Johnson County, Illinois: Power, Data Centers and the Local Economy
Home to Vienna and Goreville
No data center or power plant project is on record in Johnson County, but the national build-out still reaches it through its utility bill, its labor market and the projects next door. Johnson County is home to Vienna and Goreville. 36 MW of new generation is planned here across 1 unit, led by Birch Creek Development (solar). 36 MW of it is already under construction or built. Employers here counted 2,715 jobs in 2025, up 17.2% from 2019 (the 3rd fastest growth of 102 Illinois counties). Next door, Pulaski County has 417 MW of planned generation. Unemployment was 4.5% in August 2026, against 5.8% in 2019.
Cities and towns in Johnson County
Johnson County is home to Vienna and Goreville.
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 Johnson County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Illinois |
|---|---|---|---|---|
| Population (2020 → 2025) | 13,317 | 13,363 | ▲ 0.3% | 77th of 102 by size |
| Total jobs (2019 → 2025) | 2,316 | 2,715 | ▲ 17.2% | 3rd of 102 by growth |
| Average annual pay (2019 → 2025) | $45,562 | $61,127 | ▲ 34.2% | — |
| Unemployment rate (2019 → August 2026) | 5.8% | 4.5% | ▼ 1.3pts | — |
| Planned generation (Aug 2026) | — | 36 MW | no fleet today | 23rd of 57 by size |
Ameren Illinois Company is the largest utility serving Johnson County, one of 4 with territory here. Its residential customers paid an average 15.26¢/kWh in 2024. 13,363 people live here, up 0.3% since 2020.
Who powers Johnson County
Utilities with service territory in Johnson 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% |
| Southeastern IL Elec Coop, Inc | Cooperative | Bundled | 22,731 | 14.47¢ | 12% |
| Egyptian Electric Coop Assn | Cooperative | Bundled | 13,707 | 15.53¢ | 42% |
| Southern Illinois Elec 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.
No operating power plant is located in Johnson County in the EIA-860M inventory. Its power comes over the grid from plants elsewhere.
Planned generation 1
| Plant | Technology | MW | Status | Year | Owner |
|---|---|---|---|---|---|
| Blue Branch Solar | Solar Photovoltaic | 36 MW | Under construction (≤50%) | 2027 | Birch Creek Development |
The Johnson County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 2,715 | $61,127 | 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 Johnson County
No data center, local measure or delayed project is on record in Johnson County. Illinois has 28 local measures on record statewide.
Johnson County and its neighbors
Of the 6 counties that border Johnson County, Pulaski 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 |
|---|---|---|---|---|---|---|
| Johnson County | 13,363 | ▲ 17.2% | — | 36 MW | — | — |
| Massac County | 13,502 | ▼ 7.3% | — | 2 MW | 1 | — |
| Pope County | 3,672 | ▼ 9.1% | — | — | — | — |
| Pulaski County | 4,820 | ▼ 22.9% | 5 MW | 417 MW | — | — |
| Saline County | 22,772 | ▲ 7.0% | 270 MW | 4 MW | — | — |
| Union County | 16,656 | ▲ 3.5% | 2 MW | — | — | — |
| Williamson County | 67,225 | ▲ 4.7% | 266 MW | 12 MW | — | — |
More of Illinois
Johnson County, answered from the record
Who provides electricity in Johnson County, Illinois?
4 utilities have service territory in Johnson County in the EIA-861 2024 report: Ameren Illinois Company, Southeastern IL Elec Coop, Inc, Egyptian Electric Coop Assn, Southern Illinois Elec Coop. The largest, Ameren Illinois Company, charged residential customers 15.26¢/kWh on average in 2024.
How much new power is planned in Johnson County?
36 MW across 1 units in the August 2026 EIA-860M inventory, 36 MW of it under construction or built. The largest owner is Birch Creek Development.
Are there data centers in Johnson County?
The SAVRN Data Center Map has no data center in Johnson County. The nearest activity on record is next door in Pulaski County.
Is Johnson County adding jobs?
Employers counted 2,715 jobs in 2025 against 2,316 in 2019 (+17.2%, BLS QCEW).
Does Johnson County have a data center moratorium?
No county-level measure is on record for Johnson County. Illinois has 28 local measures statewide, listed on the state page.