Firm service
service required to be available at all times
Firm services, also called uninterruptible services, are services, such as electricity (firm power) and natural gas supplies, that are intended to be available at all times during a period covered by an agreement. Also, the service is not subject to a prior claim from another customer and receives the same priority as any other firm service. Conditional firm service is similar to firm service in that it is reserved and has priority over interruptible service. However, it can have restrictions, such as times when it would be curtailed before firm service but after interruptible service. The cost per unit with this service is called a firm rate or uninterruptible rate.
The opposite of firm service is non-firm service, also called interruptible service or as-available service. The cost per unit for this service is called a non-firm rate or interruptible rate. The interruptible load is the portion of a utility's load that comes from customers with interruptible service.
Firm service cannot be interrupted during adverse conditions, such as periods of high demand. However, firm service may also refer to service that is covered by a long-term contract, such as a year or more.
The public source identifies “Firm service” as service required to be available at all times. This brief keeps that definition visible, then builds a research path around Firm, service and required.
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This entry incorporates text from “Firm service” 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.