Demand for flow batteries and other long-duration energy storage technologies is growing, even if their current cost does not yet make them competitive in the commercial market. Interest should only increase as the industry closes coal-fired power plants, brings more renewable energy resources online and seeks ways to manage the resulting imbalances between energy production and demand.
But a decarbonized grid isn’t the only issue driving interest in long-duration storage technologies. As the February 2021 winter storms in Texas demonstrated, the grid is not fail-safe. Disasters — natural and otherwise — can cause major power outages that put human lives in danger. When these events happen, stored energy can be a true lifesaver.
In fact, the state of California is already taking action. To address the state’s well-documented energy needs, the California Energy Commission is supporting a massive investment in energy storage to manage the generation supply curve.
Electrification programs create further demand for stored energy. As more electric vehicles take to the streets, long-duration solutions can be used to help power charging stations. Elsewhere, companies like Microsoft and Google expect long-duration technologies to play an important role in their pledges to shift data centers from net zero carbon initiatives — where carbon offsets counterbalance emissions — to zero carbon initiatives that depend on 100% carbon-free energy.
Flow batteries — rechargeable fuel cells that store chemical energy in external tanks instead of within the battery proper — are seen by many as the next-generation alternative to the lithium-ion batteries now commonly used for energy storage. Depending on their chemistry, flow batteries can ramp up quickly, cycle multiple times a day, provide longer service — easily eight or more hours — and have up to 30 years of usable life if properly maintained. Many flow batteries are also being developed with modularized systems with an eye for scaling up solutions to utility scale. The liquid electrolytes they use to charge and discharge also pose little or no fire risk.
In sum, flow battery technology can deliver products with good performance and capacity. Reports on some vanadium flow batteries show only a 1% drop in energy storage capacity after 10 years of use.
Still, multiple barriers — most notably, high production costs and few financial incentives — have limited the application of the emerging longer-duration battery storage technologies now entering the market. New federal funding for demonstration flow battery projects may do for flow batteries what electric vehicle research and development did for lithium-ion.
In the meantime, the industry remains fluid. Disruption created by COVID-19 led some manufacturers to return to their research labs, where they focused on increasing electrolyte energy density. While some energy storage companies struggle to stay afloat, others have consolidated, merging supply chains and acquiring patents that may deliver competitive advantages.
For example, Largo Clean Energy, a manufacturer of vanadium redox flow batteries, acquired VionX Energy Corp. and is now commercializing the flow battery technology VionX previously owned. Largo Clean Energy reports plans to establish 1.4 gigawatt-hours (GWh) of annual battery stack manufacturing capacity at a new plant in Massachusetts.
Similarly, Lockheed Martin and Oriden LLC announced a teaming agreement in 2020 for future energy storage projects using Lockheed Martin’s flow battery technology. Two other flow battery providers — RedT Energy and Avalon Battery — merged in 2020 to form Invinity Energy Systems. Meanwhile, iron electrolyte flow battery company ESS Inc. announced plans in May 2021 to go public.
