In the late 70s and early '80s, solar entrepreneurs, including Exxon, Reynolds Aluminum, GE, Grumman Aircraft, and all the little guys like me, were trying all kinds of things to see what worked. We all knew that if you put a black surface in a box it would get hot. How to make the rest of the system work was the problem. Another problem was how to keep it from tearing itself to pieces over time.