!! History Commons Alert, Exciting News

Follow Us!

We are planning some big changes! Please follow us to stay updated and be part of our community.

Twitter Facebook

US Solar Industry


Project: US Solar Industry
Open-Content project managed by matt, Derek, KJF, mtuck

add event | references

1767: First Solar Collector Built

Swiss scientist Horace de Saussure builds the world’s first solar collector. It is later used by Sir John Herschel to cook food during his South Africa expedition in the 1830s. [US Department of Energy, 2002 pdf file]

Entity Tags: Horace de Saussure

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology

Robert Stirling applies for a patent for his “Economiser” at the Chancery in Edinburgh, Scotland. Stirling, a minister in the Church of England, is an amateur scientist and inventor. His “Economiser” is a “heat engine” that uses the sun’s thermal energy to produce small amounts of power. Lord Kelvin later uses one of Stirling’s working models to demonstrate the value of solar power in his university classes. The “Economiser” is later used as part of the design of the “Dish/Stirling System,” a solar thermal electric technology that concentrates solar energy to produce power. [US Department of Energy, 2002 pdf file]

Entity Tags: Robert Stirling

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology

French mathematician August Mouchet conceives the solar-power steam engine. Mouchet and his assistant Abel Pifre build the world’s first true solar-powered engines and use them for a number of applications. The Mouchet engine is the predecessor of modern parabolic dish collectors. [US Department of Energy, 2002 pdf file]

Entity Tags: Abel Pifre, August Mouchet

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology

1880: Bolometer Invented

Samuel P. Langley invents the bolometer. His device measures light from starlight and from the sun’s rays. It is constructed of a fine wire connected to an electric circuit. When starlight or sunlight falls on the wire, the wire becomes slightly warmer, increasing the electrical resistance of the wire. [US Department of Energy, 2002 pdf file]

Entity Tags: Samuel P. Langley

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology

1883: Inventor Describes Selenium Solar Cells

American inventor Charles Fritts describes the first solar cells made from selenium wafers. Fritts hopes that his cells might compete with the coal-fired power plants of Thomas Edison, but Fritts’s cells operate at less than one percent efficiency, far below the threshold for practical applicability. [US Department of Energy, 2002 pdf file; American Physical Society, 2013]

Entity Tags: Charles Fritts

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology

Inventor Clarence Kemp of Baltimore patents the first commercial solar water heater. Kemp, who sells cutting-edge home heating equipment, combines the older practice of exposing metal tanks to sunlight with the scientific principle of the “hot box” (see September 27, 1816), thus increasing the tanks’ capability of collecting and retaining heat. He calls his invention the “Climax.” He first markets it to Eastern “gentlemen” whose wives have gone on holiday for the summer, leaving them to their own devices. Kemp sells his heaters by claiming that they will reduce the effort needed to perform housekeeping duties, especially for men unaccustomed to lighting the gas furnace or stove to heat water. Later, Kemp will find a brisk market for his Climax heaters in warmer states such as California. By 1897, a third of the households in Pasadena will use the Climax to heat water in their homes. [California Solar Center, 2001; US Department of Energy, 2002 pdf file]

Entity Tags: Clarence Kemp

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology, Commercial Involvement

Despite the initial success of the “Climax” solar water heater (see 1891), consumers are dissatisfied with a major drawback of the heater: its inability to keep the water it heats hot for more than a few hours. Inventor William J. Bailey of the Carnegie Steel Company separates the solar heater into two components: a heating element exposed to the sun and an insulated storage unit kept inside the home. Bailey’s invention allows families to have solar-heated water day and night, and even into the next morning. The device keeps water in narrow pipes instead of a large tank, allowing the water to retain its heat longer and for less water needing to be exposed to the sun at any given time. Bailey calls his invention the Day and Night, and by 1918 sells over 4,000 of the heaters. [California Solar Center, 2001; US Department of Energy, 2002 pdf file]

Entity Tags: William J. Bailey

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology, Commercial Involvement

By the 1930s, the solar water heater industry is essentially killed off in California by discoveries of huge natural gas reserves in the Los Angeles basin. William Bailey, who has grown rich selling his solar-powered water heaters (see 1909-1918), adapts his design for a thermostatically-controlled gas water heater. His Day and Night Solar Water Heater does quite well in Florida, where a building boom has brought in an influx of new residents, many of whom have to pay high rates for hot water. Florida’s semi-tropical climate and its housing boom creates an excellent selling environment for Bailey’s “hybrid” water heater. By 1941, over half of Florida residents heat their water with solar or solar-gas heaters. However, declining energy rates after World War II combined with an aggressive effort by Florida Power and Light to increase electrical consumption by offering electric water heaters at bargain prices brings the state’s solar water heater industry to its knees. [California Solar Center, 2001]

