Mouchout, Auguste

Auguste Mouchout was a French mathematics teacher who, in 1861, designed and patented the first machine that generated electricity with solar thermal energy electricity by the exposure of the sun. He made a number of notable public demonstrations of his inventions. With Abel Pifre, he demonstrated a solar generator that powered a steam engine at the 1878 Paris Exhibition. Mouchot's exhibition engine included a mirror over 13 feet (3.96 meters) in diameter and a 21-gallon (79.5 liters) boiler. The boiler generated seven atmospheres of pressure and drove an ice-maker that produced a “solar” block of ice. During another exhibition in 1882, a solar powered steam engine powered a printing press that produced 500 copies per hour of Pifre's newspaper, named Soleil-Journal (Sun newspaper). In 1869, Mouchot wrote what is believed to be among the first books ever devoted to solar energy: Le Chaleur Solaire et les Applications Industrielles.

Mouchout began his work with solar energy in 1860 after expressing grave concerns about his country’s dependence on coal. His initial experiments involved a glass-enclosed, water-filled iron cauldron, in which sunlight passed through a glass cover, heating the water. This simple arrangement boiled water, but it also produced small quantities of steam. Mouchout added a reflector to concentrate additional radiation onto the cauldron, thus increasing the steam output. He succeeded in using his apparatus to operate a small, conventional steam engine. Impressed by Mouchout’s device, Emperor Napoleon III offered financial assistance, which Mouchout used to produce refinements to the energy system. Mouchout’s work help lay the foundation for our current understanding of the conversion of solar radiation into mechanical power driven by steam.

The publication of his book on solar energy, La Chaleur solaire et ses Applications industrielles (1869), coincided with the unveiling of the largest solar steam engine he had yet built. This engine was displayed in Paris until the city fell under siege during the Franco-Prussian War in 1871, and was not found after the siege ended.

In September 1872, Mouchout received financial assistance from the General Council of Indre-et-Loire to install an experimental solar generator at the Tours library. He presented a paper on the generator to the Academy of Sciences on 4 October 1875, and in December of the same year he presented to the Academy a device he claimed would, in optimal sunshine, provide a steam flow of 140 liters per minute. Later the following year he sought permission from the ministry to take leave from his teaching position in order to develop an engine for the Universal Exhibition of 1878, and in January 1877 obtained a mission and a grant for the purchase of materials and execution of his solar engines in French Algeria, where sunlight was in abundance. The director of science missions recommended Mouchout to the Governor of Algeria, stressing the importance of his mission to France, "for science and for the glory of the University”.

Returning to metropolitan France in 1878, Mouchout and his assistant Abel Pifre displayed Mouchout's engine at the Universal Exhibition in Paris, and won a Gold Medal in Class 54 for his works, most notably the production of ice using concentrated solar heat. However, the continuing economic benefits of the Cobden-Chevalier Treaty, combined with a more efficient internal transportation for coal delivery, meant that coal became increasingly cheaper in France, reducing the necessity for research into alternative energy. The French government assessed in a report that solar energy was uneconomical, deeming Mouchout's research no longer important and ending his funding.


  • Cleveland, Cutler (Lead Author); Peter Saundry (Topic Editor). 2008. "Mouchout, Auguste." In: Encyclopedia of Earth. Eds. Cutler J. Cleveland (Washington, D.C.: Environmental Information Coalition, National Council for Science and the Environment). [First published in the Encyclopedia of Earth September 15, 2006; Last revised December 1, 2008; Retrieved July 29, 2009]. 
  • Wikipedia Contributors, Augustin Bernard Mouchot, Wikipedia The Free Encyclopedia, Accessed 29 July 2009.

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