Datacenter Sites in Union County, Ohio
Union County has 12 scored datacenter candidate sites averaging 56.0/100 DC Readiness, with a catalogued aggregate of 4,200 MW. FEMA rates local natural-hazard risk as "Relatively Moderate". The county has a datacenter tax incentive on record.
At a glance
Union County, Ohio has 12 scored datacenter candidate sites averaging 56.0/100 DC Readiness, roughly in line with the Ohio average of 53.2. It ranks 69th of 85 Ohio counties by number of sites and 15th by average score. The top-scoring site is MARYSVILLE at 64.7/100.
Site-selection context for Union County
Incentive detail: DC sales tax exemption on equipment and electricity (2022 law); JobsOhio grants.
How does Union County compare with other counties in Ohio?
By number of scored sites, Union County ranks 69th of the 85 Ohio counties with a county page, holding 0.3% of the state's 3,933 sites. Its average DC Readiness of 56.0/100 ranks 15th in the state and is roughly in line with the national average of 53.0. Nationally it has the 2244th-largest site inventory of 2,964 counties with five or more sites. 0 sites score 70 or higher and 7 score 55 or higher.
What types of datacenter sites are in Union County?
Substation-Adjacent sites are the most common (5, 42% of the county's inventory), followed by greenfield (5) and former mine (2). 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 Union County?
Industrial electricity averages 8.26¢/kWh and commercial 10.69¢/kWh. FEMA's National Risk Index rates the county "Relatively Moderate" (30). WRI water stress is low. 14 fiber providers report service in the county. The climate runs 900 cooling degree days a year with a mean temperature of 51°F. Land is valued around $8,151 an acre.
By site type
Top datacenter sites in Union County
| Site | Type | Voltage | Capacity | Queue wait | Score |
|---|---|---|---|---|---|
| MARYSVILLE | Substation-Adjacent | 765 kV | 1,000 MW | 5.2 yrs | 64.7 |
| Greenfield (CORRIDOR - MARYSVILLE) | Greenfield | 765 kV | 1,000 MW | 5.2 yrs | 60.0 |
| Greenfield (FLATLICK - MARYSVILLE) | Greenfield | 765 kV | 1,000 MW | 5.2 yrs | 59.5 |
| UNKNOWN152449 | Substation-Adjacent | 138 kV | 100 MW | 5.2 yrs | 58.2 |
| UNKNOWN141217 | Substation-Adjacent | 138 kV | 100 MW | 5.2 yrs | 58.2 |
| UNKNOWN113285 | Substation-Adjacent | 138 kV | 100 MW | 5.2 yrs | 58.1 |
| UNKNOWN113252 | Substation-Adjacent | 138 kV | 100 MW | 5.2 yrs | 55.9 |
| Greenfield (MARYSVILLE - UNKNOWN177055) | Greenfield | 345 kV | 600 MW | 7.6 yrs | 53.5 |
| Mine Site | Former Mine | — | — | 5.2 yrs | 51.8 |
| Mine Site | Former Mine | — | — | 5.2 yrs | 51.8 |
| Greenfield (UNKNOWN152449 - TAP153615) | Greenfield | 138 kV | 100 MW | 5.2 yrs | 51.1 |
| Greenfield (UNKNOWN113252 - TAP163085) | Greenfield | 138 kV | 100 MW | 5.2 yrs | 49.0 |
Every scored site in Union County
All 12 sites, best first.
- MARYSVILLE · 64.7
- Greenfield (CORRIDOR - MARYSVILLE) · 60.0
- Greenfield (FLATLICK - MARYSVILLE) · 59.5
- Substation-Adjacent site · b44d13a3 · 58.2
- Substation-Adjacent site · d02596b2 · 58.2
- Substation-Adjacent site · 23c28fb3 · 58.1
- Substation-Adjacent site · 7fd3c1c0 · 55.9
- Greenfield (MARYSVILLE - UNKNOWN177055) · 53.5
- Mine Site · 30c692f5 · 51.8
- Mine Site · 41a802ad · 51.8
- Greenfield (UNKNOWN152449 - TAP153615) · 51.1
- Greenfield (UNKNOWN113252 - TAP163085) · 49.0
Union County datacenter FAQ
How many datacenter sites are in Union County?
12 scored datacenter candidate sites, averaging 56.0/100 DC Readiness. That is the 69th-most of 85 Ohio counties with five or more sites.
What is the highest-scoring datacenter site in Union County?
MARYSVILLE scores 64.7/100 DC Readiness, the highest of the 12 scored sites in Union County (a substation-adjacent site).
Does Union County offer datacenter tax incentives?
DC sales tax exemption on equipment and electricity (2022 law); JobsOhio grants.
What is the natural-hazard risk in Union County?
FEMA's National Risk Index rates Union County as "Relatively Moderate" (score 30).
What are industrial electricity rates in Union County?
Average industrial electricity is 8.26¢/kWh and commercial is 10.69¢/kWh in Union County.
More in Ohio
- All datacenter sites in Ohio· 3,933 sites
- Operating datacenters in Ohio
- Electric substations in Ohio
- Cuyahoga County· 348 sites · avg 55.2
- Lucas County· 221 sites · avg 53.8
- Hamilton County· 177 sites · avg 56.7
- Lorain· 139 sites · avg 53.5
- Summit County· 129 sites · avg 55.5
- Jefferson County· 125 sites · avg 49.2
- Substation-Adjacent sites in Ohio
- Greenfield sites in Ohio
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 Union County, Ohio”, https://gridcensus.com/datacenter-sites/ohio/union-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 Union County, Ohio 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.