Retrospective benefit-cost evaluation of DOE investment in photovoltaic energy systems
This study is a retrospective analysis of net benefits accruing from the U.S. Department of Energy’s (DOE) investment in photovoltaic (PV) technology development. The study employed a technology cluster approach. That is, benefits measured for a subset of technologies in a meaningful cluster, or portfolio, of technologies were compared to the total investment in the cluster to provide a lower bound measure of return for the entire cluster.1
The technologies selected for analysis were PV module technologies. PV modules are encapsulated sets of solid-state solar cells that convert solar energy into electricity. They are perhaps most recognizable as the flat-plate solar panels mounted on roof-tops, affixed to signal posts, or assembled in large arrays that compose solar farms. PV modules are usually characterized by the material technologies that compose the cells. These may be crystalline silicon (c-Si) or “thin films” of semiconductor material, particularly cadmium telluride (CdTe), copper indium diselenide (CIS), and amorphous silicon (a-Si).
PV technologies have benefited from long-term DOE investment that has supported core cell and module technology R&D, manufacturing process development, and the technology infrastructure supporting that R&D. Between 1975 and 2008, the period of analysis for this study, researchers in industry, academia, and DOE’s national laboratories received financial and technical support to hasten the development and market introduction of higher quality, longer lived, and lower cost PV modules.