SourceJeffrey Grossman explains that fulvalene diruthenium shows the potential to replace ruthenium. Fulvalene diruthenium can absorb solar energy. After trapping solar energy it can achieve a higher-energy state where it can remain stable ad infinitum. If a stimulus can be given in the form of heat or a catalyst, it reverts to its unique shape, releasing heat in the process.
Professor Grossman states, "It takes many of the advantages of solar-thermal energy, but stores the heat in the form of a fuel. It's reversible, and it's stable over a long term. You can use it where you want, on demand. You could put the fuel in the sun, charge it up, then use the heat, and place the same fuel back in the sun to recharge."