Soitec of Bernin, France has announced a new step in its SmartCell project by raising the record for concentrated photovoltaic (CPV) module solar energy conversion efficiency from 36.7% (announced in July 2014) to 38.9%
Previously (last December), it was announced that a stand-alone SmartCell four-junction solar cell had raised the efficiency record for solar cells from 44.7% to 46%. Now, the four-junction SmartCell has been integrated into a CPV module.
Developed by Soitec in cooperation with Fraunhofer Institute for Solar Energy Systems ISE of Freiburg, Germany and French research center CEA-Leti, the four-junction solar cell uses technologies and know-how inherent in Soitec's Smart Cut and bonding techniques (which enable optimal semiconductor combinations, says Soitec).
"While we announced earlier this year Soitec's refocus on its core semiconductor materials business, we also decided to keep all assets related to our SmartCell project in the company's new strategic scope," notes CEO Paul Boudre. "Indeed, it opens many business opportunities in different kinds of industries for Soitec. In the present case, the SmartCell paves the way for further cost reductions in solar energy, as it can be integrated in a record-efficiency CPV module suitable for mass production," he adds.
CPV modules use Fresnel lenses to concentrate sunlight onto small, multi-junction solar cells. For the new module efficiency record, SmartCells were integrated in a CPV module employing the same platform as existing CPV modules using traditional three-junction cells. The SmartCells proved to have a superior conversion yield due to their four junctions.
The record module efficiency has been measured indoors and outdoors. More than 10,000 outdoor data sets have been recorded. Fraunhofer ISE performed a detailed analysis and revealed a module efficiency of 38.9±0.9% for a 1000W/m2 direct normal irradiation (DNI) and a 25°C cell temperature. The record module has an aperture area of 812cm2 and uses 36 lenses, secondary optical elements and SmartCells.
SmartCell's development has been supported by Germany's Federal Ministry for Economic Affairs and Energy and the Federal Ministry for Environment (through the Magnus project) and by the French government's 'Investissements d'Avenir' ('Invest for the Future') program (through the GUEPARD project, managed by the French environment and energy management agency - ADEME).
