The development of grid storage solutions is critical if the power grid is to switch to entirely renewable energy sources.
The problem is that renewable energy is largely weather-dependent, so we need backup power sources to take up the slack when demand outstrips the supply of renewable energy. This often means that conventional fossil fuel power plants stay in operation and continue putting carbon dioxide into the atmosphere.
Large-scale grid storage batteries are probably the best solution, but they are typically expensive and don’t scale very well.
One promising grid storage solution is redox flow battery technology, which uses two tanks of liquids functioning as anode and cathode. Pumps circulate the liquids to a reaction chamber where they are kept separate by a membrane that allows ions to pass back and forth while cycling the battery. It’s easily scalable, but very expensive to install and maintain.
Stanford University and the Department of Energy have developed a flow battery that could prove to be an even better grid storage solution. The new lithium-polysulfide flow battery only uses an anode liquid with one pump and no membrane. The liquid passes by a lithium cathode to transfer ions during battery cycling.
With half the parts, less expensive anode liquid, and no expensive membrane to maintain, the new battery can be scaled even easier than traditional redox flow batteries.