Solar Energy
History of Solar Energy
Solar energy has been used since the 7th century B.C. The sun’s energy was used for heat, cooking, light, and to light fires. Ancient Greeks and Romans designed architecture to use the sun’s capacity to light and heat indoor spaces.
7th Century B.C. – Ancient peoples use a magnifying glass to concentrate the sun’s rays onto fuel and light a fire.
3rd Century B.C. – Greeks and Romans use mirrors to light torches.
2nd Century B.C. – Greek scientist Archimedes experiments with using the reflectivity of bronze shields to focus sunlight and set fire to enemies’ wooden ships.
A.D. 20 – Chinese people use mirrors to light torches.
1st-4th Century – Roman bath houses are designed to use the sun’s warmth to heat water.
13th Century – Pueblo ancestors in North America build cliff dwellings facing south to take advantage of the sun’s warmth during winter.
1767 – Swiss scientist Horace de Saussure builds the first solar collector.
1816 – Scottish minister Robert Stirling applies for a patent for his economiser heat engine, which will later be used in solar thermal electric technology that concentrates the sun’s thermal energy to produce electric power.
1839 – French scientist Edmond Becquerel discovers the photovoltaic effect. He finds that while experimenting with an electrolytic cell made up of two metal electrodes in an electricity-conducting solution, the electricity generation increases when exposed to light.
1860s – French mathematician August Mouchet starts work on a solar-powered steam engine; over the next 20 years, he and his assistant, Abel Pifre, build these engines, which are early versions of the modern parabolic dish solar collectors.
1873 – Willoughby Smith discovers the photoconductivity of selenium.
1876 – William Grylls Adams and Richard Evans Day discover that selenium produces electricity when exposed to light.
1880 – Samuel P. Langley invents the bolometer, which measures light from distant stars as well as the sun’s heat rays.
1883 – American Charles Fritts conceives of the first solar cells made of selenium wafers.
1887 – Heinrich Hertz discovers that ultraviolet light changes the lowest voltage capable of causing a spark to jump between two metal electrodes.
1891 – US inventor Clarence Kemp patents the first commercial solar water heater.
1904 – Wilhelm Hallwachs discovers that copper and cuprous oxide put together are photosensitive.
1905 – Albert Einstein publishes a paper on the photoelectric effect (along with his famed theory of relativity!).
1908 – William J. Bailey invents a solar collector that uses copper coils and an insulated box. This is roughly the same design solar collectors use today!
1914 – Scientists note a barrier layer in photovoltaic devices.
