Sign In
Definitions - FGH
A     B     C     D     E     FGH     IJK     L     M     NO     PQ     R     S     TUV     WXYZ    
A supplementary environmental impact statement issued subse-quent to and expanding upon a specific facility planning supplement, including alternative locations for a proposed new facility and environmental effects associated with each alternative location.
A supplementary environmental impact statement that identifies the need for a specific new transmission facility proposed as part of BPA's annual construction program and that outlines in preliminary form the probable environmental effects of constructing the facility.
The variation of the strength of received signals due to atmospheric conditions.
A scale for measuring temperature where water freezes at 32°F and boils at 212°F.
A type of control circuit that prevents improper operation of the controlled function in the event of a circuit failure.
An unintentional short circuit in a power system, due to a breakdown of insulation between a conductor and the ground or between conductors.
An abnormal current flow resulting from a fault.
Occurs when the fault current flows to ground.
A portable device or automatic sys-tem (automatic fault locator) that indicates where a fault occurred on a transmission line; useful for speeding up the dispatch of repair crews.
A fault location system developed by BPA that uses precision clocks at substations to time tag traveling voltage waves to determine fault location and automatically report it to the dispatch center.
See Federal Base System.
See Federal Columbia River Power System.
See Federal Columbia River Transmission System.
See Federal Energy Regulatory Commission.
Technique of right-of-way pruning that results in undulating boundaries rather than a tunnel effect. Obtained by topping and pruning of trees adjacent to the right-of-way and regrowing shrubs and grass within the right-of-way.
The Federal agencies in the Pacific Northwest that buy most of their electricity directly from BPA—U.S. Bureau of Reclamation, U.S. Bureau of Mines, Fairchild Air Force Base, U.S. Navy bases (Puget Sound Naval Yard, Jim Creek, Bangor), and Department of Energy, Richland-Midway.
The resources BPA uses to serve the firm energy loads of its customers, consisting of the Federal Columbia River Power System hydroelectric projects and resources acquired by BPA under long-term contracts.
Federal Columbia River Power System (FCRPS)
The transmission system constructed and operated by BPA and the hydroelectric dams constructed and operated by the U.S. Army Corps of Engineers and the Bureau of Reclamation in the Northwest. Each entity is separately managed and financed, but the facilities are operated as an integrated power system.
Federal Columbia River Transmission System (FCRTS)
The electric transmission system in the Pacific Northwest built and operated by BPA. Often referred to as the Federal transmission grid, or the BPA grid.
Federal Columbia River Transmission System Act (FCRTSA)
A 1974 Federal law that provided for operation, maintenance, and continued construction of the Federal transmission system in the Pacific Northwest by using revenues from the Federal Columbia River Power System; formed the Federal Columbia River Transmission System; and made BPA responsible for the power system and the transmission system.
See Federal Energy Regulatory Commission.
The Federal agency that reviews hydroelectric projects and applications for operating licenses, and regulates interstate aspects of electric power and natural gas industries. The agency to which BPA submits its proposed power rate adjustments for approval. Formerly Federal Energy Administration.
Amount of firm energy in excess of BPA’s firm contractual commitments.
The hydroelectric dam components of the Federal Columbia River Power System, not including transmission components.
See Federal Columbia River Transmission System.
1) A line from a generating plant or an interchange point between a transmission system and a load or distribution system. 2) A customer line coming from a BPA substation.
See firm energy load carrying capability.
See Federal Energy Regulatory Commission.
See fish guidance efficiency.
See cable.
A ground wire with optical fibers in the center of the conductor. Typically suspended above the phase conductors of a transmission line and used to provide protection against lightning.
The degree to which an information system or portion of a system accurately reproduces at its output the form of the signal that is input.
1) A space throughout which a magnetic force or an electrical charge is active. 2) Area offices, District offices, and other BPA work areas not located at BPA headquarters in Portland, Oregon.
The effects on objects in the vicinity of conductors carrying electric currents and resulting from electric and magnetic fields.
See capacity.
In an electric system, a device that blocks certain frequencies while allowing other frequencies to pass. In a direct-current power system, a device that attenuates the varying component of the current when alternating current is converted to direct current.
The investments and funds reported after current assets on a company balance sheet. BPA is limited by law to accumulate financial resources only with the U.S. Treasury as cash deposits. Unused borrowing authority is also a financial resource.
The use of funds generated from borrowing or current revenues to pay for long-lived capital assets. Also see financial resources.
Financing of projects or activities through revenues from the sale of power and other electric services.
