Alta Devices Solar Panel NREL-certified at 23.5 Percent Efficient

Thin-film solar array at Dimbach, Germany

For the second time in as many months, a solar manufacturer is announcing record conversion efficiencies for its solar energy-harvesting products.

In this case, the company is Alta Devices of Santa Clara, California, and the efficiency rating – of 23.5 percent – is for its solar panels made from gallium arsenide (GaAs) on thin-film.

The previous honorable mention was in January, to First Solar. Inc. (Nasdaq: FSLR), which announced record efficiencies of 14.4 percent for its solar module. For First Solar, the record was kind of ho-hum – the company is a leader in the field and consistently breaks its own and other records.

Not so Alta Devices, a relative startup (2007) whose GaAs technology was exhibited last June at the 37^th IEEE Photovoltaic Specialist Conference in Seattle. This is the same technology which achieved – at the solar cell level – record efficiencies of 28.2 percent. Alta’s business focus is on improving the production economics of high-efficiency solar photovoltaic (PV) applications.

The panel rating has been verified by the National Renewable Energy Laboratory, or NREL, one of a dozen laboratories working under the wing of the U.S. Department of Energy’s Energy Efficiency & Renewable Energy (EERE) division to develop more efficient renewable energy and energy efficiency technologies. NREL is the only one of the 12 to take technology from infancy to commercialization.

Fortunately, Alta Devices didn’t have to go it alone, as did some early solar startups. In addition to venture capital funding, the company is also engaged in the DOE’s SunShot Initiative via Dow Solar, which last year received a $12.8 million, three-year grant to study cost reductions in building integrated photovoltaic (BIPV) products.

Dow Solar chose Alta and several other companies to help make the production-cost breakthrough and drive down the cost of solar energy in thin-film BIPV, as developed for a solar roofing shingle under Dow's brand name Powerhouse.

The ultimate goal is to put solar energy on the same cost-per-kilowatt- hour (kWh) footing with fossil fuel energy – a paradigm known as grid parity.  In the case of the SunShot Initiative, this goal has been expressed as six cents per kWh by 2020.

In 2009, Alta also received $3 million in DOE Solar Incubator Program funding, which it used to create a dual-contact cell with antireflective coating, optimized polyhedron cell geometry (via a resolution of the Euler equation?), and interconnection methods which capture the inherent efficiency of gallium arsenide.

Alta, which is in the process of expanding its initial manufacturing run, building strategic production partnerships, and selecting its first large, commercial manufacturing site, says it can afford to use even expensive GaAs because its deposition process produces a 1-micron thick cell which can easily be lifted off the substrate and reused multiple times.

Another big winner in the solar efficiency department is Semprius of Durham, North Carolina, which announced a high concentrating photovoltaic (HCPV) efficiency of 33.9 percent on January 31, also using GaAs.