'Concentrated PV' solar power plant hits mark in Spain

SolFocus on Tuesday said that it has begun installation of its concentrated photovoltaic arrays at a 3-megawatt solar power plant in southern Spain.

The first 200 kilowatts of solar power to go live will be part of 500 kilowatts that SolFocus will provide in a project sponsored by Spain's Institute of Concentration Photovoltaic Systems, or ISFOC by its Spanish acronym.

SolFocus, which we first covered when it was spun out of Xerox Palo Alto Research Center in 2006, is one several companies pursuing concentrated solar photovoltaics, where mirrors or lenses focus light onto solar cells to produce more electricity. Tracking systems that mount the solar arrays follow the sun during the day to maximize light input.

A 6.2 kilowatt array, part of a solar power plant project in Spain.

(Credit: SolFocus)

The technology competes with solar thermal where parabolic troughs or dishes are also used to concentrate light. But instead of producing electricity from solar cells, the heat from the sun is used to produce steam which turns an electrical generator. (Click here for an FAQ and photo gallery on concentrated photovoltaics, or CPV.)

Utilities are betting on these approaches, along with solar farms equipped with hundreds or thousands of light-tracking traditional solar panels, to make solar power plants.

The Southwest region of the U.S. and Spain have emerged as two of the most desirable places to install these plants.

But different solar technologies are better suited for different environments.

Because they align with the sun very closely, a concentrating photovoltaic power plant will not perform as well on cloudy days, whereas a power field with hundreds of traditional flat-plate solar panels could still generate a significant amount of electricity. The 10-megawatt solar park in Bavaria, Germany, uses flat panels with tracking devices.

SolFocus' design concentrates the light hundreds of times, while companies targeting smaller solar energy systems for corporate buildings have only 3 or 5 times concentration.

The solar power plants are small compared with a typical coal-fired or natural gas-driven plant, which can be hundreds of megawatts. But utilities are investing in solar power plants to meet renewable energy mandates or for peak power needs.