Tesla is good at grabbing headlines, but its dominance of the stationary battery storage market is not a sure thing no matter how many Gigafactories it builds, not with battery giants like Samsung, LG Chem, and BYD in the game.

Imergy is another player that has its eye on the prize, which is hundreds of billions in profits over the next several decades as the world transitions to distributed renewable energy. While everyone else is relying on lithium-ion battery technology, Imergy is pursuing a different course. The Imergy vanadium-flow batteries are different in several important ways.

For one, a lithium-ion battery must be protected from getting too hot. If it does get too hot, it can burst into flames, as happened on board Boeing’s Dreamliner prototype airplanes a few years ago. Lithium-ion batteries need special shielding and a dedicated cooling system, both of which add weight and expense. They also have a limited number of times they can be discharged and recharged and do not tolerate being fully discharged or fully charged very well.

The Imergy vanadium flow battery uses vanadium as a catalyst. While pure vanadium is expensive, Imergy gets theirs from fly ash left over from burning coal or from slag that results from making steel. Both are capable of yielding vanadium that is 98.5% pure, which is enough for its liquid battery process. Since the vanadium is not consumed in the energy storage process, it can be recycled when a flow battery reaches the end of its useful life.

The other big advantage of the Imergy vanadium flow battery is that it is scalable. That means it can be customized to hold precisely the amount of energy required simply by resizing the liquid electrolyte tanks. Such customization is not possible with lithium-ion batteries.

Imergy is focusing most of its attention on Africa and India. Often, an Imergy system is part of a telecommunications installation in a remote area where residents rely on expensive diesel fuel to run generators. The Imergy system allows them to purchase small amounts of renewable electricity for lighting and other household purposes for far less money. The company plans to leverage its experience in such harsh climates to improve its products and drive down costs of production before entering markets in the developed world like the US, UK, and Europe.

Imergy CEO Bill Watkins tells Forbes his company has started doing business with FoxConn in China, the same company that produces products for Apple. “That’s our secret – how to make vanadium batteries cheap… We think we can get our cost under $300/kWh for the whole system including power electronics and packaging. The recent Tesla announcement shows lithium has a role, but not for multiple daily charges or long duration, or unlimited cycles. If you are deep cycle discharging more than two hours a day,we are by far the most effective solution.”

Notice that the prices Tesla announced recently for itsPowerWall residential batteries do not include an inverter or installation — items which can double the quoted cost. For a thorough cost analysis of Tesla’s batteries and Imergy’s, see: Tesla Powerwall & Powerpacks Per-kWh Lifetime Prices vs Aquion Energy, Eos Energy, & Imergy.

Imergy has just announced a deal with SunEdison to supply 1,000 grid storage units “to store solar generated electricity for SunEdison’s rural electrification and solar powered mini-grid projects in India.” While its prices may not be the lowest of all its competitors, its batteries reportedly last longer with less maintenance, which helps make them the better business proposition when all factors are considered. That said, Imergy offers only 5–10 year warranties.

The stationary battery storage race is on. Looking down the road, Imergy likes its chances. We’ll see!