Solar History

The first recorded solar device was a collector invented by the Swiss scientist Horace de Saussure in 1767. He experimented with trapping solar heat using boxes made of glass, and later refined his design to include outer shells of black wood coated with insulation. Though he was initially experimenting with solar energy and determining the nature of solar power (of note, he proved that the sun shines on the earth in equal measure, but that the atmosphere is what traps solar heat and causes differences in temperature) his designs were also later used as the first solar ovens.

In 1816, Robert Stirling applied for a patent for what he called his "economiser", which is an engine capable of running off of heat. This engine later became a predecessor for the dish collector, which is used to generate energy by capturing and converting thermal energy to produce electricity. This engine was later used in the dish/Stirling system, a solar thermal electric technology that concentrates the sun's thermal energy in order to produce power.

French scientist Edmond Becquerel discovers the photovoltaic effect while experimenting with an electrolytic cell. He observed electricity generation increased when exposed to light.

August Mouchet conceives the idea for solar-powered steam engines. In the following two decades, he and his assistant, Abel Pifre, constructed the first solar powered engines and used them for a variety of applications. These engines became the predecessors of modern parabolic dish collectors.

William Grylls Adams and Richard Evans Day discover that selenium can produce electricity when exposed to light. Though it wasn't efficient enough to be used to produce energy on its own, it proved the phenomenon can occur naturally (and could be reproduced) without heat or moving parts.

Charles Fritts, an American inventor, described the first solar cells made from selenium wafers.

Baltimore inventor Clarence Kemp patented the first commercial solar water heater.

Wilhelm Hallwachs discovered that a combination of copper and cuprous oxide is photosensitive.

Albert Einstein published his paper on the photoelectric effect (along with a far less important and influential paper on his theory of relativity).

William J. Bailley of the Carnegie Steel Company invents a solar collector with copper coils and an insulated box, a design which is roughly the same today.

Jan Czochralski developed a way to grow single-crystal silicon. This greatly increases the efficiency of silicon-based cells.

Albert Einstein wins the Nobel Prize for his theories (1904 research and technical paper) explaining the photoelectric effect.

Audobert and Stora discover the photovoltaic effect in cadmium sulfide (CdS).

Photovoltaic technology is born in the United States when Daryl Chapin, Calvin Fuller, and Gerald Pearson develop the silicon photovoltaic (PV) cell at Bell Labs-the first solar cell capable of converting enough of the sun's energy into power to run everyday electrical equipment. Originally their silicon solar cells had a 4% efficiency, but later achieved 11% efficiency.

Western Electric began to sell commercial licenses for silicon photovoltaic (PV) technologies. Early successful products included PV-powered dollar bill changers and devices that decoded computer punch cards and tape.

Passive solar buildings in the United States were in such demand, as a result of scarce energy during the prolonged W.W.II, that Libbey-Owens-Ford Glass Company published a book entitled Your Solar House, which profiled forty-nine of the nation's greatest solar architects.

Architect Frank Bridgers designed the world's first commercial office building using solar water heating and passive design. The Bridgers-Paxton Building is now in the National Historic Register as the world's first solar heated office building, and has been operating since its construction.

William Cherry, U.S. Signal Corps Laboratories, approaches RCA Labs' Paul Rappaport and Joseph Loferski about developing photovoltaic cells for proposed orbital satellites, paving the way for the solar-power standard in space.

Hoffman Electronics achieves 8% efficiency in their photovoltaic cells.

T. Mandelkorn, U.S. Signal Corps Laboratories, fabricates n-on-p silicon photovoltaic cells. These cells are critically important for use in space as they're resistant to the degrading effects of radiation.

The Vanguard I space satellite used a small (less than one watt) array to power its radios. Later that year, Explorer III, Vanguard II, and Sputnik-3 were launched with PV-powered systems on board. Despite faltering attempts to commercialize the silicon solar cell in the 1950s and 60s, it was used successfully in powering satellites. It became the standard energy source for space applications and remains so today.

Hoffman Electronics achieves 14% efficient photovoltaic cells.

