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Solar Energy in the Ancient World
The history of solar energy dates back to the very ancient times. Man harnessed solar energy by burning biomass such as wood, dried animal dung, and peat at the beginning of history.
Many ancient civilizations used passive solar energy designs to keep buildings warm. The walls and floors collected solar heat during the day and released them at night. The ancient Roman civilization improved on such these designs to use glass on windows to trap solar warmth and glasshouses to grow exotic plants.
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Early History of Photovoltaics
The discovery of selenium in 1818 made it possible to trap solar energy for future use. Selenium, a trace meta,l is a conductor of electricity. Its conductivity rises thousandfold when exposed to direct sunlight.
The discovery of selenium notwithstanding, the impetus for harnessing energy from the sun as a source of energy came because of the political rivalry between England and France. The high prices of English coal and problems in supply made the king of France patronize scientists to find alternate sources of energy, and this led to three noteworthy developments:
- Edmund Becquerel, a French physicist first observed the principle of photovoltaics in 1838. He published findings about electric currents in certain materials like selenium.
- Auguste Mouchout, another French scientist followed up on Edmund’s ideas and in 1860 patented a design for a mechanical steam engine running on solar energy. He later connected the steam engine to a refrigeration device to illustrate that the sun’s rays could contribute to producing ice!
- Charles Tellier installed the first solar energy system for heating household water on top of his roof.
The French however soon renegotiated a cheaper deal for the supply of coal from England, and considered Mouchout’s solar powered steam engine and Charles Tellier’s solar water heater no longer necessary.
The English took off from where the French left. Between 1873 and 1886, William Adams and Richard Day wrote the first book on Solar Energy called “A Substitute for Fuel in Tropical Countries." They developed a 2.5 horsepower steam engine running on solar energy, much bigger than Mouchout's 0.5 horsepower engine.
The harnessing of solar power caught up in America simultaneously. In 1868 John Ericsson developed a solar powered steam engine similar to the one developed by Mouchout.
Albert Einstein’s description of the photoelectric effect in 1905 was a landmark in the history of solar energy. Einstein received the Nobel Prize for his theories on the photoelectric effect in 1921.
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Developments in Solar Energy Technology in the Early 20th Century
The turn of the 20th Century witnessed two major developments in the history of utilizing solar energy. Aubrey Eneas formed the Solar Motor Company, the first solar energy company in the world, and Henry Willsie built two huge solar plants in California that successfully used solar power at night after generating it during the day. Between 1906 and 1914, the Sun Power Co of Franch Shuman built the largest and most cost-effective solar energy system covering 10,000 square feet plus. All these ventures, however, were commercial failures.
1909 is a landmark year in the history of solar water heaters, for that’s when William Bailey of California developed a successful model of a solar water heater by separating the water tank from the solar collector. This prototype remains in use today. In 1936, Charles Greeley Abbott developed an efficient solar boiler that remained popular until the 1950s when cheaper gas became available.
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Developments in Solar Energy Technology in Late 20th Century
Charles Fritz had developed the first solar cell that turned the sun's rays into electricity in 1883. His solar cell, however, had a conversion rate of only around two percent, meaning that of the total energy that hits the surface of the cell, only two percent converts to usable energy.
The next noteworthy event in the history of photovoltaic cells occurs in 1953 when Calvin Fuller, Gerald Pearson, and Daryl Chaplin of Bell Laboratories improved on Charles Fritz’s solar cell by using silicon to enhance the efficiency rate to six percent. The efficiency was later enhanced to 11 percent, providing solar cells with practical value. By 1960, Hoffman Electronics increased the efficiency of the solar cell to 14 percent, and recent research has improved the solar cell efficiency to 20 percent. The increase of energy efficiency of the solar cells made it suitable for commercial use, and the first such commercial application of solar cells were to supply energy for satellites.
A major drawback of the solar cell was its high cost of $300 per watt that made it unaffordable to ordinary users. The OPEC energy crisis of the 1970s made it imperative to find alternative forms of energy. The US Department of Energy funded the Federal Photovoltaic Utilization Program, and businesses received incentives to develop solar energy technology. This led to the establishment of 150 businesses that manufactured solar cells, with annual sales of $0.8 billion.
The subsequent research and mass production has led to a dramatic drop in prices and solar cells now cost about $20 per watt. This huge cost savings opened the use of solar cells in railroads, lighthouses, offshore oilrigs, buoys, remote homes, and even in watches, calculators, and toys.
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Contemporary Developments in Harnessing Solar Energy
The development and mass production of solar cells notwithstanding, energy from fossil fuels remains a cheaper source of energy compared to solar cells. Luz Co., a Los Angeles based company that produced 95 percent of the world's solar-based electricity shut shop in the 1980s after investors withdrew when the price of non-renewable fossil fuels declined.
The Gulf War of 1990 renewed interest in solar power as an alternative to energy from fossil fuels. Frank Bridgers had developed the first solar water heated office building in the mid-1950s, but it was the post Gulf-War tax credits and incentives for solar electric homes and heating systems that made solar heating popular. Today, nearly 1.2 million buildings in the US have solar heating capabilities.
The history of solar energy substantiates the scope of solar energy to become a practical and viable source of energy.