More than 2,000 years ago, the Greeks and Romans used mirrors to concentrate the sun’s energy and light torches for their religious ceremonies. And even the photovoltaic effect — a means to convert light into electricity that remains a key technology today — dates back nearly 200 years, to French scientist Edmond Becquerel’s groundbreaking work.
Despite this long history and a record of extraordinary technological advances, solar power remains an almost imperceptible speck in the global energy picture, the source of less than 1 percent of world energy production in 2008. But that might be changing, as environmental concerns and geopolitics drive new solar research and implementation. Ken Zweibel, head of the George Washington University Solar Institute, maintains that “a massive switch from coal, oil, natural gas and nuclear power plants to solar power plants could supply 69 percent of the U.S.’s electricity and 35 percent of its total energy by 2050.”
Although methods for taking advantage of energy produced from the sun are myriad, the U.S. government narrows the field to five major areas. Two of those five — photovoltaics and concentration of solar power (CSP) — hold out hope for large-scale power generation, with solar hot water, passive solar and solar process heat playing important but lesser roles.