate for power, and we get this rate increase every year, we can expect to get our money back by 10.5 years. Power then will be a whopping 41 cents/kwh. That power rate would be hard to believe, but given the corner we have painted ourselves into as a nation, that scenario cannot presently be ruled out.

A decision by the Dept. of Public Utility Control (DPUC) is expected by December 8, 2006. I'm not holding my breath.

Going Green: What Next?

2006-11-26T10:53:00.000-08:00

The solar panels were an okay deal, and the environment is better off as a result, but they didn't directly help with the oil security issues, although they were some help with the natural gas supply issue. We are out about $11K, and so far, we don't as yet have back-up power. We have alternative power that is grid-tied, but it doesn't help us in the event of another power outage. So what do we do next?

It is the oil situation that has me the most concerned, so it makes sense to concentrate on that area. We have two issues here. First, we, like virtually everyone else in America, use automobiles for the bulk of our transportation. Second, living on the East Coast, we use heating oil to heat our house. Heating oil wasn't our choice, for it was in the house when we bought it, and (fortunately, I now believe) natural gas is not available on our street, probably due to the rocky soil. It seems like we have to work on both gasoline and heating oil (and we have improved both--I just need to post it).

The first question to ask is how much do we use? With 2 cars getting between 22 and 25 mpg and with roughly 8000 miles driven annually on each, we use about 700 gallons of gasoline annually. That's just a guess. Funny thing that we don't know what it is exactly. Nonetheless, our usage is on the lower side for most people in America, but can we improve upon it without a loss in lifestyle?

On the issue of heating, we probably use 1000 to 1500 gallons of heating oil each year for space and water heat. Again, I can't give the exact amount, but now that I think about it, I think I'll try to find the old bills and actually see if we can reconstruct how much we have used in the past.

Both these components come from oil, and not just our lifestyle depends upon it, our actual existence does, for if the heating oil supply was disrupted somehow, the one fireplace in our house would not be enough to heat the house. Yes, if worse came to worse and we did suffer a major heating oil disruption, we could reduce our space to only the living room and live there, but I'd prefer to not even go there unless we have to.

Again, the question is can we move off oil (and fossil fuels in general) and still maintain our lifestyle without a significant cost impact? To date, we've done two things so far: bought hybrids, and put in a geothermal heat pump. We'll look at those in turn to see how well they've helped.

Solar Panels: Financial Analysis

2006-11-21T12:31:00.000-08:00

Were the solar panels a good deal? To answer that question, we need to do a cost-benefit analysis. We can compare the cash flows assuming we did and didn't purchase the panels. There are many assumptions about presently unknown variables, such as the cost of power in 15 years.

The bottome line is that putting in the panels as an investment isn't necessarily a slam-dunk, but it does help tremendously from a risk management perspective, and if one is taking a view of the future of tight energy supplies, then the analysis is pretty good. Whether or not it was a good decision from an investment point of view will only be determined by what happens with energy prices in the future. Let's explore.

The cost for the array was $10,878.20. This was after the CT Clean Energy Fund rebate (which was handled by the installer) but before the $2000 federal tax credit. We used this tax credit to offset the cost of cutting down some trees. These trees were probably going to be cut down anyway, so should we include that amount or not? The difference is rather large (16% cost difference). I suppose one can show both scenarios to see the difference if we include the credit or not. As one of the trees we cut down was our neighbor's tree, to be honest about it, we need to keep the federal credit out of our calculation, because we wouldn't have cut that one down if we hadn't needed to. In the meantime, let me just say "Thank you very much" to our neighbor, for without that one tree gone, we wouldn't have met the requirements for the rebate at all.

A simple way to look at the financials is to ask how long will it take for the array to pay for itself. With a cost of 17.0 cents/kwh and 2422 kwh generated per year, we save $411.74 per year thereby requiring 26.4 years to pay for itself [1]. Is it really that bad? The answer is "no" for a couple of reasons. The first one is that we get clean energy credits for each kilowatt-hour (kwh) we generate, and the second is that the cost of power can change, and at this point, it looks like it will be going up. Let's look at the credits first.

