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About This Technology

Photovoltaic cells convert light energy directly into electrical power for applications ranging from wristwatches and water pumps to homes and space vehicles. Manufacturers can produce cells of just a few square centimeters or combine modules into arrays of unlimited size. The cells are silent, produce no emissions, have no moving parts, feature very low operation and maintenance costs, and typically last for more than 25 years. PV systems offer reliable, economical power in areas in which grid power is not readily available. With sufficient cost reduction, grid-connected PV systems also could find a market for on-site, emissions-free renewable electricity production in urban areas. Thermophotovoltaics, an emerging branch of the PV field, eventually could offer high-density, sunlight-independent power, expanding PV use to new applications such as thermal heating, water pumping, and hot water for household needs.

PV products are economical and well established in remote-power applications in industrialized and developing nations. The next decade will see significant improvements in system cost and performance that will expand existing uses and open large new markets. The PV industry hopes that a combination of government subsidies, favorable utility and environmental regulations, consumer preference for "green" power, and new building-integrated PV products will provide sufficient sales volume to help lower costs for applications in which small, on-site, grid-connected systems begin to be commercially viable. Utility-scale grid-connected power production is a distant prospect because of the low cost of power from competing technologies. Establishment of an appropriate financing and business infrastructure, along with cost reductions, would multiply PV sales to the enormous potential market for household- and village-scale electric power in rural areas of developing nations.

Improved understanding of cell materials and production processes has enabled substantial improvements in the performance and production cost of PV cells. Several thin-film and organic PV technologies, which are just beginning or approaching commercial production, offer the possibility of very low PV costs in the future. Unit shipments could grow by a factor of ten each time that PV prices drop by 50%, creating tremendous opportunities for module producers, production-equipment vendors, silicon suppliers, and makers of balance-of-system equipment such as power inverters, charge controllers, batteries, and tracking systems. As thin-film–PV technologies become competitive in large-scale applications, opportunities will arise for large-area deposition systems and glass and stainless-steel substrates. Building-integrated PV products and low-cost residential-scale systems would be attractive to architects and utility companies serving clients who favor renewable energy. Rural utility companies can use PV power to serve small isolated loads. Builders of wireless communication networks will continue to find PV power ideal for running remote transmission units. PV systems can bring clean, quiet power to remote resorts, camping areas, and environmentally sensitive areas. Integrated PV modules can extend the operating time of battery-powered portable-electronic devices.