# St. Louis County, Missouri: Power, Data Centers and the Local Economy Home to Florissant, Chesterfield and Wildwood The data center boom is not abstract in St. Louis County: it is on the ground here. The SAVRN Data Center Map lists 7 data centers in St. Louis County, 8% of Missouri's total. St. Louis County is home to Florissant, Chesterfield, Wildwood and University City. 1,041 MW has retired here since 2019, including Meramec (coal, 648 MW, 2022). 648 MW of new generation is planned here across 3 units, led by Union Electric Co - (MO) (natural gas), the largest pipeline among Missouri's counties. Construction employs 32,990, up 11.9% since 2019. 7 data centers on the SAVRN Data Center Map, 8% of Missouri's 1,041 MW of generating capacity retired since 2019 648 MW of new generation planned here, natural gas leading ## Cities and towns in St. Louis County St. Louis County is home to Florissant, Chesterfield, Wildwood and University City. Florissant51,124 residents Chesterfield49,309 residents Wildwood34,955 residents University City34,657 residents Ballwin30,901 residents Kirkwood29,331 residents Maryland Heights27,559 residents Hazelwood24,849 residents Webster Groves23,450 residents Creve Coeur18,480 residents Manchester18,069 residents Ferguson17,953 residents Clayton17,807 residents Overland15,474 residents Eureka13,341 residents Jennings13,093 residents St. Ann12,617 residents Crestwood12,207 residents Town and Country11,619 residents Bridgeton11,277 residents Bellefontaine Neighbors10,368 residents Ellisville10,315 residents Des Peres9,102 residents Richmond Heights9,093 residents And 16 smaller places. Unincorporated communities (governed by the county): Affton, Castle Point, Concord, Glasgow Village, Lemay, Mehlville, Oakville, Old Jamestown, Sappington, Spanish Lake, St. George. 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. Louis County | Measure | Then | Now | Change | Rank in Missouri | |---|---|---|---|---| | Population (2020 → 2025) | 1,003,365 | 990,911 | ▼ 1.2% | 1st of 115 by size | | Total jobs (2019 → 2025) | 610,438 | 589,803 | ▼ 3.4% | 93rd of 115 by growth | | Average annual pay (2019 → 2025) | $61,534 | $78,741 | ▲ 28.0% | — | | Construction jobs (2019 → 2025) | 29,488 | 32,990 | ▲ 11.9% | 45th of 71 by growth | | Electrical contractor jobs (2019 → 2025) | 4,131 | 4,381 | ▲ 6.1% | — | | Power line construction jobs (2019 → 2025) | 810 | 1,223 | ▲ 51.0% | — | | Data processing and hosting jobs (2019 → 2025) | 3,234 | 3,661 | ▲ 13.2% | — | | Unemployment rate (2019 → August 2026) | 3.1% | 4.2% | ▲ 1.1pts | — | | Generating capacity added since 2019 | — | 0 MW | | — | | Generating capacity retired since 2019 | — | 1,041 MW | | — | | Planned generation (Aug 2026) | — | 648 MW | 1895% of today's fleet | 1st of 14 by size | Unemployment was 4.2% in August 2026, against 3.1% in 2019. Electrical contractors employ 4,381, up 6.1% since 2019 against up 21.5% statewide, at an average $95,158 a year. Employers here counted 589,803 jobs in 2025, down 3.4% from 2019. Its power plants have 34 MW of capacity, 100% of it natural gas. Union Electric Co - (MO) is the largest utility serving St. Louis County. Its residential customers paid an average 12.56¢/kWh in 2024. 990,911 people live here, down 1.2% since 2020, 1st of 115 Missouri counties by population. ## Who powers St. Louis County ### Utilities with service territory in St. Louis 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% | 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 | Technology | Capacity | Share | |---|---|---| | Natural gas | 34 MW | 100% | | Largest plants | Owner | Technology | MW | Since | |---|---|---|---|---| | Trigen St. Louis | Centerstream STL, LLC | Natural gas | 34 MW | 1999 | ### Planned generation | Plant | Technology | MW | Status | Year | Owner | |---|---|---|---|---|---| | Castle Bluff Energy Center | Natural Gas Fired Combustion Turbine | 216 MW | Planned, approvals not started | 2027 | Union Electric Co - (MO) | | Castle Bluff Energy Center | Natural Gas Fired Combustion Turbine | 216 MW | Planned, approvals not started | 2027 | Union Electric Co - (MO) | | Castle Bluff Energy Center | Natural Gas Fired Combustion Turbine | 216 MW | Planned, approvals not started | 2027 | Union Electric