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

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

Circuit – Path that electricity follows.

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

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

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

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

Energy Efficiency Rating (EER) – 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.

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

Geothermal Energy – 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.

Ground-Fault Circuit Interrupter (GFCI) – 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.

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

Hydroelectric Plant (hydro) – A facility that produces electric energy by releasing water from a reservoir through generators.

Insulator (nonconductors) – 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.

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

Kilowatt-hour (kWh) – 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.

Line – A carrier of electricity on an electric power system.

Load – 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.

Meter – A device used to measure and record the amount of electricity used by a consumer.

Nuclear Energy – Energy produced from the splitting of atoms.

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

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

Power Plant – A place where electricity is produced.

Solar Power – 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.

Transformer – 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.

Voltage – The force which pushes electricity through a wire.

Watt – A unit of electrical power.