Financing arrangements between BPA and other entities to use sources of capital other than BPA’s borrowing authority from the U.S. Treasury or congressional appropriations to fund new capital assets.
Funds acquired through the sale of BPA bonds to the U.S. Treasury, as authorized in the Federal Columbia River Transmission System Act and the Pacific Northwest Electric Power Planning and Conservation Act, to finance long-lived transmission, conservation, fish and wildlife, and other authorized purposes.
A written determination, following publication of an environmental assessment, stating why an action would have no significant impact, thus making an environmental impact statement unnecessary.
Young or small fish, especially very small salmon or trout.
1) In the utility industry, guaranteed or assured. Refers to a guaranteed supply of power or to guaranteed access to a means to transmit power. 2) Referring to loads, guaranteed service for a defined need, usually defined for a given period of time.
See capacity.
See rates.
See energy.
See load.
In planning, the total amount of firm energy that can be produced and shaped to load (load shaping) under critical streamflow conditions.
See load.
See load.
The maximum firm peak load a purchaser’s system is entitled to receive, over a fixed period of time, from resources included in the Pacific Northwest Coordination Agreement planning process.
See power.
See resource.
For the utility power sales contract, a list of firm resources to be used by the customer in serving its own load.
See sales.
See energy.
For the Federal government, the twelve-month period from October 1 through September 30 (FY 1994 is October 1, 1992 through September 30, 1994). Also see calendar year, operating year.
A program put forth by the Northwest Power Planning Council to protect, mitigate, and enhance fish and wildlife, as mandated by the Pacific Northwest Electric Power Planning and Conservation Act. Funded by BPA.
The percentage of the total number of out-migrating fish approaching a dam’s turbine intake that are deflected away from the intake by a fish guidance device such as a fish screen.
A series of pools, similar to a staircase, constructed to enable salmon or other fish to bypass a dam.
A computer model used to evaluate the survival rates of anadromous fish under alternative conditions as they pass through the Columbia and Snake rivers.
A joint agencies/tribes operations center that aids the passage of fish in the Columbia River by managing the Water Budget, flow augmentation, and other available water designated for fish.
The features of a dam that enable fish to move around, through, or over the it without harm; generally an upstream fish ladder or a downstream bypass system.
A device that helps guide fish away from turbines at a hydroelectric dam. Also see submersible traveling screen (STS).
See costs.
See expenses.
See fault location acquisition reporter.
A disruptive discharge through the air around or over the surface of an insulator produced by the application of a voltage of sufficient magnitude to cause the breakdown path to become ionized and result in an electric arc or fault. Can be caused by lightning surges on a transmission line.
A 1936 act declaring flood control a national purpose, and its 1944 extension.
An elevation below which a reservoir’s forebay must be maintained at certain times of year to prevent downstream flooding, as determined by the U.S. Army Corps of Engineers.
The lowlands adjoining inland and coastal waters. A relatively flat and flood-prone area.
The volume of a fluid that passes a point in a defined channel per unit of time.
The area between the maximum and minimum water levels in a reservoir.
The lines of force of a magnetic or electrostatic field.
The particulate matter that remains after combustion of a material entrained in the gas stream. May in large part be captured by an air pollution control device and, generally, disposed as a solid waste.
See fiber optic overhead groundwire.
See insulator.
See Freedom of Information Act.
See finding of no significant impact.
Heat transferred through a medium such as air or water by currents caused by a device powered by an external energy source.
See outage.
See reserves.
See spill.
Literally means, superior force. See uncontrollable force.
The portion of the reservoir at a hydroelectric plant that is immediately upstream of the generating station.
To make a conjecture beforehand.
A long-term forecast prepared annually by BPA on Pacific Northwest electricity use based on forecasts for each end-use sector and system loads. Used for resource planning.
An estimate of the level of energy, excluding transmission and distribution losses, that is likely to be needed at the point of use at some time in the future.
As used at BPA, a projection composed of five alternative U.S. and Pacific Northwest economic outlooks, based on projections of economic growth, inflation rate, employment rate, energy prices, the composition of economic activities (i.e. manufacturing and non-manufacturing), and demographics, and used as assumptions in projecting the range of future electricity use in the region.
An estimate or projection of the amount of energy that must be generated to meet load, including estimates of electricity use for each end-use sector as well as transmission and distribution losses.
A forecast prepared by BPA or its customers of the loads that BPA would be expected to serve at each POD.
An estimate of expected revenues in a future period derived by applying rates either currently in effect or proposed.
