What Is Long-Duration Energy Storage?

Renewable energy sources like wind and solar get a lot of the press, but no matter what technologies you look at, storage is the real key. We take a short look at long-term energy storage and how it will change the world. In mid-October, California set out an ambitious goal to bring long-term, grid-scale energy storage into operation by 2026. Their criteria are big. The project must be capable of generating 50 mW or more, and maintain that level for at least eight hours. Essentially, they’re looking for the ability to power as many as 32,000 homes for a full eight hours. Eight hours makes sense. The ability to store power when alternative energy sources like solar and wind aren’t as productive means that both technologies are immediately more useful as long-term options for replacing fossil fuels. But getting to this level of energy storage may not be easy. While lithium-ion batteries have led the way in energy storage for a number of years, but they’re limited. Most lithium-ion batteries can operate at their max output for about four hours, and while there are batteries capable of hitting the eight-hour mark, most are not economically viable.  What many businesses, states, and countries are facing is essentially a chicken and the egg scenario. Until intermittent energy sources, like most renewables, are implemented, there’s no need to invest in energy storage. Conversely, until energy storage is cost-effective and capable of long-duration storage, it’s not worth investing in more renewable energy sources. That’s a key reason why California’s proposal is so important for developers. Building an energy storage system that can at least initially replace power “peakers” (often gas-powered energy plants designed to handle short-term changes in load) with stored power from sustainable sources is a start. States like New York have already begun shutting down outdated “peakers” with energy storage units, though they are well-short of being capable of replacing 100% of those facilities. The real key to bringing energy storage technology to grid-scale will be by implementing smaller-scale batteries through micro-grids at individual facilities or specific development regions. As investment and technologies improve, we’ll create more cost-effective batteries to pair with the other various forms of energy storage that, together, will change the way the world is powered. Long-duration energy storage is Want to learn more? Contact Keen today!