Rare metal could power rechargeable solar battery

Daily Mail : Researchers at MIT are investigating the possibility of using a rare metal, ruthenium, that can absorb sunlight, store the energy, and release it as pure heat to create a “rechargeable heat battery.” When molecules of fulvalene diruthenium absorb sunlight, they change shape into a long-lived semistable state. When the molecules interact with a catalyst, they snap back into their original form, releasing heat. Such a system could be far more effective than conventional solar-thermal ones, which require insulation and gradually lose heat. The drawback is the metal’s rarity—ruthenium comes from the same family as platinum.