For years, scientists have been tinkering with transparent solar panels that can double as windows. We’ve alerted readers to pioneering efforts in “Goodbye, Rooftop Solar Panels” (22 Oct 2015) and “A Window That’s Also a Solar Panel” (1 Feb 2022).

Those versions converted ultraviolet and near-ultraviolet light from direct sunshine into electricity, with an efficiency of about 10 percent—creditable efforts, but disappointing in a world of solar panels averaging efficiency twice that high.

Now engineers at Switzerland’s EFPL technical university have found a way to boost the solar windows’ performance to 15 percent efficiency in direct sunlight and jumping to 30 percent in ambient, or less direct, light.

Their breakthrough: a new version of transparent photosensitized dyes that can capture light across the entire spectrum of visible light and convert it to power.

The see-through cells are flexible, not brittle like glass, and can be made in a range of hues.

The panels are already being used in greenhouses and skylights.

Now the Copenhagen International School has covered its exterior with 12,000 of the panels, which are generating about 300 megawatt-hours electricity annually, about half the school’s yearly electricity needs.

TRENDPOST: In 2017, Michigan State University researchers created a transparent solar collector that could be used as a window covering. If the collector became a standard part of glass windows, it could supply 40 percent of U.S. electricity demand, the scientists calculated.

Solar windows and solar panels together could approximately double that figure. With widespread use of storage batteries in addition, the need for a centralized electricity grid could virtually disappear.

Copenhagen International School’s electricity-generating windows.

Photo: Copenhagen International School
Skip to content