Entity Tags: William J. Bailey

Category Tags: History of Pre-Modern Solar Dev/Use, Non-Silicon Technology, Commercial Involvement, Utilities and the Solar Industry

Semiconductor researcher Russell Shoemaker Ohl of Bell Laboratories is poring over silicon samples, one of which has a crack in the middle. Electrical current flows through the cracked sample when exposed to light. The crack, likely formed when the sample was made, actually marks the boundary between regions containing different levels of impurities, so one side is positively “doped” and the other negatively doped. Ohl has inadvertently created a “p-n junction,” the basis of a solar cell. When an excess positive charge builds up on one side of the p-n barrier, and a similar excess charge builds up on the other, negatively charged side, an electric field is created. The cell can be hooked up into a circuit, and incoming photos striking the cell can “kick” electrons loose and start a current flowing. Ohl patents the solar cell, which operates at about one percent efficiency. [American Physical Society, 2013]

Entity Tags: Bell Laboratories, Russell Shoemaker Ohl

Category Tags: History of Pre-Modern Solar Dev/Use, Silicon Technology

Bell Laboratories scientists Daryl Chapin, Calvin Fuller and Gerald Pearson develop the silicon photovoltaic cell, launching the US’s photovoltaic technology industry. The PV cell is the first to convert enough solar energy to run everyday electrical equipment. Chapin had been working on magnetic materials at Bell Labs, and wanted to develop a source of power for telephone systems in remote humid locations, where dry cell batteries degraded rapidly. Chapin determined that solar energy was the most promising of the alternative energy sources available, but found the existing selenium solar cells (see 1883 and 1940) far too inefficient. Fuller and Pearson were working together to control the properties of semiconductors by introducing impurities. When the two introduce gallium and lithium to a piece of silicon, they create a p-n junction, allowing electrical current to be generated. The silicon cell produces far more electricity than they had anticipated. Pearson informed Chapin to concentrate on silicon cells, and the three work together to improve the properties of the silicon cells. Eventually, the three use a silicon cell with boron and arsenic impurities to create a satisfactory solar cell, and link several together to form what they call a “solar battery.” Their battery produces energy at about a six percent efficiency rating. Bell publicly demonstrates the new battery by using it to power a toy Ferris wheel and a radio transmitter. The New York Times writes that the silicon solar cell “may mark the beginning of a new era, leading eventually to the realization of one of mankind’s most cherished dreams—the harnessing of the almost limitless energy of the sun for the uses of civilization.” Bell Labs later produces a PV cell that achieves 11% efficiency. [US Department of Energy, 2002 pdf file; American Physical Society, 2013]

Entity Tags: Daryl Chapin, Calvin Fuller, Gerald Pearson, Bell Laboratories

Category Tags: Silicon Technology

US Signal Corps Laboratories scientist William Cherry discusses developing photovoltaic (PV) cells (see 1954) for proposed orbiting Earth satellites with RCA Labs’ Paul Rappaport and Joseph Loferski. Two years later, the Signal Corps Laboratories successfully fabricates a new silicon PV cell more resistant to radiation and thusly more useful for space-based energy generation. [US Department of Energy, 2002 pdf file]

Entity Tags: Joseph Loferski, Paul Rappaport, US Signal Corps Laboratories, William Cherry

Category Tags: Non-Silicon Technology

The US’s Vanguard I space satellite uses a small solar array, generating less than one watt, to power its radios. Later that same year, the Explorer III, Vanguard II, and Sputnik-3 satellites all use PV-powered systems (see 1956-1958) to power its systems. While commercial uses for solar energy in the United States (see 1955) is less than successful during this period, silicon solar cells become a mainstay of satellites and subsequent space exploration vehicles. In 1962, Bell Telephone Laboratories launches the first telecommunications satellite, Telstar. This satellite generates 14 watts of electricity via its PV cells. [US Department of Energy, 2002 pdf file; Smithsonian National Air and Space Museum, 2013]

Entity Tags: Bell Laboratories

Category Tags: Other Nations' Policies, Silicon Technology, US Policies

August 28, 1964: Nimbus Satellites Use PV Array

NASA begins the Nimbus satellite program by launching the first Nimbus satellite, powered by a 470-watt PV array. The Nimbus satellites are primarily for research into more complex satellite systems, and for collecting atmospheric data. [US Department of Energy, 2002 pdf file; National Space Science Data Center, 12/3/2009]

