Energy Glossary

A B C D E F G H I J K L M N O P Q R S T U V W Z

A

  • Aggregator

    A group or organization that represents energy consumers to buy electricity or natural gas in a deregulated or restructured energy industry.

  • Alternating Current

    An electric current which reverses direction repeatedly due to a change in voltage occurring at the same frequency. Abbreviated as AC or ac.

  • Ampere

    Electric current produced by one volt applied across a resistance of one ohm. It is also equal to the flow of one coulomb per second.

  • Ancillary Services

    Necessary services that must be provided in the generation and delivery of electricity. As defined by the Federal Energy Regulatory Commission, they include: coordination and scheduling services (load following, energy imbalance service, control of transmission congestion); automatic generation control (load frequency control and the economic dispatch of plants); contractual agreements (loss compensation service); and support of system integrity and security (reactive power, or spinning and operating reserves).

B

  • 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.

  • Basis

    The differential that exists between the futures price for a given commodity and the Cash or Spot price for the same or related commodity. Basis may reflect different time periods, product forms, qualities or locations. Cash minus Futures equals Basis.

  • BCF

    Billion Cubic Feet.

  • Bilateral Agreement

    Written statement signed by a pair of communicating parties that specifies what data may be exchanged between them.

  • Broker

    A retail agent who arranges or negotiates for the purchase and sale of electricity or natural gas. Brokers usually act on the behalf of others and do not buy energy for their own end-use customers.

  • BTU

    Short for British Thermal Unit, a standard unit of energy which is a common measure of heating value for different fuels. One Btu is equal to the amount of heat required to raise the temperature of one pound of liquid water by 1 degree Fahrenheit at its maximum density, which occurs at a temperature of 39.1 degrees Fahrenheit.

  • Bundled Utility Service

    All generation, transmission, and distribution services provided by one entity for a single charge. This would include ancillary services and retail services.

  • Burnertip

    Refers to the location at which the gas is being consumed by the End-user. Generally off the local distribution company or gas utility system.

C

  • 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.

  • Capacity Release

    The assignment or release of firm transportation rights from one shipper (the Releasing Shipper) to another shipper (the Replacement Shipper) on a permanent or temporary basis.

  • Cash Market

    The market for a cash commodity where the actual physical product is traded (same as spot market).

  • CCF

    100 cubic feet.

  • City Gate

    The location where natural gas transfers from the interstate gas pipeline to the local utility's distribution system.

  • 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 peak loads that occur in the same time 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.

  • Competitive Power Suppliers

    Companies that sell power - also called electricity providers, power generators or energy marketers. Your power is delivered by the local electric utility/distribution company (DISCO).

  • Congestion

    A condition that occurs when insufficient transfer capacity is available to implement all of the preferred schedules for electricity transmission simultaneously. Conservation

  • Conservation

    Reduction of energy use.

  • Cubic Foot

    The most common unit of measurement of natural gas volume. It is the amount of gas that can fit within a space one foot times one foot times one foot in volume. One cubic foot of pipeline-quality gas contains approximately 1,000 BTU.

D

  • Decatherm (or, Dekatherm)

    Ten therms or 1 million Btu. One decatherm is equal to approximately 1,000 cubic feet (Mcf).

  • Default Service

    The electric generation service provided to any consumer who does not or is unable to arrange for or maintain electric generation services with an electric supplier after deregulation begins.

  • Degree Day

    A measure of the coldness of the weather (heating degree day) or its heat (cooling degree day) based on the extent to which the daily mean temperature falls below or rises above 65 degrees Fahrenheit.

  • Dekatherm

    A dekatherm is 1 million Btu's.

  • Delivery Month

    The month specified in a given contract for delivery of the actual physical commodity.

  • Delivery Point

    Location(s) designated at which delivery may be made in fulfillment of contract terms ‑ usually where the sale or transportation of gas exits the pipeline’s system.

  • Demand Charge

    A charge for gas or electric service based on actual or estimated peak daily (or hourly, weekly, monthly) usage of a customer.

  • 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.

  • Deregulation

    The elimination of regulation from a previously regulated industry or sector of an industry (such as electricity or natural gas); sometimes used interchangeably with restructuring.

  • Derivative

    Financial instrument derived from a cash market commodity, futures contract or other financial instrument. Derivatives can be traded on regulated exchange market or over-the-counter. For example, futures contracts are derivatives of physical commodities, options on futures are derivatives of futures contracts.

  • Direct Current

    (DC) electrical current that normally flows in one direction only.

