HelioVolt, which specializes in copper indium gallium selenide (CIGS) solar cells, has raised an additional $24 million, bringing the total injected into the company to more than $100 million. The latest investors include Sequel Venture Partners, Noventi Ventures and Passport Capital.
CIGS solar cells are not as efficient as crystalline silicon solar cells, the dominant type of cell on the market. HelioVolt's first cells will likely have an efficiency rating of 10 percent to 12 percent, meaning that they can convert 10 percent to 12 percent of the sunlight that strikes them into electricity. Commercially available silicon solar cells already perform at 22 percent efficiency.
CIGS cells, though, will be cheaper, say proponents. HelioVolt will make them by printing the active CIGS material onto glass sheets and thermally bonding it. By contrast, silicon solar cells are made with the same sort of processes needed to make flat-screen TVs.
The catch? No one yet mass produces CIGS cells. Producing these cells in large numbers as cheaply as promised has proven difficult. Nanosolar, which designs and will make its solar cells in California, is expected to start shipping product in modest volumes later this year.
HelioVolt plans to use the money it has raised this year--it got $77 million back in August--to build CIGS plants. Limited production is expected to start in the middle of next year and ramp into volume production by the first quarter of 2009.
Venture capitalists have poured more than $344 million into five CIGS companies in the last few years--Nanosolar, Miasole, Solopower, Solyndra and HelioVolt.
Elsewhere in the CIGS world, a rumor floating around that Miasole cut about 50 employees and will close its Shanghai operation is not true, says founder Dave Pearce. They let go some contractors, but that's it. It's good to clear the air.
"We have recently hired a number of senior engineering, operations and sales resources, not laid them off. We have no plans to shut down our Shanghai operations," he wrote News.com in an e-mail.