World's Largest Solar Tower Power Plant now on line

With 1.291 mirrored heliostats and a 54 story high tower the World's largest solar power tower plant located near Seville in Spain in now on line generating 20 megawatts (MW) of electricity, enough to supply 10,000 homes. Developed by Spanish engineering company Abengoa, the PS20 plant is the world's second commercial power tower and is now the largest in the world. Concentrating solar thermal technology has been used in desert areas in Spain and the southwest U.S. for decades and is seeing a resurgence as utilities seek to reduce reliance on fossil fuels.
A solar thermal plant generates electricity in much the same way a conventional coal fired or nuclear power plant does, just that the heat source is different. Up to 80% of the world's electricity is generated using the Rankine cycle to heat water into high pressure steam that drives a turbine that is connected to an electrical generator. In a tower concentrator system the heat is provided by a field of heliostats, or mirrors, that focus sunlight onto a receiver held near the top of a tower. At the PS20 plant each heliostat is 1291 ft2 (120 m 2), which gives the entire heliostat field an area of 155,000 m 2. Each heliostat tracks the sun throughout the day on two axes and concentrates the radiation onto a receiver located on the upper part of the 531 ft (162 m) tower. The receiver converts 92% of received sunlight into steam which is piped down to a turbine driven generator at the base of the tower.
The same site also has the world's second largest and first commercial power tower plant PS10 which has been operational since 2007. PS10 features 624 mirrors pointed at a 377 ft (115 m) tower and generates 10 MW. A second 20 MW tower is also in the works at the same site. All of these structures are part of the envisioned Solucar complex slated to produce 300 megawatts by 2013. When complete the Solucar solar thermal power station complex will deliver electricity to 240,000 homes.
The PS20 plant brings Spain’s total solar capacity up to 3,000 MWs, making it a close second to the world’s leading solar producer Germany (with a capacity of close to 4,000 megawatts). Spain is the third largest producer of Wind Power in the world, behind the US and Germany, with 16,740 megawatts wind capacity installed at the end of 2008.