ABSTRACT
PV improved as the result of: 1) Scientific contributions in the 1800s and early 1900s, in Europe and the US, that provided a fundamental understanding of the ways that light interacts with molecular structures; 2) A breakthrough at a corporate laboratory in the US in 1954 that made a commercially available PV device; 3) A major government R&D and public procurement effort in the 1970s in the US; 4) Japanese electronic conglomerates serving niche markets in the 1980s and in 1994 launching the world’s first major rooftop subsidy program, with a declining rebate schedule; 5) Germany passing a feed-in tariff in 2000 that quadrupled the market for PV and developing production equipment that automated and scaled PV manufacturing; 6) Chinese entrepreneurs building factories of gigawatt scale in the 2000s and creating the world’s largest market for PV from 2013 onward; and 7) A cohort of adopters with high willingness to pay, accessing information from neighbors, and installer firms that learned from their installation experience, as well as that of their competitors to lower soft costs.
