Europe's first commercial concentrating Planta Solar 10 or PS10 solar power tower operates near the Southern Spanish city of Seville. The 11 megawatt (MW) solar power tower produces electricity with 624 large movable mirrors called heliostats, it took four years to build and so far cost 35 million Euros.

Suppliers

The mirrors were delivered by Abengoa, the solar receiver was designed and built by Tecnical-Tecnicas Reunidas, a Spanish Engineering Company; and the Solar Tower was designed and built by ALTAC, another Spanish Engineering and Construction Company.

Specification

Each of the mirrors has a surface measuring 120 m² (1,292 square feet) that concentrates the sun's rays to the top of a 115 meter (377 ft) high, 40-story tower where a solar receiver and a steam turbine are located. The turbine drives a generator, producing electricity. As of May 2007, this power is three times more expensive than power from conventional sources, but prices are likely to fall, as they have with wind power and as the technologies develop.

Future plans

PS10 is the first of a set of solar power generation plants to be constructed in the same area that will total more than 300 MW by 2013. Power generation will be accomplished using a variety of technologies. The first two power plants to be brought into operation at Sanlúcar la Mayor are the PS10, and Sevilla PV, the largest low concentration system photovoltaic plant in Europe.

Energy storage

The PS10 solar power tower stores heat in tanks as superheated and pressurized water at 50 bar and 285°C. The water evaporates and flashes back to steam, when pressure is lowered. Storage is for one hour. It is suggested that longer storage is possible, but that has not been proven yet in an existing power plant. However, there are many consideration for using molten salt as an energy storage medium due to the great capability of storing energy for long period of time with some insignificant losses.