Golden, Colorado [RenewableEnergyAccess.com] A solar cell produced by Boeing Spectrolab under a subcontract with the U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory is recognized as one of this year’s most significant innovations by Research & Development (R&D) Magazine.
The NREL/ Boeing Spectrolab R&D 100 Award for 2007 recognizes the High-Efficiency Metamorphic Multi-junction (HEMM) Concentrator Solar Cell, the first solar cell to break the 40 percent conversion efficiency barrier – the solar equivalent of breaking the four-minute mile.
“Once again, DOE’s labs are at the cutting edge of innovation with new technology developments to enhance America’s economic and national security,” U.S. Secretary of Energy Samuel Bodman said. “My heartiest congratulations to the DOE researchers and scientists that have won R&D Magazine’s prestigious awards this year.”
The Boeing Spectrolab HEMM approach represents a powerful new technology for designing super-efficient multi-junction solar cells. The HEMM solar cell is a triple-junction device – a solar cell with three layers – that uses “mismatched” materials. Typically in a triple-junction cell the atoms are evenly spaced, which generally results in superior electrical performance. But, with the HEMM approach, the atoms are unevenly spaced, giving designers more materials to choose from to create even higher-efficiency solar cells.
The HEMM solar cell has a conversion efficiency of 40.7 percent at 240 suns. This means that when sunlight concentrated up to 240 times the normal intensity of the sun is focused onto the cell, 40.7 percent of that solar energy is converted into electrical energy.
“This R&D 100 award is another important milestone in NREL’s 30-year history of developing clean energy technologies, many of which are now available to the consumers,” NREL Director Dan Arvizu said.