A reclamation technique that returns the rock and soil of the overburden to mined cuts or pits, leaving the land in a configuration similar to the original form.
The radioactivity in the environment including cosmic rays from space and radiation that exists everywhere—in the air, earth, and man-made materials; people in the U.S. receive 1,000 to 2,500 microsieverts (100 to 250 millirems) of background radiation per year.
See best available control technology.
An emission control device that uses a fabric to trap particulate matter such as fly ash and prevent it from exiting a plant stack after a combustion or industrial process. Works on the same principle as a vacuum cleaner.
A statement showing the financial position of a business on a given date. It shows the financial resource, debts, and residual interest (the difference between what it owns and what it owes) of the business; assets = liabilities + owner equity.
A continuous range of frequencies extending between two specified limiting frequencies, often referred to as frequency band.
The difference, in hertz, between the highest and lowest frequencies of a band. The bandwidth limits of a device such as a filter, attenuator, or amplifier are generally taken to be the two frequencies that are attenuated 3.0 decibels below a reference frequency within the band, usually that frequency with the highest value.
A short expression for a transformer bank’s neutral connection which may be a source of relay current (usually used for backup).
A ridge usually of sand or gravel, formed in a stream bed or shoreline by tidal or current action.
See Bonneville Average System Cost.
1) The study case that is most representative of the cases evaluated under a specific set of conditions. 2) In power flow studies, the study case that represents a most probable generation pattern among available generation and assumes all facilities in service. Variations to the base case are examined to assess performance for other- than-normal conditions.
1) In a demand sense, a load that varies only slightly in level over a specified time period. 2) In a supply sense, a plant that operates most efficiently at a relatively constant level of generation.
A power plant generally operated at a relatively constant level of generation to carry baseload because its fuel and operating characteristics make constant generation that most efficient, e.g. coal, nuclear.
A reference impulse insulation strength expressed in terms of the crest value of the withstand voltage of a standard lightning impulse voltage wave. The standard lightning impulse wave rises to a crest value in 1.2 microseconds and drops to one-half crest value in 50 microseconds.
A reference switching impulse insulation strength expressed in terms of the crest value of the withstand voltage of a standard switching impulse voltage wave; the standard switching impulse voltage wave rises to a crest value in 250 microseconds and drops to one-half of crest value in 2500 microseconds.
The land area drained by a river and its tributaries. Also see Columbia River Basin.
Pressed mats of mineral wool insulation sold in various lengths.
A combination of cells, wet or dry, in which chemical action takes place to produce direct current.
See British Columbia Hydro and Power Authority.
The maximum degree of emission reduction achievable (considering energy, environmental, and economic impacts and other costs) through use of production processes and available methods, systems, and techniques. Air quality affected by this technology is a major concern for BPA.
An electron of either positive or negative charge emitted by an atomic nucleus or neutron in the process of transformation.
See basic lightning impulse insulation level.
Under section 6(h) of the Pacific Northwest Electric Power Planning and Conservation Act, credits on BPA power bills to individual utilities or equivalent cash payments for resources that a utility supplies. Encourages BPA customers to conserve or generate power that BPA would otherwise serve.
The BPA policy that interprets 6(h) of the Pacific Northwest Electric Power Planning and Conservation Act. Prescribes eligibility and how billing credits will be granted and administered.
A measure of electric power usage at a customer’s metered point of delivery used in the computation of a customer’s bill, and therefore in projections of a utility’s revenue.
The interval between BPA meter-reading dates for each utility’s point of delivery, normally 30 days. Readings are typically made on the last day of each month.
The conversion of organic wastes into methane (natural gas) through the action of micro-organisms.
The energy derived by converting complex carbohydrates in organic matter into energy, either by using it directly as a fuel or by processing it into liquids and gases.
Organic matter, derived from living organisms, including wood, grain crops, algae and other aquatic plants, and waste and residues from livestock, agriculture, logging, and municipal operations, that can be used as a fuel.
The process by which organic materials are burned for direct energy use or electrical generation, or by which these materials are converted to synthetic natural gas.
The disconnection of the source of electricity from all the electrical loads in a certain geographical area. Brought about by an emergency forced outage or other fault in the generation, transmission, or distribution system serving the area.
Pressed mats of mineral wool or other material sold in continuous rolls which may be cut to any length and often used as insulation.
See U.S. Bureau of Land Management.
The downward movement of a mass of earth, often caused by excessive soil saturation.
A large furnace in which water-filled tubes are heated to produce steam.
See nuclear reactor.
Connecting together in such a way as to assure electrical conductivity.
Evaluations of the credit quality of bonds usually made by independent rating services such as Moody’s (Investor Service), Standard & Poor’s (Corporation), and Fitch Investors Service. Ratings are intended to measure the probability of the timely repayment of principal and interest on the bonds.
The replacement of existing high-interest bonds with new bonds to reduce interest rates and/or to remove a restriction of the bonds being replaced.
Intermediate and long-term debt instruments whereby BPA “sells” bonds to the U.S. Treasury with terms ranging from three to 45 years for the purpose of financing BPA and, in certain cases, Bureau of Reclamation or U.S. Army Corps of Engineers, assets. Short-term bonds are those used to finance capital assets in which the term is significantly less than the service life of the asset (terms us-ually three to five years). Notes issued to the U.S. Treasury are financial instruments not to exceed two years, used by BPA to finance construction work in progress. Total notes outstanding cannot exceed $250 million. Total of bonds and notes outstanding cannot exceed $3.75 billion.
