Timeline of Solar Power (Part 1, 1816-1960)
Go to Part 2: Time-Line of Solar Power 1961-2009
History of Photovoltaics
1767 - Horace de Saussure, a physicist born in Geneva, Switzerland created a ‘hot box’, with a black lining, and glass cover. He noted when the sun shined on the box, the black surface inside the box reach temperatures of 228 degrees Fahrenheit. He noticed that the rays of sunlight heated the box, but the glass prevented the heat from escaping. Although he was unsure of any practical applications, he was sure similar boxes could have some future use. Sir John Herschel used a similar box to heat food on an African expedition in the 1830s.1816 - Robert Stirling develops a heat engine in his home in Edinburgh, Scotland. This engine is later used in solar thermal electric technology to convert sun energy to electric power (the ‘Stirling System’).
1839 – Alexandre-Edmond Becquerel (A. E. Becquerel) , a French physicist discovers the photovoltaic effect after experimenting with two electrodes in a conductive solution exposed to light. Edmund discovers that light exposure in the right environment produces electricity. Efficiency levels were too low for any practical applications, but a key concept of photovoltaics was born.
Pictured below: In 1839, A. E. Becquerel, a French physicist who studied the solar spectrum, discovered the Photovoltaic effect.
1861 – August Mouchet creates a parabolic reflector based steam engine. The reflector concept is a predecessor of modern day dish collectors. The original collector simply collected light and converted it to steam power—it did not create electricity.
1873 - Willoughby Smith, an English electrical engineer finds the element selenium is very sensitive to strong light (photoconductive). He used selenium rods to continually test conductivity of underwater telegraph wires as they were installed between Dover and Calais. Ironically, the selenium gave inconsistent test results, which lead to his discovery that the conductivity of selenium is reduced when exposed to strong light.
1876 - William Grylls Adams, a professor of Natural Philosophy and Richard Evans Day (Adam’s student at the time), discovered that selenium discharged electricity when exposed to light, proving electricity could be made without extreme heat or moving parts. Early attempts to use the resulting electricity to power devices failed.
1883 - Charles Fritts, an American inventor develops the first photovoltaic cell by using selenium and a thin layer of gold. The efficiency of this device is only 1% and the cost is high, making it impractical for use as a power generator.
Pictured below: A modern day solar power farm with wind turbines in the background.
1887 - Heinrich Hertz, a German physicist, discovered that charged objects exposed to ultraviolet light more readily lost their charge. He created a coil with a spark gap and observed the size and length of sparks that occurred when photosensitive material was exposed to ultraviolet light. This was described as the photovoltaic effect, which Albert Einstein later explains (Hertz never explained the phenomena occurring, he simply observed that it did occur).
1888 - Edward Weston, an English chemist, receives patent US389124, "Solar cell", and US389125, "Solar cell".
1894 - Melvin Severy receives patent US527377, "Solar cell", and US527379, "Solar cell".
1897 - Harry Reagan receives patent US588177, "Solar cell"..
1891 - Clarence Kemp, Baltimore, USA, patents the first Solar Water Heater (although Romans used rooftops containers to heat water centuries ago, this is the first patent of this kind)
Pictured Below: an example of a modern day vacuum tube solar water heater.
1901 - Nikola Tesla receives the patent US685957, "Apparatus for the Utilization of Radiant Energy", and US685958, "Method of Utilizing of Radiant Energy".
1902 - Philipp von Lenard observes the variation in electron energy with light frequency.
1904 - Albert Einstein describes the photoelectric effect in a published article. Wilhelm Hallwachs discovers a blend of copper and cuprous oxide is photosensitive.
Pictured below: In 1921 Albert Einstein received the 1921 Nobel Prize is Physics for his service to theoretical physics incluidng the theores of special relativity and general relativity. The award was also given for his discovery of the laws governing the photoelectric effect.
1913 - William Coblentz receives US1077219, "Solar cell".
1914 - Sven Ason Berglund patents "methods of increasing the capacity of photosensitive cells".
1916 - Robert Millikan, an American physicist, conducts experiments and proves the photoelectric effect.
1918 - Scientist Jan Czochralski, born in Kcynia, Poland, invented the “Czochralski process”, a way of making single crystals of metal. Eventually, the “Czochralski process” is applied to create single-crystal silicon.
1920 - Flat plate collectors are used in solar water-heating systems in florida and southern California.
1923 - Nobel Price awarded to Albert Einstein for his published work explaining the photoelectric effect.
Below: In this 1936 photo taken at the convention of the American Association for the Advancement of Science at Atlantic City, NJ , Dr. Charles Abbott (of the Smithsonian Institute) demonstrates the solar power machine. His version of the machine was a substantial improvement over previous models.
1951 - p-n junction growing makes it possible to create a germanium crystal cell
1954 – Pearson, Chapin, and Fuller of Bell labs invents the first silicon solar cell with an efficiency of 4.5%, improving the efficiency six months later to 6.0%. The media responds well, and the New York Times predicts that solar power will ultimately become a source of “limitless energy of the sun”.
Pictured Below: a modern day silicon solar collector.
1955 – Western Electric offers commercial silicon pv technologies through licensing.
1957 – Hoffman Electronics announces the discovery of solar PV cells with 8% efficiency, patent #2,780,765.
1958 – Hoffman Electronics creates photovoltaic cells with 9% efficiency and the first solar powered satellite, Vanguard I, is launched. U.S. Signal Corp.’s vanguard satellite solar power system operates for eight years.
Vanguard I satellite, launched on March 15, 1958 was the second USA satellite in space, but the first satellite to utilize solar power.
1959 – Hoffman Electronics develops and begins selling 10% efficient PV cells.
1960 – Hoffman Electronics further enhances PV cells, achieving 14% efficiency.
Go to Part 2: Time-Line of Solar Power 1961-2009