Renewable Energy: Tandem solar cells harvest more solar energy

Berlin “Silicon solar cells are now reaching their limits,” explains Jan-Philipp Becker from the Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW) in Stuttgart. The blue-black shimmering modules have enjoyed an unparalleled triumph: They probably make up more than 90 percent of all systems and have not only gotten better over the years, but also cheaper.

Solar cells are now considered the cheapest way to generate energy. Today, however, the laws of physics and technology are clearly slowing down this process and making improvements increasingly difficult.

With perovskite solar cells, however, a technology is now in the starting blocks that has a similar level of efficiency and is simpler and therefore probably cheaper to produce on a large scale.

The newcomer has a fundamental advantage: in solar cells, in simplified terms, sunlight gives off energy to electrons, which can then move freely and drive a refrigerator or an electric motor as electrical current before they flow back to the solar cell.