The solar industry has struggled to gain a foothold in the mainstream. And the Solyndra bankruptcy was no help. But residential installations are growing due to a shift from the sale of solar systems, to leasing agreements.
The reason that the residential solar industry has begun to buck this general trend is because, instead of appealing to our heartstrings, it has begun to appeal to our checkbooks. The innovation that made this possible — selling solar services instead of solar panels — was pioneered in the commercial market by Jigar Shah. Though Shah was trained as a mechanical engineer, his most important bit of engineering was financial: in 2003, he started a company called SunEdison, which offered something called a solar-power purchase agreement (P.P.A.) to commercial customers.