California Energy Commission-backed project will see North America’s largest Vanadium Flow Battery power sustainable rebar production for U.S. construction industry.
Monday 15 June 2026
Invinity Energy Systems is pleased to announce the sale of what will be the largest vanadium flow battery system in North America to date: a 32 MWh system destined to prove the role the Company’s vanadium flow batteries can play at the heart of America’s most ambitious industrial revival.
Pacific Steel Group (“PSG”), a leading reinforcing steel fabricator in the United States, has selected Invinity’s technology for its Mojave Micro Mill (the “Mill”) in Kern County, California. PSG expects this Mill, the first to be built in the state in 50 years, will be one of the cleanest steel mills in the U.S., producing world class, low-emission American steel at scale.
The battery system, supported by grant funding from the California Energy Commission’s Long-Duration Energy Storage (LDES) Program and awarded to PSG, will provide critical energy storage for this landmark facility, proving how the next era of American steel manufacturing can be powered with the same clean energy ambition that defines the Mill itself.
“The California Energy Commission is proud to support this milestone in clean energy innovation – one that advances California’s decarbonization goals while strengthening a vital domestic industry. The long-duration capabilities and versatility of Invinity’s vanadium flow battery will support the operational efficiency and resilience of the steel plant, and optimize the plant’s use of clean, renewable energy.”
– Jonah Steinbuck, Director of the Energy Research & Development Division, California Energy Commission
Invinity PSG Signing June 2026
Johnson Chiang, Executive Chairman, Asia and Mark Olson, VP of Mill Operations, Pacific Steel Group
Invinity’s Johnson Chiang and John Hasar with Mark Olson at PSG’s Mojave Mill
Johnson Chiang and Mark Olson at the Mojave Mill
Collocated with a solar array rated at over 40 MWp, Invinity’s battery will deliver on-demand, low-carbon, locally generated power to the Mill. With that power, the facility will recycle 500,000 tons of scrap metal annually into sustainable, seismic-grade steel rebar for the U.S. construction industry: American steel, from American scrap metal, powered by American sunshine.
“Pacific Steel Group is currently constructing the first steel mill to be built in California in more than 50 years. From the outset, our vision has been to develop one of the world’s cleanest and most sustainable steel manufacturing facilities. To support that goal, we integrated renewable energy generation and advanced battery storage into the project’s design. Following a thorough evaluation process and support from the California Energy Commission, we are proud to partner with Invinity Energy Systems on this transformative project, which represents a significant step forward for both California’s manufacturing sector and its clean energy future.”
– Mark Olson, VP of Mill Operations, Pacific Steel Group
Invinity’s vanadium flow batteries were selected for this project due to their technical, operational and safety characteristics, particularly their ability to cycle heavily to match the energy-intensive power requirements of the Mill. As part of the competitive selection process, Invinity was also able to evidence a strong project delivery track record both globally and in the USA, including several other California Energy Commission-funded battery projects delivered in recent years.
“I’m very pleased that Invinity has again been selected to deliver the heavy-duty storage solutions required by large-scale businesses. Pacific Steel Group’s mission is to prove an innovative path towards a fundamentally cleaner steel industry. We believe this project will prove that Invinity’s products are second to none in making that mission a reality.
“We also greatly appreciate the support of the California Energy Commission in this project and look forward to working with them, and our growing group of California-based customers, to further plan for how our products can deliver the reliable, low-cost power Californians will demand of their future electric grid.
“Finally, all of us at Invinity are very excited for how this project will accelerate plans to expand our U.S.-based manufacturing operations. Those operations will not only enhance our existing service and support capabilities, but also to deliver made-in-America products to customers in the U.S. and beyond. With numerous LDES schemes and a significant need for energy storage in the U.S. already in play, the opportunity to provide American-made vanadium flow batteries is an important next step on our journey.”
– Matt Harper, President, Invinity Energy Systems
Project construction commenced in June 2025, with the Mill expected to enter operation in mid-2027. Delivery of the batteries – which Invinity will manufacture in the USA – is expected to commence in Q1 2027.
Pacific Steel Group is a leading independent reinforcing steel fabrication and placement company with offices throughout the Western United States and corporate offices in San Diego, California.