Madison County, Iowa: Power, Data Centers and the Local Economy
Home to Winterset and Earlham
The data center boom is not abstract in Madison County: it is on the ground here. Electrical contractors employ 53, up 152.4% since 2019 against up 25.6% statewide, at an average $53,505 a year. The SAVRN Data Center Map lists 1 data center in Madison County. Madison County is home to Winterset, Earlham, St. Charles and Truro. The Moratorium Tracker holds 1 local measure here (1 in force); the latest is “One-year data-processing-facility moratorium”. Construction employs 362, up 17.5% since 2019, and construction is 1.6 times as concentrated here as in the U.S. economy.
Cities and towns in Madison County
Madison County is home to Winterset, Earlham, St. Charles and Truro.
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 Madison County
1st = the most. Ranks cover counties with a value on record.
| Measure | Then | Now | Change | Rank in Iowa |
|---|---|---|---|---|
| Population (2020 → 2025) | 16,631 | 17,270 | ▲ 3.8% | 41st of 99 by size |
| Total jobs (2019 → 2025) | 3,842 | 4,194 | ▲ 9.2% | 5th of 99 by growth |
| Average annual pay (2019 → 2025) | $38,009 | $51,986 | ▲ 36.8% | — |
| Construction jobs (2019 → 2025) | 308 | 362 | ▲ 17.5% | 20th of 81 by growth |
| Electrical contractor jobs (2019 → 2025) | 21 | 53 | ▲ 152.4% | — |
| Unemployment rate (2019 → August 2026) | 3.3% | 3.3% | ● 0.0pts | — |
| Generating capacity added since 2019 | — | 4 MW | — | |
| Generating capacity retired since 2019 | — | 0 MW | — |
Employers here counted 4,194 jobs in 2025, up 9.2% from 2019 (the 5th fastest growth of 99 Iowa counties). 4 MW of that came online in 2019 or later, mostly petroleum. Its power plants have 137 MW of capacity, 87% of it wind. MidAmerican Energy Co is the largest utility serving Madison County, one of 6 with territory here. Its residential customers paid an average 11.01¢/kWh in 2024, below the 13.77¢ median for Iowa utilities. 17,270 people live here, up 3.8% since 2020. Unemployment was 3.3% in August 2026, against 3.3% in 2019.
Who powers Madison County
Net change in operating capacity since 2019: +4 MW. Colors follow the fuel legend above.
Utilities with service territory in Madison County
| Utility | Ownership | Service | Residential customers (systemwide) | Residential price, 2024 | Commercial share of sales |
|---|---|---|---|---|---|
| MidAmerican Energy Co | Investor Owned | Bundled | 632,436 | 11.01¢ | 18% |
| Interstate Power and Light Co | Investor Owned | Bundled | 417,153 | 17.90¢ | 29% |
| Clarke Electric Coop Inc - (IA) | — | — | — | — | — |
| Farmers Electric Coop, Inc - (IA) | — | — | — | — | — |
| Waverly Municipal Elec Utility | — | — | — | — | — |
| City of Winterset - (IA) | — | — | — | — | — |
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 2
| Technology | Capacity | Share |
|---|---|---|
| Wind | 120 MW | 87% |
| Petroleum | 10 MW | 7% |
| Natural gas | 8 MW | 6% |
| Largest plants | Owner | Technology | MW | Since |
|---|---|---|---|---|
| Macksburg Wind Project | MidAmerican Energy Co | Wind | 120 MW | 2014 |
| Winterset | City of Winterset - (IA) | Petroleum | 18 MW | 1956 |
The Madison County labor market
| Industry (2025) | Jobs | Average pay | Concentration vs U.S. |
|---|---|---|---|
| All industries | 4,194 | $51,986 | 1.00 |
| Construction | 362 | $58,094 | 1.63 |
| Electrical contractors | 53 | $53,505 | 1.75 |
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 Madison County
1 data center in Madison County is on the SAVRN Data Center Map.
Local measures 1
| Measure | Status | Date | |
|---|---|---|---|
| One-year data-processing-facility moratorium | In force | 2026-06 |
Madison County and its neighbors
Of the 7 counties that border Madison County, Polk 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 |
|---|---|---|---|---|---|---|
| Madison County | 17,270 | ▲ 9.2% | 137 MW | — | 1 | 1 |
| Adair County | 7,403 | ▲ 16.2% | 1,152 MW | — | — | — |
| Clarke County | 9,574 | ▲ 6.3% | — | — | — | 1 |
| Dallas County | 118,457 | ▲ 21.3% | 1 MW | — | 9 | — |
| Guthrie County | 10,782 | ▲ 3.2% | 214 MW | — | — | — |
| Polk County | 516,546 | ▲ 3.9% | 1,066 MW | — | 30 | — |
| Union County | 11,829 | ▼ 3.3% | 424 MW | — | — | — |
| Warren County | 57,331 | ▲ 15.7% | 44 MW | — | 2 | — |
More of Iowa
Madison County, answered from the record
Who provides electricity in Madison County, Iowa?
6 utilities have service territory in Madison County in the EIA-861 2024 report: MidAmerican Energy Co, Interstate Power and Light Co, Clarke Electric Coop Inc - (IA), Farmers Electric Coop, Inc - (IA). The largest, MidAmerican Energy Co, charged residential customers 11.01¢/kWh on average in 2024.
What power plants are in Madison County?
2 operating plants with 137 MW of capacity. The largest is Macksburg Wind Project (120 MW, wind).
Are there data centers in Madison County?
Yes. The SAVRN Data Center Map lists 1 data center in Madison County.
Is Madison County adding jobs?
Employers counted 4,194 jobs in 2025 against 3,842 in 2019 (+9.2%, BLS QCEW). Construction went from 308 to 362.
Does Madison County have a data center moratorium?
The SAVRN Moratorium Tracker holds 1 local measure for Madison County, 1 in force.