Many municipalities have voted to require a minimum amount of their power to come from renewable sources. Also, most if not all utilities give consumers the option of selecting a green source for their power. Practically, all electrons get mixed together on the power grid, so it isn't possible to select exactly which power source you are getting your power from, but from a mix of sources, you can allocate your load to greener suppliers. For instance, our power provider, Connecticut Light & Power, allows the consumer to pay a little extra for supplies from a green source through their "CTCleanEnergyOptions" program (http://www.cl-p.com/community/environment/clean.asp). By selecting a clean source, you pay about 1.1 cents more per kwh, but you can feel good by knowing you are helping support renewable energy projects.

We have sold our renewable energy certificates to Massachusetts Energy Consumers Alliance at a fixed rate of 6 cents per kwh (http://www.massenergy.com/Solar.REC.Sale.html) for the next 3 years. Somehow they can afford to pay us this amazingly good rate just for being green. It is a big difference to us, for that gives us an extra $145.32 annually in income that can be applied to our capital costs. That reduces the payback time to 19.5 years and makes the present annual rate of return on investment just over 5%.

This "renewable energy certificates" may leave some people scratching their heads. It certainly does me. Frankly, it seems to make more sense to generate the clean power and sell the credits than it does to fork out more money for somebody else to collect. But, that may not be possible for some people, either because they rent their residence and/or because of the high capital costs to install the array, and, if the decision has been made on the municipal level, it may not be possible to meet the demands of the citizens without a renewable credit market from which to buy green power.

So, present value gives us a return comparable to investing in treasuries. An added benefit is that the savings we get from the panels in electricity cost is not taxable (although the renewable credits presumably are), but treasury interest is taxable, thus improving the economics from an after-tax perspective.

What about the power cost? For starters, power costs in CT are one of the highest in the USA at the moment. The economics would be different in the Midwest where cheap coal rules even with the generous CT rebate. But what about the future? Over the past 10 years, we've risen from about 10 cents per kwh to the present 17 cents, but most of that rise has been in the last 2-3 years. Could it go back down? Certainly. Will it? I'm suggesting not.

What could make the power costs go down? One of the issues in CT is the fact that we don't have enough transmission lines for the present load. This is known as congestion, and it can be a serious problem, especially in high demand times in the middle of the summer. There is a federally mandated congestion charge that is part of the transmission cost. This charge should be reduced once a new underground transmission line goes into our area. However, the biggest contribution to the power cost is the cost of the marginal fuel, and that is presently natural gas, and for the foreseeable future, this will be the prime driver of price increases in the future, and thus the economics are tied to the price of fossil fuels.

Power prices hit a low in CT in 2003 at 10.5 cents/kwh, and it was as low at 10 cents/kwh back in 1990. Let's use this as our risk scenario for possible bad outcome on our $11,000 investment (Frankly, as we still get most of our power from our grid, we'd be happy if this happened). Also, let's also assume the renewable energy credits go away, and then our savings is only $254 annually. In this case, we are only receiving a return of 2.3% annually, and it will take 42 years to get our money back. On the flip side, power prices rose 22% annually for the last 3 years! Assuming that rate continues (also highly unlikely--substitution would come in a big way if this were to happen), the panels pay for themselves in 7 years and earn a tremendous return thereafter.

So here is the bottom line. If I am wrong and power prices go down, we are out maybe $4-5000 after 20 years. If prices stay where they are, we break even from an investment standpoint relative to treasuries, and if power costs continue to rise, we do better. The only argument that can now be made is that you shouldn't compare the solar panels to treasuries but to a better investment class such as equities that give you a better return. I have to argue that I'm doing one better, because, I have fixed my future expenses--known expenses-- and have insured for a consistent and stable power source, and so now I have more certainty. I know I'm going to use the power, and I am now in control of it as opposed to the power company or the state.

There is also the risk of the alternative investment class to consider. My own equity investments have not been particularly stellar in performance, and the cost of the array is definitely less than what I lost in the the stock market crash of 2000. For me, installing the panels was a no-brainer, and I'd do more if it weren't for the remaining issues of shading from other trees on our neighbor's lot.

