ESS Iron Flow Chemistry

Powerful technology transforming the utility grid

For most people, iron flow chemistry probably isn’t the first type of battery system that comes to mind. If you really care about clean, reliable, and cost effective long-duration energy storage, it should be.

ESS iron flow battery solutions are mature, second-generation systems that offer unmatched cost and sustainability with performance so dependable, it’s guaranteed through an independent insurer: Munich Re.

Conventional battery chemistries, with limited cycle life, can hope for a 7- to 10-year lifecycle before needing augmentation. ESS iron flow chemistry lasts 20 years or more with no capacity fade or degradation.

A flow battery is an electrochemical cell where two chemical solutions are separated by a membrane. Ions are exchanged across this membrane, producing chemical energy and electricity.

Cleaner and more sustainable: Thanks to food-grade, earth-abundant iron, salt, and water for the electrolyte, ESS batteries are the easiest to site and safest to operate systems on the market. Because iron flow chemistry doesn’t use rare-earth minerals like vanadium and lithium, it produces less environmental harm in materials sourcing and production processes. That’s part of the reason it’s a more affordable choice.

6 to 12 hour Energy Center diagram

Lowest cost per kWh: For applications that can use 6+ hours of discharge and frequent cycling, the Energy Center™ delivers the lowest cost per KWh over its 25-year lifetime.

The superiority of iron flow chemistry: Lowest levelized cost of storage (LCOS)

Our Energy Warehouse units offer an industry leading Levelized Cost of Storage advantage.

Zero degradation over 20,000 cycles: Iron flow batteries circulate liquid electrolytes to charge and discharge electrons via a process called a redox reaction. The word “redox” is a contraction of the words “reduction,” which represents a gain of electrons, and “oxidation,” or a loss of electrons. ESS uses the same electrolyte on both the negative and positive sides of the equation, eliminating cross-contamination and degradation. This is why ESS chemistry remains stable for an unlimited number of deep-cycle charge and discharge cycles.

Our patented electrode design and control system, coupled with our simple, yet elegant electrochemistry, allows you to operate longer, at higher efficiency and deeper discharge levels. Unlike typical batteries packaged as fixed cells or modules, a flow battery has significantly more energy storage capacity, which gives the user the flexibility to align both the power and amount of electricity stored precisely to a project’s requirements today and for the future.

Safer by design
ESS iron flow batteries present no fire, chemical, or explosive risk, eliminating the need for fire suppression equipment, secondary containment, or hazmat restrictions. Its chemistry has a pH similar to soda and wine and contains no toxic materials. In addition, the battery system is fully recyclable at end-of-life.