How battery storage is playing a role in Minnesota's clean energy transition

NINA MOINI: Time now for our check-in with the MPR News regional team. Today we're talking to reporter Kirsti Marohn, who reports as part of our Getting to Green series. And today, she's sharing a story with us about how the storage of batteries is playing a role in Minnesota's clean energy transition. Thanks for being with us again, Kirsti.

KIRSTI MAROHN: Hi, Nina. Thanks for having me.

NINA MOINI: Of course. So I'm really curious about this. So the state's clean energy transition, what does that look like?

KIRSTI MAROHN: Yeah, well, two years ago, the Minnesota State legislature passed a law requiring that electric utilities get 100% of their electricity from carbon-free sources by 2040. So that's things like solar, wind, nuclear-- sources of energy that don't produce greenhouse gases that contribute to climate change. So we're seeing utilities retiring power plants that burn fossil fuels like coal. We're seeing them add more wind and solar energy. And then, of course, Xcel Energy owns two nuclear plants in Minnesota, and it plans to keep operating those.

NINA MOINI: So how do batteries play a role in clean energy in this case?

KIRSTI MAROHN: Yeah, well, there's a lot of great things about wind and solar. I mean, it's very cheap to build right now. You don't have to pay for fuel. But one issue with those is that they are sort of weather dependent, right? I mean, at times, they produce a lot of energy. There might be times when the sun's not shining as much, or the wind's not blowing as much.

And so, there's sort of this variability. And that doesn't always match with the demand or the times that we see people really needing or wanting to use electricity. So without a way to store that energy, it's got to be used as soon as it's produced. So here's an example. Like, the wind blows a lot at night, and so wind energy is really cheap and plentiful at night. But the times when people really use a lot of electricity is, late afternoon, they get home from work.

NINA MOINI: Right.

KIRSTI MAROHN: They crank up the AC or throw that load of laundry in. And so there's this discrepancy. So the idea with batteries is that you can charge them when electricity is plentiful, and the price of electricity is low. And then you can discharge them or use that electricity when you need it during those peak times. So it should kind of help smooth out the demand and maybe stabilize prices as well.

NINA MOINI: Yeah, so I hear you kind of saying it's got to make sense for how people actually use that everyday electricity. So what are some of the ways that the state is using the batteries?

KIRSTI MAROHN: Yeah, well, we're seeing in a lot of different ways. I mean, we use batteries in all aspects of our lives now these days, right? We use them in our cell phones and laptops, and if you drive an EV. This is sort of the same concept. It's just a little bit bigger scale. So we're starting to see homes and businesses installing batteries, sometimes as sort of a backup source of power in case there's an outage.

And then we're also seeing utilities using them to store that excess energy in electricity. So we're seeing some utilities are building-- sort of co-locating batteries with solar or wind projects so that they can charge up those batteries when it's sunny or windy and then dispatch them or use that energy in times when they need it.

And then we're also seeing some standalone battery projects starting to get built. Those are just not connected to a solar or wind farm. They're just connected to the electric grid. And these different ways or different levels of batteries, I think they're allowing utilities to ramp up the amount of solar and energy that they are using and just helping manage that demand.

NINA MOINI: Are there different ways some of the bigger names, like, say, Xcel Energy, are leaning into this, too?

KIRSTI MAROHN: Yeah, Xcel is doing a couple of different things. They have their Sherco coal-fired power plant in Becker, in central Minnesota. They're retiring that coal plant, and they're building this huge solar project there. And they're also looking at making it an energy hub. So they want to install big lithium batteries that could store energy and then dispatch it when needed.

They also have this plan to create a network of smaller batteries across the state. These would be like the size of a shipping container. They'd maybe take up a parking space or two at a business or a nonprofit. And then Xcel could use these batteries. They could control them to store electricity and relieve when there's congestion on the grid. And they say maybe they wouldn't have to make as many expensive upgrades to the electric grid as well.

NINA MOINI: OK, and so I understand there are some skeptics, though of Xcel's plan. What are some of their concerns there?

KIRSTI MAROHN: Yes, some of the utility watchdog groups, they like the idea of these batteries. They're a little concerned that Xcel would have a monopoly on these, would own these batteries and would operate them. They think maybe it should be opened up to competition.

And then there's also a question of, would Xcel customers benefit from this? These batteries are expensive. I think this plan would be like $430 million, or up to that amount, over three years. So they say, would customers benefit from this or would Xcel just sort of profit from this plan? And so there's still that debate going on. And this plan would need the approval of state regulators.

NINA MOINI: So what else are you going to be watching for as this continues, and utility companies in the state are looking to build more of these?

KIRSTI MAROHN: Well, I think it's just a fascinating area. I mean, this technology is changing so rapidly. I mean, we've seen new innovations. We've seen prices of batteries dropping. I think that's why there's this interest right now. There's new innovations coming down the pike, like solid state batteries, which the inside is-- the center is a solid, instead of a liquid, electrolyte. And they're supposed to be safer and faster charging.

There's also iron air batteries. Xcel wants to have a pilot project at the Sherco plant that would use these. And it's an iron and air battery. So it can store energy for a longer period of time than a lithium battery, like up to four days. And then it would use less critical materials and just basically iron and air, which is really interesting.

So I think we're going to see this area as really changing rapidly. I think there's just still going to be a lot of questions about the cost, the upfront cost of doing batteries. And regulators are going to have to weigh the potential benefits, making the electric grid more efficient and reliable and carbon-free with the impact on our electric bills.

NINA MOINI: Absolutely. Gosh, I really just love the whole Getting to Green series, Kirsti. I think people should check it out at mprnews.org. You and the team are really keeping an eye on these changes and things that are evolving and what benefits the environment that we all share. Before I let you go, I have to ask if you saw the Northern Lights at all. You live north of the Twin Cities. I mean, what did you see? Did you pop outside? What was it looking like where you were?

KIRSTI MAROHN: I did. I wasn't expecting him so early in the evening. And we were out walking the dog, and I just-- we looked up.

NINA MOINI: Nice.

KIRSTI MAROHN: And the colors were just amazing, the red and green. I'd never seen red like that. So it was really fun-- the best I've ever seen in my lifetime.

NINA MOINI: Yeah, I did not go outside because usually, I don't think I'm going to see them. And then Paul Huttner informed me yesterday that it was probably a once-in-a-lifetime event. So, [LAUGHS] cool. I'm glad you saw it, Kirsti. Thanks for stopping by. Take care.

KIRSTI MAROHN: Thanks, Nina.

NINA MOINI: That's MPR News reporter Kirsti Marohn.