A remote hillside in the Nevada desert may hold the keys to developing the next generation of affordable energy storage systems. One of the world’s largest deposits of vanadium, a hard, silvery gray mineral often mixed to create high-quality steel, is located underground on this site. First discovered in the 1950s, the site is now being developed into a large-scale mining operation, known as the Gibellini Mine, by Vancouver, Canada-based American Vanadium. The company, which partners with German flow battery manufacturer GILDEMEISTER, requires an affordable and secure supply of vanadium to develop its redox flow batteries.
With the majority of global vanadium supplies coming from China, a domestic source of the metal could be instrumental in reducing battery costs. Despite the recent success of lithium ion (Li-ion) batteries, alternative technologies such as flow batteries address several shortcomings of Li-ion chemistries.
There are several types of flow batteries with different characteristics currently competing for market share, including iron-chromium, zinc-bromine, and vanadium redox. Well-suited to stationary applications, vanadium-based batteries offer several advantages over Li-ion systems. Vanadium-based batteries can fully discharge with minimal degradation of key components, leading to a longer duration discharge and greater life expectancy. Additionally, vanadium flow batteries are much safer than certain Li-ion chemistries, as they have no thermal runaway issues, which is a key consideration for systems located on densely populated distribution networks.
Significant improvements to flow batteries have been made in recent years as more companies enter the space and competition heats up. One area in which flow batteries must improve is energy density; Li-ion and other batteries are much more energy-dense, giving them an edge in any project with limited space. A recent milestone was achieved by UniEnergy Technologies with its vanadium-based flow battery, allowing a standard 500 kW, 4-hour system to be containerized and installed in a 1,000-square-foot pad. The system has an expected operating life of 20 years and can be installed for around $750 per kWh.
As with most advanced batteries, makers of vanadium-based systems must reduce costs to fully capitalize on the diverse market opportunities available. Fortunately, advances are being made in that area as well. California-based Imergy, for example, claims that it will soon reduce costs enough to offer a vanadium-based flow battery for around $300 per kWh. One reason for the low price is Imergy’s ability to use lower-grade vanadium, recycled from mining waste and other sources. While vanadium flow batteries are currently somewhat more expensive than most Li-ion chemistries, they have the advantage of a longer life expectancy, allowing the upfront cost to be spread over several decades.
An Uncertain Future
Navigant Research’s report, Energy Storage for the Grid and Ancillary Services, found that flow batteries are likely to account for 2,357 MWh of capacity in 2020, about 7% of the total market for grid-scale systems. However, these figures could increase dramatically with breakthroughs in system efficiency and cost. A consistent, low-priced supply of key components, such as vanadium, could help rapidly reduce costs. Additionally, greater diversity and competition among suppliers of key flow battery components can drive down manufacturing costs. Given the very ambitious price reductions being forecast by manufacturers, many may be relying on market developments such as the Gibellini Mine to allow flow batteries to compete effectively with Li-ion.