How efficient are solar panels? How much energy can they produce per square foot?
Solar thermal panels are rated with efficiencies ranging from 50% to 78%, producing about 1000 BTUs per square foot per day – or 290 Watt-Hours per day per square foot. Electric solar panels have efficiencies ranging from 11%-15% and produce about 12 watts per square foot – or 72 Watt-Hours per day per square foot. Also, electric panels typically cost more than thermal panels. For the same financial investment, a thermal system produces 5 times more energy than an electric system. This explains why thermal systems are a superior way to harvest the sun’s energy. If you want ecology to rhyme with economy, thermal panels are the logical choice!
