Solar power throughout history
People were taking advantage of the Sun to heat and light their houses and buildings already in ancient times.
One example is Socrates’ house from 400 BC. The house was built so it was warm in winter and cool in summer. This was achieved by positioning doors, windows and other openings to make optimal use of the sun’s position in the sky.
It is said that he also surrounded large stone walls with mirrors which accumulated heat during the day and released it at night. Furthermore, Socrates was probably first to heat water with the rays of the Sun.
Later on, people got hot water by pouring it into barrels painted black and left to stand in the Sun. The working principle was that these dark containers absorbed the Sun’s rays, and the energy from the rays was transformed into heat.
In 212 BC it is thought that Archimedes used mirrors for the first time to concentrate the energy of the sun’s rays. It is said that when Syracuse was under siege from the Roman Fleet that he set light to the sails of the enemy ships using burning mirrors.
In 1615 Frenchman Salomon de Caux invented a small solar driven engine which is the first documented mechanical apparatus driven by solar energy.
In the USA already during the 1800s they were talking about thermal solar energy. It was Frenchman Edmund Bequerel who came upon the idea of converting sunlight into electricity (the photovoltaic effect). He built the first solar cell that could convert half a percent of sunlight to electricity. However, the material was so expensive in relation to the small amounts of electricity produced that it was unprofitable. The project was shelved and actual research into solar energy did not gather speed again until the 1950s.
In the 1860s the French mathematician August Mouchet put forward the idea of a solar-driven steam engine.
These innovations and progress laid the foundation of the modern concentrated solar energy technology we use today.