The ratio of Bonneville's total annual system cost to Bonneville's total annual system sales. Expressed in mills/kilowatthour.
The Federal power marketing agency under the Department of Energy responsible for marketing wholesale electric power from 30 Federal dams and one non-Federal nuclear plant throughout Washington, Oregon, Idaho, and western Montana and portions of California, Nevada, Utah, and Wyoming. BPA also sells and exchanges power with utilities in Canada and California. Also known as Bonneville.
A 1937 Federal law creating BPA and directing it: 1) to promote the widest possible use of electricity; 2) to sell Federal power at the lowest possible rates; and 3) to give preference in the sale of Federal power to public bodies, such as municipalities and public utility districts, and rural cooperatives.
The statutory authority that permits a Federal agency to incur debt for specified purposes and to repay the debt through the use of borrowed moneys. Usually the funds are borrowed from the U.S. Treasury, but in a few cases agencies may borrow directly from the public.
The uncombusted materials that accumulate in the bottom of a boiler and that must be removed and, generally, disposed of as solid waste.
A means to increase the thermal efficiency of a steam electric generating system by converting low-level waste heat into electric power.
Descriptive of tower and substation structures designed largely with horizontal and vertical members, resulting in more expensive but simpler and aesthetically more pleasing structures than conventional lattice structures.
See Bonneville Power Administration.
See Federal Columbia River Transmission System.
The geographic area which includes Oregon, Washington, Idaho, Montana west of the Continental Divide, portions of Nevada, Utah, and Wyoming that lie within the Columbia River Basin, and any contiguous areas not more than 75 miles from the above areas of a rural electric cooperative customer served by BPA on the effective date of the Pacific Northwest Power Planning and Conservation Act and whose distribution system serves both within and without the region.
See anchor, swamp.
See bus scheme.
See nuclear reactor.
British Columbia Hydro and Power Authority (B.C. Hydro)
The largest electric utility in British Columbia, owned by the provincial government; commonly called B.C. Hydro.
A measure of heat quantity in the English system, equal to the amount of heat energy necessary to raise the temperature of one pound of water by one degree F; replaced by joules in the metric system, one Btu equals 1055 joules.
An intentional reduction of energy loads in an area by the partial reduction of electrical voltages which results in lights dimming and motors losing efficiency.
See basic switching impulse insulation level.
See British thermal unit.
In energy conservation, the number of units of energy, expressed in British thermal units, equal to the energy of one kilowatthour (3,413 Btu).
1) Under Federal law, a system that allows emission sources to propose means to comply with a set of emissions limitations. Often this means sources can meet total emissions limitations by large decreases in emissions where control costs less, in return for a comparable relaxation of controls at a second, more expensive control point. 2) A boundary around a facility. Emission points within this boundary contribute to a facility's environmental impact and the plant's "site emission limit."
Authority provided by law and becoming available during the budget year to incur obligations against revenues on a permanent basis and against borrowing authority.
The fiscal year (October 1 through September 30) for which BPA’s budget document is prepared.
A substation that receives power at high voltage, usually 230 kV or 115 kV, and has transformers to step the voltage down to a lower voltage for distribution to serve local load.
See conductor configurations.
See U.S. Bureau of Reclamation.
A conductor or group of conductors that serves as a common connection for two or more circuits and is used to interconnect equipment of the same voltage. In substations, BPA uses mostly rigid bus made of aluminum pipe which varies in size from 50 millimeters to 220 millimeters (2 inches to 8 inches) in diameter.
An insulating structure, generally of porcelain and conical or cylindrical in shape, having a central conductor and provisions for mounting on a piece of equipment or wall; insulates the conductor and permits carrying current through a grounded barrier, such as a transformer tank, circuit breaker, or building wall.
an arrangement of a conductor or group of conductors used to interconnect circuits and breakers in a substaton.
Descriptive of a method of interconnecting several circuits and breakers in a switchyard so that three circuit breakers can provide dual switching to each of two circuits by having the circuits share one of the breakers, thus a breaker and one-half per circuit; this scheme provides reliability and operating flexibility, and is generally used at 500 kV when more than five lines terminate in a substation.
Two buses with a single breaker for each line position, and generally an extra breaker (bus tie) between the buses for use in any line position when the line breaker is taken out of service (bypassed). Only the main bus normally carries current, and the auxiliary bus carries current only when a line breaker has been bypassed over the bus tie breaker.
An arrangement of circuit breakers in a substation that has one breaker for each line position, with a single bus closing back on itself, to form a ring (two breakers must be opened to clear or isolate a fault. Taking a line or breaker out of service requires opening the ring, limiting the application of this scheme usually to four to six positions).
A conservation program that, in effect, purchases electrical energy in the form of conservation measures installed by a consumer. The consumer is paid a certain amount per kilowatthour of energy saved.
Boiling water reactor. See nuclear reactor.
1) The water released from a project that does not go through the turbines or over the spillway; may include leakage, navigation lock releases, and fish ladders. 2) In a switching operation, refers to taking a circuit breaker out of service and providing an alternate path. See main and auxiliary bus scheme under bus scheme.
A channel or conduit in a dam that provides a route for fish to move through or around the dam without going through the turbine units. Also see fish ladder, fish screen.