MIT Technology Review October 10, 2019
To be as cheap, reliable, and flexible as natural gas, such a battery system would have to cost less than $10 per kilowatt-hour. Today’s best grid batteries, large lithium-ion systems, cost hundreds of dollars per kilowatt-hour (precise estimates vary). A US based company is working to hit that target by what seems to be using a sulfur-based solution as the anolyte. Sulfur is extremely cheap and can store a lot of energy. They are exploring the possibility of bidirectional power plants. Long duration storage is another approach taken by some companies. Thermal methods are inherently inefficient, since it’s hard to prevent the heat or cold from leaking away. Producing or burning most liquid fuels creates the very climate emissions we’re looking to avoid. Under its “DAYS” program, ARPA-E has invested more than $30 million in 12 startups or research groups trying to crack the problem of grid storage. So, if someone can make them cheap and long-lasting as well, they could plug into any grid. That would enable wind and solar to provide far more of our electricity and, in turn, for clean electricity to meet much more of our total energy needs. But those remain very big ifs…read more.
Telsa’s grid battery plant in Kauaʻi, Hawaii. Credit: TESLA