Lithium-ion batteries power computers, cell phones, and increasingly, automobiles. They started out being rather expensive but have become dramatically cheaper over the last decade, with prices dropping about 90%. Batteries are needed to store clean power from wind and solar generation and lithium-ion batteries are increasingly being used for that purpose as well.
Utility-scale energy storage requires substantial battery installations and battery cost is still very much an inhibiting factor in the widespread adoption of the technology. Lithium-ion battery costs continue to drop but because they require expensive materials like lithium and cobalt, there are limits to how low their prices are likely to get.
As a result, researchers have continued to seek ways to produce batteries made out of cheaper materials. Among the more promising technologies are flow batteries, which are rechargeable batteries in which electrolyte flows through electrochemical cells from tanks.
Flow batteries are much larger than lithium-ion batteries and include physical pumps to move electrolytes. They typically are sold inside shipping containers. Clearly, such batteries are not suitable for use in vehicles, much less in consumer electronics. Nevertheless, they represent a practical option for grid storage.
A company called ESS has developed an iron flow battery suitable for utility energy storage. Clean energy firm CSB Energy plans to install iron flow batteries at several solar projects across the U.S. that will store enough energy to provide power 50,000 homes for a day. According to ESS, the iron-based batteries should sell for about half the price of lithium-ion batteries by 2025 and be able to store energy for longer periods.
Photo, posted March 21, 2021, courtesy of Nenad Stojkovic via Flickr.