Timeline of solar cells

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A conventional silicon solar cell
Price per watt history for conventional (c-Si) solar cells since 1977
Swanson's law – the learning curve of solar PV
Growth of photovoltaics – worldwide cumulative capacity since 1992

The timeline of solar cells begins in the 19th century when it is observed that the presence of sunlight is capable of generating usable electrical energy. Solar cells have gone on to be used in many applications. They have historically been used in situations where electrical power from the grid was unavailable.



  • 1901 - Philipp von Lenard observes the variation in electron, energy with light frequency.
  • 1904 - Wilhelm Hallwachs makes a semiconductor-junction solar cell (copper and copper oxide).
  • 1905 - Albert Einstein publishes a paper explaining the photoelectric effect on a quantum basis.
  • 1913 - William Coblentz receives US1077219, "Solar cell."
  • 1914 - Sven Ason Berglund patents "methods of increasing the capacity of photosensitive cells."
  • 1916 - Robert Millikan conducts experiments and proves the photoelectric effect.
  • 1918 - Jan Czochralski, a Polish scientist, produces a method to grow single crystals of metal. Decades later, the method is adapted to produce single-crystal silicon.
  • 1920s - Solar water-heating systems, utilizing "flat collectors" (or "flat-plate collectors"), relied upon in homes and apartment buildings in Florida and southern California.


  • 1932 - Audobert and Stora discover the photovoltaic effect in Cadmium selenide (CdSe), a photovoltaic material still used today.
  • 1935 - Anthony H. Lamb (“Tony” Lamb) receives patent US2000642, "Photoelectric device."[1]
  • 1941 - Russell Ohl files patent US2402662, "Light sensitive device."
  • 1948 - Gordon Teal and John Little adapt the Czochralski method of crystal growth to produce single-crystalline germanium and, later, silicon.[2]
  • 1950s - Bell Labs produce solar cells for space activities.
  • 1953 - Gerald Pearson begins research into lithium-silicon photovoltaic cells.
  • 1954 - On April 25, 1954, Bell Labs announces the invention of the first practical silicon solar cell.[3][4] Shortly afterwards, they are shown at the National Academy of Science Meeting. These cells have about 6% efficiency. The New York Times forecasts that solar cells will eventually lead to a source of "limitless energy of the sun."
  • 1955 - Western Electric licences commercial solar cell technologies. Hoffman Electronics-Semiconductor Division creates a 2% efficient commercial solar cell for $25/cell or $1,785/watt.
  • 1957 - AT&T assignors (Gerald L. Pearson, Daryl M. Chapin, and Calvin S. Fuller) receive patent US2780765, "Solar Energy Converting Apparatus." They refer to it as the "solar battery." Hoffman Electronics creates an 8% efficient solar cell.
  • 1958 - T. Mandelkorn, U.S. Signal Corps Laboratories, creates n-on-p silicon solar cells, which are more resistant to radiation damage and are better suited for space. Hoffman Electronics creates 9% efficient solar cells. Vanguard I, the first solar powered satellite, was launched with a 0.1W, 100 cm² solar panel.
  • 1959 - Hoffman Electronics creates a 10% efficient commercial solar cell, and introduces the use of a grid contact, reducing the cell's resistance.



