Solar Windows Could Meet Nearly All of America's Electricity Demand
By Joe McCarthy
There's an estimated 5 to 7 billion square meters of glass surfaces in the U.S. For windows on homes, cars and buildings, these glass surfaces perform a few basic functions—letting light and fresh air in when open, and blocking bugs and keeping the cold out when closed.
Now they could all serve another, altogether revolutionary, purpose—generating electricity.
A new paper in the journal Nature Energy describes how transparent solar panels could be placed over all windows and transparent surfaces in the U.S. to generate energy and decrease reliance on fossil fuels.
If that happens, nearly all the electricity demands of the U.S. could be met in conjunction with rooftop solar panels, and as long as storage capabilities are improved.
"Highly transparent solar cells represent the wave of the future for new solar applications," said Richard Lunt, leader author of the report at Michigan State University, in a press release. "We analyzed their potential and show that by harvesting only invisible light, these devices can provide a similar electricity-generation potential as rooftop solar while providing additional functionality to enhance the efficiency of buildings, automobiles and mobile electronics."
Lunt's team at Michigan State University created a plastic technology called a transparent luminescent solar concentrator. You simply place the plastic over a glass surface—a house or car window or even a cellphone screen—and it begins to convert sunlight into electricity.
The plastic doesn't obscure visibility because it's harvesting invisible wavelengths from the sun. This energy is then passed onto strips of photovoltaic solar cells that exist on the outer edges of the sheet.
The technology is currently far less efficient than traditional solar panels—5 percent efficiency versus around 15 percent to 18 percent efficiency—and it isn't market-ready, but Lunt and his team believe the technology will become just as efficient and ubiquitous as normal panels in the years ahead.
After all, the technology is new and could follow the same rapid arc of efficiency improvement that traditional panels followed.
"Traditional solar applications have been actively researched for over five decades, yet we have only been working on these highly transparent solar cells for about five years," Lunt said in the press release. "Ultimately, this technology offers a promising route to inexpensive, widespread solar adoption on small and large surfaces that were previously inaccessible."
In the U.S., for instance, the price of solar has dropped by 60 percent in less than a decade and this decrease is expected to continue as China invests enormous amounts of money into research and development of solar technology.
Offshore wind power has recently become a viable investment, and has the potential to provide all of the world's energy needs, according to a recent study.
According to The Global Wind Energy Council, Denmark gets more than 40 percent of its energy from wind power, and China and the U.S. get around 4 percent to 5 percent, which is closer to the global average. Solar, meanwhile, generates around 1.3 percent of global electricity demands.
Fossil fuels still account for the vast majority of electricity generation—but with advances like transparent solar sheets, that could soon change.
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Reposted with permission from our media associate Global Citizen.