What happened in this Energy story?

Ameren Missouri's 20-year integrated resource plan would raise natural gas from about 5% to 60% of its generation mix by 2045, adding 10.6 GW of new gas capacity to serve surging data-center demand while retiring every coal plant in its fleet.

What is a key fact in this story? (1)

**Ameren Missouri** filed a 20-year integrated resource plan raising natural gas from ~5% to 60% of its generation mix by 2045, while retiring all coal — including Sioux Energy Center by end of 2035 and all four Labadie Energy Center units by end of 2042.

What is a key fact in this story? (2)

The plan adds **10.6 GW of new gas** alongside 3.6 GW of solar, 1.5 GW of wind, 2.4 GW of storage, and 1.2 GW of new nuclear, with both advanced large-scale reactors and small modular reactors under consideration and an extension sought for the Callaway nuclear plant beyond 2044.

Ameren Missouri Plan Shifts to 60% Gas, Retires All Coal — SkimNews

By Utility Dive · Summarized & edited by Kapil Samant · 2026-09-30

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Ameren Missouri filed a 20-year integrated resource plan raising natural gas from ~5% to 60% of its generation mix by 2045, while retiring all coal — including Sioux Energy Center by end of 2035 and all four Labadie Energy Center units by end of 2042.
The plan adds 10.6 GW of new gas alongside 3.6 GW of solar, 1.5 GW of wind, 2.4 GW of storage, and 1.2 GW of new nuclear, with both advanced large-scale reactors and small modular reactors under consideration and an extension sought for the Callaway nuclear plant beyond 2044.
Data center load is the stated driver: base customer deliveries are projected to grow 60% from 2027 to 2030, large-load deliveries are forecast to compound at 20% annually from ~1,400 GWh in 2027 to 44,676 GWh in 2046, and Ameren has committed to 2.8 GW of large-load demand by 2030 — nearly double its 1.5 GW 2025 forecast.
Sierra Club strategist Jenn DeRose called the plan "pollution-heavy" and said Ameren is "still digging," while Ameren Corp. Chairman, President and CEO Martin Lyons Jr. said it provides "a clear path for maintaining reliability."
Ameren separately filed a $343 million rate increase in June that could raise residential monthly bills by about 10%, per local news reports — a separate cost that could land on customers even before the new gas capacity comes online.

Why it matters: Ameren Missouri is locking in a gas-dominant fleet through 2045 even as environmental groups attack the buildout and the company itself retires coal — meaning Missouri ratepayers could end up paying for both the $343 million rate hike and the new gas infrastructure needed to power data centers, with 2.8 GW of large-load demand already committed by 2030.