Flow batteries may rule grid-scale storage
May overtake lithium-ion batteries before end of the decade Metal Tech News - May 28, 2021
Last updated 6/2/2021 at 3:25pm
While lithium-ion batteries have a major head start when it comes to the storage of renewable electricity, European analysts predict that flow batteries may overtake the stationary power storage market within a decade, and investments by the Biden administration could help make these forecasts a reality.
Vanadium redox flow batteries – variably called flow batteries or vanadium redox batteries – are the most common and technologically advanced of the flow batteries.
Taking advantage of vanadium's ability to exist in a solution in four different oxidation states and using this property to make a battery that has just one element for both the positive and negative side of the battery, vanadium redox flow batteries have been touted as the superior choice for large-scale energy storage.
When it comes to cost, flexibility, quick response, reliability, and safety, vanadium and other flow batteries offer several advantages over lithium-ion and other batteries for keeping energy grids energized and stable.
With global governments turning to intermittent sources of energy such as wind- and solar-generated electricity, it is expected that these advantages will make redox flow batteries an increasingly attractive storage option for this variable renewable energy.
IDTechEx, a United Kingdom-based market and business research firm, predicts that flow batteries might overtake lithium-ion batteries in terms of total storage capacity by 2031.
"We are looking at the solution, but most of the time we forget the problem," IDTechEx penned in an announcement of a new report, "Redox Flow Batteries 2021-2031."
In this case, the problem is increased use of intermittent renewable energy injects a higher degree of variability and uncertainty into the supply and demand balance of electrical grids.
The solution is a cost-effective and reliable large-scale storage technology that can serve as a buffer between the ebbs and flows of variable renewable electricity and completely different undulations in the demands of people and businesses plugging into that power.
Based on scientific studies, IDTechEx believes redox flow batteries will likely be an increasingly important part of that solution.
"Driven by the adoption of an increasing amount of variable renewable energies, stationary storage devices – besides li-ion batteries – are approaching the market, and IDTechEx foresees a large adoption of redox flow batteries toward the end of the next decade," the research firm penned in an introduction to its report.
The Biden administration agrees with this potential and recently announced it will invest up to $20 million for research and development to advance the manufacturability of mid-sized flow battery systems.
Department of Energy, which is administering the program, will partner with industry to address technical and manufacturing challenges that have prevented flow battery systems from achieving cost targets and commercial viability.
"Mature flow battery technologies will allow the U.S. to store and dispatch clean energy from renewable generation sources on a grid-scale, enabling flexible, resilient, and secure infrastructure," DOE penned in a March announcement of the flow battery funding opportunity.
Considering that the biggest challenge facing large-scale flow battery competitiveness is lithium-ion batteries have roughly a two-decade head start in terms of research, development, and economies-of-scale, the government investment will offer flow batteries a large boost to achieving DOE's objectives.
Probably the largest technical disadvantage of redox flow batteries is low energy density, which is more of a challenge for mobile applications and easily overcome by more cost-effective scalability for stationary storage.
The ion-exchange membranes that separate the positive and negative electrolytes, which often account for up to 40% of the cost of redox flow battery stacks, are the single biggest financial factor for this technology.
The DOE funding, which is seeking proposals for collaborative research and development projects to improve manufacturing of individual flow battery components and integrate them into prototype systems, will likely help find solutions to this membrane dilemma.
Steering stationary storage toward flow batteries would also help alleviate another dilemma to the global transition to low-carbon energy and e-mobility – the demand for the lithium-ion battery metals and minerals cobalt, graphite, lithium, manganese, and nickel that is already being pushed to extraordinary levels by the electric vehicle sector.
Broadening the energy storage horizon would also diversify the raw materials used – making climate goals easier to achieve and potentially spreading the demand and lowering the costs for stationary and e-mobility batteries.