Entity Tags: Nimbus Program

Category Tags: Silicon Technology, US Policies

Dr. Elliot Berman, with assistance from scientists with the Exxon Corporation, designs a far less costly solar cell than has been previously available, lowering the price of electricity generated by the cell from $100/watt to $20/watt. Berman’s cell soon powers navigation warning lights and horns on offshore gas and oil rigs, lighthouses, railroad crossings, and a number of domestic solar applications. Solar energy becomes more popular in remote locations far away from electricity provided by grid-based utilities. [US Department of Energy, 2002 pdf file]

Entity Tags: Elliot Berman, ExxonMobil

Category Tags: Silicon Technology

The University of Delaware, home to the world’s first solar energy research institute (see 1972), builds a PV-powered residence called “Solar One.” The system is a PV/thermal hybrid, with roof-integrated arrays having surplus power fed through a special meter during the day, and power purchased from the local utility at hight. The arrays also act as flat-plate thermal collectors, with fans blowing the warm air from over the array to phase-change heat-storage bins. [US Department of Energy, 2002 pdf file]

Entity Tags: University of Delaware

Category Tags: Silicon Technology

Australian Hans Tholstrup drives the world’s first solar-powered car, named the “Quiet Achiever,” along the 2,800 mile stretch between Sydney and Perth in 20 days, ten days faster than the first gasoline-powered car to make the same run. Tholstrup later founds the “World Solar Challenge” in Australia, considered the world championship of solar car racing. [US Department of Energy, 2002 pdf file]

Entity Tags: Hans Tholstrup

Category Tags: Silicon Technology, Other Nations' Policies

1988: Solar Power Technologies Patented

Dr. Alvin Marks patents two solar power technologies: Lepcon and Lumeloid. Lepcon consists of glass panels covered with a large array of millions of aluminum or copper strips, each less than a micron wide. As sunlight hits the metal strips, the energy in the light is transferred to electrons in the metal, which escape at one end in the form of electricity. Lumeloid uses a similar approach but substitutes less expensive sheets of filmed plastic for the glass panels and covers the plastic with conductive polymers. [US Department of Energy, 2002 pdf file]

Entity Tags: Alvin Marks

Category Tags: Non-Silicon Technology

1994: NREL Constructs Efficient Solar Cell

The National Renewable Energy Laboratory (see 1994) develops a solar cell made from gallium indium phosphide and gallium arsenide that exceeds 30% conversion efficiency. [US Department of Energy, 2002 pdf file]

Entity Tags: National Renewable Energy Laboratory

Category Tags: Silicon Technology

1996: US DOE Launches ‘Solar Two’ Facility

The US Department of Energy, in conjuction with a consortium of industry representatives, launches its “Solar Two,” an upgrade of its Solar One solar power project in Daggett, California (see 1982). The facility is in operation through 1999. It demonstrates how solar energy can be stored efficiently and economically to be used during times when the sun is not shining. [US Department of Energy, 2002 pdf file]

Entity Tags: US Department of Energy

Category Tags: Public Finance, Silicon Technology, Private Finance

Scientist Subhendu Guha leads the invention of flexible solar shingles, a roofing material designed to convert sunlight to electricity. The solar shingles replace the usual asphalt shingles, and are connected to the utility grid, feeding the collected power through an inverter and producing electricity for the customer. [US Department of Energy, 2002 pdf file]

Entity Tags: Subhendu Guha

Category Tags: Silicon Technology

Spectrolab and the National Renewable Energy Laboratory jointly develop a PV solar cell that converts over 32% of the sunlight it collects into energy, a high mark for conversion efficiency. The cell uses three layers of PV materials, and performs best when exposed to sunlight concentrated by a series of lenses and mirrors. [US Department of Energy, 2002 pdf file]

Entity Tags: National Renewable Energy Laboratory, Spectrolab

Category Tags: Silicon Technology

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), the standard current for household wiring and for the power lines that supply electricity to homes. [US Department of Energy, 2002 pdf file]

Entity Tags: Sandia National Laboratories

Category Tags: Non-Silicon Technology

A firm named TerraSun develops a method of using holographic film to concentrate sunlight upon solar cells. Instead of using the usual Fresnel lenses or mirrors to concentrate light, the TerraSun design bases its efficiency on the contention that holographic film allows the more selective use of sunlight, allowing light not being used for power production to pass through the transparent modules. The holographic film transfer method is well suited for use in skylights. [US Department of Energy, 2002 pdf file]