  • Distribution

    The delivery of electricity or natural gas to the retail customer's home or business through local electrical lines or gas pipelines.

  • Distribution Company

    The company that delivers power to your home or business, also known as your local electric utility/distribution company. (DISCO)

  • Downstream

    A pipeline closer to the market area as opposed to an upstream pipeline which is closer to the production area.

  • Dual Fuel Capacity

    Ability of a facility to use more than one kind of fuel for the same purpose non­-concurrently.

E

  • Electric Supplier

    An entity (including an energy marketer or energy services company – or ESCO) licensed or approved by a state utility regulatory agency to provide electricity supply to consumers. With energy choice, consumers can choose their electric supplier. The energy is then delivered by the consumer's utility distribution company.

  • Electric Utility

    Any person or state agency with a monopoly franchise (including any municipality) that sells electric energy to end-use customers.

  • End-Use

    The ultimate use to which energy service is put, such as water heating and air conditioning.

  • Energy

    The capacity for doing work as measured by the capability of doing work (potential energy) or the conversion of this capability to motion (kinetic energy). Energy has several forms, some of which are easily convertible and can be changed to another form useful for work.

  • Energy Service Company (ESCO)

    Companies that offer customers energy and energy-related products and services; required to be approved or licensed by state public utility commissions.

  • Energy Source

    The primary source that provides the power that is converted to electricity through chemical, mechanical, or other means. Energy sources include coal, petroleum and petroleum products, gas, water, uranium, wind, sunlight, geothermal, and other sources.

  • Expiration Dates

    The dates and times after which trading in options or futures contracts terminate, and after which all contract rights or obligations become null and void.

F

  • Federal Energy Regulatory Commission (FERC)

    The Federal Energy Regulatory Commission regulates the price, terms and conditions of natural gas and electricity sold in interstate commerce and regulates the price, terms and conditions of all wholesale transactions. FERC is the federal counterpart to state utility regulatory commissions.

  • 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.

  • Firm Service (FT)

    The highest quality of sales or transmission service offered to customers under a filed rate schedule that anticipates no planned interruption. It also receives the highest priority of service.

  • Forced Outage

    The shutdown of a generating unit, transmission line or other facility, for emergency reasons or a condition in which the generating equipment is unavailable for load due to unanticipated breakdown.

  • Frequency

    The number of complete alternations or cycles per second of an alternating current. It is measured in Hertz. The standard frequency in the US is 60 Hz. However, in some other countries the standard is 50 Hz.

  • Fuel Charge

    The rate charged per kilowatthour (or cubic feet) to cover the costs of the fuel used to produce power (or gas).

  • Fuel Loss

    Fuel loss is associated with transporting natural gas across a pipeline system (also referred to as Line Loss or Shrinkage).

G

  • Gas Adjustment Factor

    An adjustment to a LDC sales rate to reflect the fluctuating cost of purchased gas.

  • Gas Day

    The standard day by which gas is nominated (e.g. 10:00 am to 10:00 am the following day).

  • Gas Turbine Plant

    A plant in which the prime mover is a gas turbine. A gas turbine consists typically of an axial-flow air compressor, one or more combustion chambers, where liquid or gaseous fuel is burned and the hot gases are passed to the turbine and where the hot gases expand to drive the generator and are then used to run the compressor.

  • Generation (Electricity)

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

  • Generation Company

    A regulated or non-regulated entity (depending upon the industry structure) that operates and maintains existing generating plants. The generation company may own the generation plants or interact with the short-term market on behalf of plant owners. In the context of restructuring the market for electricity, the generation company is sometimes used to describe a specialized "marketer" for the generating plants formerly owned by a vertically-integrated utility.

  • Gigawatt (GW)

    One billion watts.

  • Gigawatt hour (GWh)

    One billion watt-hours.

  • Grid

    A system of interconnected power lines and generators that is managed so that the generators are dispatched as needed to meet the requirements of the customers connected to the grid at various points.

H

  • Hedging Contracts

    Contracts which establish future prices and quantities of electricity independent of the short-term market. Derivatives may be used for this purpose.

  • Henry Hub

    A pipeline interchange near Erath, LA where a number of interstate and intrastate pipelines interconnect. Used as the standard delivery point for the NYMEX gas futures contract.

  • Hertz

    (Hz) unit of frequency. One Hertz equals one complete cycle per second of an ac source. Abbreviated Hz. Named after the German physicist Heinrich R. Hertz 1894. This unit replaces the former "cycles-per-second."

