St. Charles County, Missouri: Power, Data Centers and the Local Economy
Home to O'Fallon, St. Charles and St. Peters
St. Charles County is one of the places the data center build-out is physically happening. The SAVRN Data Center Map lists 1 data center in St. Charles County. St. Charles County is home to O'Fallon, St. Charles, St. Peters and Wentzville. The Moratorium Tracker holds 1 local measure here (1 in force); the latest is “Six-month data center moratorium”. 1 project is on the Delay Watchlist, including St. Charles County Data Center Moratorium. Owners plan to retire 1,099 MW more by 2035, led by Sioux in 2028.
Cities and towns in St. Charles County
St. Charles County is home to O'Fallon, St. Charles, St. Peters and Wentzville.
- Foristell also extends into Warren County.
Unincorporated communities (governed by the county): Defiance.
Residents are 2025 Census estimates for the part of each city, town or township inside this county. Census publishes no annual estimate for unincorporated communities.
What changed in St. Charles County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Missouri |
|---|---|---|---|---|
| Population (2020 → 2025) | 406,407 | 426,499 | ▲ 4.9% | 3rd of 115 by size |
| Total jobs (2019 → 2025) | 151,936 | 162,655 | ▲ 7.1% | 31st of 115 by growth |
| Average annual pay (2019 → 2025) | $47,693 | $62,680 | ▲ 31.4% | — |
| Construction jobs (2019 → 2025) | 8,817 | 9,841 | ▲ 11.6% | 46th of 71 by growth |
| Electrical contractor jobs (2019 → 2025) | 898 | 994 | ▲ 10.7% | — |
| Unemployment rate (2019 → August 2026) | 2.5% | 3.3% | ▲ 0.8pts | — |
| Generating capacity added since 2019 | — | 0 MW | — | |
| Generating capacity retired since 2019 | — | 0 MW | — |
Construction employs 9,841, up 11.6% since 2019. Its power plants have 1,104 MW of capacity, 100% of it coal, the 9th largest fleet in Missouri. Employers here counted 162,655 jobs in 2025, up 7.1% from 2019. Electrical contractors employ 994, up 10.7% since 2019 against up 21.5% statewide, at an average $76,056 a year. Unemployment was 3.3% in August 2026, against 2.5% in 2019. Union Electric Co - (MO) is the largest utility serving St. Charles County, one of 2 with territory here. Its residential customers paid an average 12.56¢/kWh in 2024. 426,499 people live here, up 4.9% since 2020, 3rd of 115 Missouri counties by population.
Who powers St. Charles County
Utilities with service territory in St. Charles County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Union Electric Co - (MO) | Investor Owned | Bundled | 1,095,619 | 12.56¢ | 44% |
| Cuivre River Electric Coop Inc | Cooperative | Bundled | 72,974 | 11.07¢ | 4% |
Customer counts, prices and sales shares cover each utility's whole system in the state, not only this county. Commercial sales include data centers.
Operating power plants 2
| Technology | Capacity | Share |
|---|---|---|
| Coal | 1,099 MW | 100% |
| Solar | 4 MW | 0% |
| Largest plants | Owner | Technology | MW | Since |
|---|---|---|---|---|
| Sioux | Union Electric Co - (MO) | Coal | 1,099 MW | 1967 |
| O'Fallon Renewable Energy Center | Union Electric Co - (MO) | Solar | 4 MW | 2014 |
Scheduled to retire
| Plant | Technology | MW | Year |
|---|---|---|---|
| Sioux | Coal | 1,099 MW | 2028 |
The St. Charles County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 162,655 | $62,680 | 1.00 |
| Construction | 9,841 | $80,173 | 1.14 |
| Electrical contractors | 994 | $76,056 | 0.85 |
Concentration is the BLS location quotient: 1.0 means the industry holds the same share of local jobs as it does nationally. Industry rows count private employers; cells BLS suppresses are left out.
Data centers and local rules in St. Charles County
1 data center in St. Charles County is on the SAVRN Data Center Map.
Local measures 1
| Measure | Status | Date | |
|---|---|---|---|
| Six-month data center moratorium | In force | 2026-07 |
Delay Watchlist 1
| Project | Status | Cause | MW | |
|---|---|---|---|---|
| St. Charles County Data Center Moratorium | moratorium in force | — |
St. Charles County and its neighbors
Of the 7 counties that border St. Charles County, St. Louis County carries the most build-out activity: data centers, planned generation and operating plants combined.
| County | Population | Jobs since 2019 | Operating MW | Planned MW | Data centers | Local measures |
|---|---|---|---|---|---|---|
| St. Charles County | 426,499 | ▲ 7.1% | 1,104 MW | — | 1 | 1 |
| Calhoun County IL | 4,300 | ▲ 4.5% | — | — | — | — |
| Franklin County | 108,090 | ▲ 0.6% | 2,389 MW | — | — | — |
| Jersey County IL | 21,160 | ▲ 3.6% | 110 MW | — | — | — |
| Lincoln County | 66,676 | ▲ 9.4% | 150 MW | — | — | — |
| Madison County IL | 263,110 | ▲ 5.9% | 701 MW | 8 MW | — | — |
| St. Louis County | 990,911 | ▼ 3.4% | 34 MW | 648 MW | 7 | — |
| Warren County | 39,016 | ▲ 17.8% | 439 MW | — | — | — |
More of Missouri
St. Charles County, answered from the record
Who provides electricity in St. Charles County, Missouri?
2 utilities have service territory in St. Charles County in the EIA-861 2024 report: Union Electric Co - (MO), Cuivre River Electric Coop Inc. The largest, Union Electric Co - (MO), charged residential customers 12.56¢/kWh on average in 2024.
What county is O'Fallon, MO in?
O'Fallon is in St. Charles County, Missouri. About 96,101 people live there (2025 Census estimate).
What county is St. Charles, MO in?
St. Charles is in St. Charles County, Missouri. About 72,561 people live there (2025 Census estimate).
What county is St. Peters, MO in?
St. Peters is in St. Charles County, Missouri. About 61,479 people live there (2025 Census estimate).
What power plants are in St. Charles County?
2 operating plants with 1,104 MW of capacity. The largest is Sioux (1,099 MW, coal).
Are there data centers in St. Charles County?
Yes. The SAVRN Data Center Map lists 1 data center in St. Charles County.
Is St. Charles County adding jobs?
Employers counted 162,655 jobs in 2025 against 151,936 in 2019 (+7.1%, BLS QCEW). Construction went from 8,817 to 9,841.
Does St. Charles County have a data center moratorium?
The SAVRN Moratorium Tracker holds 1 local measure for St. Charles County, 1 in force.