Entity Tags: TerraSun

Category Tags: Non-Silicon Technology

ATS Automation Tooling Systems of Canada begins marketing its Spheral Solar technology for producing solar cells. The ATS cells use tiny silicon beads bonded between two sheets of aluminum foil. The cells are much lower in cost than multicrystalline silicon solar cells. The technology was invented by Texas Instruments in the early 1990s, but that firm did not follow up on initial research. [US Department of Energy, 2002 pdf file]

Entity Tags: ATS Automation Tooling Systems

Category Tags: Silicon Technology

Union Pacific Railroad installs 350 blue-signal rail yard lanterns, featuring energy saving light-emitting diode (LED) technology with solar cells, at its North Platt, Nebraska, rail yard, the largest rail yard in the United States. [US Department of Energy, 2002 pdf file]

Entity Tags: Union Pacific Railroad

Category Tags: Silicon Technology

The “Pathfinder Plus,” a solar-powered, remotely piloted aircraft upgraded from a previous version (see August 6, 1998), flies two successful test runs. The first demonstrates its use as a high-altitude platform for telecommunications and the second shows its ability as an aerial imaging system for coffee growers. The Pathfinder is capable of staying aloft for weeks or even months. Its wings are covered in solar arrays that power most of the craft’s electric motors, avionics, communications, and other electronic systems, and it has a battery-powered backup system. [US Department of Energy, 2002 pdf file]

Category Tags: Silicon Technology

Author and computer scientist Ramez Naam writes a column for Scientific American explaining how “Moore’s Law” is at work in the dropping cost of solar energy generation. The benefits are obvious, he writes: “If humanity could capture one tenth of one percent of the solar energy striking the earth—one part in one thousand—we would have access to six times as much energy as we consume in all forms today, with almost no greenhouse gas emissions. At the current rate of energy consumption increase—about 1 percent per year—we will not be using that much energy for another 180 years.” Currently, solar energy only makes up 0.2 percent of the world’s energy production, mostly because the systems to capture and use solar energy are, he says, “expensive and inefficient.” But that is changing for the better. Moore’s Law is an observation made by Intel co-founder Gordon Moore in 1965, in which he said that the number of transistors per square inch on integrated circuits had doubled each year. Moore predicted that trend would continue. Later observations codified the “law” to say that the number of transistors per square inch would double approximately every 18 months, in essence doubling the amount of computing power available to a given computer every 18 months. Naam is extrapolating the law to apply to the exponential decrease in the cost of generating solar energy. “If similar dynamics worked in solar power technology,” he writes, “then we would eventually have the solar equivalent of an iPhone—incredibly cheap, mass distributed energy technology that was many times more effective than the giant and centralized technologies it was born from.” Naam takes data generated by the National Renewable Energy Laboratory (NREL—see 1977) to note that since 1980, the cost of solar energy has dropped from $22 to $3 per watt. It is an almost perfect exponential drop, on average, trending at an average of a 7 percent drop in the dollars per watt cost per year. 2010 data indicates that the drop in price may be accelerating. Two main factors are driving this price drop: solar manufacturers are continually improving their abilities to reduce the costs of developing solar energy systems, and the efficiency of solar cells is rising dramatically. Laboratory results show solar efficiencies as high as 41 percent, and inexpensive thin-film methods (see 1972 and 1988) are achieving up to 20 percent efficiency in the lab, twice as high as most of the solar systems in use today. Moreover, installation costs are dropping as rapidly as technology costs. Naam writes that the trends indicate that the cost of solar will rival that of average retail conventionally generated electricity, about 12 cents per kilowatt hours, by 2020, or sooner. By 2030, solar electricity will cost half of what it will cost to generate electricity with coal. Naam writes: “Solar capacity is being built out at an exponential pace already. When the prices become so much more favorable than those of alternate energy sources, that pace will only accelerate.” Naam concludes: “The exponential trend in solar watts per dollar has been going on for at least 31 years now. If it continues for another 8-10, which looks extremely likely, we’ll have a power source which is as cheap as coal for electricity, with virtually no carbon emissions. If it continues for 20 years, which is also well within the realm of scientific and technical possibility, then we’ll have a green power source which is half the price of coal for electricity. That’s good news for the world.” [Scientific American, 3/16/2011; Investopedia, 2013]

