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)
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