The outlook for electricity use in the Pacific Northwest after the effects of the Model Conservation Standards and other conservation programs have been taken into account. The amount of electricity that would actually be sold by utilities if they developed the least-cost mix of generating and conservation resources to meet future growth.
A prediction of the flow of water in each river in the Columbia Basin at any given time based on snowpack readings and weather forecasts.
A regional forecast made by summing the individual utility firm load forecasts. Used as a check on the regional forecast, for transmission system planning, and in disaggregating the regional forecast.
A quantitative estimate of the supply, cost, and availability of new generation and conservation resources.
For system operations, resource planning, rate setting, and financial planning purposes, BPA uses various methods of calculating amounts of electricity that Pacific Northwest consumers may use in the future.
See load.
1) In the BPA load forecast, the five possible levels (high, medium-high, medium, medium-low, and low) of Pacific Northwest electricity use in the future. 2) In BPA resource planning, the possible levels combined with the estimated probability that each level will occur.
See fuel.
Formula power transmission rate. See rates.
See turbine.
A Federal law that outlines BPA’s and other Federal agencies’ responsibility to make internal information and documents available to the public.
The repetition rate of a periodically recurring quantity, commonly stated in hertz (Hz), kilohertz (kHz), or megahertz (MHz). The standard frequency of alternating-current power in the U.S. is 60 Hz. Also see system frequency.
The process of designating certain frequency bands within a communication system to specific uses and/or users.
See relay.
A rapid temporary rise in streamflow caused by heavy rains or rapid snowmelt.
Infant fish.
Any substance that can be expended to produce heat or some other form of energy.
Any liquid, solid, or gaseous fuel produced from organic matter, including wood chips, alcohol, methane, and gasification syngas.
fossil fuel
A combustible solid, liquid, or gaseous material, rich in carbon, formed from the remains of plants and animals. Common fossil fuels include coal, natural gas, and derivatives of petroleum such as fuel oil and gasoline.
Fuel containing enriched fissionable materials that when placed in a nuclear reactor will support a self-sustaining fission chain reaction and produce heat in a controlled manner.
An electrochemical cell that derives electrical energy directly from the chemical reaction of a fuel and an oxidant on a continuous basis. Chemical potential rather than thermal difference provides the driving force for this form of electrical energy production.
The ratio (commonly expressed in percent) of the heating value of a fuel used to the power output of a generating plant.
Electric energy generated at a hydroelectric plant as a substitute for energy that would otherwise have been generated at a thermal-electric plant.
A rod, tube, plate, or other mechanical shape or form into which nuclear fuel is fabricated for use in a nuclear reactor.
The process by which the percentage of the fissionable material, U-235, is increased above that contained in natural uranium.
As it applies to end users, changing from one type of energy consumption to another such as from electric heating to natural gas heating.
See non- and small generating public utilities.
See costs.
The process of assigning costs to portions of an electrical system on the basis of the function performed by those portions. BPA classifies all costs between generation functions and transmission functions.
The lowest frequency component of a periodically recurring, complex (multi-frequency) wave.
An overcurrent protective device with a circuit-opening fusible part that is heated and severed by the passage of excessive current through it.
That portion of a device associated exclusively with one electrically separated conducting path of the main circuit of the device. A fuse or switching device, called single-pole if it has only one pole. May be multipole, such as three-pole, if the poles are coupled in such a manner to operate together. Also called a switch pole.
See U.S. Fish and Wildlife Service.
See fiscal year.



See giga.
See gauss.
See sport fish.
High-energy, short-wavelength electromagnetic radiation, frequently accompanying alpha and beta emissions and always accompanying fission. Similar to X-rays but are usually more energetic and are nuclear in origin. Very penetrating and best stopped or shielded against by dense materials, such as lead or depleted uranium.
A chemical or heat process used to convert a solid material such as coal into a gas for use as a fuel.
An integrally constructed substation in which all the apparatus (circuit breakers, disconnect switches, current and voltage transformers, and surge arresters) are isolated from air in metal tanks filled with sulfur hexafluoride (SF-6) gas.
See turbine.
A unit used to measure magnetic field strength. The intensity of the earth’s magnetic field, near the surface of the earth, is on the order of one-half gauss (0.1 Telsa).
The provisions common to all BPA power sales contracts that contain detailed information on delivery, equipment, billing, metering, and other provisions required by statute.
The provisions common to all BPA transmission contracts that contain detailed information on delivery, equipment, billing, metering, and other provisions required by statute.
