As concerns about global warming and unsustainable electricity usage continue to grow, researchers from Lawrence Berkeley National Laboratory say they have produced a window coating that can separate heat from light and may promote significant reductions in a building’s energy usage.
In 2011, the researchers published a study demonstrating that such a technology was possible, and they are now looking to commercialize it. In March 2012, Delia Milliron, a staff scientist at Berkeley Lab whose lab oversaw the research, along with Guillermo Garcia, a former UC Berkeley graduate student who worked on the project as part of his doctorate, helped found Heliotrope Technologies. The company is moving to bring this technology to the marketplace. Garcia said the company hopes to achieve this in three to five years.
The researchers published an article about these “smart windows” Aug. 15 in Nature, and they say that once applied, this coating will allow windows to perform in three modes, depending on weather and sunlight conditions. In its “cool” mode, a window allows light, but not heat, to enter. While in its “dark” mode, it blocks both light and heat. The window can also exist in a “bright mode,” letting in both light and heat.
While windows that can transition from transparent to opaque already exist, this new coating is unique in that it allows a user to control both visible light and near-infrared light, which produces heat. A window with this coating can thus selectively accept one but not necessarily the other.
“What makes this a promising business is the fact that its a lot cheaper than other companies,” Garcia said. “When it comes to this smart window, we’re creating the second generation.”
Garcia completed his doctorate in 2012 and is now Heliotrope’s chief technology officer.
The company has already garnered significant interest and has raised approximately $2 million from investors in addition to grants from the federal government, Garcia said.
In 2010, the team at Berkeley Lab received $3 million from the Department of Energy to support development of a coating that could be sprayed on windows to allow them to adjust to weather conditions. The department’s Better Buildings Initiative, which funds projects such as this one, aims to promote development of energy-saving technologies. Indeed, while Garcia could not say exactly how much energy was saved, he said that “the preliminary data has showed it is beneficial.”
Anna Llordes, a co-author on the paper and a project scientist at the Molecular Foundry, said she was pleasantly surprised by the attention the technology has received.
“People are excited because in one single piece of work, you can find science, material processing, fundamentals of electronic materials and an application to the real market,” she said. “When you work in a lab, you never know what’s going to be interesting.”