Notes:
[1] In the original analysis, the annual savings was 17.7 cents which made the economics a little better.

How Much Oil Did the Solar Panels Save?

2006-11-19T15:22:00.000-08:00

How much oil did the new solar panels save? Short answer is not very much.

To get an estimate, I went to the website of the Energy Information Administration (EIA) which is part of the Department of Energy (DOE). If ever there is a government agency that is worth their salt, it is the EIA. (I'd also put NOAA into that category, but that is a topic for another blog). If one has any interest whatsoever in understanding energy issues in the USA and the world, then a visit to the EIA website (http://www.eia.doe.gov/) is a necessary stop. I wouldn't put a lot of trust in their forecasts, but their compilation of historical data is outstanding.

In their section on electricity, one can find the generation data for all states and for the USA as a whole.

The first pie chart shows the generation portfolio for Connecticut. The primary fuel source is nuclear followed by natural gas, cola, renewable, oil, hydro, and lastly other types. For the USA, the generation mix is a little different as seen in the second pie chart. Compared to the rest of the nation, CT uses substantially more nuclear power and substantially less coal.

The striking feature of both charts is how little oil is used (listed at Petro in the bar graphs). Nationally, only 3% of the electricity is generated using petroleum or products. In CT, the fraction is 5%. These values were obtained from the October Monthly data and are the actual fuel mix for the year 2004. One has to go back to before the oil crises in the 1970s to get a higher fraction of oil use in electricity generation.

So how much oil was supplanted? It is tempting to just say that only 5% of the solar power generated by our tiny array was used to supplant the oil, but that isn't exactly correct. The thing that is missed is that with respect to power generation, the different fuel types are used at different times of the day and in different seasons. Power usage peaks in the late afternoon and in the summer.

Generally, the cheapest power to make is generated first, followed by the next cheapest, etc. The base power is nuclear, and this gets generated whenever the power plants are not down for maintenance. Next come hydro (if available) and coal followed by natural gas. Petroleum is usually the last one to be called, and it doesn't happen too often unless the petro plant is a "must run" station that is needed for the stability of the power grid.

The power supplanted, then, is the fuel with the marginal cost at the time that it is generated. Most of the time when the solar power is being generated (mainly summer months and midday), this will be natural gas, but it could also be the other components. I haven't calculated the exact amount, for that would have to be done with hourly data. These hourly data are possible to get, but it would take a bit of time and effort to work out. I may try it in the future, but I haven't done it as yet. But it is safe to say that hardly any coal and nuclear have been eliminated by the solar panels, the bulk of the solar power is substituting for natural gas, and some of the petro is also being substituted out.

The bottom line is that the solar array hasn't as yet made an appreciable dent in my oil consumption, but it has reduced the natural gas usage. This is important if one is concerned about greenhouse gases (and it isn't clear at the moment that I am), but it isn't optimal if that is your primary concern either, for more greenhouse gases are generated by coal and oil than by natural gas.

To eliminate the coal by solar, one has to generate enough for the day usage and also generate and store enough of the solar (or wind) power to last you through the night time as well. It is difficult to see how one could eliminate coal entirely, unless the entire roof of the house was covered with solar panels (not practical today but potentially possible someday), and a large battery or other backup system (which I presently do not have) is installed.

So why did I put in the solar panels then? That is a very good question.

The first answer is that if I had thought about the generation data beforehand, I may not have done the array first. If someone is on a limited budget and looking for methods to reduce dependence on foreign oil or reduce greenhouse gases, the money is best put towards better gas mileage or other forms of heating the home if fuel oil is used. Eventually though, I would have gotten around to it.

The second answer is that natural gas has its own problems (notice the price of natural gas lately?), and I'm trying to stay away from natural gas as well. Further, the use of the sun for power generation fits into the vision of how I think things will go if the peak oil and the peak natural gas people are even half right. That needs elaboration (in a future post).

There is also the fact that any net reduction in natural gas, especially permanent ones like solar panels, will probably end up reducing the use of oil, because the markets tend to used the cheaper sources, and presently that is usually natural gas, so if users of solar power are no longer using as much natural gas for power generation, the price will be lower, making it an even better alternative to oil and products, insuring more natural gas gets used in other areas such as petroleum refining, etc. This substitution, though very real, is a second level effect.

