CPV modules set to power Edwards Air Force Base

21 Nov 2012

US company Semprius will provide 2400 modules mounted on dual-axis trackers – enough to deliver 200 kW of power to the base.

A 200 kW high-concentration photovoltaics (HCPV) system is to be installed at the Edwards Air Force Base in southern California next year, featuring modules manufactured by the North Carolina company Semprius.

As part of a $2.3 million Department of Defense (DoD) contract awarded to Pratt & Whitney Rocketdyne (PWR), the project is designed to demonstrate the performance and cost-effectiveness of the technology.

Partly because of its high up-front costs, CPV is typically touted as a solar technology that is suited to utility-scale installations. While much smaller than other CPV solar farms planned for nearby San Diego, the Edwards deployment is expected to produce more than 400,000 kWh of electricity annually, enough to power around 40 homes.

The installation will feature 12 dual-axis HCPV units, each comprising approximately 60 square meters of the Semprius modules, says PWR.

New facility
The agreement comes just a couple of months after venture-backed Semprius formally opened its new module manufacturing facility in Henderson, NC. The company has been working with PWR over the past 18 months to refine the technology, and the modules made by Semprius offer world-record conversion efficiency of just under 34%.

Semprius’ approach to CPV differs from its peers, in that its high-efficiency modules are based on tiny solar cells (0.36 mm²) produced using a proprietary micro-transfer printing process that was developed initially at the University of Illinois. The firm also uses a higher concentration ratio (1111x suns) than the more typical level of 500x.

In a statement announcing the planned Edwards installation, PWR’s program manager for renewable energy Randy Parsley said: “Having spent several years evaluating emerging PV technologies, we’ve selected Semprius because of the potential of their technology to drive down the cost of solar electricity significantly.”

Tough times
The potential for CPV to be cost-effective in sunny locations has long been touted by its proponents, but the larger competitors in the sector appear to be struggling. Amonix, Soitec and SolFocus – historically touted as the three leading CPV protagonists – each has its own problems:

Back in July, Amonix shut its manufacturing facility in Nevada, citing intense competition and low levels of demand. Last week saw Soitec reveal huge financial losses due, in large part, to its investment in CPV manufacturing sites in Germany and San Diego, before Greentech Media revealed that SolFocus was effectively up for sale, despite working on some major CPV deployments.

One of Semprius’ investors is the German engineering and power systems giant Siemens, which last month announced that it would exit the solar power market and withdraw from the high-profile Desertec project that may one day provide Europe with solar electricity generated in the Sahara.

Given that Siemens' venture wing had bought a 16% stake in Semprius last year, that did not look like good news for the CPV firm. But at the time of the Siemens announcement, Semprius CEO Joe Carr told optics.org that it would be “business as usual” while the German company sought a buyer of its solar business.

In a note to the company’s partners shortly after Siemens’ announcement in late October, Carr wrote: “The decision by Siemens to sell its solar unit had nothing to do with Semprius, its people or technology. Siemens remains highly supportive of the company and [its] stated goal is to find a ‘good home’ that will continue to support Semprius products.”

“It also presents an opportunity for Semprius to bring in a new strategic investor as part of its expansion plans,” Carr added. “From an operational standpoint for Semprius, it remains business as usual.”