Data centers are the factories that run the internet. We rely on them every day for things like sending emails, watching videos and uploading photos. Now, even larger data centers to help power artificial intelligence are being proposed and built here in Wisconsin.
Data centers require millions of gallons of water to operate. Some can consume as much energy as a whole town. To learn more about their potential environmental impacts, WUWM reporter Eddie Morales spoke with Amy Barrilleaux. She's the communications director at Clean Wisconsin, an environmental advocacy group.
This conversation has been edited for length and clarity.
Eddie Morales: What are data centers?
Amy Barrilleux: Data centers are buildings that house computer servers and other computer components to basically handle our digital lives. So if you're streaming a movie or if you're looking at your email or any of those things where there's a cloud and you're not sure where those things are physically located, they do have a physical location at a data center.
I think it's important to understand there's a difference between a data center and an AI or hyperscale data center. Wisconsin's had data centers for a reasonably long time, certainly a decade or more, but we haven't had hyperscale or AI data centers finished to this point.
But a hyperscale data center is much, much larger and can use as much energy or more than a large city in Wisconsin. That is where I think people are starting to see the scale of what's happening with a lot of concern.
Can you explain the scale of data centers and put into perspective the energy and resources that it takes to operate them?
We're seeing these AI data center campuses as large as 2,000 acres in Wisconsin. And so that's quite a large footprint with very large buildings in the hundreds of thousands of square feet. What we're also seeing is that there's going to be a lot of energy use associated with these facilities.
At Clean Wisconsin, we tried to put it in a perspective that people could understand. We're seeing data centers proposed, or now planned, in Wisconsin that are over a gigawatt in terms of their power demand.
Clean Wisconsin did a home to gigawatt comparison. So, how many homes worth of energy demand is that? In Wisconsin, one gigawatt is the energy demand of more than a million homes. We only have, I think, about 2.6 or 2.8 million homes in Wisconsin.
When we look at some of the data centers that have been approved so far, Microsoft, Vantage, the Meta Data Center in Beaver Dam, we are talking about facilities that use far more energy than all of the homes in Wisconsin combined. These facilities will be huge cities worth of energy. I believe Dane County has said that the data center proposed in Dane County will use more than two times as much energy as the entire county uses right now.
When we talk about energy production, we have an enormous gas plant or nuclear power plant's worth of energy will be needed for a single AI data center. Resources that we typically would need for a whole region of Wisconsin would be needed to power one data center.
That's why I'm trying to paint a picture of the scale. Not just Wisconsin, but globally, we've never seen anything like this. When we talk about these projects coming to Wisconsin — one or two or three or four of these big hyperscale data centers — the magnitude of impact is something that is very difficult to get your head around.
What impact does that energy consumption have on local residents in these areas and on businesses?
There are layers of impact. The first, most immediate, impact that we're seeing play out, at least with the data centers that have been approved thus far, is that tech companies want to make sure that those data centers don't go down. So, if we have a power outage or something like that, those data centers stay online because they are not just serving people in Wisconsin, but they're serving people all over the globe, right? It's part of a system.
In order to do that, they have a backup. In the case of Microsoft data center, and from what we understand other data centers, that's diesel generator backups. That means that on the site of the Microsoft data center in Mount Pleasant, they've gotten air permits to have hundreds of diesel generators on site, which will be started at least monthly to test.
If you live near a data center that's got hundreds, if not close to 1,000 diesel generators starting up on site once a month and all the air pollution that brings with it, that's going to have an immediate impact for the people who live right in the area. If you're talking about southeastern Wisconsin, that area is already in nonattainment for air pollution, for ozone air pollution. A diesel generator — a whole bunch of them — is really a terrible thing for the people who are living in these communities.
Secondly, I know there's a lot of concern about water use. Just like if you're sitting with your laptop and you feel like it gets hot on your lap, data centers use a lot of energy and they need to be cooled because of all the processing that's happening within those buildings. Again, these are big, huge, giant windowless buildings with a lot of computer components in them.
It was the case that data centers used a lot of water on-site for cooling. There's new technology that tech companies really like to tout that's called a closed-loop cooling system. They use less water on-site, although they certainly do use water, especially on the hottest, driest days of the year when our water systems are most stressed. But those closed-loop cooling systems can use more energy than the regular ones that use direct water.
Energy comes with a huge water footprint. In Wisconsin, energy production is responsible for more than 70% of water withdrawals. So when you have a data center that's using an entire city or more worth of energy, and you have power plants built to meet those needs, then you're going to see an increase in water withdrawals to cool those power plants.
When we talk about data center water use, we have to look at the entirety of its water use. Not just what's happening on those 2,000 acres, although certainly water will be used, but what's happening in the region.
With the Microsoft data center, we saw a gas plant build out that's underway to serve that data center. We're seeing another, I think, four or five new gas plant proposals in Wisconsin to meet the needs of increasing demand. As that plays out, we need to really understand what that's going to mean for our aquifers, for our lakes and our rivers, for our water systems that we all rely on, again, especially during those hottest, driest days of the year. When we talk about localized impact, those are two really important things to keep in mind.
