The U.S. company Solar Junction set the gold standard for solar cell efficiency last year at 43.5 percent, a worldwide mark that it has just shattered with a new solar cell efficiency record of 44 percent. This baby ain’t no hothouse flower, either. All the lab work is behind it and it’s ready for commercial production, which (by the way) will take place right here in the U.S. thanks to support from the Department of Energy.
We Built New Solar Cell Efficiency Record!
Solar Junction was spun out of Stanford University research in 2007 as a technology transfer, the same year that the SunShot Incubator program was established in the Department of Energy (yes, under the Bush Administration). The aim of the program was to support the development of promising new solar power technologies in the U.S.
In 2011, President Obama bundled DOE’s long-running solar programs into a powerful new SunShot Initiative, aimed at bringing solar power up to price parity with fossil fuels while creating new green jobs in the energy sector.
One component of SunShot is the SUNPATH initiative, a job-creating program that targets promising new alternative energy technologies for commercial production in the U.S. Solar Junction won a $5 million Department of Energy award through SUNPATH in 2011.
Added to a $15 million pile from the private sector, the award enabled Solar Junction to tweak its technology up to 44 percent while expanding production at its facility in California.
Production will also expand at a facility in Bethlehem, Pennsylvania owned by Solar Junction’s U.K. investment and manufacturing partner, IQE.
How Solar Junction Broke the Solar Cell Efficiency Record
We taxpayers also had a hand in certifying Solar Junction’s bragging rights to world’s greatest, since the efficiency record was confirmed by DOE’s National Renewable Energy Laboratory as well as Europe’s largest applied research organization, the Fraunhofer Institute.
Solar Junction’s technology is based on concentrating photovoltaics (CPV), which ramp up efficiency by using low-cost lenses, like magnifying glasses, to focus more solar energy onto a relatively small solar cell.
The company has squeezed more juice out of the system by pairing the lenses with a low-cost, high-efficiency multi-junction solar cell. Multi-junction refers to using different materials like layers in a sandwich to absorb the maximum amount of solar energy possible through a greater range of the light spectrum. The technology was initially developed to power satellites in space, but until recently it was too pricey to compete with fossil fuels on earth.
Solar Junction’s proprietary multi-junction solar cell is called A-SLAM™, which stands for Adjustable Spectrum Lattice Matched. The atomic structure of crystalline material used in the A-SLAM™ cell shares the basic characteristics of solar cell technology that has proven reliable for decades, while Solar Junction’s unique “ultra-concentration tunnel junctions” provide for optimal concentration.
Image (cropped): Courtesy of Solar Junction via prnewswire.
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Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.