When generating power from renewable energy sources with variable outputs, such as the difference between a strong wind and a calm day at a wind farm or between night and day at a PV plant, having an energy storage solution is a big plus. But utility-scale battery storage is not cheap, and battery life is limited, so the bulk of the grid's energy storage is pumped-storage hydroelectricity.
However, a new version of the iron-air battery has been developed by researchers at USC, which could be the battery solution to help balance the loads on grids fed from renewable energy sources such as wind and solar. The researchers are calling the air-breathing battery "eco-friendly", and claim that it can be produced at 10% of the cost of modern lithium-ion batteries.
"Iron is cheap and air is free. It's the future." - Sri Narayan, professor of chemistry at USC
According to the researchers, the new batteries solve a problem which plagued earlier versions of the iron-air battery: loss of up to 50% of the battery's energy due to a competing reaction within them from hydrogen generation. The new battery was built with a small amount of bismuth sulfide added, which stops the hydrogen reaction and lowers the energy loss from the battery to just 4%
The team is continuing to develop the technology, and are now working to make the new iron-air battery capable of storing even more energy using less materials. The study, which was funded by the Advanced Research Projects Agency for Energy (ARPA-E), can be found here: A High-Performance Rechargeable Iron Electrode for Large-Scale Battery-Based Energy Storage