If you live in Minnesota, it’s likely you’ve seen media coverage about the work underway at the site of Xcel Energy’s Sherco power plant as the utility adds both solar and battery storage. In my role at Fresh Energy, I’ve been keeping a close eye on the project and participated in a variety of convenings about it as it’s taken shape. Let’s dive into some details about what is in the works.
As you approach the City of Becker along US-10 on a cold winter morning, plumes of water vapor and greenhouse gases billow from the Sherco coal facility’s stacks, visible for miles against the pale blue Minnesota sky. Large transmission towers march alongside the highway, their wires heavy with electricity flowing from the plant to power homes and businesses throughout the region—wires that soon will be flowing with clean energy instead.
By December 31, 2030, Xcel Energy will retire the Sherco coal facility, replacing the electricity with Sherco Solar 1, 2, and 3—gleaming arrays of solar panels built near the former site of the coal plant. Meanwhile, Xcel is collaborating with Form Energy, whose manufacturing is in Pennsylvania and West Virginia, to develop innovative iron-air batteries capable of storing clean energy for multiple days, improving reliability on the grid.
Xcel Energy’s innovative battery pilot project will test a 710-megawatt (MW) solar facility with a 10-MW, 100-hour, multiday battery at Xcel’s Sherco facility. Regulators at the Minnesota Public Utilities Commission approved the pilot project because Minnesota is moving toward decarbonization, and the development of long-term duration energy storage will be essential to managing the electric grid along the way.
Xcel successfully raised money for the Form Energy long-duration, iron-air battery pilot from Breakthrough Energy Ventures (founded by Bill Gates) and from the U.S. Department of Energy (DOE). The DOE requires tracking the costs borne by both Xcel’s Minnesotan and Coloradan residents who are hosting their “first-of-a-kind” technology deployment.
Rechargeable iron-air batteries are currently the best technology for multiday, 100-hour electricity storage. Form Energy’s “reversible rusting of iron” batteries are expected to cost less than 1/10th the cost of lithium-ion batteries (which only store four hours of electricity). Iron is one of the most widely-produced, lowest-cost materials in the world. Form Batteries contain no heavy metals and non-flammable aqueous electrolytes. Iron has high recyclability.
The Form Energy batteries are being manufactured at Form Energy’s Factory 1 in Weirton, West Virginia. The town was founded in 1909 by Edward Weir who bought 105 acres of land to build one of the country’s largest steel mills. The Weirton steel mill became West Virginia’s largest employer and allowed tens of thousands of people to raise their families, send children to school, and live the American dream. Steel manufacturing ceased recently at Weirton, and Form Energy Factory 1 was a $760 million local investment that will supply at least 750 full-time jobs. Fortunately, Weirton has a population with local manufacturing know-how. The factory will produce 500 MW of batteries annually. Each battery is about the size of a washer and dryer side by side.
Here in Becker, the batteries will be housed in weatherproof metal enclosures to keep them protected from the bitter cold in the winter and hot sun in the summer. The battery anodes are made of iron, and the cathodes use the surrounding air to soak up the nearby solar energy to “unrust,” using an electric current from the solar panels to convert rust into iron. Later, the iron plates can rust and feed electric current back into the grid as needed, traveling along the towering transmission lines along US-10 to power Minnesota’s homes and businesses.
Form Energy estimates the 10-MW multiday energy storage project could deliver up to $34 million of gross value to Minnesota customers. They project that the iron-air project would result in up to about $1 million in fuel savings during a single polar vortex event.
Fresh Energy has been selected by Xcel to serve on its battery pilot advisory group, and we are working with both Xcel and Form Energy, providing expertise and advice. Construction of the pilot started in the second quarter of 2024. The construction is expected to be complete by the end of 2025, and Fresh Energy will be on site for the battery deployment tour. The pilot will continue for 10 years and will provide important information on cost and reliability.
Stay tuned for continued updates! And with Spring and Earth Day right around the corner, please keep in mind that I am available and happy to present on this and more aspects of my work at Fresh Energy. Much of my time throughout the year is dedicated to presenting to businesses, college classes, congregations, clubs like Rotary, and beyond! So please reach out if you’d like to learn more about what this could look like for the groups you’re involved in who would like to learn more about how Fresh Energy is taking on the climate crisis through clean energy policy here in Minnesota and beyond. There is a form you can fill out on my bio page here.