Bell Telephone Laboratories launches the first telecommunications satellite, the Telstar (initial power 14 watts).

Sharp Corporation succeeds in producing practical silicon photovoltaic modules.

Japan installs a 242-watt, photovoltaic array on a lighthouse, the world's largest array at that time.

Peter Glaser conceives the idea of the satellite solar power station

The Odeillo solar furnace, located in Odeillo, France was constructed. This featured an 8-story parabolic mirror.

Dr. Elliot Berman, with help from Exxon Corporation, designs a significantly less costly solar cell, bringing price down from $100 a watt to $20 a watt. Solar cells begin to power navigation warning lights and horns on many offshore gas and oil rigs, lighthouses, railroad crossings and domestic solar applications began to be viewed as sensible applications in remote locations where grid-tied utilities could not exist affordably. This paves the way for the off-grid system.

The French install a cadmium sulfide (CdS) photovoltaic system to operate an educational television at a village school in Niger.

The Institute of Energy Conversion is established at the University of Delaware to perform research and development on thin-film photovoltaic (PV) and solar thermal systems, becoming the world's first laboratory dedicated to PV research and development.

The University of Delaware builds 'Solar One,' one of the world's first photovoltaic (PV) powered residences. The system is a PV/thermal hybrid. The roof-integrated arrays fed surplus power through a special meter to the utility during the day and purchased power from the utility at night. In addition to electricity, the arrays acted as flat-plate thermal collectors, with fans blowing the warm air from over the array to phase-change heat-storage bins.

The U.S. Department of Energy launches the Solar Energy Research Institute (National Renewable Energy Laboratory), a federal facility dedicated to harnessing power from the sun.

NASA installs a solar power system on the Papago Indian Reservation located in southern Arizona-the world's first village PV system. The system is used to provide for water pumping and residential electricity in 15 homes until 1983, when grid power reached the village. The PV system was then dedicated to pumping water from a community well.

ARCO Solar becomes the first company to produce more than 1 megawatt of photovoltaic modules in one year.

At the University of Delaware, the first thin-film solar cell exceeds 10% efficiency using copper sulfide/cadmium sulfide.

Paul MacCready builds the first solar-powered aircraft, which flies from France to England across the English Channel. The aircraft had over 16,000 solar cells mounted on its wings, which produced 3,000 watts of power.

The first, photovoltaic megawatt-scale power station goes on-line in Hisperia, California. It has a 1-megawatt capacity system, developed by ARCO Solar, with modules on 108 dual-axis trackers.

Australian Hans Tholstrup drives the first solar-powered car almost 2,800 miles between Sydney and Perth in 20 days. This is 10 days faster than the first gasoline-powered car to do so. Tholstrup is the founder of the World Solar Challenge in Australia, considered the world championship of solar car racing.

The U.S. Department of Energy, along with an industry consortium, begins operating Solar One, a 10-megawatt central-receiver demonstration project. The project established the feasibility of power-tower systems, a solar-thermal electric or concentrating solar power technology.

Volkswagen of Germany begins testing photovoltaic arrays mounted on the roofs of Dasher station wagons, generating 160 watts for the ignition system.

Worldwide photovoltaic production exceeds 9.3 megawatts.

ARCO Solar completes a 6-megawatt photovoltaic substation in central California. This 120-acre, unmanned facility supplies the Pacific Gas & Electric Company's utility grid with enough power for over 2,000 homes.

Solar Design Associates completes a stand-alone, 4-kilowatt powered home in the Hudson River Valley.

Worldwide photovoltaic production exceeds 21.3 megawatts, with sales of more than $250 million.

The Sacramento Municipal Utility District commissions its first 1-megawatt photovoltaic electricity generating facility.

The University of South Wales breaks the 20% efficiency barrier for silicon solar cells under 1-sun conditions.

The world's largest solar thermal facility, located in Kramer Junction, California, was commissioned. The solar field contained rows of mirrors that concentrated the sun's energy onto a system of pipes circulating a heat
transfer fluid. The heat transfer fluid was used to produce steam, which powered a conventional turbine to generate electricity.

