Cascade County, MT. Reports to the NorthWestern Energy balancing authorityThe organization that balances electricity supply and demand in a reporting area.Definition ↗.
Nameplate capacity, operating generatorsFull nameplate rating of the operating generators, before ownership shares. MW measures rated power; annual output is energy in MWh.Definition ↗
60.4MW
Source & method
Sum of generator nameplate MW with operational status code OP in the inventory year; one row per generator; unscaled by ownership
2024 inventory · reported · derived · valid · final
Net generationEnergy produced over the stated period after the plant’s own use, including signed storage output. Plant output is not allocated to owners or buyers.Definition ↗
228,009MWh
2024
Source & method
Sum of EIA-923 annual net generation over the plant's unique prime-mover x energy-source rows; negative values (pumping, station use) retained
2024 calendar year · reported · derived · valid · final
Net generation MWh / (operating nameplate MW x hours in year); only when every operating generator was operating before the year began and none retired during it
2024 calendar year · reported · derived · valid · final
derived: net_generation_mwh@2024 / (nameplate_mw_op x 8784 h)
Ownership basisHow a generator's owners were established: from EIA-860's ownership schedule (reported), from EIA's rule that a unit absent from a complete schedule is wholly owned by its operator (derived), or unknown.Definition ↗
OwnerAn organization with a reported share of a generator. Owned MW applies that share to operating nameplate capacity; it does not establish who buys the output.Definition ↗Investor-owned utilityNorthWestern Energy ↗
60.4MW owned
Operating nameplate MW x ownership fraction, once per generator; reported schedule or EIA-860 schedule-4 default. Ownership source & rules ↗
Generators at this plant
Unscaled nameplateA generator’s rated maximum power, in MW. Capacity is a rating, not how much electricity it produced.Definition ↗
2 generators, including non-operating units where reported. Status is the inventory-year status.
Generator
Technology / statusWhether a generator or project is operating, planned, on standby or retired, as its source reports it.Definition ↗
NameplateA generator’s rated maximum power, in MW. Capacity is a rating, not how much electricity it produced.Definition ↗ · MW
Ownership basisHow a generator's owners were established: from EIA-860's ownership schedule (reported), from EIA's rule that a unit absent from a complete schedule is wholly owned by its operator (derived), or unknown.Definition ↗
This plant has no coal, gas, oil or waste generator, so it has no combustion unit for EPA to monitor and no CEMS data exists. That is not a claim of zero emissions: the atlas reports only what EPA-monitored units filed. Source
Latest inventoryThe newest complete monthly inventory, with dated status and capacity changes beside the annual baseline totals.Definition ↗ · August 2026
Operating
1 of 2 units changed since the baseline inventory: COC2 capacity changed (August 2026).
Operating nameplate capacity, latest inventoryOperating nameplate MW in this monthly inventory. Compare it with the annual baseline; do not add the two inventories together.Definition ↗
59.4MW
· provisional
Source & method
Sum of nameplate MW over generators whose current-valid EIA-860M workbook assertion has status OP; dated by the complete inventory edition; never added to the baseline aggregate
Planned nameplate capacity, latest inventoryNameplate MW proposed or under construction in this monthly inventory, separate from operating MW. Planned dates are forecasts.Definition ↗
Not applicable
· provisional
Source & method
Sum of nameplate MW over generators whose current-valid EIA-860M workbook assertion is a proposal or construction stage (P, L, T, U, V, OT, TS); a proposal is not a commitment and its date is a forecast
Retired or cancelled nameplate capacity, latest inventory
Not applicable
· provisional
Source & method
Sum of nameplate MW over generators whose current-valid EIA-860M workbook assertion is retired, cancelled or indefinitely postponed (RE, CN, IP); retired is not demolished
Units whose current EIA-860M assertion differs from the baseline inventory year.
Unit
Change
As of
Baseline → latest status
Nameplate · MW
COC2
capacity changed
August 2026
OP → OP
32MW → 31MW
Lifecycle of the units
Each unit's operating span from its reported operating date to its retirement date or to the August 2026 inventory (the vertical line). Dashed spans start at a planned operating date, a forecast; a short bar marks a planned retirement. Standby and out-of-service units are hatched.
Units as a table
Unit lifecycle from EIA-860M, August 2026.
Unit
State
Operating since
Planned
Retired
MW
COC1
Operating
July 1958
—
—
28.4MW
COC2
Operating
July 1958
—
—
31MW
Independently dated by EIA-860M; the baseline facts above stay the validated edition. Planned dates are forecasts; retired is not demolished.
Approximate service areasAn approximate utility service area. The boundary cannot identify the supplier for a particular address.Definition ↗ containing the plant’s location. A geographic candidate, not a supply relationship.
Within 3 km of the reported plant point, nearest first. BPA’s published lines, HIFLD-compiled lines of other owners and HIFLD 2022 substations; nearness does not establish an electrical connection.
Catalyst Cooperative, PUDL v2026.9.0, derived from U.S. EIA Forms 860/923
Data transformed by PUDL from U.S. EIA forms; selected fields republished; EIA data is public with dated acknowledgment (https://www.eia.gov/about/copyrights_reuse.php)
Catalyst Cooperative, PUDL v2026.9.0, derived from U.S. EIA Forms 860/923
Data transformed by PUDL from U.S. EIA forms; selected fields republished; EIA data is public with dated acknowledgment (https://www.eia.gov/about/copyrights_reuse.php)
Catalyst Cooperative, PUDL v2026.9.0, derived from U.S. EIA Forms 860/923
Data transformed by PUDL from U.S. EIA forms; selected fields republished; EIA data is public with dated acknowledgment (https://www.eia.gov/about/copyrights_reuse.php)
Catalyst Cooperative, PUDL v2026.9.0, derived from U.S. EIA Forms 860/923
Data transformed by PUDL from U.S. EIA forms; selected fields republished; EIA data is public with dated acknowledgment (https://www.eia.gov/about/copyrights_reuse.php)