Energy Glossary

ATC (Available Transmission Capacity) - The amount of power that can be transferred reliably over an interconnected transmission system.

Community-Owned Utility - A non-profit electric, gas, and/or water provider owned by and accountable to its customers and controlled by locally elected officials.

Control Area - An entity, such as a utility or an ISO, which has the responsibility for maintaining the balance of energy supply and demand and ensuring reliability within its grid.

Demand - The amount of electricity consumed by customers. Electric demand is expressed in kilowatts or megawatts.

Distribution - The locally located wires, transformers, meters, and other equipment used to deliver electricity from substations into homes and businesses.

Generation - The act of producing the commodity of electricity at a power plant.

Independent System Operator (ISO) - The independent, non-profit organization that ensures the efficient use and reliable operation of the transmission grid under its control.

Investor-Owned Utility - A for-profit electric, gas, and/or water company owned by and accountable to shareholders, and regulated by the California Public Utilities Commission.

Kilowatt (KW) - 1,000 watts

Megawatt (MW) - 1 million watts

Peak Load - The highest electrical demand within a particular period of time. Daily electric peaks usually occur on weekdays in the late afternoon; annual peaks in desert climate occur on hot summer days.  

Substation - An electrical facility that steps up or steps down voltage in utility power lines. Some of the equipment in a substation includes circuit breakers, switches, protective relays, and equipment necessary to properly create a reliable electric transmission system.

Transformer - A device that reduces high voltage electricity to voltage that is safe for residential and commercial use.

Transmission - The transporting of bulk power over long distances through high-voltage wires.

Voltage - The amount of force necessary to move energy through the transmission system (like water pressure).

Watt - Unit of power, the rate at which energy is supplied at a point in time. 

IID Energy Facts