Alta Devices rolls out military 'charging mat'

WASHINGTON – Mobile power specialist Alta Devices said Thursday (Jan. 4) it is initially targeting a reference design for a solar “charging mat” that incorporates the company’s thin-film GaAs material in solar cells used to generate electricity to power mobile devices. The company said a charging device for military applications would have dimensions a bit larger than a sheet of paper.

Alta Devices (Sunnyvale, Calif.) claims energy conversion records for its GaAs-based solar chargers, including a 28.8 percent rating for its solar cells and 24.1 percent for its solar modules. The cells convert sunlight into electricity, and the company said its strategy revolves around generating as much electricity as possible in a small space.

The five-year-old solar company’s approach is “very design-in centric” and it is “working with customers to embed the technology into their products,” said Rich Kapusta, Alta’s vice president of marketing. The company has been sampling its thin-film GaAs solar material for about a year.

Alta Devices’ solar technology is based on a manufacturing technique for producing extremely thin layers of GaAs solar cells. Alta’s said its flexible solar cells are about 1-micron thick and deliver higher energy densities than traditional solar cells while reducing the cost of materials. The thin layers of solar cell material are grown and lifted off GaAs wafers, meaning remaining material on the wafers can be reused to make additional solar cells.

Alta currently operates a pilot manufacturing line in Sunnyvale that produces limited quantities of GaAs cells. The company said it is initially targeting military applications since there is a growing need for lighter power supplies on the battlefield and a willingness to pay a premium for the material. Weight savings would be critical for military applications since batteries account for one-third of a foot soldier’s 100-pound load. Alta claims its chargers can reduce mobile power weight by 25 pounds.

The company eventually wants to move the technology to broader mobile power markets, including consumer, automotive and even unmanned aircraft, where Alta thinks it can achieve greater economies of scale. Kapusta said Alta expects to announce new customers during the first quarter of 2013 and plans to build a production facility “somewhere in the U.S.” capable of producing enough solar cells to generate up to 40 megawatts of electricity.

Alta said its single-junction solar cell achieves conversion efficiencies of about 29 percent. A future triple-junction version could achieve efficiencies of as high as 38 percent, the company claims.

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