Those public utility customers of BPA who own or control generating facilities and use this generation to serve a portion of their loads. Also referred to as scheduling or computed requirements customers.
Resources that generate electric power, as opposed to conservation resources.
The generator or generators, associated prime movers, auxiliaries, and energy supplies that are normally operated together as a single source of electric power. In a generating plant, stored energy, such as water behind a dam or fossil fuel, is used to operate a prime mover that in turn operates a generator providing electrical energy.
A utility that owns generating facilities that can meet all or most of its customers’ demand for electricity.
1) The act or process of producing electricity from other forms of energy, such as hydro, coal-fired steam turbines, or photovoltaic conversion systems. 2) The amount of electrical energy produced.
The boundaries within which a generating with automatic generation control capability controls its loads. BPA has more than 120 customers with generation control areas. More often referred to as load control area.
1) In a power plant, the machine that converts mechanical energy to electrical energy. 2) A utility that owns or acquires the output of a generating resource.
1) The heat energy available in the rocks, hot water, and steam in the earth’s subsurface. 2) Geothermal generation uses steam from geothermal sources to run turbines and generate electricity.
A prefix indicating a billion (1,000,000,000); 109 in scientific notation.
One million kilowatts; one billion watts.
One million kilowatthours; one billion watthours.
A theory that the earth’s atmosphere is gradually increasing in average temperatures, resulting from the accumulation of greenhouse gases primarily from the burning of fossil fuels and removal of forests and vegetation.
The device that gauges the speed of a turbine and activates measures to control this speed.
See generating public utility.
See corona ring.
See insulator.
An area restricted from use for buildings and allowed to remain in a natural state or retained for agricultural use. Greenbelts act as effective screens in mitigating or reducing certain kinds of environmental impacts.
The warming of the lower atmosphere and the surface of the earth resulting from the reflection of infrared radiation by carbon dioxide, water vapor, and other gases in the atmosphere, resulting in higher temperatures than would exist in the absence of the effect.
Gases, including carbon dioxide (CO2), methane (CH4), nitrogen oxides (NOx), nitrous oxide (N2O), and water vapor (H2O) that contribute to the greenhouse effect.
See transmission grid.
The total cost BPA assumes for the power purchased from utilities under the residential exchange, equal to the utility’s exchange load times the quotient, calculated by dividing the contract system cost by the contract system load.
The total dollars owed to BPA by utilities for power sold to the utility under the residential exchange, equal to the utility’s exchange load times the priority firm exchange rate.
A connection from electrical equipment to a ground mat or to the earth, used to insure that the equipment (housing or structure) will be at the same potential (voltage) as the earth.
Current flowing in the earth or in a grounding connection.
ground fault
See fault.
See ground mat.
A system of interconnected bare conductors arranged in a pattern or grid, normally buried below the surface of the earth, primarily to provide safety for workers by limiting voltage differences within its perimeter to safe levels. Also called a ground grid.
See relay.
A power transmission system in which one of the conductors is replaced by the ground.
A protective wire strung above the conductors on a transmission line to shield the conductors from lightning; also called shield wire or overhead ground wire.
A steel wire used to support or strengthen a structure.
See anchor.
See gigawatt.
See gigawatthour.
See general wheeling provision.



See henry.
The place where a population (human, animal, plant, or microorganism) lives and its surroundings, both living and non-living.
Non-metallic rope and small pulley for raising and lowering tools and equipment to transmission line workers.
A device for attaching insulator strings to suspension structures.
A sinusoidal wave having a frequency that is an integral multiple of a fundamental frequency. For example, a complex wave whose frequency is twice that of the fundamental frequency is called the second harmonic. Harmonics in a power system cause distortion of the normal sinusoidal voltage waveform.
A facility for incubating and hatching fish eggs, raising and releasing juvenile fish, and holding adult fish for spawning.
The main screening tool used by the Environmental Protection Agency to evaluate risks to public health and the environment associated with abandoned or uncontrolled hazardous waste sites. Sites are scored and then ranked according to the potential for spread of hazardous substances through the air, surface water, or groundwater and on other factors such as nearby population. The score is the primary factor in listing and ranking a site on the National Priorities List.
Any material designated by the Environmental Protection Agency as posing a threat to human health and/or the environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically reactive. Reporting is required whenever more than an EPA-designated amount is spilled or emitted into the environment.
The byproducts of society that can pose a substantial or potential hazard to human health or the environment when improperly managed. Possesses at least one of the following characteristics: ignitability, corrosivity, reactivity, or toxicity. Also see Resource Conservation and Recovery Act.
