This is an excerpt from EERE Network News, a weekly electronic newsletter.
Spectrolab Concentrating Solar Cell Sets Efficiency Record
Spectrolab, Inc. announced in late July its achievement of a record efficiency for a terrestrial solar cell. Using concentrated sunlight, Spectrolab's new cell converts 36.9 percent of the sun's energy into electricity. The achievement shows promise for one of DOE's goals for solar electric devices: to develop solar modules that convert more than 33 percent of the sun's energy into electricity. See the press release from The Boeing Company, Spectrolab's parent company.
Concentrating solar power systems use lenses and reflective surfaces to focus sunlight onto a relatively small solar cell. The design aims to produce a low-cost solar electric module by minimizing the amount of expensive semiconductor material used for the solar cells in each module. Spectrolab's new cell achieves high efficiency by effectively stacking up three solar cells—each tuned to capture different frequencies of light—and combining them into one device, called a multijunction cell (in this case, a triple-junction cell). For more information, see the "Concentrator Systems" and "Multijunction Cells" pages on the DOE Photovoltaics Program Web site.