Solar panels on roofs are commonplace, but can the sunlight that hits building facades be used to generate power? Researchers at the University of Kassel have developed a special solar concrete. It contains granite, so it's capable of conducting electricity.

Solar panels on roofs are commonplace, but can the sunlight that hits building facades be used to generate power? Researchers at the University of Kassel have developed a special solar concrete. It contains granite, so it's capable of conducting electricity. Once the concrete has hardened, scientists spray it with various layers of organic liquids. The result is a dye-sensitized solar cell that produces electricity through artificial photosynthesis.