  • Horsepower

    A unit of power equal to 746 watts.

  • Hub

    A geographic location where multiple participants (e.g. pipelines) trade services.

  • Hydroelectric Plant

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

I

  • Independent System Operator (ISO)

    A neutral, independent, and (typically non-profit) organization with no financial interest in generating facilities that administers the operation and use of the transmission system. ISOs exercise final authority over the dispatch of generation to preserve reliability and facilitate efficiency, ensure non-discriminatory access, administer transmission tariffs, ensure the availability of ancillary services, and provide information about the status of the transmission system and available transmission capacity.

  • Internal Combustion Plant

    A plant in which the prime mover is an internal combustion engine. An internal combustion engine has one or more cylinders in which the process of combustion takes place, converting energy released from the rapid burning of a fuel-air mixture into mechanical energy. Diesel or gas-fired engines are the principal types used in electric plants. The plant is usually operated during periods of high demand for electricity.

  • Interruptible Service

    “Utility" or “LDC" service which expects and permits interruption on short notice, generally in peak load periods, in order to meet the demand by firm service customers. Interruptible service customers usually pay a lower rate than firm service customers.

  • Interruptible Transportation (IT)

    “Pipeline” service which expects and permits interruption on short notice, generally in peak-load periods, in order to meet the demand by firm service customers. IT service customers usually pay a lower rate than firm transportation customers.

  • Interstate Pipeline

    Pipeline extending across several states. Such a pipeline is involved in interstate commerce and is therefore regulated by the FERC.

  • Intrastate Pipeline

    Pipeline whose system provides service within a single state's boundaries. Such a pipeline is not involved in interstate commerce and is therefore regulated by the individual state regulatory commission.

  • 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.

J

  • Joule

    A unit of work or energy equal to one watt for one second. One kilowatt hour equals 3,600,000 Joules. Named after James P. Joule, an English physicist 1889.

  • Joule's Law

    Defines the relationship between current in a wire and the thermal energy produced. In 1841, an English physicist James P. Joule experimentally showed that W = I2 x R x t where I is the current in the wire in amperes, R is the resistance of the wire in Ohms, t is the length of time that the current flows in seconds, and W is the energy produced in Joules.

K

  • Kilovolt

    (kV) unit of electrical potential equal to 1000 volts.

  • Kilovolt Amperes

    (kVA) a unit of apparent power equal to 1000 volt amperes. Here, apparent power is in contrast to real power. On ac systems the voltage and current will not be in phase if reactive power is being transmitted. Usually abbreviated kVA or KVA.

  • Kilowatt (kW)

    One thousand watts.

  • Kilowatt-hour (kWh)

    The basic unit of electric energy equal to one kilowatt of power supplied to or taken from an electric circuit steadily for one hour. One kilowatt-hour equals 1,000 watt-hours.

L

  • LDC

    See Local Distribution Company.

  • Line Loss

    The fuel loss associated with transporting natural gas across a pipeline system (also referred to as Shrinkage or Fuel Loss).

  • Liquefied Natural Gas (LNG)

    A market is said to be “liquid” when it has a high level of trading activity and open interest.

  • Liquidity

    A market is said to be “liquid” when it has a high level of trading activity and open interest.

  • LMP

    Stands for Locational Market Pricing.

  • Load (Electric)

    The amount of power drawn from a utility system at a given point in time. The peak load is the highest amount of power drawn down at any one time, or the utility's maximum capacity or demand.

  • Load Factor

    The ratio of average energy demand to maximum demand for a time period, such as one year, one month, or one hour. An end user with a high load factor uses energy at a consistently higher level year-round than an end user who may use energy specifically for heating or cooling.

  • Local Distribution Company (LDC)

    A business entity that obtains its primary revenues from the operations of a local retail gas distribution system and operates no transportation system other than connections within its own system or to the system of another company. Most often, an LDC is a utility.

  • Long-Term Contract

    A supply contract in the physical market covering energy deliveries of more than 18 months. Mid-term and long-term contracts are significant because they extend over a heating season.

M

  • Market Clearing Price

    The price at which supply equals demand for the Day Ahead and/or Hour Ahead Markets. Market-Based Pricing

  • Market-Based Pricing

    Electric service prices determined in an open market system of supply and demand under which the price is set solely by agreement as to what a buyer will pay and a seller will accept. Such prices could recover less or more than full costs, depending upon what the buyer and seller see as their relevant opportunities and risks.

  • Maximum Demand

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

  • MCF

    Thousand Cubic Feet

  • Megawatt (MW)

    One million watts.

