History of Photovoltaic (PV) Solar Energy
1876: When William Grylls Adams and his student, Richard Evans Day, discovered that an electrical current could be started in selenium solely by exposing it to light, they felt confident that they had discovered something completely new. Werner von Siemens, a contemporary whose reputation in the field of electricity ranked him alongside Thomas Edison, called the discovery “scientifically of the most far-reaching importance.” This pioneering work portended quantum mechanics long before most chemists and physicist had accepted the reality of atoms. Although selenium solar cells failed to convert enough sunlight to power electrical equipment, they proved that a solid material could change light into electricity without heat or any moving parts.
1905: In 1905 Albert Einstein published the first theoretical work describing the photovoltaic effect titled “Concerning an Heuristic Point of View Toward the Emission and Transformation of Light.” In the paper, he showed that light possesses an attribute that earlier scientists had not recognized. Light, Einstein discovered, contains packets of energy, which he called light quanta.
Einstein’s bold and novel description of light, combined with the  discovery of the electron, gave scientists in the second decade of the twentieth century a better understanding of photo electricity. They saw that the more powerful photons carry enough energy to knock poorly linked electrons from their atomic orbits in materials like selenium. When wires are attached, the liberated electrons flow through them as electricity. By the 1920s, scientists referred to the phenomenon as the “photovoltaic effect.”
1953: In 1953, Bell Laboratories (now AT&T labs) scientists Gerald Pearson, Daryl Chapin and Calvin Fuller developed the first silicon solar cell capable of generating a measurable electric current. The New York Times reported the discovery as “the beginning of a new era, leading eventually to the realization of harnessing the almost limitless energy of the sun for the uses of civilization.”
1958: While early efforts to commercialize the silicon solar cell faltered, the US Army and Air Force saw the device as the ideal power source for a top-secret project – earth-orbiting satellites. But when the Navy was awarded the task of launching America’s first satellite, it rejected solar cells as an untried technology and decided to use chemical batteries as the power source for its Vanguard satellite. The late Dr. Hans Ziegler, probably the world’s foremost expert in satellite instrumentation in the late 1950s, strongly differed with the Navy. He argued that conventional batteries would run out of power in days, silencing millions of dollar worth of electronic equipment. In contrast, he argued, solar cells could power a satellite for years. Through an unrelenting crusade led by Dr. Ziegler to get the Navy to change its mind, the Navy finally relented and, as a compromise, put a dual power system of chemical batteries and silicon solar cells on the Vanguard. Just as Ziegler predicted, the batteries failed after a week or so, but the silicon solar cells kept the Vanguard satellite communicating with Earth for years.
1970’s: While the use of solar cells in space flourished during the 1960s and early 1970s, down on Earth electricity generated from the sun seemed very distant. Cost was never a factor for space cells. Manufacturers worried more about size, efficiency and durability: the cost of the launch, and the continuing operation of equipment once in space far outweighed the cost of power in space applications. But on Earth, the primary criterion was, and still is, cost per kilowatt hour.
Solar-cell technology proved too expensive for terrestrial use until the early 1970s when Dr. Elliot Berman, with financial help from Exxon Corporation, designed a significantly less costly solar cell by using a poorer grade of silicon and packaging the cells with cheaper materials. Bringing the price down from $100 a watt to $20 per watt, this approach yielded solar cells that could compete in situations where people needed electricity distant from power lines. Off-shore oil rigs, for example, required warning lights and horns to prevent ships from running into them but had no power other than toxic, cumbersome, short-lived batteries. Compared to their installation, maintenance and replacement, solar modules proved a bargain. Many gas and oil fields on land but far away from power lines needed small amounts of electricity to combat corrosion in well heads and piping. Once again, electricity from the sun saved the day. Major purchases of solar modules by the gas and oil industry gave the fledgling terrestrial solar cell industry the needed capital to persevere.
1978: On Nov. 4, 1978 Jimmy Carter signs Solar Photovoltaic Energy Research, Development, and Demonstration Act.
“I am signing today H.R. 12874, the Solar Photovoltaic Energy Research, Development, and Demonstration Act of 1978, a bill that authorizes an aggressive program of research, development, and demonstration of solar photovoltaic energy technologies. The bill’s long-term goal is to make electricity from photovoltaic systems economically competitive with electricity from conventional sources…
“It is still too early to concentrate on commercialization of photovoltaics. Photovoltaic systems hold great promise, but in the short run we must emphasize research and development, including fundamental work on the physical properties of these systems…
“Therefore, I will not propose to the Congress that a broad Federal solar photovoltaic purchase program tied to the specific goals of this act be undertaken soon. Rather, consistent with congressional intent, we will focus on research and development that will accelerate cost reductions. We will also continue, where appropriate, small, carefully targeted photovoltaic purchases to meet technical objectives. This approach should lay a firm foundation for the advancement of solar power from photovoltaics in the future.”
Due to dedicated research worldwide, the efficiency of photovoltaics has continued to increase while production costs have dropped substantially over the years; especially significant were cost reductions seen in the 2005-2009 timeframe. Currently with a wholesale cost of roughly $1.00 a watt for low-end crystalline-silicon-based photovoltaic solar modules and under $5.00 a watt for an entire completed solution (including inverters, mounting systems, racking, wiring, other components and installation labor), on a residential scale PV solar is becoming cost competitive with traditional energy sources, and will become even more so as the costs of coal, gas and oil continue to increase. – Jim Bartlett, Co-Founder & CEO, Arise Energy Solutions, LLC