Electric Utility Terms

Ampere

The unit of measurement of electrical current produced in a circuit by 1 volt acting through a resistance of 1 ohm.

Baseload

The minimum amount of electric power delivered or required over a given period of time at a steady rate.

Baseload Capacity

The generating equipment normally operated to serve loads on an around-the-clock basis.

Boiler

A device for generating steam for power, processing, or heating purposes or for producing hot water for heating purposes or hot water supply. Heat combustion source is transmitted to a fluid contained within the tubes in the boiler shell. This fluid is delivered to an end-use at a desired pressure, temperature, and quality.

Capacity

The amount of electric power delivered or required for which a generator, turbine, transformer, transmission circuit, station, or system is rated by the manufacturer.

Capacity Charge

An element in a two-part pricing method used in capacity transactions (energy charge is the other element). The capacity charge, sometimes called Demand Charge, is assessed on the amount of capacity being purchased.

Circuit

A conductor or a system of conductors through which electric current flows.

Cogenerator

A generating facility that produces electricity and another form of useful thermal energy (such as heat or steam), used for industrial, commercial, heating, or cooling purposes.

Coincidental Demand

The sum of two or more demands that occur in the same time interval.

Coincidental Peak Load

The sum of two or more peakloads that occur in the same interval.

Combined Cycle

An electric generating technology in which electricity is produced from otherwise lost waste heat exiting from one or more gas (combustion) turbines. The exiting heat is routed to a conventional boiler or to a heat recovery steam generator for utilization by a steam turbine in the production of electricity. This process increases the efficiency of the electric generating unit.

Combined Cycle Unit

An electric generating unit that consists of one or more combustion turbines and one or more boilers with a portion of the required energy input to the boiler(s) provided by the exhaust gas of the combustion turbine(s).

Current (electric):

A flow of electrons in an electrical conductor. The strength or rate of movement of the electricity is measured in amperes.

Demand (Electric)

The rate at which energy is delivered to or by a system, part of a system, or piece of equipment, at a given instant or averaged over any designated period of time.

Demand-Side Management

The planning, implementation, and monitoring of utility activities designed to encourage consumers to modify patterns of electricity usage, including the timing and level of electricity demand. It refers only to energy and load-shape modifying activities that are undertaken in response to utility-administered programs. It does not refer to energy and load-shape changes arising from the normal operation of the marketplace or from government-mandated energy-efficient standards. Demand-side Management (DSM) covers the complete range of load-shape objectives, including strategic conservation and load management, as well as strategic load growth.

Distribution

The delivery of electricity to retail customers (including homes, businesses, etc.).

Distribution System

The portion of an electric system that is dedicated to delivering electric energy to an end user.

Electric Plant (Physical)

A facility containing prime movers, electric generators, and auxiliary equipment for converting mechanical, chemical, and/or fission energy into electric energy.

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 oversite authority.

Electric Service Provider

An entity that provides electric service to a retail or end use customer.

Energy Efficiency

Programs that are aimed at reducing the energy used by specific end-use devices and systems, typically without affecting the services provided.

• reduce overall electricity consumption

  • Usually done through more advanced equipment

Federal Energy Regulatory Commission (FERC)

A quasi-independent regulatory agency within the Department of Energy having jurisdiction over interstate electricity sales, wholesale electric rates, hydroelectric licensing, natural gas pricing, oil pipeline rates, and gas pipeline certification.

Firm Power

Power or power-producing capacity intended to be available at all times during the period covered by a guaranteed commitment to deliver, even under adverse conditions.

Generating Unit

Any combination of physically connected generator(s), reactor(s), boiler(s), combustion turbine(s), or other prime mover(s) operated together to produce electric power.

Generation (Electricity)

The process of producing electric energy by transforming other forms of energy; also, the amount of electric energy produced, expressed in watthours (Wh)

Generator

A machine that converts mechanical energy into electrical energy.

Greenhouse Effect

The increasing mean global surface temperature of the earth caused by gases in the atmosphere (including Carbon Dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbon).

Grid

Layout of an electrical distribution system.

Hydroelectric Plant

A plant in which the turbine generators are driven by falling water

Independent Power Producers

Entitles that are also considered nonutility power producers in the US. These facilities are wholesale electricity producers that operate within the franchised service territories of host utilities and are usually authorized to sell at market=based rates. Unlike traditional electric utilities, Independent power producers do not possess transmission facilities or sell electricity in the retail market.

Independent System Operators

An independent, Federally-regulated entity that coordinates regional transmission in a non-discriminatory manner and ensures the safety and reliability of the electric system.

Interruptible Load

Program activities that can interrupt consumer load at times of seasonal peak load by direct control of the utility system operator or by action of the consumer at the direct request of the system operator.

Investor-Owned Utility

A class of utility whose stock is publicly traded and which is organized as a tax-paying business, usually financed by the sale of securities in the capital market. It is regulated and authorized to achieve an allowed rate of return.

Load (electric)

The amount of electric power delivered or required at any specific point or points on a system. The requirement originates at the energy-consuming equipment of the consumers.

Maximum Demand

The greatest of all demands of the load that has occurred within a specified period of time.

MCF

One thousand cubic feet

Natural Gas

A natural occurring mixture of hydrocarbon and nonhydrocarbon gases found in porous geological formations beneath the earth’s surface, often in association with petroleum. The principal constituent is methane.

ohm

The unit of measurement of electrical resistance. The resistance of a circuit in which a potential difference of 1 volt produces a current of 1 ampere.

Outage

The period during which a generating unit, transmission line, or other facility is out of service.

Peak Demand

Maximum load during a specified period of time.

Peak Load Plant

A plant usually housing old, low-efficiency steam units; gas turbines; diesels; or pumped-storage hydroelectric equipment normally used during the peak-load periods.

Peaking Capacity

Capacity of generating equipment normally reserved for operation during the hours of highest daily, weekly, or seasonal loads. Some generating equipment may be operated at certain times as peaking capacity and at other times to serve loads on an around-the clock basis.

Plant

A facility at which are located prime movers, electric generators, and auxiliary equipment for converting mechanical, chemical, and/or nuclear energy into electric energy.

Plant Use

The electric energy used in the operation of a plant. Included in this definition is the energy required for pumping at pumped-storage plants.

Plant-Use Electricity

The electric energy used in the operation of a plant. This energy total is subtracted from the gross energy production of the plant; for reporting purposes the plant energy production is then reported as a net figure. The energy required for pumping at pumped-storage plants is, subtracted and the energy production for these plants is then reported as a net figure

Prime Mover

The engine, turbine, water wheel, or similar machine that drives an electric generator; or a device that converts energy to electricity directly.

PURPA

The Public Utility Regulatory Policies Act of 1978 - States are required to implement utility conservation programs and create special markets for co-generators and small producers who meet certain standards, including the requirement that States set the prices and quantities of power the utilities must buy from such facilities.

Qualifying Facility QF

A cogeneration or small power production facility that meets certain ownership, operating, and efficiency criteria established by the Federal Energy Regulatory Commission FERC pursuant to PURPA

Reactive Power

The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and transformers. Provided by generators, condensers, or electrostatic equipment (like capacitors)