Talk of spray-painting may conjure images of graffiti or street utility work, but scientists at the University of Sheffield in the United Kingdom recently revealed that the technique can be used to harness the sun’s power.

Many renewable-energy laboratories are developing paints and coatings that can convert solar rays into energy, but the Sheffield researchers are the first to develop a method to fabricate a perovskite-based solar coating using a spray-applied process. Perovskite is a mineral made of calcium titanium oxide and is widely distributed throughout the Americas, Europe, and Asia. Unlike the earlier organic semiconductor coatings, the perovskite version is more efficient and less carbon-intensive to produce.

"There is a lot of excitement around perovskite-based photovoltaics,” said Sheffield physics professor and the project's lead researcher, David Lidzey, in a press release. "Remarkably, this class of material offers the potential to combine the high performance of mature solar-cell technologies with the low embedded-energy costs of production of organic photovoltaics.”

A close-up of the spray head (left), and a diagram defining the spray pattern.
Alex Barrows and Jon Griffin A close-up of the spray head (left), and a diagram defining the spray pattern.

The perovskite-based cells can achieve a 19-percent efficiency rating compared to the pervasive silicon-based cells' 25-percent rating. However, the new spray-painted material requires much less energy to make than silicon, and the technology is developing quickly, with promising applications in a variety of solar technologies. "I believe that new, thin-film photovoltaic technologies are going to have an important role to play in driving the uptake of solar energy, and that perovskite-based cells are emerging as likely thin-film candidates,” Lidzey said.

The development suggests new opportunities to cover a variety of building materials with solar-harvesting coatings, although further research is needed to determine its durability and longevity. Perhaps a mobile version will one day be available, providing graffiti artists with the ability to paint and generate renewable power simultaneously.

Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.