# Warren County, Illinois: Power, Data Centers and the Local Economy Home to Monmouth Township, Monmouth and Roseville Township No data center or power plant project is on record in Warren County, but the national build-out still reaches it through its utility bill, its labor market and the projects next door. Warren County is home to Monmouth Township, Monmouth, Roseville Township and Spring Grove Township. Next door, Mercer County has 1 data center. Electrical contractors employ 10, up 25.0% since 2019 against up 3.9% statewide, at an average $52,130 a year. 35 MW of that came online in 2019 or later, mostly solar. Its power plants have 35 MW of capacity, 100% of it solar. 35 MW of operating power plants, mostly solar -0.8% total jobs since 2019, now 6,346 15.26¢ per kWh for Ameren Illinois Company residential customers, 2024 ## Cities and towns in Warren County Warren County is home to Monmouth Township, Monmouth, Roseville Township and Spring Grove Township. Monmouth Township9,599 residents Monmouth8,599 residents Roseville Township1,116 residents Spring Grove Township932 residents Tompkins Township857 residents Roseville843 residents Kirkwood650 residents Greenbush Township521 residents Sumner Township476 residents Alexis425 residents · 56% of the city Coldbrook Township423 residents Floyd Township399 residents Kelly Township355 residents Hale Township318 residents Ellison Township306 residents Berwick Township297 residents Little York267 residents Lenox Township259 residents Swan Township232 residents Point Pleasant Township132 residents - Alexis also extends into [Mercer County](https://savrn.com/power-supply-chain-map/illinois/mercer-county). Unincorporated communities (governed by the county): Cameron. 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 Warren County | Measure | Then | Now | Change | Rank in Illinois | |---|---|---|---|---| | Population (2020 → 2025) | 16,837 | 16,222 | ▼ 3.7% | 65th of 102 by size | | Total jobs (2019 → 2025) | 6,396 | 6,346 | ▼ 0.8% | 53rd of 102 by growth | | Average annual pay (2019 → 2025) | $37,276 | $46,233 | ▲ 24.0% | — | | Electrical contractor jobs (2019 → 2025) | 8 | 10 | ▲ 25.0% | — | | Unemployment rate (2019 → August 2026) | 4.2% | 3.6% | ▼ 0.6pts | — | | Generating capacity added since 2019 | — | 35 MW | | — | | Generating capacity retired since 2019 | — | 0 MW | | — | Unemployment was 3.6% in August 2026, against 4.2% in 2019. Ameren Illinois Company is the largest utility serving Warren County, one of 2 with territory here. Its residential customers paid an average 15.26¢/kWh in 2024. Employers here counted 6,346 jobs in 2025, down 0.8% from 2019. 16,222 people live here, down 3.7% since 2020. ## Who powers Warren County ### Utilities with service territory in Warren County | Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales | |---|---|---|---|---|---| | Ameren Illinois Company | Investor Owned | Bundled | 1,060,894 | 15.26¢ | 28% | | McDonough Power Coop | — | — | — | — | — | 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 | |---|---|---| | Solar | 35 MW | 100% | | Largest plants | Owner | Technology | MW | Since | |---|---|---|---|---| | Earp Solar, LLC | Birch Creek Power, LLC | Solar | 35 MW | 2024 | ## The Warren County labor market | Industry (2025) | Jobs | Average pay | Concentration vs U.S. | |---|---|---|---| | All industries | 6,346 | $46,233 | 1.00 | | Electrical contractors | 10 | $52,130 | 0.22 | 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 Warren County No data center, local measure or delayed project is on record in Warren County. Illinois has 28 local measures on record statewide. ## Warren County and its neighbors Of the 5 counties that border Warren County, Mercer 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 | |---|---|---|---|---|---|---| | Warren County | 16,222 | ▼ 0.8% | 35 MW | — | — | — | | Fulton County](https://savrn.com/power-supply-chain-map/illinois/fulton-county) | 32,901 | ▲ 4.6% | 156 MW | — | — | — | | Henderson County](https://savrn.com/power-supply-chain-map/illinois/henderson-county) | 5,984 | ▲ 8.8% | 1 MW | — | — | — | | Knox County](https://savrn.com/power-supply-chain-map/illinois/knox-county) | 47,767 | ▼ 2.4% | 16 MW | 5 MW | 1 | — | | McDonough County](https://savrn.com/power-supply-chain-map/illinois/mcdonough-county) | 25,916 | ▼ 7.2% | 171 MW | 10 MW | — | — | | Mercer County](https://savrn.com/power-supply-chain-map/illinois/mercer-county) | 15,229 | ▲ 1.0% | 10 MW | 42 MW | 1 | — | ## More of Illinois [All Illinois countiesThe state power page and county mapOpen →](https://savrn.com/power-supply-chain-map/illinois)[Knox County47,767 peopleOpen →](https://savrn.com/power-supply-chain-map/illinois/knox-county)[Fulton County32,901 peopleOpen →](https://savrn.com/power-supply-chain-map/illinois/fulton-county)[McDonough County25,916 peopleOpen →](https://savrn.com/power-supply-chain-map/illinois/mcdonough-county)[Mercer County15,229 peopleOpen →](https://savrn.com/power-supply-chain-map/illinois/mercer-county)[Henderson County5,984 peopleOpen →](https://savrn.com/power-supply-chain-map/illinois/henderson-county) ## Warren County, answered from the record ### Who provides electricity in Warren County, Illinois? 2 utilities have service territory in Warren County in the EIA-861 2024 report: Ameren Illinois Company, McDonough Power Coop. The largest, Ameren Illinois Company, charged residential customers 15.26¢/kWh on average in 2024. ### What power plants are in Warren County? 1 operating plant with 35 MW of capacity. The largest is Earp Solar, LLC (35 MW, solar). ### Are there data centers in Warren County? The SAVRN Data Center Map has no data center in Warren County. The nearest activity on record is next door in Mercer County. ### Is Warren County adding jobs? Employers counted 6,346 jobs in 2025 against 6,396 in 2019 (-0.8%, BLS QCEW). ### Does Warren County have a data center moratorium? No county-level measure is on record for Warren County. Illinois has 28 local measures statewide, listed on the state page. --- Canonical: https://savrn.com/power-supply-chain-map/illinois/warren-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/).