Vanadium Flow Batteries Are Coming For Your Gas Power Plants

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Prying the death grip of fossil energy from the global economy is a tough hill to climb. One challenge is the growing need for energy storage beyond the capabilities of lithium-ion battery technology. Li-ion batteries last for several hours, but the energy storage systems of the future must keep producing those clean kilowatts for at least half a day and preferably much longer. On the plus side, new longer lasting, long duration systems are beginning to emerge, and flow batteries are in the running.

Flow Batteries & The Long Duration Energy Storage Systems Of The Future

Even at the relatively short duration of four hours for Li-ion batteries, the US Department of Energy anticipates that energy storage systems can replace gas “peaker” plants, which are commonly used only to provide additional electricity during periods of peak demand.

Replacing baseload gas power plants that operate continuously is a next-level task for longer-duration systems. In that field, pumped hydropower continues to dominate. Pumped hydropower is a proven, mature technology, but it is limited by geography and water availability as well as environmental and cultural concerns. Here in the US, pumped hydropower still accounts for about 95% of all long duration energy storage capacity.

More flexible, location-agnostic  technologies are beginning to emerge for long duration energy storage, such as compressed air and thermal storage systems (see more long duration news here).

Flow batteries are also in the mix. They operate on the ability of two specialized fluids to generate electricity when in motion. The fluids literally flow next to each other, separated by a thin membrane that enables ions to pass through.

CleanTechnica took note of some emerging flow battery technologies back in 2014. “Flow batteries score points for longevity, as they do not degrade over time as do lithium-ion batteries, for example,” we observed.

“That makes flow batteries ideal for intermittent energy storage. They can sit idle for long periods without losing their charge, and they can be revved up to speed almost instantly when called into action,” we added.

“Until recently, typical flow batteries were bulky affairs, but along with lower costs more compact systems have been emerging,” we added.

Vanadium Flow Batteries Are Coming…

Unlike its apparent namesake vibranium, vanadium is an abundant metal commonly used in the steel and titanium industries. It can be mined from the Earth or recovered from industrial waste. In mineral form it also crops up in various foods, including mushrooms and black pepper.

Abundance, non-toxicity, and relatively low cost are three reasons why vanadium is among the substances favored for flow batteries. It can exist in two iconic states, so it can be used in both of the two fluids used in flow batteries.

Corralling vanadium into a cost-effective energy storage system is not as simple as it may sound, partly due to heat management issues. Manufacturing costs have been another sticky wicket.

Back in 2020, the US Department of Energy issued the $20 million Energy Storage Grand Challenge, aimed at supporting innovations that reduce the cost of manufacturing flow batteries.

“The ability to manufacture flow battery systems of sufficient size is required in order to meet the expected demand for stationary grid storage,” the Energy Department explained. “The current sizes of flow battery cells, in which the most advanced materials and components have been demonstrated, are orders of magnitude below system sizes relevant for commercial use.”

…For Your Gas Power Plants

Among the flow battery firms to cross the CleanTechnica radar is the UK firm Invinity Energy Systems. Back in November of 2020, we spotted the firm’s vanadium flow batteries at work in a tidal energy project in Scotland.

Invinity is also bringing its flow batteries to the US. Under the “code-name” of Mistral, the new batteries were announced in a new round of funding for energy storage projects from the US Department of Energy, issued last September. Invinity’s funding agreement calls for 84 megawatt-hours’ worth of Mistral flow batteries to be installed at six different sites.

CleanTechnica is reaching out to see if the agreement has gone into the contracting stage. If all goes according to plan, the systems will be deployed next year. Five of the six sites will be developed in the Midwest and Southeast regions by a US consortium called the National Renewables Cooperative Organization, which overlaps with rural electric cooperative utilities.

“Invinity and its NRCO consortium partners expect these projects to improve energy independence in the rural communities they serve and, more broadly, demonstrate the benefits of longer duration energy storage technologies,” Invinity explains. “Each of the five projects will be operated by individual electric cooperative utilities and feature a 14.4 MWh Invinity VFB comprising a single Mistral array that will balance intermittent wind and solar generation and improve grid resilience.”

The Energy Department’s Pacific Northwest National Laboratory will provide technical assistance. The lab will also host the sixth installation, a 12 megawatt-hour flow battery system, capable of discharging for a solid 24 hours. As described by Invinity, the lab will be investigating and assessing various use cases for vanadium flow batteries over the next 10 years under its Lab Call platform, including applications for grid operators and microgrids.

Next Steps For Flow Batteries

On its part, Invinity is anticipating widespread use for its flow batteries. The US electric cooperative system is a good place to start. The five utilities tapped to host Invinity’s flow batteries are just the tip of an iceberg composed of 900 rural electric cooperatives that trace their roots back to Depression-era programs aimed at uplifting impoverished rural communities. Because these utilities are member-owned, not-for-profit entities with a community benefit mission (socialism!), they tend to have more leeway to experiment with potentially beneficial new technologies.

“The U.S. Department of Energy helps shape how the world generates, distributes and consumes electric power,” Invinity Chief Commercial Officer Matt Harper also enthused in a press statement.

“What Invinity and PNNL discover in the Lab Call program will enhance the ability of our batteries to deliver the flexibility, robustness and safety that NRCO’s member cooperatives and the communities they serve demand and that the future grid will require,” he added.

That remains to be seen. In the meantime, last week the global firm Dentons took note of a £25 million direct equity investment in Invinity by the UK Infrastructure Bank, described as “a British policy bank, wholly owned and backed by HM Treasury.”

“UKIB was set up to partner with the private sector and local government to increase investment in infrastructure projects that help deliver the UK Government’s ambitions for tackling climate change and promoting regional and local economic growth across the country,” explained Dentons, which is advising the institution on its investment.

As noted by Dentons, the stake of £25 million is part of a new fund aimed at propelling Invinity’s flow batteries to the next level. Energy Storage News also reports that the firm Korea Investment Holdings is embarking on an investment that could total  £28 million.

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Photo (cropped): Flow batteries leverage the ability of two specialized fluids to generate electricity when set in motion adjacent to each other (courtesy of Invinity).