By Sandy Dechert, Planetsave
In the close race for PV efficiency, copper indium gallium (di)selenide cells have taken the lead again in tests at the Atsugi Research Center in Kanagawa, Japan. The Fraunhofer Institute, Europe’s largest application-oriented research organization, has independently verified the results.
A Solar Frontier 0.5cm2 CIS configuration achieved 20.9% conversion efficiency, a world record for thin-film photovoltaic technologies. Solar Frontier is dedicated to creating the most economical, ecological solar energy solutions on Earth, and CIS modules require 60% less energy to produce than crystalline silicon.
The company conducted joint research with the New Energy and Industrial Technology Development Organization to achieve this result, which exceeds the conversion efficiency of traditional (and higher-cost) crystalline silicon PV. Cadmium telluride thin-film cell efficiency approaches that of CIS (record of 19.6% as of 2013). In reaching 20.9%, Solar Frontier has broken its own record.
Says Satoru Kuriyagawa, Chief Technology Officer of Solar Frontier:
“Solar Frontier’s new 20.9% efficiency record resulted from a CIS cell cut from a 30cm by 30cm substrate produced using a sputtering-selenization formation method—the same method we use in our factories. The significance is twofold: it ensures we can transfer our latest achievement into mass production faster, and it proves the long-term conversion efficiency potential of Solar Frontier’s proprietary CIS technology. Solar Frontier has entered into the next phase in the development of CIS technology, and we look forward to building on this achievement and driving our efficiency even higher.”
Actual performance of solar PV modules after installation does depend on surrounding environment and climate. At temperatures above 25°C, all PVs suffer performance losses. CIS and CdTe, the less ecologically attractive competitor, are both promising in these non-test conditions.