ESS Iron Flow Chemistry
Powerful technology transforming the utility grid
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.
ESS iron flow battery solutions are mature, second-generation systems that offer unmatched cost and sustainability with performance guaranteed through an independent insurer: Munich Re.
Conventional battery chemistries, with limited cycle life, deliver a 7- to 10-year lifecycle before requiring augmentation. ESS iron flow chemistry delivers 25 years or more with no capacity fade or degradation.
Cleaner and more sustainable
ESS batteries are easy to site and safe to operate. Iron flow chemistry doesn’t use critical minerals such as vanadium, lithium, or cobalt, reducing the environmental impacts associated with the supply chain and reducing their lifecycle greenhouse gas footprint.
Lowest cost per kWh: For applications that use 6+ hours of discharge and frequent cycling, the ESS systems deliver the lowest cost per KWh over a 25-year operating design life.
The superiority of iron flow chemistry: lower levelized cost of storage (LCOS)
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.
Safer by design
ESS iron flow batteries are safe and non-toxic, reducing the need for fire suppression equipment, secondary containment, or hazmat precautions. Iron flow chemistry has a pH similar to soda or wine and contains no toxic materials. In addition, the battery system is substantially recyclable at end-of-life.
Designed to meet customer needs
Scalable: ESS power modules’ streamlined architecture allows them to power our turnkey Energy Warehouse product line and still be scalable enough to support Energy Center deployments delivering MWh or GWh of storage. An enhanced power module architecture also allows double the plating capacity of prior generations, extending the module-level discharge duration to up to 16 hours. In addition, the entire ESS battery assembly is designed to facilitate robotic manufacturing for precision quality.
Easy operation and maintenance: Each ESS power module is individually controlled and power conditioned through independent DC-DC converters and stack level monitoring. Stacks run at their ideal operating point and can be monitored for battery health and optimal performance. Any faults can be detected early and isolated from the rest of the system, allowing for enhanced uptime and system safety.
The ESS iron flow battery uses the same electrolyte on both positive and negative sides. And the proton pump maintains the state of charge and battery health.