  • Megawatt hour (MWh)

    One million watt-hours.

  • MISO

    Name of wholesale power pool that serves the Ohio Grid. The Midwest Independent Transmission System Operator, Inc. is the official name of the ISO covering that region and serves a total of 11 States.

  • MMBtu

    One million British Thermal Units, one dekatherm. Approximately equal to thousand cubic feet (Mcf) of natural gas.

N

  • Natural Gas

    A naturally occurring mixture of hydrocarbon and non‑hydrocarbon gases found in rock formations. Its principal component is methane.

  • Nomination

    A request for service by a shipper under a Service Agreement. Most nominations are made on a daily basis, although mid-day nominations are possible on some systems.

  • Non-Coincidental Peak Load

    The sum of two or more peak loads on individual systems that do not occur in the same time interval. Meaningful only when considering loads within a limited period of time, such as a day, week, month, a heating or cooling season, and usually for not more than 1 year.

  • Non-Firm Power

    Power or power-producing capacity supplied or available under a commitment having limited or no assured availability.

  • Non-Utility Power Producer

    A corporation, person, agency, authority, or other legal entity or instrumentality that owns electric generating capacity and is not an electric utility. Non-utility power producers include qualifying cogenerators, qualifying small power producers, and other non-utility generators (including independent power producers) without a designated franchised service area, and which do not file forms listed in the Code of Federal Regulations, Title 18, Part 141.

  • Nuclear Fuel

    Fissionable materials that have been enriched to such a composition that, when placed in a nuclear reactor, will support a self-sustaining fission chain reaction, producing heat in a controlled manner for process use.

  • Nuclear Power Plant

    A facility in which heat produced in a reactor by the fissioning of nuclear fuel is used to drive a steam turbine.

  • NYMEX

    New York Mercantile Exchange. A regulated exchange where natural gas, electricity, oil and other commodities' Futures Contracts and other Derivatives are traded. (similar to stock or exchange rate futures markets)

O

  • Off-Peak

    The hours of the day that represent lower electrical demand. These are the less expensive hours of the day (e.g. Nightime when demand is low).

  • Ohm

    A unit of electrical resistance. A circuit resistance of one ohm will pass a current of one ampere with a potential difference of one volt. Abbreviated using the Greek letter omega (W). Named for the German physicist George Simon Ohm 1854.

  • Ohm's Law

    Defines the relationship between voltage, resistance, and current. In 1828 the German physicist George Simon Ohm showed by experiment that the current in a conductor is equal to the difference of potential between any two points divided by the resistance between them. This may be written as I = E / R where E is the potential difference in volts, R is the resistance in Ohms, and I is the current in amperes.

  • On-Peak

    The hours of the day that represent higher electrical demand. These are the expensive hours of the day (e.g. Mid-day when demand is high).

  • Open Access

    A regulatory mandate to allow others to use a utility's transmission and distribution facilities to move bulk power from one point to another on a nondiscriminatory basis for a cost-based fee.

  • Operational Flow Order (OFO)

    Order issued by a pipeline or LDC to protect the operational integrity of the pipeline or distribution system either by restricting service or requiring affirmative action by shippers.

  • Outage

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

P

  • Peak Demand

    The 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.

  • Pipeline Capacity

    A service provided by a pipeline for a fixed monthly reservation charge which gives a transporter the right to move up to a maximum daily quantity of gas between defined points on the pipeline’s system.

  • 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. A plant may contain more than one type of prime mover. Electric utility plants exclude facilities that satisfy the definition of a qualifying facility under the Public Utility Regulatory Policies Act of 1978.

  • Power

    The rate at which work is performed or that energy is transferred. Electric power is commonly measured in watts or kilowatts. A power of 746 watts is equivalent to 1 horsepower.

  • Power Marketers

    Business entities engaged in buying, selling, and marketing electricity. Power marketers do not usually own generating or transmission facilities. Power marketers, as opposed to brokers, take ownership of the electricity and are involved in interstate trade. These entities file with the Federal Energy Regulatory Commission for status as a power marketer.

  • Power Pool

    An association of two or more interconnected electric systems having an agreement to coordinate operations and planning for improved reliability and efficiencies.

  • Power Sources

    The different types of fuels that can be used to produce electricity; nuclear, fossil fuels (oil, coal, and natural gas) and renewable energy resources.

  • Prompt Month

    The futures contract closest to maturity (also called nearby month or spot month).

