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16 March 2009


GreenVolts and NREL to commercialize IMM multi-junction solar cells

Concentrating photovoltaic (CPV) system maker GreenVolts of San Francisco, CA has entered into a development relationship to commercialize the inverted metamorphic (IMM) multi-junction solar cell design of the National Renewable Energy Laboratory (NREL) of Golden, CO, USA.

The US Department of Energy (DoE), which oversees NREL, has committed $500,000 for GreenVolts to co-develop NREL’s patents and bring the technology to market. GreenVolts has also signed a licensing agreement with NREL to commercialize their patents.

Founded in 2005, GreenVolts’ CPV technology integrates optics (an off-axis micro-dish aluminum reflector mirror) as well as solar tracking together with GaAs-based multi-junction solar cells into a system that aims to produce the lowest-cost utility-scale solar energy for wholesale distributed generation.

The two-year agreement aims to transfer NREL’s IMM solar cell technology to GreenVolts so that the firm can develop a customized cell tailored to its optical system, and to accelerate the widespread commercialization of the technology through its high-volume manufacturing partners. The development agreement will be completed in multiple phases, each of which will build towards GreenVolts delivering a customized, reliable IMM device cost effectively fabricated at high volume.

“This new IMM technology is key to a tremendous leap forward in solar cell efficiency,” claims NREL director Dan Arvizu. “We are pleased to be working with GreenVolts to both refine these advancements and provide for a viable way to bring them to market.”

NREL’s IMM technology last August reported record solar cell efficiency of 40.8% at 326x concentration (since exceeded by Fraunhofer ISE's 41.1%, although NREL reckons that its technology promises further substantial increases). GreenVolts says that a customized solar cell should enable it to optimize its CPV system by increasing efficiency and reliability while reducing the overall cost of energy.

“We look forward to working closely with NREL to develop a quality high-volume, low-cost manufacturing process to ensure that this next-generation technology will be readily available,” says GreenVolts’ founder & CEO Bob Cart.

Under a Cooperative Research and Development Agreement (CRADA), technical representatives from both parties cooperate to make technical advances. Throughout the CRADA, NREL will provide necessary technology specifications and process information as well as advice and assistance in device optimization and technology transfer. NREL will also provide test and measurement services to qualify the results of the transfer process, including reliability.

Video: GreenVolts - Utility-Scale Solar, courtesy of GreenVolts and Vimeo.

See related item:

GreenVolts secures $30m Series B funding

Search: GreenVolts NREL CPV IMM solar cell GaAs multi-junction solar cell