Date: Feb 28, 2018
To compete with lithium-ion, flow battery costs need to come down; insurance could help bridge that gap.
Lithium-ion batteries rule the market for energy storage. Flow battery makers want a share of that market, but they have a tough time competing on costs.
Researchers working on new materials for flow batteries are trying to bring down those costs, but the innovation that could make the biggest difference could come from the financial sector, not a laboratory.
At GTM Media’s Energy Storage Summit in December, 500 senior level energy professionals were asked whether lithium-ion batteries would continue to dominate the market for energy storage. A quarter of the respondents said they would. That is not very surprising, but nearly half, 46%, said that flow batteries have the best chance of supplanting li-ion batteries.
Just out of reach?
Flow batteries are one of those technologies that seems to be perpetually just out of reach. According to GTM data, flow batteries have about a 5% share of the U.S. stationary storage market compared with lithium-ion’s 95% share. (Lead acid batteries have about a 0.5% share.)
“Flow battery manufacturers say they are already competitive; you can draw your own conclusions,” Daniel Finn-Foley, senior energy storage analyst at GTM Research, told Utility Dive.
After Tucson Electric Power signed a power purchase agreement with NextEra Energy for a solar-plus-storage system at less than $0.045/kWh last spring, ViZn Energy Systems said it would replicate the deal with its own technology at $0.04/kWh.
That hasn’t happened, but ViZn sees a market opportunity. The company says its flow batteries — it uses a zinc-iron chemistry — have an edge over lithium-ion because they can cycle more frequently and have a longer life span so, unlike lithium-ion batteries, they do not face replacement costs part way through the life of a project.
Flow batteries are also safer — they are not liable to explode — and they do not have the duration limitations of lithium-ion batteries. Flow batteries can run well past the four-hour mark that is the practical limit of many lithium-ion battery installations.
Disadvantage: cost
Flow batteries have several advantages over lithium-ion technologies, but at this point in market evolution, they have one big disadvantage: cost. Lithium-ion batteries cost roughly $300/kWh. They set the price to beat in the market; and it is a target that is moving in one direction: down.
StorEn Technologies claims to have developed a disruptive flow battery technology that can produce a 50% cost reduction. “We are targeting a price of $400/kWh with a 25 year duration with no decay,” Angelo D’Anzi, the company’s chief technology officer, told Clean Technica.
StorEn’s claims and ViZn’s zinc-iron chemistry aside, the most prevalent flow battery technology uses vanadium, a relatively rare element that is costly and hard to dispose of properly. Researchers working to come up with viable alternatives have tried a variety of chemistries, including variations on vitamin B2, and are using computer modeling to design molecules that could improve on existing flow battery chemistries.
