Making Renewable Power More Viable For The Grid. “Air-breathing” battery can store electricity for months, for about a fifth the cost of current technologies. Wind and solar power are increasingly popular sources for renewable energy. But intermittency issues keep them from connecting widely to the U.S. grid: They require energy-storage systems that, at the cheapest, run about $100 per kilowatt hour and function only in certain locations. Now MIT researchers have developed an “air-breathing” battery that could store electricity for very long duration for about one-fifth the cost of current technologies, with minimal location restraints and zero emissions. The battery could be used to make sporadic renewable power a more reliable source of electricity for the grid.