http://www.quietsolarenergy.com/will-new-technolog
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Posted On: 12/13/2014 12:57:07 PM
http://www.quietsolarenergy.com/will-new-tech...olar-power
Quantum dots can potentially recover a third of light energy normally lost as heat.
“I’ve been telling people for some time, ‘If you’re doing research, it should be between 30 and 50 percent efficiency.’”
The material is expensive, however, and adding layers is complex and costly. Multi-junction cells are so pricey that for now, use is limited to specialized applications like satellites. But Yablonovitch is convinced that if production were scaled up, prices would fall. He’s seen it happen before. “When I started [with] solar 35 years ago… the prices of the panels were 100 times greater than they are today,” he said.
Another new design involves quantum dots — nanometer-sized crystals able to confine energized electrons and help them knock loose others. The process, called “multiple exciton generation,” can potentially recover a third of light energy normally lost as heat.
“That third of energy — that’s a huge chunk you’re throwing away,” said Matthew Beard, an NREL senior scientist collaborating on developing quantum dots at Los Alamos National Laboratory’s Center for Advanced Solar Photophysics. Quantum dots could boost efficiencies into the range of multi-junction cells for much lower cost, he said.
Assembling the dots into a cell, however, requires a “whole other level of chemistry,” and scientists are still working on how to do that. The current top efficiency is a fairly dismal 8.6 percent. “But the encouraging thing is that there is progress,” Beard said. “We started out at two or three percent in 2009, and now we’re at close to nine.” Theoretically, solar cells with a single quantum dot layer could convert up to 45 percent of the sun’s energy into electricity, he said.
Even silicon is reaching for a bigger piece of the sun. California-based rooftop panel manufacturer SunPower just announced it will begin mass-producing silicon cells with 25 percent efficiency — just a point below the element’s practical maximum — for the home solar market in 2017. The efficiency gains come via recipe changes that improve the material’s ability to carry charges. Design tweaks also allow more light into the front of the cell.
While the new panels will initially cost more than current models, the increased output will make electricity cheaper in the end, said SunPower
Quantum dots can potentially recover a third of light energy normally lost as heat.
“I’ve been telling people for some time, ‘If you’re doing research, it should be between 30 and 50 percent efficiency.’”
The material is expensive, however, and adding layers is complex and costly. Multi-junction cells are so pricey that for now, use is limited to specialized applications like satellites. But Yablonovitch is convinced that if production were scaled up, prices would fall. He’s seen it happen before. “When I started [with] solar 35 years ago… the prices of the panels were 100 times greater than they are today,” he said.
Another new design involves quantum dots — nanometer-sized crystals able to confine energized electrons and help them knock loose others. The process, called “multiple exciton generation,” can potentially recover a third of light energy normally lost as heat.
“That third of energy — that’s a huge chunk you’re throwing away,” said Matthew Beard, an NREL senior scientist collaborating on developing quantum dots at Los Alamos National Laboratory’s Center for Advanced Solar Photophysics. Quantum dots could boost efficiencies into the range of multi-junction cells for much lower cost, he said.
Assembling the dots into a cell, however, requires a “whole other level of chemistry,” and scientists are still working on how to do that. The current top efficiency is a fairly dismal 8.6 percent. “But the encouraging thing is that there is progress,” Beard said. “We started out at two or three percent in 2009, and now we’re at close to nine.” Theoretically, solar cells with a single quantum dot layer could convert up to 45 percent of the sun’s energy into electricity, he said.
Even silicon is reaching for a bigger piece of the sun. California-based rooftop panel manufacturer SunPower just announced it will begin mass-producing silicon cells with 25 percent efficiency — just a point below the element’s practical maximum — for the home solar market in 2017. The efficiency gains come via recipe changes that improve the material’s ability to carry charges. Design tweaks also allow more light into the front of the cell.
While the new panels will initially cost more than current models, the increased output will make electricity cheaper in the end, said SunPower
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