Finally, the primary reason is that it made sense from a financial (as well as a power) risk management perspective. The financial aspect is the subject of the next post.

Solar Panels: What We Got

2006-11-07T07:49:00.000-08:00

Great dreams can be dashed quickly by a dose of reality. When the sales representative from Sunlight Solar (John Sych) came to do an analysis of the house, he quickly pointed out the pros and cons. A great pro was that the roof was sloped at a good 45 degrees, so it was well positioned for sunlight in both the winter and summer. One con is that the roof was oriented some to the East Southeast, as opposed to directly South, so the exposure to the Sun's path wasn't ideal, but that was a minor thing. The biggest con was definitely the trees on our property and our neighbor's property.

I had been eyeing our offending trees for some time and was looking for an excuse to take them down. The solar panel was definitely going to be the excuse, but our neighbor's trees were another matter. It was pointed out that the neighbor's trees were the bigger offenders, and they would cut the afternoon sun rather significantly. Not thinking it that big of a deal, I told him that wouldn't affect my decision, but then John informed me that the rebate is contingent upon a system that doesn't have too much shade.

To get the rebate at the time that I got it (the rules have since changed slightly), the solar panel system needs to produce 75% or more of the theoretical amount for a system oriented south at the best angle and with no shading. John's guess that a system on our roof would be close to failing the test, but he'd have to take the measurements and get back to me, and sure enough, the initial design failed.

After speaking with the neighbors, they agreed to let me take one of the shading trees down, but not the worst one (it is a nice tree, I have to admit) provided I paid for the removal. Putting the federal tax credit towards that, getting the array still made sense. So, we cut the tree down along with some in my yard. John came back out and said he could get an array to pass, but it would have to be smaller in size than originally intended to get the system to pass the efficiency requirement. Done! The picture below shows the front roof in the late afternoon in early November, the shadow of the neighbor's tree is clearly present.

The original plan of covering the front and some of the back roof to max out the rebate was thereby reduced to about a third of the original desired size. Of course I could still put more up, but it would mean foregoing the rebate, and without the rebate, the economics aren't as clear cut. In the meantime, I keep eyeing that neighbor's tree. If we had thought about it before we did the renovation, I'm guessing we would have tried to put a roof up in the back that wouldn't have had the shading issues and built our expansion around a good solar roof, but that is definitely hindsight.

We ended up with a 2.58 kilowatt peak array consisting of 12 of the 215 watt Sunpower panels (www.sunpowercorp.com), and a 2 kilowatt inverter (www.pvpowered.com) that converts the DC power from the panels into AC power that is on the electric grid.

The installation was done by Sunlight Solar by early May, 2006, and it went off pretty much without a hitch. All I did was write 3 checks, namely an initial deposit, a midpoint payment, and a final one upon state inspection. They took care of the rebate, and it all went exceedingly well. Since then, the panel has worked as advertised, producing the power at the rate that they estimated it would.

In the summer, the 2.5KW array should cover 30% of the power needs (based upon the usage we had prior to our renovation), but it only gives 10-15% of our historical power usage in the winter. The smallness of these numbers speaks to the difficulty of replacing all fossil fuel plants with solar panels--it just isn't so easy. A need exists to become more efficient with the generated power to make it work autonomously, or a serious reduction in living standards would be required. One area of work in the future is to deal with this issue. A combination of more panels and better use may do it, but we'll have to see.

I'll post more on the performance of the solar panels and how much it is relative to our electricity use. Part of the problem is that we are still having work done on the house, so we haven't reached our normal usage patterns yet. This doesn't affect the amount generated, but it speaks to the expected coverage of our needs from solar alone.

An interesting question to ask is how much did our array help in reducing our dependence on oil, and specifically foreign oil. The answer is a surprisingly small. That is the subject of the next post.

