I have received four bids from two different contractors to install solar our house. I am considering a “conventional” PV system, looking at sizes varying from 2.62 kw to 3.15 kw. There is also a new type of system we are considering, which is manufacturedin the Twin Cities, called TenK solar. The owners of this company claim to have designed solar panels that produce 15%-20% more output than the current systems on the market. For the square footage our roof has, we could get a system of at least 3.33 kw, but probably closer to 3.75 kw.
Each kw produces about 1200 kilowatt hours of electricity annually, assuming no snow is covering the panels. A kilowatt hour is equivalent to one 100 watt lightbulb turned on for 10 hours, or one 2000 watt hair-dryer turned on for 30 minutes.
Our system can be expected to produce about 3,600 killowatt hours of electricity per year and off-set about 6,000 pounds of CO2 emissions. From my analysis, even with all the incentives, the payback for the systems is about 25-30 years. In today’s economic climate, that would not pass the muster for most rational investment decisions. But if you factor in an assumption that utility rates will rise significantly over the years, and you put a value on the reduction of CO2 emissions, and you think like the Iroquois tribes did in considering the impact of our decisions on the next seven generations, it makes perfect sense!