In the aftermath of Hurricane Sandy, people are asking themselves what they can do to lessen their reliance on centralized systems for their electricity, heat and transportation needs. As climate change brings the potential for more intense and frequent extreme weather events, the desire for alternative energy options is becoming more prevalent. Few experts doubt that the energy regime of the future will bear little resemblance to our current system, but what technologies are available and economically viable today?
Okay, so you’ve got some equipment, you’ve got some know-how and you are ready to get out there and become a solar installer. Sounds easy enough, I mean everyone is talking about it, right? Well yes, but before you start going onto people’s roofs and drawing high-voltage DC electricity from the sun, you should know the common mistakes that others (many others) have made before you. This is by no means a list of all the questions you will have, or problems you will run into, but it should help dispel some misconceptions you may have about solar energy.
I learned that solar PV panels lose their efficiency as they get hotter, but I also know that solar thermal collectors use water heated by the sun for use in the home. I could just use the water to simultaneously cool the PV panels and then get heated for hot water use, I’m a genius!
I don’t blame anyone for thinking this, I know I did at first, as I’m sure 90% of people first learning about solar energy have. The truth is that the math doesn’t work out. In order for your hot water to be a sufficient for uses such a showering and washing dishes, it should be in the tank at 120° Fahrenheit, which means it would have to be 130°F on the roof and the solar panels would have to be 140°-150°F. This is a far cry from the optimal temperature of most solar PV brands at 77°F. So either you’ll be showering in cold water, or you’ll be waiting an awfully long time to get a return on those inefficient solar panels (which you’ll need to combat the 140° temperature outside)