The terms described below are commonly used on this website.

Distributed Generation (DG) - A system where electric power is generated at various locations near the point of use (as opposed to at a central power generating facility).

Combined Heat and Power (CHP) - A system that generates electrical power and also provides heat to meet all or part of the loads in a facility.

Operational Reliability (OR) - Various measures or metrics that assess or quantify the reliability of a given system or technology.

Facility - A commercial, institutional, or industrial location or site that has one or more Power Units installed.

Power Unit (PU) - An individual DG/CHP generation unit or system.

Monitoring Unit (MU) - A collection of Power Units at a facility that are grouped together for the purposes of monitoring.

Standard Industrial Classification (SIC) - A US government system for classifying (by numeric code) business establishments (being replaced by NAICS).

North American Industry Classification System (NAICS) - A North American system for classifying (by numeric code) business establishments (developed in 1999 as a replacement for SIC).