One of the most under utilized forms of renewable energy in the United States today. It works great, can provide a vast amount of hotwater for all your needs, all year long. Very cost effective for commercial usage. Engineers and Architects educate yourselves! Solar thermal is overwhelming more efficient then solar PV. Solar Thermal requires less square footage. Things are changing and solar thermal is becoming more popular. In many countries solar thermal is as common as cable TV is here in the United States.