In a move to turn glass into an energy harvester, NEXT Energy Technologies has developed an organic thin film technology that allows daylight to pass through while converting solar energy to electricity.
That technology is now on display at Patagonia’s Ventura, Calif., headquarters. The outdoor clothing retailer allowed NEXT to install 22 solar windows on its south façade. The electricity generated powers charging stations so employees can charge phones and other devices. Glassfab Tempering Services provided the glass.
The project, which began on Dec. 13, 2022, is part of a NEXT product demonstration that aims to provide real-time information on the company’s solar windows.
The technology can potentially offset up to 40% of energy in a traditional commercial building, depending on where the building is, says Jeff Horowitz, NEXT’s director of business development and partnerships.
“What’s great about the technology is that we preserve the functionality and look of the window, which by the way, happens to produce up to 40% of the energy in your building,” he says. “… In some locations, like Tucson, Ariz., we can get up to 50%. It’s got a lot of potential.”
According to NEXT, its windows can lower a building’s solar heat gain coefficient, which means that buildings can save anywhere from 10% of median source energy to 50% in areas such as Texas, Arizona and New Mexico compared to traditional windows.
Horowitz says that while solar windows offer considerably more benefits than traditional windows, they still lag behind traditional solar panels’ ability to capture energy. Solar-panel windows can obtain about a quarter to a third of the energy that traditional panels do.
“There’s always going to be a tradeoff with transparency and solar production,” says Horowitz. “We’re letting a lot of the visible spectrum of light pass through to be transparent, so we’re not absorbing that and turning it into electricity.”
NEXT’s coating technology is based on the organic semiconductor invented by Alan Heeger, a physicist and academic at the University of California, Santa Barbara, and Nobel Prize laureate in chemistry. The coating absorbs unwanted spectrums of light, such as UV and infrared light, where most of the sun’s energy is.
NEXT can integrate its coating onto traditional commercial window and framing systems thanks to “organic semiconducting materials that are earth-abundant, low-cost and are coated as an ink in a high-speed and low-energy process.”
Horowitz says that while NEXT is primarily focused on producing a solar cell as efficiently as possible, it has evolved to meet the needs of the window industry.
“We talked to the window industry and started understanding their needs,” he says. “For them, aesthetics really drive the market. They’re really focused on color, low haze and transparency. So, we pivoted from focusing on non-transparent photovoltaics that are lightweight and flexible to focusing on a segment of the market that can really benefit from the transparency of our photovoltaic solutions.”
Before NEXT can leap into the market, it must first learn how effective its windows are outside the lab. More than a month into the test, Horowitz says Patagonia has been happy with the results.
“It’s a great learning tool,” he says. “The longer-term goal is to deploy the technology on all [Patagonia’s] properties.”
As for Patagonia, the company is no stranger to solar energy. Corley Kenna, Patagonia’s head of communications and public policy, says that the company first adopted solar power in 1996 at its Reno distribution center. Testing NEXT’s solar windows was a perfect opportunity to develop its sustainability ambitions further.
“We’ve been using solar power at our headquarters in Ventura since 2005 and at our Reno distribution center since 1996,” says Kenna. “We rely on 100% renewable electricity for our owned and operated facilities in the United States and 76% globally, achieved through on-site and off-site installations. We have funded more than 1,000 solar arrays on homes across the U.S. and have helped install more than 600 kilowatts of solar power globally to support agriculture. Finding better ways of doing business is something we always strive to do, and we’re pleased to partner with NEXT to help us be a more responsible company.”