Entity Tags: Ramez Naam, National Renewable Energy Laboratory, Gordon Moore

Category Tags: Commercial Involvement, Silicon Technology

In a press release, Kyocera Solar announces the opening of the Arlington Valley Solar Energy II (AV Solar II) installation in Maricopa County, Arizona, near the Hassayampa Substation. Kyocera, one of the world’s largest producers of solar photovoltaic (PV—see 1954) modules and systems, operates the facility in conjunction with LS Power and the state of Arizona; Governor Jan Brewer (R-AZ) is on hand to officially open the facility. Block 1 is online; Blocks 2 through 5 are expected to be complete by the end of the year. Kyocera Solar vice president Steve Hill says: “Today’s opening of the AV Solar II mega-installation marks a major milestone in Kyocera’s four decades of manufacturing high-quality, long-lasting solar modules. We’re proud to provide US-made products to this utility-scale installation, which adds to the mega-installations around the world showcasing Kyocera’s unrivaled solar solutions including a 204MW project in Thailand and a 70MW installation in Kagoshima, Japan.” When complete, the facility will be one of the largest solar PV installations in North America and will provide 127 megawatts of power for the surrounding community. Brewer tells the press: “Thanks to our strategic location, pro-business climate, skilled workforce, and strong incentives for solar development, Arizona is a national leader in the solar industry. As an Arizona-based company, Kyocera Solar understands how critical this industry is to a secure economic and renewable energy future.” [Business Wire, 5/1/2013]

Entity Tags: Steve Hill, Arlington Valley Solar Energy II, Jan Brewer, Kyocera Solar, LS Power

Category Tags: Public Finance, Commercial Involvement, Solar Industry, Silicon Technology

Arizona Public Service (APS), the state’s largest utility company, is using a new project it calls Solana to store solar energy collected during daylight hours to serve power demands during the night, according to an article published in the New York Times. APS had a three-mile stretch of desert near Gila Bend, southwest of Phoenix, bulldozed flat, and installed a network of parabolic mirrors that focus the sun’s energy onto a series of black-painted pipes. The pipes funnel the heat to large tanks of molten salt, which traps the heat until the plant draws the heat out of the salt and uses it to generate steam and electricity. The Solana project is an attempt to overcome one of the largest drawbacks of solar energy, the dearth of energy when the sun is not shining. “We’re going to care more and more about that as time goes on,” says APS general manager Brad Albert. Other states are watching the Solana project closely; California has just approved a rule requiring the state’s utilities to install storage facilities by 2024. Robert Gibson of the Solar Electric Power Association says: “The impetus to require storage is definitely inspired by the success of solar. Hopefully the California initiative is going to kick-start this and bring down costs.” Battery storage has always been a promise, he says, but cost-effective storage “has always been a few years out.” The biggest challenge for Arizona solar users, mainly individuals with rooftop solar arrays, is generating power in the early morning hours, before the sun has risen enough to activate the panels. Arizona and California also face similar problems in the evening, when the sun is too low for the panels to work well and people are returning home. By 6 p.m., most solar arrays are working at half capacity at best, even if they are installed on tracking devices that tilt the panels to follow the sun across the sky. Solana was built with a $1.45 billion loan guarantee from the US Department of Energy. Another similar project, also built with federal loan guarantees, is the Ivanpah project in California (see September 22, 2013). Cara S. Libby of the Electric Power Research Institute says, “There will be a trend towards storage as we see more variable renewables like photovoltaics and wind being added to the grid.” The flexibility of such a system becomes more important as a utility adds higher volumes of inflexible renewables, Libby says. Solana is not the first renewable energy plant with storage; others use banks of electric batteries. But battery storage is so expensive that it is primarily used to smooth the output of the plant and not to store large amounts of energy overnight. Storing energy as heat is much cheaper, but is mechanically inefficient. [New York Times, 10/17/2013]

Entity Tags: Brad Albert, Arizona Public Service, Cara S. Libby, New York Times, Solana, Robert Gibson

Category Tags: Utilities and the Solar Industry, Non-Silicon Technology


Time period

Email Updates

Receive weekly email updates summarizing what contributors have added to the History Commons database


Developing and maintaining this site is very labor intensive. If you find it useful, please give us a hand and donate what you can.
Donate Now


If you would like to help us with this effort, please contact us. We need help with programming (Java, JDO, mysql, and xml), design, networking, and publicity. If you want to contribute information to this site, click the register link at the top of the page, and start contributing.
Contact Us

Creative Commons License Except where otherwise noted, the textual content of each timeline is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike