Flow Batteries made from Recycled Vanadium Reduce Costs

July 09, 2014 by Jeff Shepard

Imergy Power Systems, Inc. claims to have achieved a fundamental milestone in energy storage by developing a process for producing high-performance flow batteries with recycled vanadium from mining slag, oil field sludge, fly ash and other forms of environmental waste. The achievement is expected to have a number of significant impacts on the growing energy storage industry. Other manufacturers of vanadium flow batteries build their devices with virgin vanadium extracted from mining. It must then be processed to a 99% plus level of purity. Through an extensive research and development program, Imergy has developed a way to produce flow batteries with vanadium at a 98% purity level that can be harvested from environmental waste sites.

By extracting vanadium from slag, Imergy will lower the cost of obtaining and processing vanadium - the principal active ingredient in many flow battery electrolytes - by 40% relative to competitors. As a result of this technology and other developments, Imergy will be able to lower the cost of its flow batteries from $500 a kilowatt hour, already an industry benchmark, to under $300 per kilowatt hour.

Imergy's flow batteries from low-grade vanadium will also be capable of storing more energy per kilogram than conventional vanadium flow batteries by more than twice, giving cell phone operators, solar power plant developers, microgrid owners and other customers more flexibility and capacity for managing outages, curbing peak power or reducing demand charges.

The technology is also far more sustainable for the environment by using an existing waste product with little or no market value. Thousands of tons of vanadium are brought to the surface through worldwide petroleum operations alone every year. Because oil producers do not have an economical market for low-grade vanadium, the material sits in sludge deposits. Tons of vanadium also languish in copper mine tailings. By working with Imergy, fuel and mining companies can reduce their potential scope of liability and operating costs.

"This is a win all the way around. We're taking industrial sludge and turning it into a source of clean energy," said Bill Watkins, CEO, Imergy Power Systems. "At the same time, we're lowering the cost and increasing the performance of energy storage, which is going to expand the market."