A move to renewable energy requires a way to store generated heat. A German startup, Kraftblock, is working on a super-hot box that can store waste heat up to 1300°C (2372°F). The box can then be transferred from an industrial site to a different location to be used for heating a local apartment or office building.
Kraftblock is currently experimenting to find the optimum material for storing higher-temperatures. Currently, a patented nanotechnology granule containing steel slag is being utilized.