Ameren Missouri wants $343 million more a year from its electric customers, and the average household would pay about $13 extra each month if regulators agree. The utility filed the request with the Missouri Public Service Commission on June 26. New rates would start in mid-2027 after an 11-month review.
The $13 figure is for a customer using 1,011 kilowatt-hours. Ameren says the money would cover upgrades to older grid equipment, spending under its Smart Energy Plan and storm-resilience work in St. Louis and southeast Missouri following the destructive 2025 tornadoes. It also expects three energy centers to be running by the end of 2026, adding about 400 megawatts of generation.
In its news release, the company said the investments bring “significant reliability and economic benefits to Missouri families and businesses.”
The data center question
Much of the argument will turn on who pays for the growth in power demand from so-called large-load customers, a group that includes data centers. Steven Willis, Ameren Missouri’s director of regulatory affairs, said that by the end of 2029 these new users are expected to draw more than half as much electricity as every other customer in the territory combined. That territory covers most of Eastern Missouri.
Meeting that demand tends to mean new plants and lines built on a tight schedule. Ameren says big users will foot the bill for certain grid connections and pay higher rates. But the cost of new generation is not walled off, and it gets spread across all customers.
Geoff Marke, chief economist at the Missouri Office of Public Counsel, put the worry bluntly in a March memo. “Data centers have already raised the cost of service for electric utilities through socialized transmission costs, volatile wholesale markets, and increased costs for generation, transmission and distribution investments driven by unprecedented demand,” he wrote. He added that failing to charge data centers for the power they “alone need and want will raise electric bills in St. Louis and for the rest of Ameren Missouri’s service territory.”
Ameren points to protections it has written into its Large Load Tariff. Those customers must sign agreements, cover the cost of imported power while new plants are being built, and accept a base rate above what other large industrial customers pay. The company told the Fulton Sun this arrangement would save average customers $21.2 million combined.
What happens next
Over the 11 months, PSC staff will go through Ameren’s books and facilities, and consumer advocates can contest whether the spending belongs on customers’ bills. Groups wanting a seat in the case had until July 15 to join. The Consumers Council of Missouri has already moved to intervene, and the Office of Public Counsel is also expected to take part.
As of Wednesday, no public hearings had been scheduled. The PSC says customers will be told directly by Ameren and by the commission when dates are set. Comments can go to [email protected] or 800-392-4211.
Sources
- Missouri rate case could add $13 to power bills as data center demand keeps climbing
- Ameren Missouri proposes rate hike, monthly bills could rise by $13
