Solar can be intrusive. Many of the current systems have bulky equipment that takes up a lot of space and that can be considered unattractive even to the point that some homeowner associations actually ban them.
But it isn’t just vanity driving that call, it’s also the use of space. In many cases there isn’t room to install solar panels because of the space needed by the hardware.
Panels also can be limited by the performance of the technology, meaning they have to be installed in a manner to receive direct sunlight, most often westward-facing to receive the strength of the afternoon sunlight.
This is where an innovative approach steps in.
“What would you do if you could embed solar technology in products that see the sun,” asked Susan Stone, the CEO at startup Ubiquitous Energy. “It leads to lots of application space. You can embed solar in a building material because it’s just a coating.”
Invisible Solar
The Ubiquitous Energy team demonstrates first large-area coating of transparent solar technology, … [+]
With that idea in mind, Ubiquitous Energy developed the only patented and transparent photovoltaic glass coating that harnesses solar power to generate electricity. The novelty is that windows with technology look and feel like traditional windows, plus they make electricity.
When flat glass is made, it typically receives a low-emissivity (low-E) coating, then the glass is fabricated into a double pane unit. In the case of Ubiquitous Energy’s technology, all of that happens in the same way, with the same equipment, vendors, and suppliers, but in addition to the low-E coating, there are a couple layers added that become the invisible “solar panel.”
To bring the technology to scale, the global window and door manufacturer Andersen signed an agreement with Ubiquitous Energy in 2022 to jointly develop a line of energy generating products.
Brandon Berg is the senior vice president of research, development and innovation at Andersen and led the initiative to partner with Ubiquitous.
“We are able to use the horsepower of Andersen, our capabilities and our supply chain, partners, and customer base to bring this product to market,” he said. “We made our first Andersen windows with their glass in November that are now installed on a house at the top of our R&D headquarters in Bayport, Minnesota. We are generating power with them, and not only does it work, it works great.”
To date, Andersen has manufactured about 20 windows with Ubiquitous glass on a standard production line. The research on these windows includes looking at the difference between windows that face all four cardinal directions along with gathering data on how the photovoltaic component is able to harvest the non-visible portions of sunlight in the ultraviolet and the infrared while letting the visible light pass through.
“Even windows facing north are converting into power,” Berg said. “It’s not as intense as other windows, but still generating. We are trying to get data that homeowners will believe. We put a small house on the roof of the building so that all of us can relate to it and it is generating power as advertised.”
The group also performed durability tests that typical windows run through, which is a huge part of the expertise that Andersen adds to the partnership.
“We expect them to last 25 years,” Berg said. “We have a lot of know how to produce products that exist in all those environmental conditions, something that Ubiquitous doesn’t have experience with.”
The Economics
Windows at Michigan State University feature the UE Power™ transparent solar technology. UE Power™ … [+]
It’s easy for homeowners to ignore the impact that windows and doors have on a home, focusing on only the beauty and benefits. But their impact on the overall design and performance of a home is not inconsequential. They take up a fair bit of real estate on the exterior of the home, plus Berg points out that during COVID, there was a continuous trend toward more glass in the home, which directly conflicts with the energy performance of a home.
“Windows are less energy efficient than insulated walls,” he said. “We started looking at more energy performance of the product and we want to see that, plus ways to generate power.”
The Ubiquitous Energy coated Andersen window when it goes to market will produce about 50 watts per meter squared of window area or be about 20% as efficient as an opaque panel installed on the roof.
Roof panels and windows both suffer from the consequences of outdoor weather conditions, which as mentioned is where Andersen can offer its long-standing legacy.
“For example, 10 years after you install our products, we expect the amount of air coming through the windows and how well they operate will be unmatched by anyone else in the industry,” Berg said. “If the coatings on the glass aren’t performing as well 10 years after being installed, that can be pretty significant to the world.”
The partners are analyzing the pricing models and anticipate that early pricing will land at about 30% more than a conventional glass unit.
“The important thing to remember is that the buying decision isn’t about windows versus roof top panels,” Stone said. “The decision is really between a conventional window or a power generating window.”
Challenges
While the technology offers a unique opportunity to deliver new features and benefits to a home, there are challenges. Starting with the question of how to store the energy once it is harvested so it can be used when it is most needed. Basically, the power has to be transferred from the glass to a storage mechanism for later use.
One way that would solve for that is to drive functionality at the window, such as using the power for local needs like a camera, light, power door lock, or enabling other products to be used with the windows because the power is there to use. The team has developed use cases for the power generated right at the window that would include batteries in the wall.
“Another trick is how to get the power out of the glass of a door that is moving,” Berg said referring to a sliding glass door. “We are working on how to embed the technology on something that can also move. So, we’re looking at other industries to learn, but it’s just an engineering challenge that we are comfortable we will be able to solve.”
Yet, another challenge is the disruption to the trades and the labor that is needed to install windows in an already very tight job market.
The Future
Ubiquitous Energy’s transparent solar coating is made from light-absorbing dyes, sourced from … [+]
Stone points out that the materials are Ubiquitous Energy’s proprietary special sauce, which is to say that the product doesn’t care if it’s on glass or on another material. She is super excited about the potential of moving to other surfaces and says the company is also working on a flexible substrate for roofs.
Also down the line, the team would like to see the power generated in the glass have a route leading back to the grid, which they consider to be a bit further away based on today’s technology.
Meanwhile, Berg continues to challenge the company on what can be done with the glass on the outside of a home in addition to letting light in. Andersen is investing in research and development on other ways to invest in windows, such as sound control, ways to help with WiFi signals, and cellular signals.
It will be exciting to see, or to not see, where this is headed.