Washington state utility Puget Sound Energy and energy storage developer Form Energy have entered into a memorandum of understanding to look into deploying a multiday energy storage system in the utility’s footprint, the two companies announced last week.
The collaboration will explore the potential of deploying a 10-MW, 100-hour energy storage pilot in PSE’s service territory — tentatively scheduled to be deployed by the end of 2026 — using Form Energy’s iron-air battery technology.
Compared to current commercially available batteries, which largely provide about four hours of power, multiday storage technology can help offset the need for PSE to build additional generation resources used only during times of high demand, utility spokesperson Andrew Padula said in an email.
Form Energy’s iron-air battery technology — which provides durations of up to 100 hours — would allow the utility to discharge the battery during winter peaking events, when intermittent resources like wind and solar may not be generating, Padula added.
Form Energy’s technology uses a process called reversible rusting, whereby the system discharges by absorbing oxygen and converting iron into rust and charges by using an electrical current to convert the rust into iron. Other utilities and jurisdictions have also shown interest in the technology — in December, California regulators awarded the company $30 million to build a 5 MW/500 MWh battery storage project at a Pacific Gas & Electric substation, expected to come online by the end of 2025.
New York Gov. Kathy Hochul, D, in August gave Form Energy a $12 million grant to build a 10 MW/1,000 MWh demonstration project in the state, which the company expects will be online in 2026. And in July, regulators in Minnesota approved a plan to build a 10 MW/1,000 MWh Form Energy iron-air battery system for Xcel Energy’s Minnesota utility. That project is expected online by the end of 2025, and will be coupled with as much as 710 MW of solar at the site of a retiring coal plant.