Progress in U.S. photovoltaics: looking back 30 years and looking ahead 20

The development of terrestrial photovoltaics (PV) began in response to the oil crises of the 1970s. Over the past 30 years, PV researchers discovered new materials, devices, and fabrication approaches, improved device efficiency and reliability, and lowered module and system costs. Concerns over the global environment, as well as the worldwide efforts to seek alternate, indigenous sources of energy, continue to drive the investment in PV research and deployment. This paper reviews the most significant advances in U.S. research efforts over the past 30 years, and examines several scenarios for advancements in PV technologies and markets in the next 20 years.