Department of Energy Directs $520 Million for Commercial Long-Duration Energy Storage Facilities

WASHINGTON — Secretary of Energy Jennifer Granholm announced on Monday the distribution of $520 million in federal matching grants from the Office of Clean Energy Demonstrations (OCED) to finance the commercial engineering and construction of five utility-scale Long-Duration Energy Storage (LDES) facilities capable of discharging clean power for 10 to 100 continuous hours.

The demonstration facilities, deploying non-lithium technologies such as iron-flow batteries, compressed-air energy storage (CAES) in underground salt caverns, and thermal brick storage, address the fundamental multi-day intermittency challenge of renewable energy during extended winter lulls and heatwaves.

Providing Multi-Day Grid Reliability Without Fossil Peakers While standard lithium-ion batteries discharge power for 2 to 4 hours, multi-day long-duration storage systems absorb excess mid-day solar and overnight wind power and dispatch continuous electricity during prolonged multi-day grid disruptions.

"As we build out historic amounts of clean wind and solar energy, we need reliable, long-duration energy storage systems that can power communities for days at a time when the sun isn't shining and the wind isn't blowing," Secretary Jennifer Granholm said in Washington. "By investing $520 million in American-manufactured iron-flow and compressed-air storage, we are pioneering the technologies that make clean baseload power a reality, protecting consumers from extreme weather blackouts and creating high-wage union manufacturing jobs."

Selected LDES Demonstration Projects Funded project sites include:

• Kern County, California: A 100-megawatt, 10-hour iron-flow battery facility utilizing domestic iron, salt, and water electrolytes.
• Millard County, Utah: A 200-megawatt compressed-air energy storage facility utilizing solution-mined subterranean salt caverns.
• Carlton County, Minnesota: A 100-hour multi-day iron-air battery storage facility at a retiring coal generating station.
• Potter County, Texas: An advanced zinc-bromine flow battery cluster paired with wind generation.
• Pike County, Mississippi: A 150-megawatt advanced compressed-gas thermal storage hub.

Regional grid operators and electrical engineers commended the federal awards, highlighting that long-duration storage prevents billions of dollars in costly transmission line congestion and curtailment.