  • Public Utility Commission (PUC)

    Generic term for a state agency holding regulatory power over energy pricing, and issues related thereto.

  • Pumped-Storage Hydroelectric Plant

    A plant that usually generates electric energy during peak-load periods by using water previously pumped into an elevated storage reservoir during off-peak periods when excess generating capacity is available to do so. When additional generating capacity is needed, the water can be released from the reservoir through a conduit to turbine generators located in a power plant at a lower level.

Q

  • 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 the Public Utility Regulatory Policies Act (PURPA).

R

  • Receipt Point

    The point at which gas is delivered to, or received from a pipeline.

  • Regulation

    The governmental function of controlling or directing economic entities through the process of rulemaking and adjudication.

  • Releasing Shipper

    The original pipeline capacity holder of firm space on a pipeline for which reservation (demand) charges are paid. This party may release capacity for others shippers (Replacement Shippers) to use through the Capacity Release market.

  • Renewable Resources

    Naturally, but flow-limited resources that can be replenished. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time. Some (such as geothermal and biomass) may be stock-limited in that stocks are depleted by use, but on a time scale of decades, or perhaps centuries, they can probably be replenished. Renewable energy resources include: biomass, hydro, geothermal, solar and wind. In the future, they could also include the use of ocean thermal, wave, and tidal action technologies. Utility renewable resource applications include bulk electricity generation, on-site electricity generation, distributed electricity generation, non-grid-connected generation, and demand-reduction (energy efficiency) technologies.

  • Replacement Shipper

    The party acquiring capacity that has been released by another shipper (the Releasing Shipper) through the Capacity Release market.

  • Retail Market

    A market in which electricity and other energy services are sold directly to the end-use customer.

  • Retail Wheeling

    The process of moving electric power from a point of generation across one or more utility-owned transmission and distribution systems to a retail customer.

  • RTP

    Stands for Real-Time Pricing.

  • Rural Electric Cooperatives

    These are electric cooperatives located in rural areas of the country and established and operating under rules established by Congress.

S

  • Scheduled Outage

    The shutdown of a generating unit, transmission line, or other facility, for inspection or maintenance, in accordance with an advance schedule.

  • Secondary Delivery Point

    The use of a delivery point other than the contacted "Primary" Delivery Point on a Firm Transportation contract. Use of a Secondary Delivery Point is typically a lower priority service than Firm Transportation utilizing Primary Delivery points, but higher priority than Interruptible Transportation.

  • Secondary Receipt Point

    The use of a receipt point other than the contracted "Primary" Receipt Point on a Firm Transportation contract. Use of a Secondary Receipt Point is typically a lower priority service than Firm Transportation utilizing Primary Receipt points, but higher priory than Interruptible Transportation.

  • Settlement

    The price established by the NYMEX at the close of each trading session as the official price.

  • Shipper

    One who contracts for transportation of natural gas. A shipper retains title to all natural gas delivered to the pipeline while it is being transported by the pipeline.

  • Slamming

    The unauthorized switch of a Retail Supplier, or a change in supplier without the customer's knowledge or consent.

  • Spot Market

    The market for a cash commodity where the actual physical product is traded (same as cash market). Done in the month of physical delivery.

  • Spot Month

    The futures contract closest to maturity (also called nearby month or prompt month).

  • Spot Purchases

    A single shipment of fuel or volumes of fuel, purchased for delivery within 1 year. Spot purchases are often made by a user to fulfill a certain portion of energy requirements, to meet unanticipated energy needs, or to take advantage of low-fuel prices.

  • Standard Offer

    Any one of a number of packages of bundled electricity, related services, and distribution services, provided by the former monopoly utility, during a transition period to competition in generation supply. Usually proposed for the stated purpose of giving "customers who choose not to choose" the option of remaining with their existing supplier of electricity.

  • Storage

    Facilities used to store natural gas that has been transferred from its original location. It usually consists of natural geological reservoirs, such as depleted oil or gas fields.

  • Stranded Costs

    Prudent costs incurred by a utility which may not be recoverable under market-based retail competition. Examples are un-depreciated generating facilities, deferred costs, and long-term contract costs.

  • Supplier

    An entity, other than the LDC, that can perform energy and customer service functions in a competitive environment, including provision of energy and assistance in the efficiency of its use.

  • Switching Station

    Facility equipment used to tie together two or more electric circuits through switches. The switches are selectively arranged to permit a circuit to be disconnected, or to change the electric connection between the circuits.

  • System (Electric)

    Physically connected generation, transmission, and distribution facilities operated as an integrated unit under one central management, or operating supervision.