Then finally, those closed-loop water systems, real information on those is often protected as proprietary by the data center developers and the tech companies. So it's very difficult to get real clarity on those systems, but we do know that they're chemical systems.
It's our understanding that they use PFAS, which are also known as forever chemicals. There's a lot of concern about what happens when those chemicals are disposed of. How are they disposed of? What happens if there's a leak? I don't think we've found any real answers to those things.
Is Wisconsin a hotbed for data centers?
It feels like Wisconsin is a hotbed for data centers, but it almost seems like every state is a hotbed for data centers. Certainly this is not a thing that's unique to Wisconsin. But I will say that since Wisconsin passed tax incentives for tech companies, that's when you started to see data centers really start coming in and getting proposed.
These tech companies, some of the richest companies in the world, in Wisconsin do not have to pay sales tax on their computer components that are going to be in those big AI data center buildings. So I think in that sense, we're a hotbed for data center development.
Also, we have plenty of water here. We have plenty of what a tech company might consider open space. So you'll notice that they're going into agricultural areas. They need 2,000 acres for a campus and they are buying up farmland and settling in. That makes Wisconsin desirable. You're not going to see a big-acre data center plopped down in the middle of New York City. They've got to be in a place where there's going to be room.
You have really accommodating energy utilities that are buying up the parcels of land near the energy generation sites and saying, "OK data center, come here." That happened with We Energies, drawing in the Vantage data center, in fact, telling the developer, hey, you can make this even bigger than you planned. So, you're seeing this wide open door in Wisconsin and certainly tech companies are ready to run through that.
What are some arguments for data centers?
I think you need to ask yourself, what is the benefit of artificial intelligence? Or is there a benefit? That's a question for humanity. A lot of people would argue that artificial intelligence has an enormous amount of potential to solve all kinds of humanity's problems, right? But we do know that one of humanity's big problems is the climate crisis.
We do know that AI data centers are pushing us to a place where we're not going to be able to meet our climate goals if we're not really careful. We're seeing a gas plant boom. We're seeing gas plants getting built all over the place. Sometimes you have a data center and you have a gas plant right on-site. That's not going to get us anywhere when it comes to what some would argue is humanity's biggest problem right now.
I think what you're seeing is — local communities in Wisconsin that have really been starved by the state for revenue need it. That kind of falls to state lawmakers to ensure that small communities get the revenue sharing that they need, and that hasn't happened.
If you've got a multi-billion dollar project happening in a small town and you're going to get tax revenue off of that project and that project's going to pay for some things like upgrades to roads or to infrastructure, then it seems desirable.
You have communities just basically seeing dollar signs that they can get more revenue from a data center than they can get from the current land use, which is typically agriculture. I think the data center developers would say, "Hey, we're coming in here and we're going to bring billions of dollars in construction." And during construction, that is a lot of jobs.
It's unclear how many are local jobs and much of the data center is specialized. So some things will be local jobs...but some things will not be. It's kind of hard to tell how that's going to play out. But certainly while construction is in progress, you'll see a lot of revenue, a lot of economic activity. It's unclear what happens when that's all done.
One thing that I think is a real big fear is that we all know technology changes quickly and things become obsolete really fast. What happens when these hyperscale data centers aren't needed anymore — when they're obsolete — because these are very specialized buildings. So that's also a concern.
I think it's important for communities to understand that when you have a building or a series of buildings that uses as much energy as the entire city of Milwaukee, your community is not going to be the same. It's not going to be like nobody notices that.
I think communities may not fully understand what this intense level of energy need is going to look like and what it's going to be like because we don't have one in Wisconsin. We haven't seen one. We don't really know what they're like.
Looking at data centers in other states, is there a learning lesson, middle ground, or compromise that could make it the best case scenario for this happening where we live?
I think there are a few things happening in other states. Well, first, you try to get something called demand response, which means that the data center or tech company must agree that in times when our energy systems are stressed, that they can back off of their demand a little bit. Maybe we don't need to use all of the energy 24 hours a day, 365 days a year.
Instead of diesel generators, battery storage would be much better for the people in those surrounding communities. Certainly, a tech company that's willing to inject some funding into energy efficiency programs in the state so that we can at least try to get a handle on energy use statewide. Because again, that huge increase in demand is going to be a real issue, a real driver of new power plants.
That's something that I think in Minnesota, for example, you see that some of these tech companies and data centers are required to put more money into different programs that help with energy efficiency and insulation.
And on the campuses themselves, paying attention to wetland preservation and water reuse and different environmental activities to make them as efficient and able to continue to have some habitat.
Any transmission lines that are going to and from the data centers need to go through areas that are not sensitive areas for habitat or wetlands. So those are some things that we're going to be fighting for. And certainly, to power these data centers with wind and solar. We can't just become a state of power plants. It's going to be really unfortunate if that happens.
