In 2006 we decided to use sunpower for some of our energy and in summer 2007 we had a photovoltaic system installed. The sunlight collection system is pictured at right. This system turns light — not heat — into electricity. We are located at Schoharie, N.Y., 40 miles or so southwest of Albany. We turned it on on Friday, Aug. 31, 2006.
As expected, we generated a lot less as we approached the winter solstice. In September we generated an average of 9.8 kilowatt hours daily and in November only 5.7. The week before solstice on December 22 we generated only 1 KWH daily on average. Much of the loss that week was because of snow blocking the collectors but generally snow blew off or melted quite quickly. December 22 sunrise is 7:24 and sunset 4:27. The half hour or so at dawn and dusk are insufficient to operate the system so the maximum possible generating time is about eight hours.
In spring 2008 we saw some great collection days. One week (April 19-25) we generated 86.1 percent of our electricity. August 23-29, 2008, we generated 83.0 percent. But they did not top September 15-21 2007, when we generated 105.5 percent od our use. The lowest generation has always been in December: 5.5 percent of use in 2007 and only 2.0 percent of use in 2008. Our use is limited. There are just two of us and we are energy conscious. (I follow her around turning off lights.) Our average daily use during the 21 months September 2007 through May 2009 was 18.0 kilowatt hours. During that period we used 11,502 kilowatt hours: 4,977 that we generated and 6,505 that we bought. (That's 43.44 percent generated.)
We also added a solar hot water system but just as our contractor said, it is not as useful or efficient as solar electricity. The solar system does not provide enough heat to be a sole water heater and is used to pre-heat it so we use less electricity to heat it. Before its installation, we were using about 23.4 KWH daily. With solar hot water April 24 to May 23, we used an average of 18.4 KWH daily. We turned off the electric hot water for two days to see whether we could get sufficient hot water, and our electric usage dropped to 10.5. Ultimately, our "hot" water was tepid. We were gone for two hot weeks in July and still had only tepid "hot" water in the solar tank.
—Lester Hendrix, Schoharie N.Y.
email Lhendrix at NYCAP dot RR dot COM

