Torresol Energy, S.A. began operating the world’s first utility-scaleconcentrating solar power plant that uses flat heliostats and stores heat using molten salt, allowing it to sustain power through the night for around 25,000 homes in Seville, Spain.
The 19.9-megawatt Gemasolar concentrating solar power plant uses 2,650 flat mirrors called heliostats arranged over 185 hectares of land to heat molten salt. The heliostats focus sunlight on a tower where liquid is heated up to 900 degrees centigrade. It is then stored for later use at above 500 degrees centigrade in tanks beneath the tower.
Compared with water, salt retains heat longer, thus extending the plant’s daily operating hours. Stored heat is used later to generate steam and run the power generator, even at night. The Gemasolar facility can produce electricity for 15 hours solely using stored heat, the company said. Continue reading