Transparent solar panels are beginning to appear at test sites around the world. Instead of only placing solar panels on rooftops, researchers say that windows could generate clean electricity soon. Transparent solar panels, also called solar windows, look like regular glass. They allow people to see through them while at the same time producing electricity.
Normal solar panels are designed for rooftops or open fields. Transparent solar windows introduce a new concept, turning something we already use every day into a hidden source of power. “Think of your windows not just as glass, but as energy generators,” said Hunter McDaniel, CEO of UbiQD. “They look like regular windows, but they are quietly working in the background to collect sunlight and make electricity.”
Another company, Ubiquitous Energy, based in California, calls its transparent technology UE Power. Veeral Hardev, VP of Strategy at the company, explained, “Our coating allows visible light to pass through, so the view from the window remains clear. But at the same time, the glass is capturing invisible parts of sunlight, ultraviolet and infrared light, and turning them into electricity.”
The technology inside these windows is different from rooftop panels. UbiQD uses something called quantum dots, tiny materials that absorb sunlight and guide the energy to the edges of the glass, where it is turned into power. Ubiquitous Energy applies a thin transparent coating made from safe, non-toxic dyes that absorb invisible light.
McDaniel described it simply “It’s like your window has an invisible filter. It lets you see the world outside, but it doesn’t let sunlight go to waste.”
Regular rooftop panels can reach around 22 percent efficiency, meaning they convert a large portion of sunlight into electricity. Transparent solar panels, however, are less efficient. UbiQD says its technology reaches about 5 percent efficiency, while UE’s windows can produce around 200 watt-hours per day from a standard 3-by-5-foot pane.
Hardev admitted that they are not competing directly with rooftop panels. “It’s not about beating traditional panels on efficiency,” he said. “It’s about unlocking new surfaces that were never used for energy before. Every window can become a clean power source.”
Annika Döring, a spokesperson for Avancis, a German solar facade company, explained in an interview with Interesting Engineering that efficiency depends on design choices. “The lighter the glass, the less energy it produces. But for many buildings, the balance between design and power is what matters most,” she said.
New technology often comes with a higher price tag, but transparent solar windows may not be much more expensive than ordinary glass. McDaniel from UbiQD believes the premium will be around 20 to 30 percent higher than traditional windows. “When you calculate the payback, it is similar to rooftop solar before incentives. People are paying for glass anyway—so why not let the glass also produce power?” he said.
Ubiquitous Energy has partnered with Anderson Corporation, a major U.S. window manufacturer, to help bring costs down further. Their goal is to make solar windows competitive with regular windows so that they can be adopted on a large scale.
“People often ask, when will this be available for everyone?” Hardev said. “The truth is, we’re already moving from pilot projects to larger installations. It won’t be long before you can order solar windows for your home or office.”
McDaniel added, “Our vision is simple, every window should do more than just let in light. It should help power the world.”