T

  • Tariff

    A document, approved by the responsible regulatory agency, listing the terms and conditions, including a schedule of prices, under which utility services will be provided.

  • Therm

    The equivalent of 100,000 Btu or approximately 100 cubic feet of natural gas.

  • Time-of-Use (TOU) Rates

    The pricing of electricity based on the estimated cost of electricity during a particular time block, either time-of-day or by season.

  • Transformer

    A device that converts one ac voltage and current to a different voltage and current. Constructed using two or more coils of wire around a common magnetic core. The energy is transferred from one coil, usually considered the primary winding, to the other coil, the secondary winding by means of mutual induction in the magnetic core. Transformers are an efficient and economical means of transferring large amounts of ac electric power at high voltages. This is the primary advantage of ac systems over dc systems.

  • Transmission

    The movement or transfer of electric energy over an interconnected group of lines and associated equipment between points of supply and points at which it is transformed for delivery to consumers, or is delivered to other electric systems. Transmission is considered to end when the energy is transformed for distribution to the consumer.

  • Transportation

    Moving natural gas through pipelines from one place to another.

U

  • Unbundling

    Separating electric or natural gas utility service into its basic components (such as electric generation, transmission and local distribution; and natural gas production, pipeline transportation and local distribution) and offering each component separately for sale with separate rates for each component.

  • Uninterruptible Power Supply

    A device that provides a constant regulated voltage output in spite of interruptions of the normal power supply. It includes filtering circuits and is usually used to feed computers or related equipment which would otherwise shutdown on brief power interruptions. Abbreviated UPS.

  • Upstream Pipeline

    A pipeline closer to the production area, as opposed to downstream pipeline closer to the market.

  • Utility

    A regulated energy company with the characteristics of a natural monopoly.

  • Utility Distribution Companies

    The entities that will continue to provide regulated services for the distribution of electricity to customers and serve customers who do not choose direct access. Regardless of where a consumer chooses to purchase power, the customer's current utility, also known as the utility distribution company, will deliver the power to the consumer's home, business, or farm.

V

  • VAR

    Abbreviation for volt ampere reactive. Unit of ac reactive power.

  • Vertical Integration

    An arrangement whereby the same company owns all the different aspects of making, selling, and delivering a product or service. In the electric industry, it refers to the historically common arrangement whereby a utility would own its own generating plants, transmission system, and distribution lines to provide all aspects of electric service.

  • Volt

    The electrical potential difference or pressure across a one ohm resistance carrying a current of one ampere. Named after Italian physicist Count Alessandro Volta 1745-1827.

  • Volt Ampere

    (VA) a unit of apparent power equal to the mathematical product of a circuit voltage and amperes. Here, apparent power is in contrast to real power. On ac systems the voltage and current will not be in phase if reactive power is being transmitted.

  • Voltage Drop

    A voltage reduction due to impedances between the power source and the load. These impedances are due to wiring and transformers and are normally minimized to the extent possible.

  • Voltage Reduction

    Any intentional reduction of system voltage by 3 percent or greater for reasons of maintaining the continuity of service of the bulk electric power supply system.

  • Volumetric Wires Charge

    A type of charge for using the transmission and/or distribution system that is based on the volume of electricity that is transmitted.

W

  • WACOG

    Weighted average cost of gas.

  • Watt

    The electrical unit of power. The rate of energy transfer equivalent to 1 ampere flowing under a pressure of 1 volt at unity power factor.

  • Watt-hour (Wh)

    An electrical energy unit of measure equal to 1 watt of power supplied to, or taken from, an electric circuit steadily for 1 hour.

  • Wellhead

    This is the point of origin in the gas supply process.

  • Wheeling Service

    The movement of electricity from one system to another over transmission facilities of intervening systems. Wheeling service contracts can be established between two or more systems.

  • Wholesale Competition

    A system whereby a distributor of power would have the option to buy its power from a variety of power producers, and the power producers would be able to compete to sell their power to a variety of distribution companies.

  • Wholesale Power Market

    The purchase and sale of electricity from generators to resellers (who sell to retail customers), along with the ancillary services needed to maintain reliability and power quality at the transmission level.

  • Wholesale Sales

    Energy supplied to other electric utilities, cooperatives, municipals, and Federal and State electric agencies for resale to ultimate consumers.

  • Wires Charge

    Charges levied for transmission or distribution wires.

Z

  • Zones

    Subsets of a utility's overall territory based on geographical areas.