Brownfield & Retired Power Plant Sites in Idaho
6 catalogued brownfield and retired-generation sites in Idaho, listed by former capacity. Each carries an existing utility-scale grid interconnection that a new datacenter load may be able to re-use.
At a glance
What kinds of former sites are in Idaho?
By former use, the list includes 3 hydroelectric, 1 nuclear, 1 natural gas, 1 geothermal. Recorded retirement dates run from December 2006 to December 2017, with 1 retirements in 2015 or later. 6 of 6 sites with a measured distance sit within 2 miles of a transmission substation.
How does Idaho compare with other states?
Idaho ranks 49th of 50 states and DC by number of brownfield and retired-generation sites, out of 2,085 nationally. By recorded capacity (1,022 MW) it ranks 36th, against 289,280 MW across all states. The state also has 2,171 scored datacenter candidate sites, 2 of them classed as brownfield sites, averaging 51.7 on the 0–100 DC Readiness scale.
Where in Idaho are these sites?
- Bonneville County · 1
- Elmore County · 1
- Cassia County · 1
- Gem County · 1
- Caribou County · 1
- Gooding County · 1
All brownfield and retired plant sites in Idaho
| Site | Former use | Capacity | Retired | County |
|---|---|---|---|---|
| UAMPS Carbon Free Power Plant | nuclear | 762 MW | — | Bonneville |
| Bennett Mountain | gas | 220 MW | — | Elmore |
| Raft River Geothermal Power Plant | geothermal | 18 MW | — | Cassia |
| Black Canyon | hydro | 13 MW | — | Gem |
| Cove | hydro | 8 MW | 2006-12-01 | Caribou |
| Thousand Springs | hydro | 2 MW | 2017-12-01 | Gooding |
Frequently asked questions
How many retired power plants are in Idaho?
GridCensus lists 6 retired power plant sites in Idaho from EIA-860 retirement records. 2 have a recorded retirement date, 1 of them in 2015 or later.
What is the largest retired power plant or brownfield site in Idaho?
UAMPS Carbon Free Power Plant in Idaho Falls is the largest by recorded capacity, at 762 MW. It is followed by Bennett Mountain (220 MW) and Raft River Geothermal Power Plant (18 MW).
Which power plant in Idaho retired most recently?
Thousand Springs has the latest recorded retirement date in the state, December 2017, with 2 MW of capacity.
Which county in Idaho has the most brownfield and retired plant sites?
Bonneville County has the most, with 1, followed by Elmore County with 1.
Looking for a specific record? The directory lists every brownfield site, A to Z.
More on Idaho, and states with similar counts
- Datacenter candidate sites in Idaho· 2,171 sites
- Electric substations in Idaho· 274 named
- Brownfield candidate sites nationwide
- Brownfield sites by state
- Brownfield sites in Montana· 7 sites
- Brownfield sites in New Hampshire· 4 sites
- Brownfield sites in North Dakota· 8 sites
- Brownfield sites in District of Columbia· 1 sites
About this data
Source: EIA-860 retired generating units and EPA RE-Powering America's Land contaminated-site records, as published March 6, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: GridCensus, “Brownfield and retired power plant sites in Idaho”, https://gridcensus.com/brownfield-sites/idaho (data as of March 6, 2026).
Dataset updated . Screening estimates derived from public data sources.
Go deeper than the public screen
Every site and score for brownfield sites in Idaho 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.