Installing more solar panels is one way to put more of the sun’s energy on the grid. Another is to increase the amount of power each panel can generate.

The challenge for scientists is to develop solar cells that convert more of the sun’s rays to electricity, without making the technology too expensive.

“We need to take into account that when we want to improve the solar cell or increase the efficiency that the costs are not exploding,” says Eike Köhnen of the Hemholtz Center for Materials and Energy in Berlin.

Last year, Köhnen and other researchers developed a prototype that set a new efficiency record for its class.

It stacks two cells on top of each other. One is made from silicon, which is commonly used in solar cells and is good at capturing infrared light. The second is made of a low-cost material called perovskite, which captures visible light.

“And as these two parts can be converted more efficiently into electrical energy than by just one absorbing material, we can get higher efficiencies with these solar cells,” Köhnen says.

That means that they can generate more electricity from the same amount of sunshine – and help get more clean energy on the grid.

Reporting credit: Sarah Kennedy/ChavoBart Digital Media.