What I Wanted from the Solar Panels

2006-10-22T09:44:00.000-07:00

With the decision made to move away from oil, and with the prime motivation being a form of protection at the home in the event of power outages, naturally I looked into getting solar panels for energy production. Once the up-front cost is made, the power is locally generated, and it should work in the event that the grid goes down in another storm. Originally, the concept was that we'd have solar panels that worked all the time the sun was shining, plus we'd have a battery backup to get us through any power outage.

The thought to install solar had been discussed before. The architect we used to design our renovated house is big into solar power usage, and this was one of the reasons why we used him. Originally, we told him we wanted some passive solar design in the house and wanted it more energy efficient, and this he did rather well. The best part was the sun room we added to the south (and street) facing side of the house, and the next best was the windows recommendation. However, he didn't want to stop there. In one set of drawings, he showed where we could install a solar panel array if we wanted to.

It turns out it wasn't hard to make the house more efficient, for when the builders started the needed demolition in parts of the house, they found that less than a quarter of the walls had been insulated. In fact, what was and wasn't insulated didn't have any particular logic to it as some walls had partial insulation and others had none at all. In retrospect, we should have done even more insulation they we did, for we basically brought the house up the present standards. Unfortunately, when it hit me that we needed to do better than current building code, it was too late to add more. Still, the house with its outer wrapping and insulated walls and ceiling is considerably more comfortable than before, and a once drafty house now feels rather cozy. A test of whether or not the insulation is enough will be made this winter.

Our architect told us about the Connecticut solar rebate program and told me to search for the CT Clean Energy Fund, and I found the proper website that details the residential program here: http://www.ctcleanenergy.com/investment/installed_host_residentialsolar.html .

In short, the rebate is $5 per watt of generation capacity up to $25,000 per household, and this amounts to about a 50% rebate. When we installed ours, this was the rebate for all residences, but they've now changed to program to take into account the system performance, and current rebates are probably less for many people.

To get the rebate, one has to use one of the eligible participating installers, and when we looked I seem to recall that there were eight of them (there are more now). Through recommendation, we inquired with three. Two were by email and one of those didn't respond back. The other email gave us a good indication, but they were rather busy and wanted to charge for a site visit, presumably to reduce the number of lookers. That company was located out of state, and while they were definitely professionals, it seemed better to go with one closer to us.

The third qualified installer we contacted, Sunlight Solar (www.sunlightsolar.com), has a local office, and the sales manager, John Sych, who lives close by. After convincing him I was serious about installing a system, he came to the house and did a site survey. Given the generous state rebate, I was hoping to get a really great system that would max out the rebate, for the economics of it looked pretty good. However, despite being a decent investment, what we got fell short of the desire, and that is the subject of the next post.

Our Solar-Powered House

2006-10-16T09:22:00.000-07:00

Here is a picture of our modest 2.5 KW photovoltaic array. More details of its purchase is to come. Just wanted to get the picture in to put into the profile.

The Trigger

2006-10-13T09:22:00.000-07:00

Why the change? Why do this? I've heard the questions many times from neighbors, family and friends, and the people installing or working on our house, although there seems to be less of that as time goes on, and most of the response has been considerably positive.

The main presumption is that the effort to go green is motivated by environmental concerns. This is probably part of it, for I am a contributor to The Nature Conservancy, but that only puts me in the same camp as our Treasury Secretary. A good part of most environmental organizations seems to be self-promotion, and I've tried to put some money, and not very much of it that is for sure, to effective use. No, the environment isn't the main reason, its just a benefactor.

For the past 10 years, I've been and analyst and trader in energy and energy-related futures. For the bulk of the time, I've concentrated on energy demand and not worried too much about supply, except perhaps for the occasional storm in the Gulf of Mexico. There is generally a presumption that the oil and natural gas will come from somewhere, and the more pressing matters are the matching of supply to demand, not the overall long-term supply.

I've been familiar with the Peak-Oil issue and have been since 2001 when I read Ken Deffeyes' interesting book Hubbert's Peak shortly after it came out. It had been recommended to me by a grain trader who was looking for other opinions on the book, and curiously, the energy traders at the time generally discounted it. My opinion then, and less so now, was that yes, there is an issue, but there is a good chance it will work itself out. I'm still an optimist in this regard and suspect we will get through the upcoming major energy transition, but I'm not at all sure of the timing, and I'm beginning to doubt the smoothness of the transition. So, the global Peak Oil issue isn't the primary motivation either, but, along with the environment, the problem lies in the back of the head and gets a consideration.

