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Definitions - PQ
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Pacific Northwest
According to the Pacific Northwest Electric Power Planning and Conservation Act, Oregon, Washington, Idaho, and Montana west of the Continental Divide, as well as portions of Nevada, Utah, and Wyoming within the Columbia-Snake River Basin. Also includes contiguous areas not more than 120 kilometers (75 miles) from the region defined above that are part of the service area of rural electric cooperative customers served by BPA on the effective date of the act whose distribution system serves both within and without the region.
Pacific Northwest Conservation and Electric Power Plan
A 20-year power plan developed by the Northwest Power Planning Council and updated every other year. Proposes a comprehensive set of actions and projects to be undertaken to assure the region of adequate power resources, giving due consideration to conservation and fish and wildlife needs.
Pacific Northwest Coordination Agreement (PNCA)
A 1964 agreement among a group of U.S. utilities and agencies controlling power generating facilities in Washington, Oregon, and parts of Idaho, Montana, and California designed to make optimal use of the water and storage resources of the region.
A 1980 Federal law that authorizes Idaho, Montana, Oregon, and Washington to conduct long-range planning and protection of shared resources. Established the Northwest Power Planning Council. Calls for the development of cost-effective conservation and renewable energy resources and for the mitigation, protection, and enhancement of fish and wildlife affected by Federal dams.
Pacific Northwest Loads and Resources Study
BPA’s biennial study that evaluates the loads and resources of the Federal system and the Pacific Northwest region and projects the yearly average energy consumption and resource availability for the next 20 years. Often referred to as the Whitebook.
Pacific Northwest Non-Residential Energy Survey (PNNonRES)
A survey designed to get regional estimates of the energy-using equipment and physical characteristics of buildings in the Northwest. The five-year effort gathered information on occupancy patterns, type of heating and cooling systems, and other data that could not be obtained through end-use electrical metering.
Four extra-high voltage transmission lines and related substations that link the BPA power grid and California utilities. Three 500-kV alternating- current lines extend from a connection with the BPA system at John Day Dam to various points of connection in northern California. The other line is direct current and operates at 1,000 kV (± 500 kV). The DC line extends from a connection with the BPA system at the Celilo Converter Station near The Dalles Dam to the system of the City of Los Angeles at Sylmar. Also see Third AC.
Pacific Northwest Regional Preference Act
A 1964 Federal law (Public Law 88-552) that defines the Pacific Northwest region where customers have priority access to power marketed by BPA. Puts limits on BPA marketing by making any surplus energy sold outside the region recallable in 60 days.
Pacific Northwest Utilities Conference Committee (PNUCC)
A voluntary association of Pacific Northwest public and private utilities and BPA direct-service industries whose primary role is to represent its members and their interests in pending legislation and the formation of power planning policy.
A statistical comparison between two sets of data used to determine to what extent they are dissimilar.
The flow of power on transmission lines (paths) other than those over which it is scheduled, occurring because in interconnected system operation, power flows according to the impedance (resistance) of the transmission paths and not according to schedules. If loopflow is in the same direction as the normal flow on a line, the actual line flow will be the sum of the two. If the magnitude of loopflow is large, the resultant line flow could cause overloads and require schedule reductions. Sometimes called loopflow.
See resonance.
A BPA customer that supplements its own power resources with purchases from BPA. Also referred to as generating public utilities.
Airborne particles including dust, smoke, fumes, mist, spray, and aerosols. Also see pollutant.
A way of expressing tiny concentrations of pollutants in air, water, soil, human tissue, food, or other products.
The survival rate of migratory fish through, around, or over dams or other obstructions in a stream or river.
A miniature computer chip (about the size of a grain of rice) implanted in a fish to collect data on its migration.
A category of solar energy which takes advantage of the design and siting of a building to maximize the effects of natural processes, such as evaporation and heat flow, as opposed to active solar systems that require mechanical devices.
See polychlorinated biphenyl.
See power circuit breaker.
See picocurie.
See capability.
See capacity.
See demand.
See energy.
Exchange of peaking capacity for off-peak energy between two or more systems producing electrical energy.
Hours of relatively high system demand for electrical energy, usually at the beginning and end of each workday.
See capacity.
See energy.
See load.
See capacity.
A power plant that is normally operated to provide power during maximum load periods. Examples are combustion turbines and pumped storage hydro.
See reserves.
A method of assigning responsibility for demand on the basis of proportionate use at the time of system peak demand.
The time of year of relatively high system demand for electricity; in the Northwest, winter (for heating and lighting). In the Southwest, summer (for air conditioning).
