Clear Winner: Transparent, Solar Power-Generating Windows a Reality

No, it’s not April Fools’ Day, it’s the future.

When you look at the types of renewable power available – hydro, geothermic, wind, etc. – only one has the potential to completely supply the world’s energy needs — solar power. Did you know that harnessing just 0.02 percent of the solar energy that reaches the Earth would power the world? The map above shows how much surface area is required to power the entire U.S. using solar power.

Like a bad boyfriend, we’ve heard solar’s unmet promises for decades. But unlike that boyfriend, solar has worked to meet those promises. It’s cheaper, thinner, less obtrusive and now, transparent.

As you can imagine, one of the impediments of traditional solar is the space it requires coupled with its typical unattractive industrial appearance. Tesla has created slim-profile solar panels and most recently solar shingles that blend into residential rooftops. These types of rooftop solar collectors have the ability to fulfill a home’s electrical needs.  But what about multi-story residential or commercial?

Multi-story buildings simply don’t have enough roof area relative to the space beneath them for energy self-reliance. The taller the building, the smaller the ratio of roof to square footage. But what taller buildings do have is a lot of surface area. Sure, you could tack solar panels onto the exterior, but that would be like covering them in large black refrigerator magnets. Hardly the enticing architecture I’d want to look at.

Two companies are looking to change that by producing products that transform garden-variety glass into energy-producing power plants.

PHYSEE

PHYSEE is a company spun off in 2014 from the research labs of the Delft University of Technology in the Netherlands. Their concept, called PowerWindow, is to line the exterior frame of double-pane windows with thin strips of solar panel material. The technology currently generates about 8-10 watts per square meter of glass. That’s enough to keep mobile devices charged or power a 60w incandescent-equivalent LED lightbulb.

The company admits this isn’t enough power to make a building energy self-sufficient on its own. But for example, the windows in my bedroom and bathroom would easily power that room’s needs (which I grant you aren’t much).

The company trialed their technology on a newly constructed bank building in the Netherlands and most recently a high-rise apartment building. Being essentially a start-up, they are working on ramping up their manufacturing processes that will enable them to expand their operations.

One of their job openings is for a marketing manager, which explains why I received no response to questions about distribution, pricing relative to normal windows, retrofitting existing structures, and whether wider solar strips are optional to generate more power.

An option for a PowerWindow is called SmartWindow, whereby sensors are placed around the window that measure environmental factors like brightness and temperature. The data is used by their application to automatically change air handling and shade position to reduce power consumption.

Ubiquitous Energy

Another university-born company is called Ubiquitous Energy, founded in 2011 and now located in Silicon Valley. While PHYSEE taps the unused frame of the window, Ubiquitous Energy, and their ClearView Power offer, utilizes the surface of the glass itself to generate power.

Researchers hit on the idea that since the majority of sunlight is invisible to humans, why not try to harness that to generate power? Stealing the visible spectrum is partly why traditional solar panels aren’t also transparent. They identified chemicals that would react with invisible ultraviolet and infrared wavelengths to create electricity. Placing those chemicals in solution they were able to create an applied coating that would be affixed to glass as it was being manufactured. Placing the coating between double-pane glass protects it from the elements without impacting installation. Invisible, laser cut channels are cut into the film to channel the power to the window frame where it meshes with the building’s power grid.

The resulting glass could be anything up to 90 percent transparent (pretty unnoticeable) Note: It’s the rare high-rise that uses completely transparent glass (you’d be wearing sunglasses indoors). So as long as commercial-grade windows are being tinted in the factory, why not tint them with an electricity-producing tint?

Things just got interesting for Ubiquitous Energy. On June 28, AGC, the world’s largest producer of flat glass announced a collaborative development agreement to bring ClearView Power coating to mass-market applications. With revenues of $13.5 billion, Tokyo-based AGC has the global development and distribution to be a game-changer for this technology. If any of you own a new Lexus LS500 and ordered the Kiriko cut glass interior option, AGC creates it. If you’re a mid- or high-rise architect or developer, click here and book a ticket to AGC’s Georgia HQ. I suspect ClearView Power is about to get very popular.

But you know what? Being a coating, glass isn’t this pony’s only trick. Any flat surface is game. Billboards with a battery pack to generate their own night lighting. Automobile glass, while not currently capable of completely powering a car, will see electric car owners parking in the sun for a few extra miles of juice. And of course a myriad of phone and tablet screens coated to charge their batteries (although leaving them in the sun may present heat problems for the electronics). While Ubiquitous Energy admits power-generating roads could potentially use a similar coating-like technology, they believe that to be the bailiwick of another business.

In addition to rooftop solar panels, I see a “best of both worlds” here. By combining Ubiquitous Energy’s coating with PHYSEE’s edge cell installation, large buildings could harness the most electricity available today from their windows. I say “available today” because solar isn’t your bad boyfriend. It keeps getting better. Newer, more efficient iterations will come as the technology matures.

Vince Hunter, Principal with Dallas’ WDG Architecture added that, “when fully developed, this technology could impact the actual form of architecture. Imagine designing structures where the power generated by it’s windows drives overall building shape. What will future skylines make of that!”

And at some point the coating applicators will get portable enough to “paint” the exterior of existing buildings to light them up with solar power. Retrofitting will be a huge market.

Either way, developers better get cracking to keep current with new innovations. Energy-efficient buildings command higher prices from both businesses and homeowners. Even apartment tenants would pay more for no electricity bill. Would landlords rather the money goes into Oncor’s pockets or theirs?

Be left behind to your peril.

 

Remember:  High-rises, HOAs and renovation are my beat. But I also appreciate modern and historical architecture balanced against the YIMBY movement. In 2016, 2017 and 2018, the National Association of Real Estate Editors recognized my writing with three Bronze (2016, 2017, 2018) and two Silver (2016, 2017) awards.  Have a story to tell or a marriage proposal to make?  Shoot me an email [email protected]. Be sure to look for me on Facebook and Twitter. You won’t find me, but you’re welcome to look.