Why is it so hard to commercialize flow batteries?

July 17, 2019 | Case Study

Flow batteries have been in development since the 1970s, but despite being designed for stationary storage, they have failed to exceed even 3% of that market. Instead, Li-ion dominates the stationary storage landscape, accounting for 84% of total deployments since 2011. Many startups have entered the flow battery space, commercializing a variety of chemistries and system configurations, but nearly all have gone out of business: Imergy Power Systems, EnerVault, and ViZn Energy together raised more than $100 million only to go bankrupt after about eight years of operation. As of 2019, only one flow battery developer – Sumitomo Electric Industries – has installed more than 40 MWh of projects, thanks largely to a single 60 MWh installation in Japan. With annual energy storage deployments exceeding 1 GW since 2016, why are flow batteries so difficult to commercialize?