Missouri hearings Nov. 18 on Ameren's 2,100 MW West Alton plant, which has no price tag
The hearings open the first public fight over who pays to build the largest plant in Ameren's $38.1 billion plan before it earns anything in 2031, a bill shareholders partially fund with roughly $5 billion of new shares.
Vincent Jiangtwo-minute read
A notice in the mail, a plant with no price
A St. Louis customer who received Ameren's−0.30% — Ameren, down 0.30 percent as of its last quote notice as a PDF posted it to Reddit this month with one question: is this a rate increase? 7. Missouri's Public Service Commission takes that question in public on November 18, at St 1. Charles Community College in Cottleville, and by video on November 19, under case EA-2026-0226 1. What the notice does not contain is a number: Ameren has published no construction cost for the West Alton Energy Center, citing its procurement process 1.
The biggest plant in a $38.1 billion plan
West Alton is a 2,100-megawatt combined-cycle gas plant with three units built to run around the clock, filed in July to open in 2031 beside the six-decade-old Sioux plant, which Ameren plans to retire by the end of 2035 13. It is the largest single piece of the roughly 7.7 gigawatts Ameren Missouri plans to add from 2027 through 2031, an increase of about 80% in the utility's generating capacity, inside a $38.1 billion five-year capital plan 2.
West Alton is the biggest announced plant, and it lands last
West Alton is the largest single piece of Ameren Missouri's 5.3 GW of announced plants
Data
| Value | |
|---|---|
| Under construction (2027–28) | 2.3 GW |
| Solar and storage (2028–29) | 1.0 GW |
| West Alton gas (2031) | 2.1 GW |
Who carries four years of construction
The filing asks the commission to decide which costs can be recovered while the plant is still being built, a Construction Work in Progress approach that became legal under Missouri law in 2025 134. Ameren says collecting earlier would cut financing costs and cites a 2024 state analysis it says lowers project costs by millions 134.
Senate Bill 4 is the law in the way: large users must cover all upfront grid connection costs and a share of generation costs 1. Google and Amazon+1.60% — Amazon, up 1.60 percent today, named on last week's earnings call, sit inside the 2.8 gigawatts of signed service agreements with $25 billion of announced Missouri investment, and 5.6 gigawatts more wait behind them in the pipeline 26. Grant recovery without a fixed allocation and existing customers carry a data-center plant; refuse it and Ameren funds the build with debt and about $5 billion of new shares, of which $1.7 billion is already sold forward 2.
Capital spending jumped 45% in Q3 2026 as the buildout ramps
Data
| Capex | |
|---|---|
| Q4 '23 | $1.14B |
| Q1 '24 | $0.9B |
| Q2 '24 | $1.03B |
| Q3 '24 | $1.16B |
| Q4 '24 | $1.32B |
| Q1 '25 | $1.08B |
| Q2 '25 | $1.07B |
| Q3 '25 | $0.99B |
| Q4 '25 | $1.04B |
| Q1 '26 | $1.6B |
| Q2 '26 | $1.08B |
| Q3 '26 | $1.44B |
The calendar decides it
The evidentiary hearing is set for April 2027 and Ameren has asked for a decision by early spring 2027 1. The commission also expects to rule by May 2027 on a separate $343 million rate request, with new rates due June 2027 5. Watch the November 18 testimony and, above all, whether a price for West Alton appears before the vote 5. The biggest plant in Ameren's plan has a hearing calendar and no price tag.
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