MADRID - Spanish engineering company Abengoa has begun operating a 20 megawatt solar power plant that is the world's biggest, using a tower to turn the sun's rays into electricity and can supply 10,000 homes, it said on Monday.

The PS20 plant in the southern province of Seville uses 1,255 mirrors to focus solar radiation at the top of a tower 165 metres high, in order to boil water to drive a turbine and generate electricity.

Abengoa already has a 10 MW solar power tower in service and plans another 20 MW plant as part of its Solucar complex, which aims to produce 300 MW by 2013 with the addition of five 50 MW plants using parabolic troughs to concentrate solar power.

Power towers and parabolic troughs are both types of concentrated solar power (CSP).

Most solar power stations use photovoltaic (PV) panels, which directly convert solar energy into electricity, but many analysts say CSP plants may take the lead in future because they generate more power and could be more cost effective.

Spain became the world's second largest PV producer after Germany last year, with more than 3,000 MW installed, due to a generous subsidy scheme. But PV growth is expected to be slow this year because the government will cap at 500 MW new plants entitled to subsidies this year. (Reporting by Martin Roberts)

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