The final report ARPA-E produced includes a compilation of assessments of some of ARPA-E’s breakthrough energy technologies, including ESS’ Grid-Scale Rampable Intermittent Dispatchable Storage (GRIDS) project focused on improving energy density by adapting the understanding of chemical flow to the electrodes from their experience with fuel cells.
ESS adapted its cell and stack design to use iron chloride (FeCl2) electrolytes that cost less than 1/10 of the vanadiumcarrying
electrolytes. The resulting high-power cell design has demonstrated a four-fold power density increase over existing iron flow battery technologies.
With increasing production scale, continuing development of lower-cost cell components and the potential for significant increases in cycle life, ESS is positioned to be very competitive in the rapidly developing grid storage market, with the potential to deliver storage costs that minimize the impact on the levelized cost of electricity.