Electricity supplied under agreements that allow the supplier to curtail or stop service at times.

Utility service which expects and permits interruption on short notice, generally in peak-load periods, in order to meet the demand by firm service customers. Interruptible service customers usually pay a lower rate than firm service customers. Opposite of Firm Service.

the delivery of gas to a customer, subject to interruption of service at the discretion of the utility, generally because of system supply or capacity limitations. Interruption may be manually control [..]

see Firm service

Gas service that is subject to interruption at the option of the pipeline or LDC. Tariffs for interruptible service are cheaper than firm.

Electric service which may be stopped at the supplier’s discretion or in accordance with a contractual agreement.

Services pursuant to which customers receive only limited assurances regarding the availability of (i) with respect to storage services, capacity and deliverability in storage facilities or (ii) with respect to transportation services, capacity and deliverability from receipt points to delivery points. Customers pay fees for interruptible services [..]

Interruptible service contracts allow a distributing party to temporarily suspend delivery of gas to a buyer in order to meet the demands of customers who purchased firm service. Interruptible service is less expensive than firm service, and is used by customers who can either accommodate interruption, or switch to alternative fuels temporarily.