Progress in Photovoltaics: From the Laboratory to the Marketplace

Over the past 20 years, the U.S. Department of Energy (DOE) has supported an agfressive photovoltaic (PV) research and development program with industry, universities, and national laboratories. The government's investment of more than $1.2 billion, in partnership with more than #2.5 billion invested by the private sector, has resulted in the discovery of new PV materials, devices, andfabrication approaches; continuing improvements in the efficiency and reliability of solar cells and modules; and lower PV module and system costs. The improvements in technology have led to increasing market demana for PV, with nearly 90 MW of modules shipped worldwide in 1996. A rapidly growing market segment is non-grid-connected, rural electrification in developing countries. This talkreviews the rapid progress that has occurred in PV technology from the laboratory to the marketplace, including reviews of leading technology options, status and issues, and the key U.S. industrial players. The technologies include flat-plate crystalline silicon (both ingot-based and non-ingot-based [e.g., sheet], flat-plate this films (amorphous and polycrystalline silicon, cadmium telluride,and copper indium diselenide), and concentrators. The increasing demand for PV worldwide is leading to investments in new production capacity, either through new plant construction or incremental expansions of existing production lines. Crystalline and polycrystalline silicon still dominate the market, but thin films are expected to make inroads in the next few years as the new technologies arebrought on line. Continuing improvements in efficiency and reliability, new processes for fabricating PV materials and devices, and innovative PV approaches with low-cost potential are elements of an ongoing research program aimed at future advancements in PV cost and performance.