Clark County, Illinois: Power, Data Centers and the Local Economy
Home to Marshall Township, Marshall and Casey Township
No data center or power plant project is on record in Clark County, but the national build-out still reaches it through its utility bill, its labor market and the projects next door. Clark County is home to Marshall Township, Marshall, Casey Township and Casey. Next door, Sullivan County, Indiana, has 964 MW of planned generation. 166 MW of that came online in 2019 or later, mostly solar. Employers here counted 4,304 jobs in 2025, down 6.5% from 2019. Its power plants have 189 MW of capacity, 88% of it solar.
Cities and towns in Clark County
Clark County is home to Marshall Township, Marshall, Casey Township and Casey.
Unincorporated communities (governed by the county): West Union.
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 Clark County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Illinois |
|---|---|---|---|---|
| Population (2020 → 2025) | 15,456 | 15,114 | ▼ 2.2% | 71st of 102 by size |
| Total jobs (2019 → 2025) | 4,602 | 4,304 | ▼ 6.5% | 81st of 102 by growth |
| Average annual pay (2019 → 2025) | $38,567 | $46,794 | ▲ 21.3% | — |
| Unemployment rate (2019 → August 2026) | 4.5% | 4.1% | ▼ 0.4pts | — |
| Generating capacity added since 2019 | — | 166 MW | — | |
| Generating capacity retired since 2019 | — | 0 MW | — |
Ameren Illinois Company is the largest utility serving Clark County, one of 6 with territory here. Its residential customers paid an average 15.26¢/kWh in 2024. Unemployment was 4.1% in August 2026, against 4.5% in 2019. 15,114 people live here, down 2.2% since 2020.
Who powers Clark County
Net change in operating capacity since 2019: +166 MW. Colors follow the fuel legend above.
Utilities with service territory in Clark 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% |
| Norris Electric Coop | Cooperative | Bundled | 18,074 | 15.08¢ | 26% |
| Coles-Moultrie Electric Coop | Cooperative | Bundled | 8,456 | 17.14¢ | 25% |
| City of Casey - (IL) | — | — | — | — | — |
| Enerstar Power Corp | — | — | — | — | — |
| City of Marshall - (IL) | — | — | — | — | — |
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 4
| Technology | Capacity | Share |
|---|---|---|
| Solar | 166 MW | 88% |
| Petroleum | 22 MW | 12% |
| Largest plants | Owner | Technology | MW | Since |
|---|---|---|---|---|
| River Ferry Solar 1 | River Ferry Solar 1, LLC | Solar | 165 MW | 2023 |
| Marshall (IL) | City of Marshall - (IL) | Petroleum | 17 MW | 2002 |
| Casey City of | City of Casey - (IL) | Petroleum | 5 MW | 2002 |
| Marshall Solar (IL) | Altorfer Inc. | Solar | 1 MW | 2025 |
The Clark County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 4,304 | $46,794 | 1.00 |
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 Clark County
No data center, local measure or delayed project is on record in Clark County. Illinois has 28 local measures on record statewide.
Clark County and its neighbors
Of the 7 counties that border Clark County, Sullivan 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 |
|---|---|---|---|---|---|---|
| Clark County | 15,114 | ▼ 6.5% | 189 MW | — | — | — |
| Coles County | 46,607 | ▲ 0.2% | 301 MW | 300 MW | — | — |
| Crawford County | 18,648 | ▲ 8.2% | 7 MW | — | — | — |
| Cumberland County | 10,208 | ▲ 1.3% | 274 MW | — | — | — |
| Edgar County | 16,323 | ▲ 4.1% | 6 MW | — | — | — |
| Jasper County | 9,032 | ▲ 5.2% | 671 MW | — | — | — |
| Sullivan County IN | 20,831 | ▼ 2.2% | 1,548 MW | 964 MW | — | — |
| Vigo County IN | 106,512 | ▼ 1.8% | 862 MW | — | — | — |
More of Illinois
Clark County, answered from the record
Who provides electricity in Clark County, Illinois?
6 utilities have service territory in Clark County in the EIA-861 2024 report: Ameren Illinois Company, Norris Electric Coop, Coles-Moultrie Electric Coop, City of Casey - (IL). The largest, Ameren Illinois Company, charged residential customers 15.26¢/kWh on average in 2024.
What power plants are in Clark County?
4 operating plants with 189 MW of capacity. The largest is River Ferry Solar 1 (165 MW, solar).
Are there data centers in Clark County?
The SAVRN Data Center Map has no data center in Clark County. The nearest activity on record is next door in Sullivan County.
Is Clark County adding jobs?
Employers counted 4,304 jobs in 2025 against 4,602 in 2019 (-6.5%, BLS QCEW).
Does Clark County have a data center moratorium?
No county-level measure is on record for Clark County. Illinois has 28 local measures statewide, listed on the state page.