The lowering of load during times of highest demand for electricity, such as by turning off water heaters.
The share of a conservation resource that can be acquired or has been acquired. Usually expressed as a percentage of estimated possibilities for a given conservation resource.
The tube that carries the water from the forebay to the turbine.
A preservative applied to wood poles that kills fungi.
See public utility district.
The movement of water through the subsurface soil layers, usually continuing downward to a restrictive area and/or to the groundwater and water table reserves.
Priority firm power rate. See rates.
1) A conductor or conductors or piece of electrical equipment that is associated with one of three separate phases of an alternating-current power system, designated A-phase, B-phase, and C-phase. 2) The stage or progress of a cyclic movement such as a current or voltage wave.
In a power system, the displacement, in time, of the phase of one quantity (voltage or current) from the phase of the same quantity at a different or reference location. Also see power factor angle.
Air pollution caused by the chemical reactions of various pollutants emitted from different sources. Specifically, a type of air pollution that results when sunlight induces chemical reactions of other pollutants, notably nitrogen dioxide and hydrocarbons, and that is indicated by elevated ozone levels since ozone is one of the products of the photochemical reaction.
See solar cell.
The direct conversion of sunlight to electric energy through the concentration of solar radiation through thin layers of semiconductor material, such as silicon. The resulting energy is often called solar energy.
Measurement of radioactivity. One picocurie is one million millionth, or a trillionth, of a curie and equals 0.037 becquerel, and represents about 2.2 radioactive particle disintegrations per minute.
A unit to measure concentrations of radioactivity or radioactive materials, such as radon gas, in air.
A source that supplies field excitation to the main exciter of a power generator or motor.
A program that provides operating experience, usually on a small scale, for BPA to use in designing future regionwide conservation and generation development programs.
See Programs in Perspective.
See Passive Integrated Transponder Tag.
See computed requirements.
See spill.
The fiscal year following the budget year (budget year plus one). The initial year for which BPA’s budget is formulated, and the fiscal year for which the Department of Energy’s Internal Review Budget is prepared.
Short for power plant, or electric generating facility.
See capacity factor.
See circuit.
The discharge of a contaminant from a given point of origin into the air or the discharge of polluted or heated water into a body of water from its source to the point where the discharge is no longer identifiable since it has mixed with the ambient air or water.
A heavy, radioactive, man-made metallic element with atomic number 94 and whose most important isotopes (fissile PU-239 and PU-241) are both produced by neutron irradiation of the uranium isotope U-238. Used for reactor fuel and in nuclear weapons.
See power marketing agency.
See Power Marketing Decision Analysis Model.
See Pacific Northwest Coordination Agreement.
See Pacific Northwest Non-Residential Energy Survey.
See Pacific Northwest Utilities Conference Committee.
A point where a utility connects with BPA’s transmission system and where BPA delivers power. The delivered power is metered and there is a change of ownership.
See forecast.
1) The site where generation is connected to the BPA transmission system. 2) The site, usually a substation, where two electric power systems are physically linked together. Power usually flows both ways.
The location where power deliveries are metered. There may be one or more POMs for each point of delivery and they may not be at the same location as the point of delivery.
A stationary location or fixed facility from which pollutants are discharged or emitted. Any single identifiable source of pollution, such as a pipe or factory smokestack.
1) For batteries or direct current, an electrical condition determining the direction in which current tends to flow. 2) For transformers, the designation of the relative instantaneous directions of the current entering the primary terminals and leaving the secondary terminals.
A series of poles arranged to support conductors, and the structures and conductors so supported.
In a transmission or communications system, a column or columns of tapered wood, steel, or concrete, supporting overhead conductors on arms or brackets. In transmission, generally used at voltage levels of 230 kV or lower.
1.       pole: may be wood or steel.
2.       crossarm: may be a wood spar or steel.
3.       guy and anchor: steel guy wire attached to a buried anchor to provide strength needed on angle and dead-end structures.
4.       brace: attached to two poles for strengthening the structure.
Two or three poles supporting the crossarm to which the insulator strings are attached. Approximately five structures per kilometer (eight structures used per mile).
single pole
A single pole to which crossarms are attached. Approximately 12 structures per kilometer (20 structures per mile). Requires shorter spans than H-Frame. Right-of-way may be narrower. Uses davit or wishbone crossarms.
A contaminant, such as sulfur dioxide, nitrous oxide, hydrocarbons, radionuclides, carbon monoxide, and lead, present in a concentration high enough to cause adverse effects to health or the environment.
The accumulation of wastes or byproducts of human or natural activity that occurs when wastes or byproducts are discharged faster than they can degrade, assimilate, or disperse by natural processes.
