Siemens AG, the giant German electronics company, has purchased a roughly 16 percent minority stake in North Carolina-based Semprius, Inc., a manufacturer of high-concentrating photovoltaics (HCPV) that is preparing to break ground on its first manufacturing plant.

Semprius’ devices have reached 41.7 percent efficiency in laboratory testing at the National Renewable Energy Laboratory, said Semprius Staff Development Engineer Kanchan Ghosal.

The technology uses glass lenses to concentrate the sun on its triple-junction Gallium Arsenide (GaAs) photovoltaic microcells.

“The cells are 600x600 microns in area, and less than 10 microns thick,” he said.

The microcells are printed using Semprius’ patented micro-transfer printing process.

"Participating in Semprius provides us access to trailblazing technology for clean power generation," Martin Schulz, vice president of photovoltaics in the Renewable Energy Division of Siemens Energy, said in press release. "We believe the prospects are bright for high concentrating photovoltaic systems that enable significantly higher efficiencies than conventional PV modules, and at the same time, offer enormous potential to achieve competitive levelized costs of electricity."

“We expect to be cost competitive with fossil fuels at high volume,” Ghosal said. “We do not disclose our cost model, though it has been shared with our investors.”

Siemens, which makes various types of generators, including gas, steam and wind turbines, also develops concentrating solar power and photovoltaic plants.

With the buy-in into Semprius, it shows that it’s also looking at the concentrating photovoltaic market.

“The market for HCPV installations is still in its early stages but is expected to grow to a volume of up to six gigawatts by 2020. HCPV systems are a prime alternative to conventional photovoltaics and are especially suitable for regions with high direct sunlight, for example along the Earth's sunbelt,” Siemens said.

The company is now field testing its devices, Ghosal said.

“Semprius installed a 1 kilowatt system at Tucson Electric Power in August 2010,” he said. That system consists of a 48-module array mounted on a dual-axis tracker using two-junction microcells. “It has been performing as expected.”

The system has operated at an average capacity factor of 29 percent, according to a recent Semprius presentation.

“Semprius is currently developing a commercial product, which will be field tested as a 2.5-kW system in 2011,” the company said.

The company also plans to break ground on its first production facility in July, according to the press release. But Ghosal would not comment on plans for the facility.

“Details about our next steps will be available shortly,” he said.

Image courtesy of Semprius.