The trigger came January, 2006. Mid month, we had a power outage here during a typical nor'easter. As usual, the outage was caused by a tree falling on a power line, and unfortunately, there was more than one tree down during this storm. We were living in a rental home as our main home was undergoing extensive renovation. My wife was out of town on family business, and I woke up to a house that was 50 degrees F and falling. Our youngest, who had just turned one, had a cold, and there was no way we could tough out a prolonged outage. I started a fire in the fireplace, but it wasn't enough to stop the house temperature from dropping, so I packed up the kids and went to a hotel for a day and night. Power was restored about 36 hours after it had been dropped, and we were the luckier ones. According to the receptionist, the hotel went from 25% vacancy to full in the course of a couple of hours, so we were lucky there too.

The outage solidified my thinking that we wanted backup power in our house. We have experienced a power outage typically once a year at our location, and all of them have been local outages; storms knock down the older trees, causing an unending run of power disruptions. The one exception was the August 14, 2003 blackout that left 50 million without power in the North and Eastern USA and parts of Canada.

These outages were getting to me. Their continuing occurrence reveals a flaw in the concept of centralized power generation. That the rate of outages is small is not necessarily relevant if it means you lose your perishable goods and if you are not comfortable with the uncertainty of when power is to be restored, let alone if you face life and death issues. This is not to say the the people working on the grid are incompetent. In fact, the ones I've met are highly professional and very hard workers, but when the large storms come, there is an enormous amount of work for them, and the users must suffer through it if there isn't at least local backup generation.

If 2005 hadn't been such an unusual year for energy, I'm sure I would have gone straight to the diesel generator without blinking, but the other events got me thinking hard about the security of energy supply. Yes, there are issues of long term supply, but the bigger issue of severe short-term disruptions is the primary motivator. What do we do if Al Qaida is successful in disrupting supply? What if Saudi Arabia destabilizes? What about the next Katrina in the gulf? How long until that occurs? Then how about Iran or Chavez in Venezuela? The list continues, and the bottom line is that a major disruption is not out of the question, more so now than at any time since the 1970s.

The conclusion I've come to (and will explore in later posts) is that the only way to secure our energy needs is to move to more local generation, and this almost certainly means solar. It also means moving off of oil and perhaps also natural gas. Going green for me is really an attempt to insure energy security in these uncertain times. It means a reduction of energy sourcing from the regional and global scale, and that is the prime motivator.

Foreward

2006-10-11T13:04:00.000-07:00

After considerable thought, some hesitation, and a good deal of anxiety, we (my wife and I) decided to "go green." Exactly what this means, and why we have done it are the subject of this blog. The reasons for the change and the choices that have been made will be shown and discussed.

This blog is a bit of a "how-to" and an advocate for change from our present collective course. The existence of the blog is motivated by the amazing amount of interest that has surfaced regarding what we have done. I have found interest from neighbors I didn't even know we had.

The primary driver for me is the issue of energy security for my family and community, the nation, and the world in a political, economic, and natural environment that seems increasingly uncertain. The actions are an attempt, however feable, to act locally, and, thanks to the internet, to broadcast globally. It is hoped that our small actions will help encourage others to action and not just discussion and argumentation.

As a disclaimer from the very start, I must say that the choices we have made or will make are ones that are appropriate for us. They may not be right for everyone, and they may not even be enough if some of the doomsayers are right, but from the research I have done, it seems clear that there are options for everyone, and the present status quo is not a requirement.

Finally, there are many shades of green. What we do will be criticized by some as being more than enough or even frivoluous and by others as not being nearly enough or even being the wrong approach. From the outset, I don't claim to be perfect and have come to accept certain contradictions that seem inevitable in being human. All I can do is point to the direction I am going and argue why I am going that way and politely ask others to join or tell me why a different direction is better. I look forward to a good conversation, and to start it off, let me reiterate: "We are going green."