Oily, persistent substance formerly manufactured for use in electrical equipment, primarily as a dielectric in capacitors. Banned from use in the manufacture of equipment in 1979 after research showed that PCBs cause skin disease and liver damage, and are a suspected carcinogen. See dielectric.
See point of metering.
The relatively small amount of water behind a run-of-river dam which is used for daily or weekly regulation of the flow of a river.
Loss of juvenile salmon or steelhead as they migrate through the pool or reservoir of a run-of-river project.
See insulator.
Rates for electric power service that are unchanged by distance from the source of the power supply.
1) Electrically, the voltage at a point relative to some reference point. 2) The degree of electrification at a point in an electric field.
The aggregate energy capable of being developed over a specified period by practicable use of the available streamflow, reservoir storage and river gradient.
See transformer.
A device that seals the end of a power cable and provides an insulated passage of the current-carrying conductor.
An aluminum company's manufacturing unit, consisting of a fixed number of pots into which smelted aluminum is poured.
1) The rate of energy production or transfer. 2) Electrically, power is expressed in watts (the product of applied voltage and resulting in-phase current. Same as active or real power in contrast with reactive or apparent power. Used interchangeably with although technically not a synonym of energy. 3) Power delivered to a load is also termed demand.
A central power scheduling utility that matches lowest cost power offers in the Pacific Northwest with the highest offers to buy in the Southwest.
See cable.
A switching device that can interrupt a circuit in a power system under overload or short-circuit conditions, usually automatically tripped by protective relays. Allows equipment or transmission lines to be isolated from the system as required.
A network of special equipment for controlling the operation of a power system and supported by an extensive communications system that sends and receives data from the system control center and substations. Dispatchers at the system control center are surrounded by computerized displays and devices to interrogate a number of computer system evaluation programs, observe what is happening, and regulate any part of the system.
Energy delivered during on-peak hours in a particular season in exchange for an equivalent amount of energy returned during on-peak hours in a different season.
The ratio of power in watts to the product of volts times amperes. The power factor of an alternating-current transmission system is unity when the voltage and current are in phase. There is no power factor with direct-current power. See reactive power.
The amount that voltage and current are out of phase at a particular time and location.
Computer simulations (studies) of the transmission system, with representations of the complete electrical transmission system along with loads and different generation schedules to meet the loads. Used by engineers to study various operating conditions and to plan future system additions to assure reliable service to customers.
The five organizations, including BPA, overseen by the U.S. Department of Energy, that sell wholesale power from Federal sources. The other PMAs are the Alaska Power Administration, Southeastern Power Administration, Southwestern Power Administration, and Western Area Power Administration.
A computer model that simulates western U.S. bulk power markets on an hourly basis. Determines market prices and quantities for electric energy and capacity, and transmission wheeling and capacity for all major parties in the market. Used to support short- and long-term analyses of power sales, purchases, and resource acquisition decisions.
See Northwest Conservation and Electric Power Plan.
An electric utility generating station.
Two or more electric systems that are operated on a coordinated basis to supply power in the most economical manner for their combined load requirements and maintenance program. Also see Northwest Power Pool.
Under the Pacific Northwest Electric Power Planning and Conservation Act, sources of electric power, including the actual or planned electric capability of generating facilities, or actual or planned load reduction resulting from direct application of a renewable resource or from a conservation measure.
1) A contract for the sale of power. 2) The contractual agreement, usually for 20 years, between BPA and a utility, direct-service industries, or Federal customer.
1) In general, a group of one or more generating resources and connecting transmission lines operated under common management or supervision to supply load. 2) The BPA power system is the Federal Columbia River Power System. 3) An entire interconnected electric power transmission and distribution network together with connected generating plants and loads.
A set of computer programs that allow analysis of the BPA power system based on real-time measurements and also determination of what would happen if certain power equipment failed.
See transformer.
The categories of power that BPA sells at wholesale.
In marketing, power composed of firm energy, firm capacity, or both, and guaranteed to be available to the customer at all times during the period covered by a contract, except for reason of certain uncontrollable forces or service provisions.
A grade of power for delivery to industries on a contract demand basis with greater rights of restriction than firm power.
See nonfirm power.
1) Power available in varying amounts depending upon season and weather conditions and supplied by BPA to a purchaser without the guaranteed continuous availability of firm power. Often used interchangeably with surplus power. Distinct from surplus firm power. 2) That portion of power that serves an industrial load that can be interrupted.
Power that can be provided on a guaranteed basis, that is excess to system demand, and that can be provided in an agreed-upon shape.