University of South Florida develops a 15.9% efficient thin-film photovoltaic cell made of cadmium telluride, breaking the 15% barrier for the first time for this technology.

A 7.5-kilowatt prototype dish system using an advanced stretched-membrane concentrator becomes operational.

Pacific Gas & Electric completes installation of the first grid-supported photovoltaic system in Kerman, California. The 500-kilowatt system was the first distributed power effort.

The National Renewable Energy Laboratory (formerly the Solar Energy Research Institute) completes construction of its Solar Energy Research Facility, which was recognized as the most energy-efficient of all
U.S. government buildings worldwide. It features not only solar electric system, but also a passive solar design.

First solar dish generator using a free-piston Stirling engine is tied to a utility grid.

The National Renewable Energy Laboratory develops a solar cell-made from gallium indium phosphide and gallium arsenide-that becomes the first one to exceed 30% conversion efficiency.

Subhendu Guha, a noted scientist for his pioneering work in amorphous silicon, led the invention of flexible solar shingles, a roofing material and state-of-the-art technology for converting sunlight to electricity. This technology is used in integrated solar technology which allows homeowners to install low-profile panels which look just like roofing material.

1999 Construction was completed on 4 Times Square, the tallest skyscraper built in the 1990s in New York City. It incorporates more energy-efficient building techniques than any other commercial skyscraper and also includes building-integrated photovoltaic (BIPV) panels on the 37th through 43rd floors on the south and west-facing facades that produce a portion of the buildings power.

The National Renewable Energy Laboratory achieves a new efficiency record for thin-film photovoltaic solar cells. The measurement of 18.8 percent efficiency for the prototype solar cell topped the previous record by more than 1 percent.

World photovoltaic power breaks 1000 megawatts.

At the International Space Station, astronauts begin installing solar panels on what will be the largest solar power array deployed in space. Each wing of the array consists of 32,800 solar cells.

Sandia National Laboratories develops a new inverter for solar electric systems that will increase the safety of the systems during a power outage. Inverters convert the direct current (DC) electrical output from solar systems into alternating current (AC), which is the standard current for household wiring and for the power lines that supply electricity to homes.

Two new thin-film solar modules, developed by BP Solarex, break previous performance records. The company's 0.5-square-meter module achieves 10.8 % conversion efficiency-the highest in the world for thin-film modules of its kind. And its 0.9-square-meter module achieved 10.6% conversion efficiency and a power output of 91.5 watts - the highest power output for any thin-film module in the world.

A family in Morrison, Colorado, installs a 12-kilowatt solar electric system on its home-the largest residential installation in the United States to be registered with the U.S. Department of Energy's Million Solar Roofs program. The system provides most of the electricity for the 6,000-square-foot home and family of eight.

Home Depot begins selling residential solar power systems in three of its stores in San Diego, California. A year later it expands sales to include 61 stores nationwide.

The world's largest hybrid system goes on-line in Hawaii. This system combines the power from both wind and solar energy. The grid-tied system is unusual in that its solar energy capacity (175 kilowatts) is actually larger than its wind energy capacity of 50 kilowatts.

Powerlight Corporation installs the largest rooftop solar power system in the United States-a 1.18 megawatt system-at the Santa Rita Jail in Dublin, California.

A 38.7-kilowatt White Bluffs Solar Station (the largest solar power facility in the Northwest) goes on-line in Richland, Washington.

ATS Automation Tooling Systems Inc. in Canada starts to commercialize a method of producing solar cells, called Spheral Solar technology. The technology-based on tiny silicon beads bonded between two sheets of aluminum foil-promises lower costs due to its greatly reduced use of silicon
relative to conventional multicrystalline silicon solar cells. The technology was pioneered by Texas Instruments, which dropped production in the early 1990s.

Some photoelectrochemical cells simply produce electrical energy, while others produce hydrogen in a process similar to the electrolysis of water. The latter form is currently being studied as a potential way to convert solar energy into a portable, transportable form (hydrogen).