The first ever parabolic trough power plant, according to Solar Millenium, has been inaugurated. Andasol 1 was connected to the power grid back in December 2008, and has so far successfully supplied some 200,000 people in Southern Spain with electricity. Having about 510,000 m2 in collector surfaces, Andasol 1 is the world's largest solar power plant. The power plant can continue generating electricty during night hours or low sunlight periods due to large energy storage facilities.

Andasol 1 with parabolic trough collectors. (Image credit: Solar Millenium)

In the immediate vicinity of Andasol 1 are Andasol 2 and 3 power plants. Andasol 2 is in the start-up phase of development, while Andasol 3 is expected to be connected to the grid in 2011. The two power plants are identical in construction with Andasol 1, although they have smaller power capacities. They will mainly cover peak demand withing the Spanish power grid system in the summer months, caused mostly by increased energy consumption coming from air-conditioning. Each of the power plants has 50 MW of power capacity as well as thermal storage facilities. A full storage unit guarantees an additional 7.5 hours of power supply. Heat is stored using molten salt in 14 by 36 meter tanks capable of holding up to 28,500 tons of molten salt.