Rumor: New Record in CIGS Efficiency

The National Renewable Energy Labs (NREL) has upped the bar in copper indium gallium selenide (CIGS) solar cells once again, sources tell me. NREL scientists have developed a CIGS cell with 20.2 percent efficiency, inching past the 19.9 percent cell the lab announced in March. I’ve called NREL but haven’t heard word back on confirmation.

That number helps explain why VCs and investment banks continue to pour money into CIGS. Potentially, CIGS cells have the ability to convert more sunlight into power than other thin-film technologies like cadmium telluride and amorphous silicon. Cadmium telluride solar cells have a theoretical maximum of around 19.6 percent and commercial cad tel cells have an efficiency of around 10 percent. (We said nine earlier.) CIGS can also be printed, say advocates, on cheap, flexible substrates that can be integrated into building products. Cad tel solar cells, to date, need a glass substrate, which limits cad tel to rooftop applications.

CIGS cells are being produced in limited quantities around the 10 percent efficiency mark and theoretically CIGS cells could get into the mid-20 percentile or even low-30 percentile range someday.

Some of the leading CIGS companies include: Nanosolar, Solyndra, SoloPower, HelioVolt and Miasole. There are newcomers too: Telio Solar and NuvoSun.

Still, the stakes are high. Nearly a billion dollars have been invested in CIGS startups in the past couple of years and most of them have yet to start commercial production. Many companies have had to delay their CIGS solar cells due to manufacturing issues. (Chemically, the elements don’t play well together either—it’s the solar equivalent of trying to pull off a Guns N’ Roses reunion.) Even the large companies doing CIGS and CIS cells like Honda haven’t exactly been cranking these things out of the factory.