Iron flow batteries for long-duration commercial and utility-scale energy storage applications

ESS Inc. designs, builds and deploys environmentally sustainable, low-cost, iron flow batteries for long-duration commercial and utility-scale energy storage applications. The Energy Warehouse™ and Energy Center™ use earth-abundant iron, salt, and water for the electrolyte, resulting in an environmentally benign, long-life energy storage solution for the world’s renewable energy infrastructure. In the ESS iron flow battery, catholyte and anolyte are stored in separate tanks, and ESS Inc. invented Proton Pumps are used to circulate the fluids into a stack with electrodes separated by a thin membrane. This membrane permits ion exchange between the anolyte and catholyte to produce electricity.

ESS’ current generation battery design can provide up to 12 hours of energy storage over a 25-year operating life with zero degradation over 20,000 cycles. ESS batteries are also scalable, from modest behind-the-meter applications (50-90kw) up to very large-scale applications (10-100MW and beyond). ESS solutions deliver cost-effective, low-maintenance, and long-lived solutions that provide a lower Levelized Cost of Storage (LCOS) due to near-unlimited cycling capabilities. Iron flow batteries are a safe, sustainable choice, with zero fire, chemical, or explosive risk, eliminating the need for fire suppression, secondary containment, or hazmat protection.