“Our way was the easiest to get to the goal of making a switchable energy-generating window,” said Lance Wheeler, a research scientist at the US Department of Energy’s (DOE’s) National Renewable Energy Laboratory (NREL). “Now, we’re stepping back to determine the best way to do this – instead of the easiest or most convenient way.”
The DOE's Building Technologies Office is providing three years of funding for Wheeler and his newly constituted team to perfect the technology behind the window. The heart of the technology is a heat-triggered perovskite material that can be cheaper to use in window applications. "I was working on making a different material that was inspired by the material we're working on now," he said. "I found that if you took it off of the hot plate it would turn clear."
The initial version also used single-walled carbon nanotubes to capture the light, along with layers of titanium dioxide and tin oxide. When light hits this transparent glass, it prompts the release of molecules of methylamine. In turn, the glass darkens and as that happens, electricity is generated. When the sun isn't shining, the molecules are reabsorbed, and the glass becomes clear again. Part of the continuing research will center on better ways to make the switch.
The Building Technologies Office provided funding for Wheeler and Rob Tenent to participate in a two-month "entrepreneurial boot camp," working with industry mentors to develop viable ways to bring their SwitchGlaze technology to market. "It rolls off the tongue better than switchable photovoltaic window," said Wheeler.
From Wheeler's initial discovery to integrating it into a photovoltaic (PV) device took about 18 months. Now, with three years of funding, the focus is on making sure that the device is the best it can be. And while the typical path from the laboratory involves taking a small sample and seeing if it works on a