In effect, explained Grossman, this makes it possible to produce a “rechargeable heat battery” that can repeatedly store and release heat gathered from sunlight or other sources. In principle, Grossman said, a fuel made from fulvalene diruthenium, when its stored heat is released, “can get as hot as 200 degrees C, plenty hot enough to heat your home, or even to run an engine to produce electricity.”
Storing thermal energy in chemical form to make a rechargeable heat battery.