Iron in the air, if we embrace renewables

PHOTO: California Energy Commission, Flickr CC

More than a century ago, northeastern Minnesota emerged as a center for logging, iron mining and energy production. These three industries pollinated one another. 

Logs became the first commodity, shipped all over the country. Later, timber served as important infrastructure for the early iron ore mines while pulpwood became paper. Soon enough, the booming iron ore business spurred the creation of companies like Minnesota Power, which sated the hungry electrical demand of modern mines.

This all happened before any of us were born, so this industrial symbiosis might seem like some sort of eternal force. But it was merely a product of people, markets and technology — a transitory arrangement that changes with time.

The time has come again.

Earlier this month, Xcel Energy announced it would partner with Form Energy to build Minnesota’s first iron-air battery system.

I wrote about iron-air batteries last March. This new technology uses pure iron to store energy made during peak production for use during non-peak times. Essentially, it releases energy by rusting the iron and then deploys a electrical process to “de-rust” the iron, recharging the battery. This system allows renewable energy sources like wind and solar to save electricity for more than four days.

One of the biggest knocks against renewable energy goes like this: “What do we do when the sun doesn’t shine and the wind doesn’t blow?” It’s true that, even five years ago, advanced batteries struggled to store such huge amounts of energy. But these iron-air batteries can. And they can store energy for up to 100 hours, a massive improvement on the eight-hour life of other large-scale batteries.

Efficient storage of renewable energy is a nut that, once cracked, will upend the cost-to-benefit formula. Such a development would allow big power producers like Xcel and Minnesota Power to reduce their fossil fuel consumption by massive amounts. Furthermore, it would create opportunities for cities, private businesses and even residential homes to generate and store their own energy using renewable sources.

Batteries like these must be installed close to the site of renewable energy generation. That’s why Xcel is  building the new battery array next to the Sherburne County Generating Station in Becker. That’s located between St. Cloud and Minneapolis in south central Minnesota.

Xcel recently announced that its Sherco coal plant, a facility that generates 650 megawatts, will be phased out by 2030. In its place will rise the state’s largest solar panel array, a system that could generate as much as 710 megawatts. The first section of the Sherco solar project will begin construction next year. The first iron-air batteries could be ready by 2025.

We’ll learn a lot about how well this works as the Xcel project advances, but that’s no reason to wait around. The state’s new 2030 renewable energy mandate is real, and northern Minnesota has a big stake in the outcome. Not only do we mine the iron used in these batteries, but steelmakers like U.S. Steel and Cleveland-Cliffs are likewise reaching for carbon neutrality in coming decades. 

The big industries that have dominated our local economy for the last century are going through a metamorphosis. But they might not be done pollinating each other. We should imagine what other kinds of economic activity might practically sync with our changing world. In fact, we owe as much to the next generation.

Iron ore built an era of railroads and skyscrapers, and it can build a new era of renewable energy, too. We only must replace resentment with acceptance while striving for opportunity rather than resistance. 

Aaron J. Brown

Aaron J. Brown is an author and college instructor from northern Minnesota’s Iron Range. He writes the blog and co-hosts the podcast “Power in the Wilderness” on Northern Community Radio. This piece first appeared in the Saturday, July 29, 2023 edition of the Mesabi Tribune.

CORRECTION: An earlier version of this piece reversed the way iron-air batteries work. Energy is stored by turning iron oxide (rust) back into iron, then releasing the energy through rusting.


  1. Fred Schumacher says

    I posted on Facebook articles on Great River Energy’s demo project in Cambridge, MN on installation of iron-air batteries and got not a single response. If I post a photo of my wife with a zucchini, it will get 89 likes. The Ely City Council passed a resolution honoring Twin Metals, a company that has no chance of actually mining in northern Minnesota, while residents in attendance held up signs honoring all the other businesses that make Ely thrive. At Ely’s 4th of July parade, Roger Skraba rode on a semi that said “make logging great again.” It didn’t say how.

    It only take three workers to log 200 cords of wood a day: feller buncher, skidder, delimber/slasher/loader. More people haul the logs than cut them. Mining is hugely productive and is moving rapidly toward autonomous operation. It doesn’t take many people, no matter how valuable the commodity. The most dynamic towns on the range, Ely and Grand Rapids, haven’t had an active mine in decades. Mountain Iron, where Rep. Stauber held his dog-and-pony show on mining calls itself “Taconite Capitol of the World” but has one retail business on Main Street, Mac’s Bar.

    It’s bleeding obvious that money is in value added, not raw commodities. Ely and Grand Rapids provide value added tourism and retirement. They have “throughput,” that is, thousands of people move through there spending money. For the Range to get into value added iron production is a no-brainer, but the Range is mentally trapped on mining, not converting. The Range has two Class 1 railroads and is one hour from Duluth, with its four class one railroads and a deep water port. Iron-air batteries could be manufactured here and be shipped by unit train west and south to wind turbine and solar farms, or across the sea.

  2. joe musch says

    Yep ! I too read the original iron air battery article and also got few pass arounds. Thanks for keeping the information coming. That being said I do not see the greatest diffculty to be the availablity of information regarding technological transfers to expanding green but something deeper. What the impediment is in my estimation is something like the remora fish hichiking on a shark. In this case the shark is going green. We have compost recycling city wide here in Mpls. You do not even want to know the low numbers of people who use the service. I think it is the same hidden barrier at play. Another stem of this ugle weed is the forever playing trump toilet flush canard. It is conservation. Conservation requires self discipline. That ranges from having fewer children to having fewer eight wheel pick-ups. Trump does not want ot flush four times, but he is going to have to learn how pretty quickly. If we fo not take on a both specoes over population and conservation the toilet will remain plugged. We have to remember the replenish part of be fruitful and multiple. And turn off the basement light if your not down there.

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