A total power failure over a large area; usually caused by the failure of major generating equipment or transmission facilities.

A small, temporary voltage reduction implemented by a utility to conserve electric power during periods of high use.

Path that electricity follows.

A switch that opens an electric circuit when a short occurs.

A material that allows an electric current to pass through it. Also, the wire that carries electricity in an electric distribution or transmission system.

A flow of electrons through a wire or other electrical conductor. Electrons are negatively charged particles of matter.

Electric current or power that results from the movement of electrons in a conductor from a negatively charged point to a positively charged point.

A measure of how efficiently an appliance uses energy. Determined by dividing the Btu per hour output by the number of watts used. A higher EER means greater efficiency.

A protective device for electric circuits containing a wire designed to melt and open the circuit under abnormally high electric loads.

Natural heat contained in the rocks, hot water and steam of Earth’s subsurface; can be used to generate electricity and heat homes and businesses.

A device that instantly breaks the circuit when a short develops. Required for outlets that are used in bathrooms, kitchens, outdoors or wherever electrical equipment might come into contact with water.

Voltage in a power line higher than the 110 to 220 volts used in most residences.

A facility that produces electric energy by releasing water from a reservoir through generators.

Material that does not conduct electricity, such as glass, ceramics or rubber. It prevents the passage of electricity. All transmission and distribution wires are protected by insulators.

The basic unit of electric demand, equal to 1,000 watts; average household demand is 10 to 20 kilowatts.

A unit of energy of work equal to 1,000 watt-hours. The basic measure of electric energy generation or use. A 100-watt light bulb burning for 10 hours uses one kilowatt-hour.

A carrier of electricity on an electric power system.

The amount of electric power drawn at a specific time from an electric system, or the total power drawn from the system. Peak load is the amount of power drawn at the time of highest demand.

Energy produced from the splitting of atoms.

Interruption of service to an electric consumer because a power plant, transmission line or other facility is not operating.

The term used for the product of voltage and current. It is measured in watts.

A place where electricity is produced.

Energy from the sun’s radiation converted into heat or electricity. Substation – A place that contains transformers which lower electricity’s voltage so that it can be used in our homes.

A device used to raise or lower voltage in electric distribution or transmission lines. A step-up transformer raises voltage and a step-down transformer lowers voltage.

The force which pushes electricity through a wire.

A unit of electrical power.