AC (Alternating Current):  An electric current that changes direction at regularly recurring intervals. In North America, this interval is 60 cycles per second. Also expressed in "hertz" in honor of Heinrich R. Hertz, a noted physicist. Thus, the nameplate on an electric appliance may indicate 120 VAC-60 Hz. This indicates the appliance operates on 120 volts alternating current with a line frequency of 60 cycles per second (or hertz). The 60 cycles per second is determined by the speed of the rotation of generators at generating plants. AC transmission is preferred to DC because AC is transformable, and therefore, increasing transmission voltage can reduce power line losses. See DC-Direct Current.

Ad Volorum Tax: A tax based on the assessed value of real (land and improvements) and personal property.

All-Requirements Customer: An electric utility that purchases all of its wholesale power from a single supplier. 

All-Requirements Power Contract:  A contract entered into by a power supply system and its customers. In this contract, the customers agree to purchase all their wholesale power needs from the power supply system at rates prescribed in the agreement and adjusted periodically to meet the power supply system's cost of providing the power.

Asset:  Anything owned by an individual, a business, or a bank that has commercial or exchange value. Assets may consist of specific property or claims against others, in contrast to obligations due others.

Audit:  Periodic or contiguous verification of an organization's assets or liabilities. An “auditor” performs this function. The auditor may be appointed or hired by the board of directors and is responsible for carrying out this verification. Among the assets and liabilities more regularly verified are cash, loans, collateral for loans, savings, and checking accounts.

Backup Power:  Power that is needed when regularly used generating units are not in service. This may occur during short-term emergencies or longer unplanned outages, and during periods of scheduled maintenance when the units must be shut down. Short-term backup power is generally called emergency power. Long-range backup power is often provided for through reserve sharing agreements.

Base Load:  The minimum load over a given period of time.

Base Load Plant:  A generating plant that provides the basic power that is needed year around. A base load plant is designed to run most of the hours of the year.

Billing Demand:  Maximum demand adjusted for all applicable provisions of the rate schedule to which the demand charge is applied.

Billing Energy:  Metered kilowatt-hours adjusted for all applicable provisions of the rate schedule to which the energy charge is applied.

BTU (British Thermal Unit): The standard unit for measuring quantity of heat energy, such as the heat content of fuel. It is the amount of heat energy necessary to raise the temperature of one pound of water one degree Fahrenheit.

Content of Fuel, Average:  The heat value per unit quantity of fuel expressed in BTU as determined from tests of fuel samples. Examples: BTU per pound of coal, per gallon of oil, etc.

Equivalent of Fuels Burned:  The BTU equivalent of fuels burned is the aggregate heat energy of all fuels burned. Calculating total BTU content of each kind of fuel burned and totalizing to establish the BTU content of all fuels burned derives it.

Based on its BTU content, any kind and quantity of fuel burned may be expressed as an equivalent quantity of some other kind of fuel.

Bulk Power:  Technically, electrical power is the rate at which electricity is being produced or consumed at a specific instant in time. The supply of that electricity is bulk power to the Cooperative, which in turn supplies electricity to its consumers.

Capacity:  The load for which a generating unit, generating station, or other electrical apparatus is rated either by the user or by the manufacturer. See also Nameplate Rating.

Dependable: The load-carrying ability for the time interval and period specified when related to the characteristics of the load to be supplied.

Hydroelectric: The rating of a hydroelectric generating unit or the sum of such ratings for all units in a station or stations.

Peaking: Generating units or stations, which are available to assist in meeting that portion of peak load that is above base load.

Purchase: The amount of power available for purchase from a source outside the system to supply energy or capacity.

Capital Credits:  The amount of a cooperative's net margins allocated to individual members (patrons). The allocation is usually based upon the member's use of the cooperative's service. Member patronage is the amount of power purchased during a fiscal year.  A number of methods of capital credit retirement exist. The most commonly used are "last in, first out" (LIFO), "first in, first out" (FIFO), and the percentage method.

CFC:  National Rural Utilities Cooperative Finance Corporation. Established in 1969 by rural electric cooperatives, CFC provides financing from the private money market for expansion and improvements by the cooperatives. Many times, CFC loans are used along with REA loans. Offices are in Washington, D.C.

