Electricity terms · Plain language
Power grid glossary
Understand the measurements, infrastructure, operators, and market terms used across US Grid Explorer.
20 terms
Balancing authority
The responsible entity that continuously balances electricity supply, demand, and interchange within a defined area.
Read definition →MeasurementCapacity
The maximum rate at which a generator, plant, or power system is designed or reported to produce electricity at a given moment.
Read definition →MeasurementCapacity factor
The share of electricity a generator actually produced compared with what it could have produced at continuous full capacity over the same period.
Read definition →Grid operationsElectricity demand
The rate at which customers and connected equipment use electricity at a particular time.
Read definition →InfrastructureDistributed generation
Electricity generation located near the customers it serves, often connected to a local distribution system rather than the high-voltage transmission network.
Read definition →MeasurementElectricity generation
The amount of electrical energy produced by a generator or group of generators over a period of time.
Read definition →TechnologyEnergy storage
A system that takes in energy, retains it, and later returns electricity or another useful form of energy.
Read definition →InfrastructureGenerator
A machine or device that converts mechanical, chemical, solar, or other energy into electricity.
Read definition →Markets and operatorsIndependent system operator (ISO)
An independent organization that operates a regional transmission system and may administer wholesale electricity markets.
Read definition →Grid structureInterconnection
A large synchronized power network in which connected systems operate at a common frequency and can exchange electricity.
Read definition →MeasurementMegawatt (MW)
A unit of power equal to one million watts, used to describe the instantaneous output, demand, or rated capacity of electric equipment.
Read definition →MeasurementMegawatt-hour (MWh)
A unit of energy equal to one megawatt sustained for one hour.
Read definition →MeasurementNameplate capacity
The maximum rated output assigned to generating equipment by its manufacturer, commonly reported in megawatts.
Read definition →Grid structurePower grid
The connected system of power plants, transmission lines, substations, distribution equipment, controls, and customers used to deliver electricity.
Read definition →InfrastructurePower plant
A facility containing one or more generators and associated equipment used to produce electricity.
Read definition →TechnologyRenewable energy
Energy from sources that are naturally replenished, including sunlight, wind, moving water, geothermal heat, and biomass.
Read definition →Markets and operatorsRegional transmission organization (RTO)
An independent regional entity that operates transmission facilities and administers transmission service, often alongside organized wholesale markets.
Read definition →InfrastructureSubstation
A facility where electrical voltage is transformed and circuits are switched, protected, or controlled.
Read definition →InfrastructureElectric transmission
The movement of large amounts of electricity over high-voltage lines from generation areas toward distribution systems and major customers.
Read definition →Markets and operatorsWholesale electricity market
A market in which electricity, capacity, and grid services are bought and sold for resale or system operation rather than directly to most retail customers.
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Editorial standard
Short definitions, visible limits
Definitions are paraphrased from public agency terminology and written for practical use. Each term links to its primary reference and related concepts.
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