What size system do I need for my house?
Solar Electric: It depends on how much electricity you use, and how much of that use you hope to generate yourself. Our residential customers use an average of 1,100 kWh per month or 13,000 kWh per year. Your home size, heating system type, personal habits and water heating type will affect your family’s use. A typical residential system of 3 kW, with panels optimally oriented and minimum shade will produce approximately 3,000 kWh per year in our area or about 23% of the average customers use.
Solar Water Heating: Hot water is one of the largest uses of energy in your home. Residential solar water heating systems can save 2,000 to 2,800 kWh (100 to 140 therms of gas) per year. That’s 60% of the energy used to heat water in the average Oregon home. In the summer your system may provide 100% of your hot water needs. During the winter months solar will still heat your water, but not all the way to 120 degrees.