Thin-Film Solar Efficiency Breaks Through Barrier

German researchers have broken the record for thin-film PV efficiency, achieving 20.8%. 

This milestone is especially important because it is the first time thin-film has exceeded the efficiency of standard multicrystalline silicon solar, which currently reaches 20.4% for peak performance. 

One of the reasons silicon-based PV still dominates the market is its greater ability to convert sunlight into electricity.

When thin-film PV first became viable, many thought it would overtake silicon-based technologies, but lower efficiency has held it back. Thin-film, popularized mostly by First Solar, has many advantages. Using a "thin film" instead of heavy glass panels requires less material and energy to manufacture -it can be printed on sheets – and the lack of silicon also cuts costs.

"Our new record shows that CIGS thin-film technology still has untapped technological and economic potential," says Michael Powalla, a professor who heads the photovoltaics division at the Centre for Solar Energy and Hydrogen Research.

Fraunhofer Institute for Solar Energy Systems duplicated the research and confirmed it. 

"It may take a little time for the higher efficiency to be reflected in production," says Powalla, "but 16-18% in commercial modules is possible over the next few years." Even that would be a big boost because CIGS solar panels mostly attain efficiencies of 14-15% – a module always has lower efficiency than an individual solar cell.

First Solar, which has broken many records on thin-film efficiency, currently gets 16.1%.