Appendix B: Glossary

A-C

Active Power

The real power supplied by the generator set to the electrical load, measured in kilowatts (kW).

Allowance

A unit of pollution, usually expressed in tons, allowed as a source of emissions as determined by the U.S. EPA, taking into consideration mitigating factors or circumstances.

Annual Demand

The highest demand that occurs during a prescribed demand interval in a calendar year. The annual demand may be electrical (kW or kVA) or thermal (MMBtu/h or MMBtu/day).

Annunciator

A device that provides a remote indication of the status of an operating component in a system.

Automatic Paralleling

A system for starting and paralleling two or more generator sets to each other while coming up to rated frequency and voltage.

Avoided Cost

The incremental cost, which can include energy and capacity, for the electric utility to generate or purchase electricity that is avoided through the purchase of power from a cogeneration facility.

Backup Power

Electric power required during an outage of a cogeneration system. Frequently referred to as "standby power."

Best Available Control Technology (BACT)

The emission control technology required to preserve air quality and prevent degradation by requiring the maximum degree of emission reduction, which the permitting authority, on a case-by-case basis (taking into account energy, environmental, and economic impacts and other costs), determines is achievable for a facility.

Billing Demand

The demand on which a customer billing is based, as specified in a rate schedule or contract. It can be based on the contract minimum or...