Coal Slurry:  A process by which coal is ground fine enough to be suspended into a solution of water so that it may be transported by pipeline from a place close to where it is mined to the final destination for use.

Cogeneration: The combined production of power and useful heat by the sequential or simultaneous use of energy from one fuel source - the reject heat of one process becomes the energy input into a subsequent process - used for industrial, commercial, heating, or cooling purposes.

Conductor:  A material which allows the free passage of an electric current through its structure, generally it is wire, cable, or other suitable material.

DC (Direct Current):   Electricity that flows continuously in one direction as contrasted with alternating current.

Degree-Day: Used to estimate energy requirements for heating a building, this is a measure of the deviation of the mean daily temperature from a given standard, typically, 65 degrees Fahrenheit.

Delivery Point:  Term given to the physical location at which point electric energy is delivered for use by a distribution cooperative, which then delivers energy to its consumers.

Demand (Economic):  Every electric system that serves the public is subject to a demand, or load, that varies from hour to hour, day to day, and season to season. The demand, which is expressed in kilowatts (not in kilowatt hours), is a measure of the rate of electric usage. Seasonal demands are affected by the number of hours of daylight, temperature extremes and activities such as agricultural processes.

Demand (Electric): The rate at which electric energy is delivered to or by a system, part of a system, or a piece of equipment; expressed in kilowatts, kilovolt amperes or other suitable unit at a given instant or averaged over any designated period of time.  See Load.

Annual Maximum:  The greatest of all demands of the load under consideration, which occurred during a prescribed demand interval in a calendar year.

Annual System Maximum:  The greatest demand on an electric system during a prescribed demand interval in a calendar year.

Average:  The demand on, or the power output of, an electric system or any of its parts over any interval of time, as determined by dividing the total number of kilowatt hours by the number of units of time in the interval.

Billing:  The demand upon which billing to a customer is based, as specified in a rate schedule or contract. It may be based on the contract year, a contract minimum, or a previous maximum and, therefore, does not necessarily coincide with the actual measured demand of the billing period.

Coincident: The sum of two or more demands that occur in the same demand interval.

Instantaneous Peak:  The maximum demand at the instant of greatest load.

Integrated:  The demand usually determined by an integrating demand meter or by the integration of a load curve. It is the summation of the continuously varying instantaneous demands during a specified demand interval.

Maximum:  The greatest of all demands of the load under consideration that has occurred during a specified period of time.

Non-Coincident:  The sum of two or more individual demands, which do not occur in the same demand interval. Meaningful for rate purposes only.

Demand Charge:  The amount applied to billing demands to collect fixed charges and fixed operation and maintenance expenses.

Demand Interval:  The span of time over which metered kilowatts are determined.

Dispatching: The operating control of an integrated electric system involving operations such as: 

1) The assignment of load to specific generating stations and other sources of supply to affect the most reliable and economical supply as the total of the significant area loads rise or fall. 

2) The control of operations and maintenance of high-voltage lines, substations, and equipment, including administration of safety procedures. 

3) The operation of principal tie lines and switching. 

4) The scheduling of energy transactions with connecting electric utilities.

Distribution:  The act or process of distributing electric energy from convenient points on the transmission or bulk power system to the consumers. Also a functional classification relating to that portion of utility plant used for the purpose of delivering electric energy from convenient points on the transmission system to the consumers, or to expenses relating to the operation and maintenance of distribution plant.

Distribution Delivery:  Power sales delivered at 12,500 volts or less. Indicates or supplier ownership of the substation, rather than distribution cooperative ownership.

Distribution Line:  One or more circuits of a distribution system on the same line of poles or supporting structures, operating at relatively low voltage as compared with transmission lines.

Emergency Energy:  Energy to be provided in the event of a breakdown or other emergency involving sources of power or transmission which event may impair the ability of a party to meet its Native Load plus the net of Firm Power transactions.

Energy:  That which does or is capable of doing work. It is measured in terms of the work it is capable of doing; electric energy is usually measured in kilowatt-hours.

Energy Control: Refers to a control process where a centrally located main computer processing unit interconnects with and issues control commands to several remote terminal units.

