Xcel Energy has announced that Breakthrough Energy Catalyst has agreed to commit $20 million in grant funding to support two multi-day energy storage projects designed to maximize the use of renewable energy while maintaining the reliability of the grid. The grant would provide $10 million each for two 10 MW/1,000 MWh iron-air battery systems, subject to the satisfaction of certain funding conditions.

Xcel Energy and Massachusetts-based Form Energy announced in January an agreement to construct the batteries at the sites of retiring coal plants: the Sherburne County Generating Station in Becker, Minnesota, and the Comanche Generating Station in Pueblo, Colorado. The batteries will allow Xcel Energy to store renewable energy such as solar and wind when it is being produced and then later distribute the energy during periods of lower production.

“Innovative long-duration energy storage technologies are crucial to achieving 100 percent carbon-free electricity,” said Bob Frenzel, Chairman, President and CEO of Xcel Energy. “This Catalyst grant will accelerate adoption of this promising new technology, which allows us to provide higher percentages of renewable energy while still providing affordable electric service to our customers.”