Scientists at Michigan State University say they have developed a translucent solar cell which can capture energy from the invisible parts of the light spectrum, but still let in visible light.
In other words, it may soon be possible to generate solar electricity through your windows, instead of just the panels on the roof.
The transparent luminescent solar concentrator uses organic molecules created to absorb invisible wavelengths of light, such as ultraviolet and near infrared light. The material moves this invisible light to the edges of the panel, where strips of photovoltaic solar cells absorb and convert it to electricity.
"When you look at tall buildings, there is a tremendous amount of surface area. They can act as efficient collectors throughout the day," said Richard Lunt, an assistant professor of chemical engineering at Michigan State University who headed up the research. "In many buildings, we are already installing films to reject infrared light to reduce [heating and cooling] costs. We aim to do something similar while also generating power."
To commercialize his team's work, Lunt has co-founded a company called Ubiquitous Energy. He estimates we could see the first applications within five years.
Don’t get too excited just yet. The films currently converts only about 1 percent of incoming energy, compared to a typical rate of 20 percent for traditional solar panels. However, the films could be cost-effective if spread over large areas such as on the side of skyscrapers. There also are potential applications helping to power tablets and smartphones.
"Ultimately we want to make solar harvesting surfaces that you do not even know are there," Lunt said.
It’s been quite the year for solar innovations. In August, a pair of designers announced they had developed a portable outlet that absorbs solar energy and converts it to electricity for everyday use. The device can be attached to a window or wall that gets a lot of sunlight and, after eight hours of charging, holds up to 10 hours of electricity — which can then be used to charge your phone or any number of electricity-hungry gadgets.
Around the same time, Minnesota-based research group Skajaquoda announced it had developed a flexible solar panel that can wrap around any bag strap and charges its internal battery as you go about your day. The device, called Sun Strap, uses a 1.5W flexible solar panel and has a 5600 mAh built in battery that can charge any USB device such as a smartphone, tablet or camera. When fully charged, the device’s battery is capable of charging an iPhone 5 three and a half times.