EPA (Environmental Protection Agency):   A federal agency that develops rules and regulations concerning environmental protection and monitors utilities and other industries.

EPRI (The Electric Power Research Institute):   An organization financed by electric utilities for the purpose of research and development of energy resources.

FERC (Federal Energy Regulatory Commission):  In October 1977, FERC succeeded the Federal Power Commission (FPC) as the agency that sets and enforces the wholesale electric rates that investor-owned power companies charge each other, rural electric cooperatives, and other wholesale customers. The agency also licenses hydroelectric projects. It is a five-member board that is part of DOE.

Firm Energy:  The amount of electric energy that is contractually guaranteed to be available at all times from any given plant or system, or under any given contract -- even under adverse conditions such as when a given plant is out of service.

Fuel (Adjustment) Clause:  A utility company's rates are set to recover various costs; administrative expenses, cost of plant, fuel costs and others. Of these, fuel costs are the most variable and can change markedly from month to month. To avoid having a new rate case every time fuel costs fluctuate, regulatory commissions grant to the utilities fuel clauses that track fuel costs in addition to their regular (base) rates. The regular rates contain a certain amount for basic fuel expenses. The fuel clause, on the other hand, rises or falls from the basic fuel expense level depending on increases or decreases in the price of fuel burned.

Fuel Cost Charge:  An amount included in the rate schedule which collects fuel related expenses. The fuel cost charge is revised quarterly within specific guidelines of the Public Service Commission.

G & T:  Generating and transmission cooperative organizations. A cooperative supplier of wholesale power to distribution systems, other G & T's, or other utilities.

Generating Station (Generating Plant or Power Plant): A station at which are located prime movers,  electric generators, and auxiliary equipment for converting mechanical, chemical, and/or nuclear energy into electric energy.

Geothermal Heat Pump:  A heating and cooling device, which uses a fluid to transfer heat to and from the earth.

Grid:  A system of high-voltage transmission and power-generating facilities that is interconnected with a number of other bulk power supply agencies on a regional basis. A grid enables power to be transmitted from areas having a surplus to areas experiencing a shortage.

Inter-Connection Agreement:  An agreement between two adjacent utilities to connect their transmission systems. Once interconnected, the utilities may buy and sell interchange energy.

Investor-Owned Electric Utilities:  Those electric utilities organized as tax-paying businesses usually financed by the sale of securities in the free market, and whose properties representatives manage regularly elected by their shareholders. Investor-owned electric utilities, which may be owned by an individual proprietor or a small group of people, are usually corporations owned by the general public.

Kilowatt (KW): The basic measure of electric power demand, kilowatt stands for 1,000 watts.

Kilowatt Hour (KWh):   The basic measure of the use of electric energy.  One-kilowatt hour (1 kWh) is the amount of electric energy required to operate a 100-watt light bulb for 10 hours.

Kilovolt (kV):  1,000 volts (defined herein).

Load:  The amount of electric power delivered or required at any specified point or points on a system. Load originates primarily at the power consuming equipment of the customers.

Load factor represents the ratio of average demand to peak demand.  It is a measure of efficiency that tells whether a system's usage of electricity is reasonably stable or if it has extreme peaks and valleys.  For a typical utility industry load, a high load factor is better than a low load factor because it results in a lower average price per kilowatt-hour.

Margin: In financing, margin is the difference between the market value of collateral pledged to secure a loan and the face value of the loan itself.  Margin requirements are set by each financial organization.  This ratio must be maintained by the borrower to keep adequate security pledged to the financial organization for the life of the loan.  In cooperative operations, the operating margin is the amount by which net operating revenues exceed net expenditures.  Margins in this case are usually assigned to members and then allocated back to those members in the form of capital credits.

Maximum Demand:  The maximum metered kilowatts experienced during the billing period.

Megawatt (MW):  One million watts, or 1,000 kilowatts.

Megawatt-Hour (MWh):  One thousand times more than a kilowatt-hour, or 1,000 kWhs.

Municipals:  A term used to apply to the bonds issued by a whole range of domestic public agencies and authorities below the level of the U.S. government (states, counties, cities, towns, schools and various special purpose districts or agencies). Municipals also refer to municipalities that have their own electrical generating and distribution systems and/or that purchase electricity at wholesale from another electrical supplier.