Heating degree day. See degree day.
The vertical height of water in a reservoir above the turbine or the difference between the surface of the reservoir and the surface of the river immediately downstream from the turbine and dam. Also called hydraulic head.
1) The loss of energy experienced due to a reduction in head. For example, when a given volume of water released from Mica Dam in British Columbia results in low energy production because non-Treaty storage space is not full. 2) The amount of the reduction.
A measure of the ability of a material to store heat and, by definition, the amount of heat energy (calories) needed to raise the temperature of an object one degree Celsius, the heat capacity of the object being proportional to its mass.
Devices that convert thermal energy to mechanical energy, such as steam turbines, gas turbines, and internal combustion engines.
A cooling system that transfers heat from one medium to another with no direct contact between the two media. Exchangers can be water-to-water, water-to-air, air-to-air, or a refrigeration cycle. The liquid in the closed system may be other than water, and the gas may be other than air.
The increase in the amount of heat contained in a home as a result of sunshine, warm air leakage, warming of the walls and roof, and heat given off by people and equipment.
See degree day.
The amount of energy used over a given period of time to heat and cool a building.
The heat decrease in a home, resulting from heat flow through walls, windows, and roof, and air leakage.
A combination device for heating or cooling living space. Has the same functional subsystems as a refrigerator (a compressor that pressurizes a gas, a condenser that gives off heat as the compressed gas changes to a liquid, and an evaporator that absorbs heat as the liquid changes back to a gas) but in which the cycles are reversible.
1) A body that is capable of accepting and storing heat, and therefore may also act as a heat source. 2) A building component such as a wall or floor that is capable of absorbing heat and reradiating it over a period of many hours.
Times of highest electricity usage. For BPA, heavy load hours are 6 a.m. to 10 p.m., Monday through Saturday.
A measure of inductance.
The unit of frequency in cycles per second; power systems in the U.S. operate with a frequency of 60 Hz.
See nuclear reactor.
Descriptive of transmission lines and electrical equipment with voltage levels from 100 kV through 287 kV. Also see extra-high voltage, ultra-high voltage.
The unregulated streamflow database of the 50 years from July 1928 to June 1978, with data modified to take into account adjustments due to irrigation, evaporation, and other factors for the particular operating year being studied.
See heavy load hours.
Weights (usually in increments of 45 kilograms, or 100 pounds) attached to the conductor at suspension points where the vertical loading on the conductor is not adequate because of unusual terrain conditions.
A clause in many contracts that shifts responsibility from one party to another.
A unit of measurement for power which is the rate of doing work (one horsepower equals 746 watts).
Work performed on transmission lines while they are energized and in service.
See load shaping.
A computer model that simulates the hourly dispatch and short-term marketing of Northwest thermal and hydropower resources for a study period of up to four weeks. It is used to examine system capacity, marketing, and various environmental concerns that require hourly detail.
The process of sealing cracks, joints, and other nonintentional paths by which outside air may enter a residence.
A turbine generator unit used to provide auxiliary power for the operation of a power plant.
See heating/ventilating/air conditioning load.
A device or system combining two types of mechanisms, circuits, or design approaches, each of which could of itself accomplish the total function but in a different and usually less effective manner. A hybrid computer combines digital and analog computers into one functioning system.
The maximum flow that a hydroelectric plant can use for power generation.
See head.
A tool for installing compression fittings on a conductor.
The average travel time for a particle of water through a reservoir or other body of water.
1) A type of generating station or power or energy output in which the prime mover is driven by water power. 2) Short for hydroelectric power.
A group of chemical compounds containing only hydrogen and carbon.
Describes a power system or energy resource that produces electric power through use of the gravitational force of falling water.
A rotating machine that transforms mechanical power from a water-driven turbine or water wheel into electric power.
The electricity generated by using falling water to turn turbo-electric generators.
The continuous exchange of moisture between the earth and the atmosphere—evaporation, condensation, precipitation, stream runoff, absorption into the soil, and evaporation—in repeating cycles.
The combined data from snowpack measurements and climatic forecasts to predict runoff.
A radio station that reports hydrological and meteorological data to a monitoring center for weather and streamflow forecasting purposes.
A computer model simulating the operation of the Pacific Northwest electric power system that incorporates the historical streamflow record, monthly loads, thermal and other non-hydro resources, hydroelectric plant data for each project, and the constraints limiting each project’s operation.
The use of pressurized water to test a tank, pipeline, or other equipment for leaks.
See hertz.