Excess power (firm or nonfirm) for which there is no demand in the Pacific Northwest.
See Public Power Council.
See generating public utility.
Fish that prey on other fish. In the Columbia River Basin these include: squawfish, walleye, and smallmouth bass.
Fish after they have hatched from their eggs but before they have left their incubation environment. Also see fry, juvenile.
Priority access to Federal power by public bodies and cooperatives.
Cooperatives or public bodies, such as municipalities and public utility districts, that by law have priority access to Federally generated power.
1) The value of current dollars of a flow of cash over time. 2) In bond financing, the value in current dollars of debt service payments or reductions over the remaining life of the bonds.
The difference between the present value of benefits and the present value of costs.
The value of current dollars in an inflow of cash.
The value of current dollars in an outflow of cash. For example, the amount of money that would have to be put in the bank today for a particular project at a specified interest in order to have enough money in the future to pay all costs of that project.
Upper limits criteria pollutant concentrations allowed in clean air sheds. Established by the Environmental Protection Agency to protect existing air quality from being degraded significantly through new developments, such as construction and operation of new air pollution sources.
In the electric utility industry, a measure of the degree to which energy consumption levels rise or fall in response to changing prices.
The engine, turbine, water wheel, or similar machine that drives an electric generator.
See rates.
Power that is continuously available to public bodies, cooperatives, Federal agencies, and investor-owned utilities to meet their net firm load requirements within the Pacific Northwest. Also used to serve the residential and small-farm loads of utilities participating in the residential power exchange under section 5(c) of the Pacific Northwest Electric Power Planning and Conservation Act.
See rates.
See investor-owned utility.
In BPA planning, an organized set of tasks directed toward a common purpose. The means through which BPA implements its mission, generally composed of multiple subprograms, program elements, or projects. Spans multiple years and involves more than one office, (such as Transmission System Development, Energy Resources, and System Operations).
See costs.
The total funding level for a given BPA program in a given year.
See spill.
A biennial program for involving customers and other regional interests in setting strategic direction for BPA.
1) In planning, a major endeavor within a BPA program which has scheduled beginning, intermediate, and ending milestone dates. Prescribed performance requirements; close management, financial planning, and control; and a specific objective or product. 2) In hydro terms, a dam and any associated facilities.
The volume of water per unit of time entering into a project.
The volume of water per unit of time discharged from a project.
See turbine.
1) A condition in which all storage reservoirs covered by or in the Pacific Northwest Coordination Agreement are drafted in the same proportion to meet firm loads. 2) The obligation of hydro dam operators under poor water conditions to share (proportionally) the release of water stored behind their dams to supplement natural streamflows. Also see draft.
See relay.
A group of interrelated devices, such as relays, acting together to prevent damage to substation equipment or transmission lines.
The generally accepted design, practices, methods, and operation of a power system, to achieve safety, dependability, efficiency, and economy, and to meet utility and industry codes, standards, and regulations.
See power sales contract.
See power system security tools.
Voltage (potential) transformer. See transformer.
An organization formed in 1966 to represent and advocate the common legal and technical interests of public (consumer-owned) utilities in the Northwest. Interacts with BPA, the Northwest Power Planning Council, and other regional and national groups on such issues as BPA rate proceedings, BPA power marketing policies, and conservation.
A 1935 Federal law which seeks to control and limit the powers of large, national holding companies.
A nonprofit utility that provides electric power service. Also see cooperative, municipality, public utility district.
A political subdivision, with territorial boundaries for an area wider than a single municipality and frequently covering more than one county, established by voters to supply electric or other utility service. Called Public Utility Districts in Washington and Peoples’ Utility Districts in Oregon. Hold preference customer status in buying power from BPA.
A 1978 Federal law that requires utilities to purchase electricity from qualified independent power producers at a price that reflects what the utilities would otherwise have to pay for the construction of new generating resources. Designed in part to encourage the development of small-scale cogeneration and renewable resources. Also see independent power producer.
See public utility district.
See storage.
See Public Utility Regulatory Policies Act.
Pressurized water reactor. See nuclear reactor.



The electrical quality of a coil, capacitor, or circuit. Mathematically, Q is the ratio of reactance to resistance. The higher the Q, the greater the selectivity of the circuit. Also see selectivity.
A small power production or cogeneration resource developed under the Public Utility Regulatory Policies Act (PURPA) of 1978.
Each of four portions of the direct-service industry load. Determines BPA terms of delivery, with 25 percent of the load (called the top, or first, quartile) served as interruptible load and 75 percent considered firm load (but interruptible under specified circumstances to provide planning and operating reserve).