Non-Firm: A sale of power to a consumer that can be stopped any time for any reason with no further commitment of service.

NRECA:  National Rural Electric Cooperative Association. A national service organization that represents about 1,000 rural electric cooperatives in the United States. Headquarters are in Washington, DC.
 
NRTC:  National Rural Telecommunications Cooperative. A cooperative established in late 1986 to foster the development of telecommunications for rural America, especially Television Receive Only (TVRO) programming by satellite.

Off-Peak Power:  Power supplied during designated periods of relatively low system demands. See Demand.

Peak Demand:  The maximum amount of electricity used by a utility customer during any given period of time, usually a year. The peak is used to measure the amount of electric transmission, distribution, and generating capacity required to meet that maximum demand.

Peak Load:  The highest total load on a generating plant or a system during a particular period of time (same as maximum demand).

Peaking Power:  Capacity and energy normally designed for use during the maximum load period of a designated time interval.

Peaking Unit:  Generating equipment normally operated only during the hours of highest daily or weekly loads. The generating equipment is usually of the kind that can be started up and synchronized to a system in less than 1 hour.

PURPA:  Public Utility Regulatory Policy Act. One of five parts of the National Energy Act passed by Congress on October 15, 1978. It is concerned with voluntary rate standards, cogeneration, small hydro loans, interconnections and wheeling, and other regulatory policies.

Ratchet: A method of establishing a minimum billing demand based on all or some portion of a maximum demand experienced prior to the current billing month.

RUS:  Rural Utilities Services. The federal agency in the U.S. Department of Agriculture that deals generally with electric membership corporations. Among other functions, the RUS approves and guarantees loans to electric cooperatives for generation, transmission, and distribution facilities. Congress passed the Rural Electrification Act establishing REA in 1935 (now known as RUS).

SCADA: Supervisory Control And Data Acquisition
 
Scrubber: (FGD System) Flue gas desulphurization (FGD) equipment is designed to control emission of pollutants into the environment. FGD Systems remove sulfur dioxide and other by-products created from the burning of fossil fuels in power plant boilers. This process is accomplished by using lime or limestone to "scrub" the flue gas exiting the boiler before the gases are emitted to the atmosphere thorough the smokestack.

Service Area:  Territory in which a utility system is required or has the right to supply electric service to ultimate customers.

Substation: An assemblage of equipment for the purpose of switching and/or changing or regulating the voltage of electricity.

Transformer:  Extensively used by electric power systems to transform power from one voltage level to another by electromagnetic induction between circuits and the same frequency, usually with changed values of voltage and current. A step-down transformer would have less secondary voltage than primary voltage. A step-up transformer would have higher secondary voltage than primary voltage.

Transmission:  The act or process of transporting electric energy in bulk from a source or sources of supply to other principal parts of the system or to other utility systems. Also a functional classification relating to that portion of utility plant used for the purpose of transmitting electric energy in bulk to other principal parts of the system or to other utility systems, or to expenses relating to the operation and maintenance of transmission plant.

Turbine (Steam or Gas):  An enclosed rotary type of prime mover in which heat energy in steam or gas is converted into mechanical energy by the force of a high velocity flow of steam or gases directed against successive rows of radial blades fastened to a central shaft.

Utility Plant: All equipment used for the generation, transmission, and distribution of electricity, or an account in which record is kept of this equipment. Includes Plant in service, purchased or sold, in process of reclassification, leased to others, held for future use, completed construction not classified, construction work in progress, plant acquisition adjustments, other electric plant adjustments, and other utility plant.

Volt: The unit of electromotive force or electric pressure analogous to water pressure in pounds per square inch.  It is the electromotive force, which, if steadily applied to a circuit having a resistance of one ohm, will produce a current of one ampere.

Watt: The electrical unit of power or rate of doing work.  The rate of energy transfer equivalent to one ampere flowing under a pressure of one volt at unity power factor.  It is analogous to horsepower or foot-pounds per minute of mechanical power.  One horsepower is equivalent to approximately 746 watts.

Wheeling: An electric operation wherein transmission facilities of one system are utilized to transmit power from one system to another system and/or another electric utility.

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