Appalachian Energy Blog

Yes, it’s official. Our friends at the National Renewable Energy Lab , or NREL, in Golden, Colorado, have produced a timely reminder that using solar thermal panels to produce hot water is a much more effective (and cheaper) way of reducing our nation’s energy use and generally helping to save the planet, than installing solar-electric pv panels.

Their new report* starts off by looking at how many roofs are suitable for solar hot water panels - half of all homes and two-thirds of commercial buildings. But only 22% of homes are suitable for solar-electric pv systems because they need 400 square feet or more of roof space, compared with 60-90 square feet for solar hot water panels. To cut a long story short, putting solar systems on these roofs to make hot water would reduce CO2 emissions by 50-75 million tonnes per year, which would apparently have the same impact as eliminating Oregon (sorry, Oregon). And consumers would save about $8 billion a year on utility bills (sorry, utility companies).

*Technical Potential of Solar Water Heating to Reduce Fossil Fuel Use and Greenhouse Gas Emissions in the United States
NREL report1