  • 1980 - John Perlin and Ken Butti's landmark book A Golden Thread [3] published, covering 2500 Years of Solar Technology from the Greeks and Romans until the modern day
  • 1980 - The Institute of Energy Conversion at University of Delaware develops the first thin film solar cell exceeding 10% efficiency using Cu2S/CdS technology.
  • 1982 - Kyocera Corp is the first manufacturer in the world to mass-produce Polysilicon solar cells using the casting method, today's industry standard.
  • 1983 - Worldwide photovoltaic production exceeds 21.3 megawatts, and sales exceed $250 million.
  • 1984 - 30,000 SF Building-Integrated Photovoltaic [BI-PV] Roof completed for the Intercultural Center of Georgetown University. Eileen M. Smith, M.Arch. took 20th Anniversary Journey by Horseback for Peace and Photovoltais in 2004 from solar roof to Ground Zero NY World Trade Center to educate public about BI-PV Solar Architecture. Array was still generating an average of one MWh daily as it has since 1984 in the dense urban environment of Washington, DC.
  • 1985 - 20% efficient silicon cells are created by the Centre for Photovoltaic Engineering at the University of New South Wales.
  • 1986 - 'Solar-Voltaic DomeTM' patented by Lt. Colonel Richard T. Headrick of Irvine, CA as an efficient architectural configuration for building-integrated photovoltaics [BI-PV]; Hesperia, CA field array.
  • 1988 - The Dye-sensitized solar cell is created by Michael Grätzel and Brian O'Regan (chemist). These photoelectrochemical cells work from an organic dye compound inside the cell and cost half as much as silicon solar cells.
  • 1988–1991 AMOCO/Enron used Solarex patents to sue ARCO Solar out of the business of a-Si (see Solarex Corp.(Enron/Amoco) v.Arco Solar, Inc.Ddel, 805 Fsupp 252 Fed Digest.)
  • 1989 - Reflective solar concentrators are first used with solar cells.
  • 1990 - The Magdeburg Cathedral installs solar cells on the roof, marking the first installation on a church in East Germany.
  • 1991 - Efficient Photoelectrochemical cells are developed
  • 1991 - President George H. W. Bush directs the U.S. Department of Energy to establish the National Renewable Energy Laboratory (transferring the existing Solar Energy Research Institute).
  • 1992 - University of South Florida fabricates a 15.89-percent efficient thin-film cell
  • 1993 - The National Renewable Energy Laboratory's Solar Energy Research Facility is established.
  • 1994 - NREL develops a GaInP/GaAs two-terminal concentrator cell (180 suns) which becomes the first solar cell to exceed 30% conversion efficiency.
  • 1996 - The National Center for Photovoltaics is established. Graetzel, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland achieves 11% efficient energy conversion with dye-sensitized cells that use a photoelectrochemical effect.
  • 1999 - Total worldwide installed photovoltaic power reaches 1,000 megawatts.


  • 2003 - George Bush has a 9 kW PV system and a solar thermal systems installed on grounds keeping building at the White House[11]
  • 2004 - California Governor Arnold Schwarzenegger proposed Solar Roofs Initiative for one million solar roofs in California by 2017.
  • 2004 - Kansas Governor Kathleen Sebelius issued a mandate for 1,000 MWp renewable electricity in Kansas by 2015 per Executive Order 04-05.
  • 2006 - Polysilicon use in photovoltaics exceeds all other polysilicon use for the first time.
  • 2006 - California Public Utilities Commission approved the California Solar Initiative (CSI), a comprehensive $2.8 billion program that provides incentives toward solar development over 11 years.[12]
  • 2006 - New World Record Achieved in Solar Cell Technology - New Solar Cell Breaks the “40 Percent Efficient” Sunlight-to-Electricity Barrier.[13]
  • 2007 - Construction of Nellis Solar Power Plant, a 15 MW PPA installation.
  • 2007 - The Vatican announced that in order to conserve Earth's resources they would be installing solar panels on some buildings, in "a comprehensive energy project that will pay for itself in a few years."[14]
  • 2007 - Google solar panel project begins operation.[15][dead link]
  • 2007 - University of Delaware claims to achieve new world record in Solar Cell Technology without independent confirmation - 42.8% efficiency.[16]
  • 2007 - Nanosolar ships the first commercial printed CIGS, claiming that they will eventually ship for less than $1/watt.[17] However, the company does not publicly disclose the technical specifications or current selling price of the modules.[18]
  • 2008 - New record achieved in solar cell efficiency. Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) have set a world record in solar cell efficiency with a photovoltaic device that converts 40.8 percent of the light that hits it into electricity. However, it was only under the concentrated energy of 326 suns that this was achieved. The inverted metamorphic triple-junction solar cell was designed, fabricated and independently measured at NREL.[19]
  • 2010 - BP announces the closing of their photovoltaic plant in Maryland, moving all of their manufacturing work to China.[20]
  • 2010 - President Barack Obama orders installation of additional solar panels and a solar water heater at the White House[21]
  • 2011 - Fast-growing factories in China push manufacturing costs down to about $1.25 per watt for silicon photovoltaic modules. Installations double worldwide.[22]
  • 2012 - 3D PV-cel with 30% more energy efficiency[23]
  • 2013 - After three years, the solar panels ordered by President Barack Obama were installed on the White House.[24]

