The state of Colorado did its citizens a couple of favors regarding solar energy. Two years ago a referendum was passed that charges all electrical consumers some money each month on their utility bill. That money refunds up to 60% of the cost of a PV solar system, one that generates electricity. The refund turns what would otherwise be a financially terrible proposition into one that makes economic sense. The second favor is that Colorado law prohibits HOA's from banning solar devices.

With plans in hand, I submitted a proposal to our HOA. I knew that the HOA by-laws prohibited solar devices. I provided a copy of the Colorado statute, and eventually everyone came to appreciate the law and the HOA rules were changed. Shortly after, in December, I signed the contract for the PV system and ordered the hot air panel. The PV system that I contracted for consists of 30 BP 175 panels and will generate approximately 6500-kilowatt hours of electricity per year. 20 of the 30 solar panels will be installed on the east facing roof and the other 10 panels on the south facing sections of our roof. A south facing orientation is preferred, as the panels will catch more sun. However, you have to work with what you have and our house happens to have more east-facing roof. We consumed approximately 10,500 kilowatt hours last year, so this system will produce about two thirds of our electricity needs. This system is a grid-tied, net-metered system meaning that there are no batteries. When the system generates more power than we consume, the excess electricity is pumped into the grid. We only pay for the net amount of power we consume over the course of a year.

The SolarSheat hot air system is a single panel mounted on the south-facing wall of our house. It is basically a black chamber that warms up when the sun hits it. Thermostats control it, and when the air inside the panel is warmer than the air inside the house (to certain limits) it blows hot air into the house. I hope the hot air system to save about 20% of the cost of heating our house with the added benefit that the house will be warmer when the sun is shining. There is no storage of heat with this type of system. When the sun isn't shining, no heat is produced. My aborted attempt to mount the SolarSheat When the SolarSheat arrived, I attempted to install the unit myself. Because of the shadows cast by the house directly to our south, the unit had to be mounted fairly high. When I realized how high this was, I decided it was not safe for me to perform the installation and attempted to hire a contractor. It took a couple of attempts to get a contractor to perform the installation, but eventually, I was able to engage Matlock Heating and Cooling to install the unit. (www.servicemagic.com/rated.MatlockHeatingAndCool.11052847.html)

The features of the SolarSheat from inside the house (after installation).

Matlock and I agreed on a day to install the hot air unit. Shortly after, Standard Renewable Energy called and said they were ready to start that same day. It was now the middle of February and the PV system installation had been delayed due to the time it took to get a permit approved by the city of Centennial. I delayed the SolarSheat installation, as I did not want both crews on site at the same time. The PV panel and electrical installation took three days.

The SolarSheat was installed on the following Saturday by Matlock. The Solarsheat air heater could be utilized immediately, but the PV system could not be turned on until a couple of additional steps were taken. The city had to come out and inspect the system and Xcel had to send someone out to replace the current meter with a meter that can run reverse. The city inspection happened a couple of days after the installation and the meter was replaced a week after that.

Here is a picture of the electrical portion of the PV project. The inverters convert the direct current (dc) that is produced by the solar panels to 60 hz alternating current (ac) power as is provided by the power company. There are no batteries in this type of system. The grid can be thought of as a battery. However, you may be surprised to learn that if the grid goes down, the inverters go down also and the house is without power. We are still very much connected to the grid. We generally don't lose power, but it just so happened that on the second day after we turned on the system the grid went down and our house was without power.

Out door inverters and switch gear

Yes, we could have taken that $17,000 and purchased a Lexus instead of a hybrid Honda Civic (actually it would take more money than that, but you get the idea). The solar systems were a choice and obviously it is that symbol that I want to be associated with. If this does not appeal to you, I have no problem with that. The energy market deals with everyone eventually.

UPDATE June 30, 2008
The system has been up and running for exactly four months and the performance has been spectacular! We have produced almost exactly 1000 kwhr more than we have consumed. The system has produced 3095 kwh. Based on this performance, I estimate that the system will produce 7500 kwhr over twelve months. The system was rated for 6500 kwhr of production. I base the projection on getting 2900 kwhr over the next four months plus another 1500 kwhr of production over the four winter months. One reason that I believe the system is performing so well is that the east facing panel have been producing 96% of the power that the south facing panels have (which is a much higher percentage than is typically expected). This is based on the inverter data from the east facing (20 panel) array of 2037 kwhr production and the south facing (10 panel) array producing 1058 kwhr. I have two thoughts as to why the east facing array is performing so well. One is efficiency. The east facing array gets lit up early in the morning when the panels are cool. The other issue could be the weather. It is common for the afternoons to cloud up a bit and that would affect the south facing array more than the east array.

Besides the excellent output of our system, we have also consumed much less power than we have in the past. Our three year average consumption for March through June had been about 2900 kwhr. This year we consumed 2100 kwhr. This is due to some basic shutting down of devices not needed as well as a couple of projects like new low-e windows. This effect I understand is pretty common with solar system owners and is a huge benefit. Even though our system was designed to handle 65% of our prior demand, I am pretty confident that it will handle 100% (or more) of our demand in the future.

In addition to the low-e windows, I have insulated our two crawl spaces, garage door and sealed and insulated our HVAC ducts. The benefits of these actions will occur primarily this winter. After the first year of operation (and understanding our net power consumption or production) I'll consider another round of improvements intended to lower our gas consumption. For example, I will look at installing a heat pump furnance as well as a heat pump water heater.

Our most recent Xcel bill came in at $26.38 (see below). Of this $19.11 is a fixed fee every month that you pay just to be connected to Xcel's electrical and gas networks. The $7.27 balance was for the 7 therms of gas consumed for hot water and cooking. This was the least amount of gas we have consumed in this house.

I have petitioned the Public Utilities Commisssion to move the "settle-up" date from December 15 to March 15. The settle-up date is the point in the year that if you have produced excess power Xcel pays you the wholesale rate for your power and
your balance is reset to zero. I have asked them to move the date to March 15 from December 15 for the following reason. A solar system will likely have it's lowest balance coming out of the winter months (a time of high demand and low production). If I have a balance going into the winter I will expect to use it during the winter and would prefer not to get paid the wholesale rate (only to have to buy power the next month at the retail rate).

Please contact me at greg_damian@yahoo.com if you have any questions.

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