Datacenter Sites in Mills County, Iowa
Mills County has 11 scored datacenter candidate sites averaging 62.3/100 DC Readiness, with a catalogued aggregate of 2,150 MW. FEMA rates local natural-hazard risk as "Relatively Moderate". The county has a datacenter tax incentive on record.
At a glance
Mills County, Iowa has 11 scored datacenter candidate sites averaging 62.3/100 DC Readiness, about 11% above the Iowa average of 56.3. It ranks 59th of 85 Iowa counties by number of sites and 1st by average score. The top-scoring site is WALTER SCOTT ENERGY CENTER at 70.2/100.
Site-selection context for Mills County
Incentive detail: Sales tax exemption on DC equipment for $1M+ investments; property tax phase-in for new construction.
How does Mills County compare with other counties in Iowa?
By number of scored sites, Mills County ranks 59th of the 85 Iowa counties with a county page, holding 0.4% of the state's 2,572 sites. Its average DC Readiness of 62.3/100 ranks 1st in the state and is about 18% above the national average of 53.0. Nationally it has the 2327th-largest site inventory of 2,964 counties with five or more sites. One site scores 70 or higher and 10 score 55 or higher.
What types of datacenter sites are in Mills County?
Substation-Adjacent sites are the most common (8, 73% of the county's inventory), followed by greenfield (2) and industrial (1). Site type reflects how the parcel was identified — next to a substation, on a former mine or brownfield, on industrial or federal excess land — and is scored on the same 14 factors either way.
What are power cost, hazard, water and fiber conditions in Mills County?
Industrial electricity averages 6.05¢/kWh and commercial 8.43¢/kWh. FEMA's National Risk Index rates the county "Relatively Moderate" (30). WRI water stress is low. 8 fiber providers report service in the county. The climate runs 900 cooling degree days a year with a mean temperature of 48°F. Land is valued around $8,944 an acre.
By site type
Top datacenter sites in Mills County
| Site | Type | Voltage | Capacity | Queue wait | Score |
|---|---|---|---|---|---|
| WALTER SCOTT ENERGY CENTER | Substation-Adjacent | 345 kV | 600 MW | 4.3 yrs | 70.2 |
| UNKNOWN131416 | Substation-Adjacent | 345 kV | 600 MW | 4.3 yrs | 69.0 |
| UNKNOWN137755 | Substation-Adjacent | 345 kV | 600 MW | 4.3 yrs | 69.0 |
| UNKNOWN131499 | Substation-Adjacent | 161 kV | 100 MW | 4.3 yrs | 63.6 |
| EC Coal Mills County | Greenfield | — | — | 4.3 yrs | 63.3 |
| EC Coal Mills County | Greenfield | — | — | 4.3 yrs | 63.1 |
| UNKNOWN131421 | Substation-Adjacent | 161 kV | 100 MW | 4.3 yrs | 59.9 |
| UNKNOWN167607 | Substation-Adjacent | 69 kV | 50 MW | 4.3 yrs | 59.2 |
| UNKNOWN167606 | Substation-Adjacent | 69 kV | 50 MW | 4.3 yrs | 57.7 |
| UNKNOWN137757 | Substation-Adjacent | 69 kV | 50 MW | 4.3 yrs | 56.8 |
| Former Atlas "f" Missile Site #3 | Industrial | — | — | 4.3 yrs | 53.8 |
Every scored site in Mills County
All 11 sites, best first.
- WALTER SCOTT ENERGY CENTER · 70.2
- Substation-Adjacent site · bce64d07 · 69.0
- Substation-Adjacent site · a8e95df2 · 69.0
- Substation-Adjacent site · 3dd46ac1 · 63.6
- EC Coal Mills County · aadab54c · 63.3
- EC Coal Mills County · 332418d1 · 63.1
- Substation-Adjacent site · 686c98ce · 59.9
- Substation-Adjacent site · fd92867c · 59.2
- Substation-Adjacent site · 84566b3b · 57.7
- Substation-Adjacent site · a85cd607 · 56.8
- Former Atlas "f" Missile Site #3 · 53.8
Mills County datacenter FAQ
How many datacenter sites are in Mills County?
11 scored datacenter candidate sites, averaging 62.3/100 DC Readiness. That is the 59th-most of 85 Iowa counties with five or more sites.
What is the highest-scoring datacenter site in Mills County?
WALTER SCOTT ENERGY CENTER scores 70.2/100 DC Readiness, the highest of the 11 scored sites in Mills County (a substation-adjacent site).
Does Mills County offer datacenter tax incentives?
Sales tax exemption on DC equipment for $1M+ investments; property tax phase-in for new construction.
What is the natural-hazard risk in Mills County?
FEMA's National Risk Index rates Mills County as "Relatively Moderate" (score 30).
What are industrial electricity rates in Mills County?
Average industrial electricity is 6.05¢/kWh and commercial is 8.43¢/kWh in Mills County.
More in Iowa
- All datacenter sites in Iowa· 2,572 sites
- Operating datacenters in Iowa
- Electric substations in Iowa
- Black Hawk County· 126 sites · avg 58.4
- Pottawattamie County· 123 sites · avg 57.0
- Clinton County· 118 sites · avg 54.2
- Johnson County· 112 sites · avg 57.9
- Linn County· 105 sites · avg 58.3
- Dubuque County· 101 sites · avg 55.8
- Substation-Adjacent sites in Iowa
- Greenfield sites in Iowa
About this data
Source: GridCensus composite of HIFLD transmission and substation data, EIA, FEMA National Risk Index, FCC broadband data, PeeringDB and ISO interconnection queues, as published November 12, 2026 — GridCensus refreshes it monthly. See the methodology for how records are matched, cleaned and scored.
Cite as: GridCensus, “Datacenter candidate sites in Mills County, Iowa”, https://gridcensus.com/datacenter-sites/iowa/mills-county (data as of November 12, 2026).
Dataset updated . Screening estimates derived from public data sources.
Go deeper than the public screen
Every site and score for Mills County, Iowa is free to browse. Pro adds Watchtower on 25 sites, alerts when new candidate sites, datacenters or interconnection-queue requests appear in your markets, score and capacity history, and CSV export. Enterprise adds team seats, weekly data files for all 147,272 sites, the REST API and an MCP server for AI tools.