Entech’s CEO, David Gelbaum, says multi-junction cells are extremely efficient under Entech’s color-mixing, arched Fresnel lenses, thanks to how they concentrate more light on the cells and how they distribute the full-spectrum of sunlight onto the cells. The bigger advantages of the technology, however, are the cost, weight, and robustness. “By using only one-eighth as much solar cell area per Watt of array power, we save cost and weight and make it possible to better insulate and shield the smaller solar cells,” he says.
Entech has now taken its knowledge from working with Glenn over the last 25 years and incorporated it into a new ultra-light solar concentrator for terrestrial applications. In 2012, the technology won an R&D 100 Award, recognizing it as one of the top 100 technologically significant new products of 2012 by R&D Magazine.
Benefits
Entech’s new product, SolarVolt, is a concentrating photovoltaic solar module that incorporates a significant amount of technology from the SLA. “While the SLA was primarily optimized to save mass because launching into space is so expensive, SolarVolt is optimized to save cost because the terrestrial market is so cost-competitive,” says Gelbaum.
Solar technology
Entech’s SolarVolt product, incorporating NASA technology, can be used to generate electricity for utility-scale power plants, communication systems, and government and military power systems. It is most productive in sunny desert regions like Nevada.
For space, the company uses multi-junction solar cells with lenses made of space-qualified silicone rubber. For terrestrial applications, Entech uses low-cost silicon cells under acrylic plastic lenses. Because the space version does not need to resist wind and hail, there is no lens cover; SolarVolt uses a tempered glass window to protect the lenses and cells.
On Earth, SolarVolt can be used to generate electricity for applications from a fraction of a megawatt to multimegawatt systems. Commercial applications include utility-scale power plants, distributed energy for smart grid systems, communications systems, industrial building power systems, and government and military power systems.
The technology is most productive in areas with high, continuous direct normal irradiation, or DNI, which comes directly from the sun. High DNI areas in the United States include southern California, Arizona, Nevada, New Mexico, west Texas, and Colorado. As Gelbaum describes, “SolarVolt is primarily aimed at large utility-scale solar power plant applications in the sunny desert regions.”
In 2011, SolarVolt received international certification designating it has met concentrating PV module testing and construction evaluation requirements to verify its performance and reliability in hail, extreme temperatures, and wet and dry conditions.
Even as the SLA spins off for terrestrial use, NASA continues to improve it for use in space. Glenn is now partnering with Deployable Space Systems, Inc. to fuse Entech’s SLA concentrator with a lightweight, deployable structural platform called SOLAROSA, or the Stretched Optical Lens Architecture on Roll-Out Solar Array. Ad Astra Rocket Co. is interested in using SOLAROSA to support its Variable Specific Impulse Magnetoplasma Rocket engine, an advanced plasma propulsion system.
Thanks to such public-private partnerships, the future is bright where solar electric power is concerned—both on the ground and in space. “Collaborating with NASA has not only helped us to improve and refine our space and ground solar power technologies, but has helped Entech gain credibility for its technology,” says Gelbaum. “NASA is a terrific partner for small businesses like us.”
SolarVolt™ is a trademark of Entech Solar.
http://spinoff.nasa.gov/Spinoff2012/ee_6.html