The U.S. solar industry was built on tax credits. At the federal level, the Investment Tax Credit (ITC) allows both residential and commercial developers to offset 30% of their cost. Various states also offer credits.
Since it was introduced in 2006, the ITC has helped boost annual installations of photovoltaic systems — panels and related components — from 104.7 megawatts of direct current to 6,201 (MWdc) in 2014. That’s approaching enough energy to power a million average American homes.