ZoomParabolic trough power plant (Foto: „Langrock / Solar Millennium") The solar thermal power plant Andasol 3 is situated in the South of Spain and has been realised by Stadtwerke München and RWE Innogy in conjunction with Ferrostaal, RheinEnergie and Solar Millennium. The power plant has an installed capacity of about 50 megawatts, and is jointly operated by the project partners.

Largest solar energy site in Europe

Andasol 3 is the third solar thermal power plant to be installed in the Spanish province of Granada by Solar Millennium. The neighbouring projects Andasol 1 and Andasol 2, which each have an electrical output of around 50 megawatts, are already connected to the grid. The power plants, which are almost identical in their construction, have a collector surface area of over 1.5 million square metres – equal to the surface area of approximately 210 football fields – thus making it the largest solar energy site in Europe. The expected gross energy production for each power plant is 170 gigawatt hours of green energy a year. This representes a saving of approximately 450,000 tonnes of carbon dioxide as compared to conventional electricity generation.

Thermal storage system for generating electricity day and night

At the Andasol 3 site more than 210,000 parabolic mirrors capture the sunlight. These six metres wide, arched mirrors concentrate the sun’s rays to heat a transfer fluid. Then, through heat exchanging devices the thermal energy is transferred to a water/steam circuit. As in a conventional power station, this steam drives a turbine that in turn drives a generator, which produces electricity.

The Andasol 3 plant also has a thermal storage system, comprising of 30,000 tonnes of a special salt mixture. This can continue to run the turbine for 8 hours at full load, and is therefore able to reliably generate electricity even after the sun has set.

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