Most Americans' ideal home would glisten with floor-to-ceiling windows that let in natural sunlight.
However, typical windows cause homes to heat up in the summertime. The same windows also let cold air seep through in the wintertime. The leaking of air costs money, wastes energy, and isn't environmentally friendly.
Ubiquitous Energy, a California-based company, understands the homeowner's desire to have a home filled with windows, and they want to help on a national scale. Enter the solar, transparent window.
The inception of ubiquitous energy
The idea for Ubiquitous Energy spawned on MIT's campus when co-founder Mile Barr was pursuing his Ph.D. Barr and two MIT professors, Vladimir Bulović and Richard Lunt, were discussing how to make solar cheaper and more lightweight.
They dug into the physics and came across the idea if they could manipulate the light spectrum and what type of light the solar devices absorb.
"Solar devices absorb light energy from the sun; ideally, it captures the most sun possible and converts as much as possible," Hardev explained.
"The idea and concept and thinking of something transparent, if you can actually do this, apply to all types of different surfaces, where people typically didn't think about applying solar because it didn't look good. So then windows, or even things like cars, greenhouses, windows in cars, there are an endless number of applications."
Ubiquitous Energy was officially found in 2011 and won the MIT Clean Energy Prize Renewables Category.
How do solar windows work?
The current Ubiquitous Energy product is a 14 inch by 20-inch window. In the window industry, this is a significant threshold to be considered certified. This window size measures small for a typical commercial building window. But as Ubiquitous Energy's small team grows, so will the windows and the overall production.
"The bulk of energy potential is in infrared. If the solar panel didn't absorb visible light, what we see as color, then you could make a transparent device, but still, make power. Not as much as silicon (what rooftop arrays use), so it's a trade-off, but if you can do it, the idea is you can put it anywhere."
There's still a lot to figure out how a solar window will power a home or commercial building. Currently, Ubiquitous Energy's solar window has wires running through the framing and then locally powers an outlet.
Ideally, in new construction, the windows would power into the central electrical system of a home.Many new homes are being built as "smart" homes, which better equip the house to use features such as a solar window.
But for older construction, it can be more challenging to supply more than just local power near the window. The wire may only be able to run locally, or it could run-up to the roof. If a net meter approach is needed or a conduit is still being worked out.
"Most homes don't have an energy power management system, but commercial buildings do, so we can reroute or direct power to your liking or optimize to best efficiency to where it needs to be used," Hardev said.
The current test case
The lights are always on inside the conference room at Ubiquitous Energy's Redwood City headquarters. Despite this being against city code to conserve power, Ubiquitous has rigged the system because their solar glass windows are generating so much more power than the team uses in the conference room.
The conference room is the first test case for the company's pioneer product. The 100 square feet of solar windows in the meeting room locally power the LED lights and then charge a battery nearby with the excess power. The team worked with a window framing company to drill holes in the frame to run the wires through. Those wires then run through the bottom of the frame and into a battery.
Initially, when people weren't inside the conference room, the lights would automatically shut off after a certain amount of time when the censored sensed people were gone. Since the windows were producing excess power in sunny California, the team decided to rig the room to see what it would take to drain the battery.
The next phase of the company's pilot program involved two commercial buildings that were scheduled to be installed this year, however with COVID-19 shutting down most manufacturing in California and the Ubiquitous Energy team working from home; the pilot is currently delayed. Hardev said the team imagines these installations to be a couple of hundred square feet worth of windows. For context, globally, all glass and windows facilities produce around 9 billion square meters of glass a year, according to Hardev.
What will it cost?
In the solar world, everything comes down to price per KWH, but Ubiquitous Energy considers itself as operating in the window industry.
Using data from the National Renewable Energy Lab, Hardev believes in comparison to commercial solar, which is typically around $1.80 kWh, Ubiquitous Energy's analysis has them in the $1.50 kWh range.
"We like to think more of the way windows are priced," Hardev said.
To start, Ubiquitous Energy's solution would cost, all-in, between 10 and 30 percent more than a new window with a similar feature set, but did not have a power feature, but was energy efficient. While the windows would cost more upfront, the idea is customers would have a return on investment over time, as the windows start to produce their own power, reducing electricity, heating, and cooling costs for the customer.
The challenges of solar windows
For years rooftop solar companies have been faced with limitations on which homes they can install based on the type of roof, tree coverage, and the direction the roof was facing. If there wasn't enough sun, the system often didn't make sense to install because of a high cost, paired with low energy production.
Solar windows will have similar obstacles of needing to face a specific direction and needing a certain threshold of sun exposure to produce enough energy to power the home.
Most rooftop solar array installers have consultations with homeowners to explain how much energy their specific array could produce and what it would cost. Hardev said the company imagines a similar consultation setup for the window units.
However, because the windows absorb the heat from any sun exposure, Hardev says windows make sense to install regardless.
"The way we think about our tech from a window standpoint is it's purely energy efficient," Hardev explained. "Our windows' coating absorbs infrared light and deep infrared. A lot of what typically passes through a window is solar heat. Our coating is not allowing, or blocking, that heat from coming into the home. So just by itself, if we didn't connect the window to electricity, it would serve as a premium window to not let heat radiate inwards. It's an added benefit, even in locations where not that much sun, but aesthetically it helps and will help homeowners save money on heat and air conditioning costs."
Where will you be able to buy solar windows?
In the coming years, don't expect Ubiquitous Energy to become a household name. That doesn't mean the company won't be successful. Ubiquitous understands that scaling to the point of becoming a national window supplier isn't a unique skill their small team has to offer. They're mostly tech and solar people that understand the nuance behind crafting the solar glass.
Customers will be able to walk into a home improvement store and see the product as a premium offering from pre-existing window companies. These companies will be verified sellers or installers of Ubiquitous' product.
Like most products, labor is a big part of the cost of solar windows. These types of partnerships will help reduce labor costs and improve the customer experience.
"As we start out, as with any new technology, it's higher-end in terms of cost. But we are confident that when we hit economies of scale, we can quickly bring those prices down. We want it to be something everyone can buy and get access too."
Ubiquitous Energy doesn't consider rooftop solar as its competition, and it doesn't want to replace large solar farms. The team wants to take on the average window.
"We think rooftop is great, it's the most effective," Hardev said. "But if you have windows, they should be solar windows."
For traditional rooftop arrays, one of the biggest challenges is the aesthetics. "People don't like it," Hardev commented.
"Our feeling is anything you can do that makes sense to make a building or home more energy-efficient and economical, the more, the better," Hardev said. "We are a piece of the puzzle working to help this energy crisis. I know it gets political, I don't want to go there, but we are a part of the solution with wind farms and rooftop solar. We can't do it all ourselves; we are not naive to think it's just us. But our tech provides a solution to more seamless integration into the building world." comment↓