Rock County, Wisconsin: Power, Data Centers and the Local Economy
Home to Janesville, Beloit and Milton
Rock County supplies the labor the power build-out runs on. Electrical contractors employ 995, up 99.0% since 2019 against up 21.6% statewide, at an average $67,887 a year. Rock County is home to Janesville, Beloit, Milton and most of Edgerton (5,976 of its 6,121 residents). The Moratorium Tracker holds 1 local measure here (1 in force); the latest is “Town of Janesville (Rock County) data center moratorium (proposed)”. Construction employs 4,084, up 23.0% since 2019. 1,146 MW of that came online in 2019 or later, mostly natural gas.
Cities and towns in Rock County
Rock County is home to Janesville, Beloit, Milton and most of Edgerton (5,976 of its 6,121 residents).
And 1 smaller places.
- Edgerton also extends into Dane County.
- Brodhead also extends into Green County.
Unincorporated communities (governed by the county): Fulton, Hanover, Shopiere.
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 Rock County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Wisconsin |
|---|---|---|---|---|
| Population (2020 → 2025) | 163,763 | 166,472 | ▲ 1.7% | 9th of 72 by size |
| Total jobs (2019 → 2025) | 67,791 | 69,744 | ▲ 2.9% | 19th of 72 by growth |
| Average annual pay (2019 → 2025) | $47,925 | $62,479 | ▲ 30.4% | — |
| Construction jobs (2019 → 2025) | 3,321 | 4,084 | ▲ 23.0% | 24th of 61 by growth |
| Electrical contractor jobs (2019 → 2025) | 500 | 995 | ▲ 99.0% | — |
| Data processing and hosting jobs (2019 → 2025) | 658 | 422 | ▼ 35.9% | — |
| Unemployment rate (2019 → August 2026) | 3.6% | 3.7% | ▲ 0.1pts | — |
| Generating capacity added since 2019 | — | 1,146 MW | — | |
| Generating capacity retired since 2019 | — | 212 MW | — |
Next door, Dane County has 9 data centers and 361 MW of planned generation. Its power plants have 1,829 MW of capacity, 77% of it natural gas, the 2nd largest fleet in Wisconsin. 212 MW has retired here since 2019, including Rock River (natural gas, 169 MW, 2020). Employers here counted 69,744 jobs in 2025, up 2.9% from 2019. Wisconsin Electric Power Co is the largest utility serving Rock County, one of 6 with territory here. Its residential customers paid an average 19.23¢/kWh in 2024, above the 13.25¢ median for Wisconsin utilities. Unemployment was 3.7% in August 2026, against 3.6% in 2019. 166,472 people live here, up 1.7% since 2020, 9th of 72 Wisconsin counties by population.
Who powers Rock County
Net change in operating capacity since 2019: +934 MW. Colors follow the fuel legend above.
Utilities with service territory in Rock County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| Wisconsin Electric Power Co | Investor Owned | Bundled | 1,048,148 | 19.23¢ | 38% |
| Wisconsin Power & Light Co | Investor Owned | Bundled | 437,211 | 16.89¢ | 22% |
| City of Stoughton - (WI) | Municipal | Bundled | 8,391 | 12.60¢ | 41% |
| Rock Energy Cooperative | Cooperative | Bundled | 7,310 | 14.47¢ | 18% |
| City of Evansville | Municipal | Bundled | 3,806 | 15.83¢ | 42% |
| Brodhead Water & Lighting Comm | Municipal | Bundled | 1,545 | 13.21¢ | 45% |
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 11
| Technology | Capacity | Share |
|---|---|---|
| Natural gas | 1,401 MW | 77% |
| Solar | 425 MW | 23% |
| Other technologies | 3 MW | 0% |
| Largest plants | Owner | Technology | MW | Since |
|---|---|---|---|---|
| West Riverside Energy Center | Wisconsin Power & Light Co | Natural gas | 728 MW | 2020 |
| Riverside Energy Center | Wisconsin Power & Light Co | Natural gas | 675 MW | 2004 |
| Darien Solar | Wisconsin Electric Power Co | Solar | 250 MW | 2025 |
| Paddock Solar | Wisconsin Power & Light Co | Solar | 65 MW | 2023 |
| Albany Solar (WI) | Wisconsin Power & Light Co | Solar | 50 MW | 2023 |
| North Rock | Wisconsin Power & Light Co | Solar | 50 MW | 2022 |
Retired since 2019
| Plant | Technology | MW | Year |
|---|---|---|---|
| Rock River | Natural gas | 169 MW | 2020 |
| Sheepskin | Natural gas | 42 MW | 2020 |
| Fairbanks Morse Engine | Petroleum | 2 MW | 2021 |
The Rock County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 69,744 | $62,479 | 1.00 |
| Construction | 4,084 | $83,520 | 1.11 |
| Electrical contractors | 995 | $67,887 | 1.98 |
| Data processing and hosting | 422 | $62,833 | 1.95 |
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 Rock County
Local measures 1
| Measure | Status | Date | |
|---|---|---|---|
| Town of Janesville (Rock County) data center moratorium (proposed) | In force | 2026-08 |
Rock County and its neighbors
Of the 6 counties that border Rock County, Dane 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 |
|---|---|---|---|---|---|---|
| Rock County | 166,472 | ▲ 2.9% | 1,829 MW | — | — | 1 |
| Boone County IL | 53,568 | ▼ 37.4% | 18 MW | 18 MW | — | — |
| Dane County | 590,375 | ▲ 4.9% | 1,172 MW | 361 MW | 9 | 2 |
| Green County | 37,227 | ▼ 0.5% | — | — | — | 1 |
| Jefferson County | 86,505 | ▲ 0.5% | 760 MW | 249 MW | — | — |
| Walworth County | 106,127 | ▲ 8.1% | 26 MW | 324 MW | — | — |
| Winnebago County IL | 283,674 | ▼ 0.3% | 520 MW | 11 MW | — | — |
More of Wisconsin
Rock County, answered from the record
Who provides electricity in Rock County, Wisconsin?
6 utilities have service territory in Rock County in the EIA-861 2024 report: Wisconsin Electric Power Co, Wisconsin Power & Light Co, City of Stoughton - (WI), Rock Energy Cooperative. The largest, Wisconsin Electric Power Co, charged residential customers 19.23¢/kWh on average in 2024.
What county is Janesville, WI in?
Janesville is in Rock County, Wisconsin. About 66,929 people live there (2025 Census estimate).
What county is Beloit, WI in?
Beloit is in Rock County, Wisconsin. About 36,649 people live there (2025 Census estimate).
What power plants are in Rock County?
11 operating plants with 1,829 MW of capacity. The largest is West Riverside Energy Center (728 MW, natural gas).
Are there data centers in Rock County?
The SAVRN Data Center Map has no data center in Rock County. The nearest activity on record is next door in Dane County.
Is Rock County adding jobs?
Employers counted 69,744 jobs in 2025 against 67,791 in 2019 (+2.9%, BLS QCEW). Construction went from 3,321 to 4,084.
Does Rock County have a data center moratorium?
The SAVRN Moratorium Tracker holds 1 local measure for Rock County, 1 in force.