Mastercard is building a new solar facility to power its data center in O’Fallon, Missouri.
Construction began on the 40-acre project next to the St. Louis campus this spring.
The O’Fallon data center is the company’s largest in the U.S. and has significant energy needs, said Ellen Jackowski, chief sustainability officer at Mastercard. The center processes global transactions and runs artificial intelligence programs.
“Last year, it accounted for more than a third of Mastercard's annual electricity consumption,” Jackowski said. “So to put that into context: That's roughly equivalent to the electricity consumption of about 4,000 residential homes. So it's pretty significant.”
The O’Fallon location already generates about 10% of its annual electricity from an onsite solar array, but the company has committed to using 100% renewable electricity and plans to reach net-zero emissions by 2040. To get closer to that goal, Mastercard decided to build this solar project, which will be a closed system that provides energy only to the business.
“We grow the company by doing good, by bringing positive impact to society and the planet,” Jackowski said. “So for us, that includes operating efficiently, and our shift to renewable energy is a key part of that.”
It is significant that the company is doing this outside of Ameren’s system, said James Owen, executive director of Renew Missouri, a nonprofit that promotes clean energy.
“I think it is going to be a trend you're going to see, especially as Ameren is going to be moving more towards gas and more towards, I guess, potentially nuclear power,” Owen said. “This is something that large-scale customers don't want, and you're going to start seeing more of them go behind the [utility] meter.”
Ameren’s grid at this location is the dirtiest across all of Mastercard’s U.S. portfolio, according to testimony at a January zoning meeting from Andy Stancati, a senior vice president at BioStar Renewables, the developer of the project on behalf of MasterCard.
“This is one thing that’s helping keep that facility there,” Stancati said in January. “Because of how dirty the power is, there is an alternate option out there of them having to move facilities.”
A spokesperson said that Stancati does not represent or speak for Mastercard and it is not considering moving its St. Louis data facility.
About 60% of Ameren’s energy comes from coal, according to Ameren. Coal is responsible for significant planet-warming greenhouse gases, and burning coal for power emits more carbon than burning natural gas, according to the U.S. Environmental Protection Agency.
Owen said Ameren deserves credit for building a lot of solar for its Renewable Solutions program that provides clean energy subscriptions for industrial customers, but he said recent trends in St. Louis and Kansas City show big companies like Meta, Google and Mastercard aren’t happy with the cleanliness of current energy sources.
“Ameren and the St. Louis area and the state of Missouri should be embarrassed by how coal-reliant we've remained in the state for as long as we have,” Owen said.
In the coming years, Ameren plans to move away from coal. The utility recently announced it will build two new natural gas plants. Natural gas still emits greenhouse gases, but Ameren says to reach its own net-zero goal by 2045, it plans to use carbon capture or other technologies to clean up air pollution.
Jackowski said there are both financial and non-financial reasons Mastercard is pursuing renewable energy. The company’s 2024 annual report, released last week, and shows Mastercard grew net revenue while also reducing greenhouse gas emissions.
“We're seeing signs of decoupling growth from emissions, which is really significant,” Jackowski said.
Mastercard expects the new solar facility to be connected and providing electricity before 2027.
This story has been updated with information from a Mastercard spokesperson.