Co - (MO) | ### Retired since 2019 | Plant | Technology | MW | Year | |---|---|---|---| | Meramec | Coal | 648 MW | 2022 | | Meramec | Natural gas | 331 MW | 2022 | | Meramec | Petroleum | 62 MW | 2022 | ## The St. Louis County labor market | Industry (2025) | Jobs | Average pay | Concentration vs U.S. | |---|---|---|---| | All industries | 589,803 | $78,741 | 1.00 | | Construction | 32,990 | $96,451 | 1.06 | | Electrical contractors | 4,381 | $95,158 | 1.03 | | Power and communication line construction | 1,223 | $99,019 | 1.28 | | Data processing and hosting | 3,661 | $169,987 | 2.00 | 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. Louis County 7 data centers in St. Louis County are on the SAVRN Data Center Map: [see them by city and operator](https://savrn.com/data-center-map/missouri#p-st-louis). ## St. Louis County and its neighbors Of the 7 counties that border St. Louis County, St. Louis (city) 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. Louis County | 990,911 | ▼ 3.4% | 34 MW | 648 MW | 7 | — | | Franklin County](https://savrn.com/power-supply-chain-map/missouri/franklin-county) | 108,090 | ▲ 0.6% | 2,389 MW | — | — | — | | Jefferson County](https://savrn.com/power-supply-chain-map/missouri/jefferson-county) | 233,132 | ▲ 3.4% | — | — | — | — | | Madison County](https://savrn.com/power-supply-chain-map/illinois/madison-county) IL | 263,110 | ▲ 5.9% | 701 MW | 8 MW | — | — | | Monroe County](https://savrn.com/power-supply-chain-map/illinois/monroe-county) IL | 34,840 | ▲ 1.4% | 38 MW | — | — | — | | St. Charles County](https://savrn.com/power-supply-chain-map/missouri/st-charles-county) | 426,499 | ▲ 7.1% | 1,104 MW | — | 1 | 1 | | St. Clair County](https://savrn.com/power-supply-chain-map/illinois/st-clair-county) IL | 250,708 | ▼ 3.2% | 1,821 MW | 155 MW | — | — | | St. Louis (city)](https://savrn.com/power-supply-chain-map/missouri/st-louis-city) | 278,144 | ▼ 4.0% | — | — | 14 | — | ## More of Missouri [All Missouri countiesThe state power page and county mapOpen →](https://savrn.com/power-supply-chain-map/missouri)[St. Charles County426,499 peopleOpen →](https://savrn.com/power-supply-chain-map/missouri/st-charles-county)[St. Louis (city)278,144 peopleOpen →](https://savrn.com/power-supply-chain-map/missouri/st-louis-city)[Jefferson County233,132 peopleOpen →](https://savrn.com/power-supply-chain-map/missouri/jefferson-county)[Franklin County108,090 peopleOpen →](https://savrn.com/power-supply-chain-map/missouri/franklin-county) ## St. Louis County, answered from the record ### Who provides electricity in St. Louis County, Missouri? 1 utility has service territory in St. Louis County in the EIA-861 2024 report: Union Electric Co - (MO). The largest, Union Electric Co - (MO), charged residential customers 12.56¢/kWh on average in 2024. ### What county is Florissant, MO in? Florissant is in St. Louis County, Missouri. About 51,124 people live there (2025 Census estimate). ### What county is Chesterfield, MO in? Chesterfield is in St. Louis County, Missouri. About 49,309 people live there (2025 Census estimate). ### What county is Wildwood, MO in? Wildwood is in St. Louis County, Missouri. About 34,955 people live there (2025 Census estimate). ### What power plants are in St. Louis County? 1 operating plant with 34 MW of capacity. The largest is Trigen St. Louis (34 MW, natural gas). ### How much new power is planned in St. Louis County? 648 MW across 3 units in the August 2026 EIA-860M inventory, 0 MW of it under construction or built. The largest owner is Union Electric Co - (MO). ### Are there data centers in St. Louis County? Yes. The SAVRN Data Center Map lists 7 data centers in St. Louis County. ### Is St. Louis County adding jobs? Employers counted 589,803 jobs in 2025 against 610,438 in 2019 (-3.4%, BLS QCEW). Construction went from 29,488 to 32,990. ### Does St. Louis County have a data center moratorium? No county-level measure is on record for St. Louis County. Missouri has 21 local measures statewide, listed on the state page. --- Canonical: https://savrn.com/power-supply-chain-map/missouri/st-louis-county Updated: 2026-10-08. Refreshed weekly by SAVRN from EIA, BLS, BEA, Census and the SAVRN trackers. License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/).