Forced outage
shutdown condition of a power station, transmission line or distribution line when the generating unit is unavailable to produce power due to unexpected breakdown
In electrical engineering, forced outage is the shutdown condition of a power station, transmission line or distribution line when the generating unit is unavailable to produce power due to unexpected breakdown.
Forced outage can be caused by equipment failures, disruption in the power plant fuel supply chain, operator error etc.
Forced outage rate
Forced outage rate (FOR or FOAR) of a power station unit is the probability that the unit will not be available for service when required.
FOR is defined as the number of hours the unit is on forced outage over the total number of hours in a year (which is the sum of hours the power station is available for service and hours the power station is in forced outage).
Two derivative metrics are also used:
equivalent forced outage rate (EFOR, also equipment EFOR, EEFOR) has a different denominator: instead of the total number of hours in the year, only the hours when the unit was needed for load are counted.
weighted EFOR (WEFOR) is EFOR weighted by the capacity of the unit.
This brief starts where responsible research should: with the source description of “Forced outage” as shutdown condition of a power station, transmission line or distribution line when the generating unit is unavailable to produce power due to unexpected breakdown. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the places & architecture register because the source frames it as shutdown condition of a power station, transmission line or distribution line when the generating unit is unavailable to produce power due to unexpected breakdown. Its deeper value depends on whether names, dates, institutions and citations support that framing.
The strongest evidence will usually combine a dated visual record with documents produced by the authority responsible for the place. The source revision retrieved here is dated Feb 6, 2026. The linked authority identifier is Q5467538. None of the 0 selected statements returned an explicit reference.
Modern boundaries and familiar names can conceal earlier jurisdictions or structures that do not align with the present site. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Forced outage”, its source revision and the description used here.
- Expand the search: follow Forced outage primary sources, Forced outage archive and Forced research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Forced outage”?
- Which authority defined the place, boundary or structure at the relevant date?
- What physical evidence or contemporary plan supports the description?
Search terms from this dossier
This entry incorporates text from “Forced outage” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.