See also[edit]


  1. ^ Issue date: May 7, 1935. [1] [2]
  2. ^ David C. Brock (Spring 2006). "Useless No More: Gordon K. Teal, Germanium, and Single-Crystal Transistors". Chemical Heritage Newsmagazine (Chemical Heritage Foundation) 24 (1). Retrieved 2008-01-21. 
  3. ^ "April 25, 1954: Bell Labs Demonstrates the First Practical Silicon Solar Cell". APS News (American Physical Society) 18 (4). April 2009. 
  4. ^ D. M. Chapin, C. S. Fuller, and G. L. Pearson (May 1954). "A New Silicon p-n Junction Photocell for Converting Solar Radiation into Electrical Power". Journal of Applied Physics 25 (5): 676–677. doi:10.1063/1.1721711. 
  5. ^ http://www.uniquewatchguide.com/solar-watches.html
  6. ^ Alferov, Zh. I., V. M. Andreev, M. B. Kagan, I. I. Protasov, and V. G. Trofim, 1970, ‘‘Solar-energy converters based on p-n AlxGa12xAs-GaAs heterojunctions,’’ Fiz. Tekh. Poluprovodn. 4, 2378 (Sov. Phys. Semicond. 4, 2047 (1971))]
  7. ^ Nanotechnology in energy applications, pdf, p.24
  8. ^ Nobel Lecture by Zhores Alferov, pdf, p.6
  9. ^ http://www.fsec.ucf.edu/
  10. ^ http://www.vintagecalculators.com/html/calculator_time-line.html
  11. ^ White House installs solar-electric system
  12. ^ http://www.cpuc.ca.gov/static/energy/solar/
  13. ^ "New World Record Achieved in Solar Cell Technology" (Press release). United States Department of Energy. December 5, 2006. Retrieved 2008-01-16. 
  14. ^ Krauss, Leah (May 31, 2007). "Solar World: Vatican installs solar panels". United Press International. Retrieved 2008-01-16. 
  15. ^ http://www.google.com/corporate/solarpanels/home
  16. ^ "From 40.7 to 42.8 % Solar Cell Efficiency". July 30, 2007. Retrieved 2008-01-16. 
  17. ^ "Nanosolar Ships First Panels". Nanosolar Blog. Archived from the original on 2008-01-16. Retrieved 2008-01-22. 
  18. ^ "Nanosolar - Products". Nanosolar.com. Retrieved 2008-01-22. 
  19. ^ NREL Public Relations (2008-08-13). "NREL Solar Cell Sets World Efficiency Record at 40.8 Percent". National Renewable Energy Laboratory. Retrieved 2008-09-29. 
  20. ^ Steven Mufson (March 27, 2010). "BP closing Maryland solar manufacturing plant". Washington Post. 
  21. ^ Juliet Eilperin (October 6, 2010). "White House goes solar". Washington Post. 
  22. ^ Mike Koshmrl and Seth Masia (Nov–Dec 2010). "Solyndra and the shakeout: the recent solar bankruptcies in context". Solar Today. 
  23. ^ http://www.bitsofscience.org/3d-solar-cell-energy-efficiency-6206/
  24. ^ "White House solar panels being installed this week". The Washington Post. 

External links[edit]