A Guide to Green Energy Adoption for Transit Agencies Selected Glossary

The following glossary is a selection of relevant terms as defined by the U.S. Energy Information Administration. For more energy-related terms, please visit the Energy Information Administration Glossary.

Electric power: The rate at which electric energy is transferred. Electric power is measured by capacity and is commonly expressed in megawatts (MW).

Electric rate: The price set for a specified amount and type of electricity by class of service in an electric rate schedule or sales contract.

Electric rate schedule: A statement of the electric rate and the terms and conditions governing its application, including attendant contract terms and conditions that have been accepted by a regulatory body with appropriate oversight authority.

Electric utility: A corporation, person, agency, authority, or other legal entity or instrumentality aligned with distribution facilities for delivery of electric energy for use primarily by the public. Included are investor-owned electric utilities, municipal and State utilities, Federal electric utilities, and rural electric cooperatives. A few entities that are tariff based and corporately aligned with companies that own distribution facilities are also included.

Energy: The capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy). Electrical energy is usually measured in kilowatt-hours (kWh).

Grid: The layout of an electrical distribution system.

Microgrid: A group of interconnected loads and distributed energy resources within clearly defined electrical boundaries that acts as a single controllable entity with respect to the grid. A microgrid is capable of connecting and disconnecting from the grid to enable it to operate in both grid-connected or island mode (U.S. Department of Energy).

Tariff: A published volume of rate schedules and general terms and conditions under which a product or service will be supplied. See electric rate above.