Photovoltaic Timeline

A photovoltaic cell, also called a PV or solar cell, is a device which converts light(radiant) energy directly into electrical energy. PV cells are usually made from silicon. The first PV cells were very inefficient, converting less than one percent of radiant energy into electricity. Today, some solar cells have a 40 percent conversion rate.

	1904	Wilhelm Hallwachs discovered that a combination of copper and cuprous oxide was sensitive to light.
	1905	Albert Einstein published a paper on the photoelectric effect. He would win a Nobel Prize in 1921 for these theories.
	1950s	Inventors at Bell Labs (Daryl Chapin, Calvin Fuller, and Gerald Pearson) developed a more efficient PV cell (6 percent) made from silicon. This was the first solar cell capable of generating enough power from the sun to run everyday electrical equipment.
	1955	Western Electric began to sell commercial licenses for silicon photovoltaic technologies. Early successful products included PV-powered dollar bill changers and devices that decoded computer punch cards and tape
	1958	Federal support for photovoltaic technology was initially tied to the space program to provide power for the Vanguard satellite.
	1973	Spurred by the oil embargo, interest in space applications of photovoltaics grew.
	1970s	By the late 1970s, a program for the development of distributed photovoltaics was established by the U.S. Government at the Massachusetts Institute of Technology, focusing on design and demonstration issues for the buildings sector.
	1978	The Energy Tax Act established a 10-percent investment tax credit for photovoltaic applications. Solar Photovoltaic Energy, Research, Development and Demonstration Act committed $1.2 billion over 10 years to improve photovoltaic production levels, reduce costs,and stimulate private-sector purchases. Photovoltaic energy commercialization program accelerated the installation of photovoltaic systems in Federal facilities.
	1980	The Carlisle house (Massachusetts) was completed with participation from MIT, DOE, and Solar Design Associates. It featured the first building-integrated photovoltaic system, passive solar heating and cooling, superinsulation, internal thermal mass, earth-sheltering, daylighting, a roof-integrated solar thermal system, and a 7.5-peak-watt photovoltaic array of polycrystalline modules from Solarex. The Crude Oil Windfall Profit Tax was enacted and raised residential tax credit to 40 percent of the first $10,000 for photovoltaic applications, the business tax credit to 15 percent, and extended the credit to the end of 1981. More than 10 percent efficiency achieved by thin film cells. Boeing and Kodak fabricated the first thin-film photovoltaic cells with efficiencies greater than 10 percent.
	1985	The 6-megawatt Carissa Plains plant was added to Southern California Edison’s system. The project was later dismantled.
	1989	Renewable Energy and Energy Efficiency Technology Competitiveness Act sought to improve the operational reliability of photovoltaic modules, increase module efficiencies, decrease direct manufacturing costs, and improve electric power production costs. PV for Utility Scale Applications (PVUSA), a national public-private partnership program, was created to assess and demonstrate the viability of utility-scale photovoltaic electric generating systems. PVUSA participants include Pacific Gas & Electric (PG&E), DOE, the Electric Power Research Institute, the California Energy Commission, and eight utilities and other agencies.
	1990	Siemens A.G. of Munich, West Germany, acquired California-based ARCO Solar, the world’s largest photovoltaic company. The PV Manufacturing Technology (PVMaT) project began. A government/industry research and development partnership between DOE and members of the U.S. photovoltaic industry was designed to improve manufacturing processes, accelerate manufacturing cost reductions for photovoltaic modules, improve commercial product performance, and lay the groundwork for a substantial scale-up of manufacturing capacity.
	1992	The University of South Florida fabricated a 15.89-percent efficient thin-film cell, breaking the 15-percent barrier for the first time
	1993	PG&E completed the installation of the first grid-supported photovoltaic system in Kerman, California. The 500-kilowatt system was the first effort aimed at“distributed power,” where a relatively small amount of power is carefully matched to a specific load and is produced near the point of consumption. New world-record efficiencies in polycrystalline thin film and single-crystal devices, approaching 16 percent and 30 percent, respectively, were achieved in 1993.
	1994	The National Renewable Energy Laboratory developed a solar cell made of gallium indium phosphide and gallium arsenide; it was the first one of its kind to exceed 305 conversion efficiency.
	1995	Joint venture by Amoco and Enron announced their intention to use amorphous silicon modules for utility- scale photovoltaic applications.
	1998	Subhendu Guha, a scientists noted for his pioneer work in amorphous silicon, led the invention of flexible solar shingles, a roofing material and state-of-the-art technology for converting sunlight into electricity on buildings.
	1999	Construction completed on 4 Times Square in New York, New York. The office building had more energy-efficient features than any other commercial skyscraper and included building-integrated photovoltaic panels on the 37th - 43rd floors, on the south and west facing facades, to produce part of electricity needed for the building. Spectrolab, Inc., and NREL develop a 32.3% efficient solar cell. the high efficiency resulted from combining three layers of photovoltaic materials into a single cell. Researchers at NREL developed a record-breaking prototype solar cell that measured 18.8% efficiency, topping the previous record for thin-film cells by more than 1%. Worldwide, installed photovoltaic capacity reached 1000 megawatts.
	2000	First Solar began production at the Perrysburg, Ohio photovoltaic manufacturing plant. It could produce enough solar panels each year to generate 100 megawatts of power. Astronauts began installing solar panels at the International Space Station, on the largest solar power array deployed in space. each "wing" of the array consisted of 32,800 solar cells.
	2001	BP and BP Solar announced the first U.S. BP Connect gasoline retail and convenience store. The Indianapolis, Indiana service station features a solar-electric canopy. The canopy contains translucent photovoltaic modules made of thin film silicon integrated into glass.
	2007	National Renewable Energy Laboratory and Boeing Spectrolab created the High-Efficiency Metamorphic Multijunction Concentrator Solar Cell, or HEMM solar cell which achieved the highest efficiency level of any photovoltaic device to date. The HEMM solar cell broke the 40% conversion efficiency barrier, making it twice as efficient as a typical silicon cell.

Last Revised: July 2008.
Sources: U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Solar History Timeline:1900's, January 2008.
U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, "Solar Cells", October 21, 2007.
Big Frog Mountain, Alternative Energy Sources, Intro to History of Solar Electric Power, January 2008.