Solar panel use is growing exponentially, driven in part by the advent of several companies that install panels in private residences and businesses. We are putting solar panels on our cottage in Maine and hope to generate all of our electricity from them.
The typical solar panel on the market today converts only about a quarter of the Sun’s energy to electricity. While the cost of solar modules has dropped by a factor of 3 during the past 5 years, it’s still expensive to power an average sized house. Even with tax breaks, it is easy to spend $25,000 on panels.
Enter John Rogers of the University of Illinois, who recently reported that he has designed stacks of solar panels with much higher efficiency. Each layer in the stack is designed to capture a certain portion of the Sun’s spectrum, while passing the rest to layers below. A stack of 4 of Roger’s solar panels converts 42.5% of the Sunlight energy to electricity. These panels are currently being manufactured by Semprius, a North Carolina company with Siemens as an underwriting investor.
A solar house needs either batteries to store the electricity for evening use, or a connection to the grid, which can act as a battery—buying electricity during the day and returning it at night. These both add to the cost of a solar system, but the ongoing improvements in efficiency and decline in the cost of the panels themselves bode well for more widespread adoption of solar power across the U.S.
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Web Links
Stacking the deck, The Economist, February 22, 2104, p. 69
Photo, taken April 2, 2011, courtesy of Tim Fuller via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.