Researchers Design Window Solar Panels That Let Light Through

Researchers Design Colorful Windows That Effectively Harvest Ambient Light

The Copenhagen International School building in Denmark, features 12,000 blue-hued but transparent solar panels with DSC technology. (Photo: ALEXANDER2323/Depositphotos)

Solar energy is the future. In an ideal world, solar panels line rooftops, and the Sun's energy is stored in advanced replenishing batteries. But what about all that sunlight that comes streaming in through our windows? Modern technology can harvest that too. Grätzel cells, or dye-sensitized solar cells (DSCs), are a modern wonder. Looking like stained glass, these colorful windows harvest ambient light. This technology has taken a recent leap forward, as announced in Nature, to capture the entire visible light spectrum.

Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have set about improving DSC technology. Standard DSC panels feature a photosensitized dye on a semiconductor. A chemical reaction transforms the visible light hitting the panel into energy that can be stored in a battery. DSC technology previously worked with direct sunlight only, but the Swiss researchers were able to create thin film solar panels with transparent photosensitizers. These are molecules that are activated by light and that capture light from the entire visible light spectrum.

“Our findings pave the way for facile access to high-performance DSCs and offer promising prospects for applications as power supply and battery replacement for low-power electronic devices that use ambient light as their energy source,” the authors of the study wrote. In the future, these new DSCs may adorn windows of skyscrapers or even homes as an affordable and versatile solar solution. The SwissTech Convention Center has already had DSC windows since 2012, while the Copenhagen International School in Denmark hosts a whopping 12,000 blue-tinted transparent solar panels. These panels provide half the energy the school needs.

Improving the technology further like the recent discoveries of the researchers will allow further expansion of the technology. Their new molecular design allows 30 percent of ambient solar energy to be harvested. A standard modern solar panel averages 20 percent. The more efficient, the better a solution DSCs will be for a climate-friendly future.