ABSTRACT
Attempts to harness the sun’s energy for power production date back to at least 1774 when the French chemist Lavoisier and the English scientist Joseph Priestley discovered oxygen and developed the theory of combustion by concentrating the rays of the sun on mercuric oxide in a test tube, collecting the gas produced with the aid of solar energy, and burning a candle in the gas. Also, during the same year, an impressive picture of Lavoisier was published in which he stands on a platform near the focus of a large glass lens and is carrying out other experiments with focused sunlight. A century later, in 1878, a small solar power plant was exhibited at the World’s Fair in Paris. To drive this solar steam engine, sunlight was focused from a parabolic reflector onto a steam boiler located at its focus; this produced the steam that operated a small reciprocating steam engine that ran a printing press. In 1901, a 10-hp solar steam engine was operated by A.G. Eneas in Pasadena, California. It used a 700-ft2 focusing collector the shape of a truncated cone as shown in figure in this chapter. Between 1907 and 1913, the American engineer F. Shuman developed solar-driven hydraulic pumps; in 1913, he built, jointly with C.V. Boys, a 50-hp solar engine for pumping irrigation water from the Nile near Cairo in Egypt. This device used long parabolic troughs that focused solar radiation onto a central pipe with a concentration ratio of 4.5:1.
