"It's a whole new way of thinking about solar energy," says startup CEO about using transparent solar cells on buildings and electronics.
|Scooped by Duane Tilden|
With the help of organic chemistry, transparent solar pioneers have set out to tackle one of solar energy's greatest frustrations. Although the sun has by far the largest potential of any energy resource available to civilization, our ability to harness that power is limited. Photovoltaic panels mounted on rooftops are at best 20 percent efficient at turning sunlight to electricity.
Research has boosted solar panel efficiency over time. But some scientists argue that to truly take advantage of the sun's power, we also need to expand the amount of real estate that can be outfitted with solar, by making cells that are nearly or entirely see-through.
"It's a whole new way of thinking about solar energy, because now you have a lot of potential surface area," says Miles Barr, chief executive and co-founder of Silicon Valley startup Ubiquitous Energy, a company spun off by researchers at Massachusetts Institute of Technology and Michigan State University. "You can let your imagination run wild. We see this eventually going virtually everywhere."
Invisible Spectrum Power
Transparent solar is based on a fact about light that is taught in elementary school: The sun transmits energy in the form of invisible ultraviolet and infrared light, as well as visible light. A solar cell that is engineered only to capture light from the invisible ends of the spectrum will allow all other light to pass through; in other words, it will appear transparent.
Organic chemistry is the secret to creating such material. Using just the simple building blocks of carbon, hydrogen, oxygen, and a few other elements found in all life on Earth, scientists since at least the early 1990s have been working on designing arrays of molecules that are able to transport electrons—in other words, to transmit electric current. [...]
Harvesting only the sun's invisible rays, however, means sacrificing efficiency. That's why Kopidakis says his team mainly focuses on creating opaque organic solar cells that also capture visible light, though they have worked on transparent solar with a small private company in Maryland called Solar Window Technologies that hopes to market the idea for buildings.
Ubiquitous Energy's team believes it has hit on an optimal formulation that builds on U.S. government-supported research published by the MIT scientists in 2011.
"There is generally a direct tradeoff between transparency and efficiency levels," says Barr. "With the approach we're taking, you can still get a significant amount of energy at high transparency levels."
Barr says that Ubiquitous is on track to achieve efficiency of more than 10 percent—less than silicon, but able to be installed more widely. "There are millions and millions of square meters of glass surfaces around us," says Barr. [...]"<