Dimmable Windows that Generate Electricity?

“The future’s so bright, I gotta wear shades.” – Timbuk 3

Dynamic window technology may soon have buildings singing a new tune – one that’s dramatically more energy-efficient. While it seems almost sci-fi, it makes perfect sense: eliminate unwanted solar gain and heat loss with a dimmable window that changes color to match light conditions.

It’s like automatically adjusting sunglasses for your home – or skyscraper. And it puts a whole new spin on sunglasses being, well, cool.

Dynamic – or electrochromic – windows have the potential to significantly reduce energy consumption in buildings, which accounts for more than 40% of the energy used in the United States, according to the Department of Energy (DOE). Windows are a well-known energy suck, letting in too much heat in the summer, and spilling it in the winter – they alone account for 4% of total energy use in the U.S. But with the right technology, researchers claim, windows can be “net energy gainers” or “zero-energy” products.

While color-changing windows are not new (they’ve been around in various forms for over 20 years), they’ve never been commercially successful, both due to poor long-term performance and high price. But researchers and entrepreneurs are working quickly to deliver higher quality, more affordable dynamic windows to the market.

In March, the DOE awarded Sage Electrochromics a $72 million conditional loan guarantee to build a facility in Minnesota for manufacturing SageGlass, . The company has a cooperative research agreement with the National Renewable Energy Laboratory (NREL), and they’ve been working to lower the manufacturing costs. Sage is predicting a 70% drop in price over the next five years.

Windows That Generate Electricity?

Dutch company Peer+ has taken the concept a step further, making the windows not just save energy, but generate it. Just like solar PV panels, the windows convert the light into electricity, which is then used to manually control the tint of the window. Excess electricity can be pumped back into the building’s power system.

Another group working on dynamic window technology is the Lawrence Berkeley National Laboratory. They’ve just been awarded $15.9 million in stimulus money from the DOE to build and operate a National User Facility for Net-Zero Energy Buildings. The facility will be a test bed for new technologies aimed at achieving net-zero energy buildings that produce as much juice as they burn through both energy efficiency and on-site renewable energy efficiency.

The facility will be used by researchers from universities, private industry, and other government labs to undertake “an aggressive pursuit of DOE’s energy efficiency goals for widespread implementation of affordable net-zero energy buildings by 2030,” says Stephen Selkowitz, head of the Building Technologies Department of Berkeley Lab’s Environmental Energy Technologies Division.Images: sunglasses by Min Master on flickr.com; windows from peerplus.com

Hat tip to Simonn Jagers and Springwise.