Units of Electrical Measure
k kilo 103
M mega 106
G giga 109
T tera 1012
P peta 1015
E exa 1018
Voltage Measures
kV kilovolt = 103 volts
kW kilowatt = 103 watts
MW megawatt = 106 watts or 1 000 kW
GW gigawatt = 109 watts or 1 000 000 kW
TW terawatt = 1012 watts or 1 000 000 000 kW
kWh kilowatt hour one kW for the period of one hour
MWh megawatt hour one MW for the period of one hour or 1 000 kW.h
GWh gigawatt hour one million kW for the period of one hour
Definitions
Alternative Technologies New and emerging technologies used in the production and consumption of energy, such as electric and fuel cell vehicles and clean coal technologies.
Average Cost Pricing A pricing mechanism based on the average total system cost of providing a unit of electricity (per megawatt hour for wholesale, per kilowatt hour for retail) during a specific period.
Average Rate The overall average revenue per kilowatt-hour that a utility receives from a given class of customers.
BC Energy Plan A statement of B.C. government policy related to provincial energy matters issued by the Ministry of Energy and Mines and Petroleum Resources in November 2002 and February 27, 2007.
BC Hydro Dividend Under a Special Directive from the Province, BC Hydro is required to make an annual payment to the Province equal to 85 per cent of BC Hydro’s distributable surplus for the most recently completed fiscal year assuming that the debt to equity ratio, after deducting the payment, is not greater than 80:20. If the payment would result in a debt to equity ratio exceeding 80:20, then the payment will be based on the greatest amount that can be paid without causing the debt to equity ratio to exceed 80:20.
Bulk Transmission The transfer of electricity on the major high-voltage transmission system, which carries the majority of the power from the generators to the lower-voltage distribution systems.
Capability Energy capability is the amount of energy that can be generated under specified conditions by a generating unit or by the electric system over a period of time, typically expressed in gigawatt-hours per year (GWh/year).
Capacity The maximum amount of power that a device can generate, utilize or transfer, usually expressed in megawatts.
Capacity Factor The ratio of the electricity generated for the period of time considered, to the energy that could have been generated at continuous full-power operation during the same period.
Cogeneration The simultaneous production of electrical or mechanical energy and useful heat energy from a single fuel source. For example, forest sector mills can burn wood waste in a boiler to generate electricity and use low-temperature steam from the generator in pulping processes.
Combined-Cycle Generation The production of electricity using combustion turbine and steam turbine generation units simultaneously.
Congestion Congestion occurs when a transmission system cannot accommodate all transactions that would normally occur, for example, due to capacity constraints or reliability considerations.
Cost of Service The process of utility regulation whereby the regulator sets rates at a level that will cover operating costs and provide an opportunity to earn a reasonable rate of return on the invested property or capital devoted to the business. Also known as rate-of-return regulation.
Demand Response Reduction in electricity use in response to pricing incentives or request from the system operator.
Demand-Side Management (DSM) Demand-Side management are actions undertaken by a utility that result in a change and/or reduction in demend for electricity. This can eliminate or delay new capital investment for production or supply generation and transmission and improve overall system efficiency.
Distributed Generation Small scale generation situated close to or at the point of the end-use.
Distribution The transfer of electricity from the transmission network to the consumer.
Firm Energy or Power Electricity supplied at all times during the period of the agreement of its sale.
Generation The process of producing electric energy by transforming other forms of energy; also, the amount of energy produced.
Gigawatt-hour(GWh) One million kilowatt-hours. See Units of Electric Measure at the end of this section.
Green Power Electricity generation deemed to be environmentally less intrusive than most traditional generation, usually in accordance with standards established by government or regulatory agencies. Green power sources include wind, water, landfill gas, solar and others.
Greenhouse Gases (GHG) Gases such as carbon dioxide, methane and nitrous oxide, which actively contribute to the atmospheric greenhouse effect, increasing temperatures in the earth’s lower atmosphere.
Grid A network of electric power lines and connections.
Heritage Contract A power supply contract between BC Hydro's generation and distribution lines of business for 49,000 gigawatt hour per year of heritage electricity, which is priced at cost to ensure BC Hydro customers benefit from the existing low-cost hydroelectric and thermal resources in the BC Hydro system.
High Voltage Direct Current Technology primarily used to transmit electricity over long distances. Direct current power losses over long distances is considerably less than alternating current. A higher voltage is used with direct current to increase energy transmission and reduce losses.
Installed Capacity The capacity rating at the output terminals of a generating station.
Integrated System Similar to ‘grid’. An interconnected network of generation facilities, transmission lines, distribution lines and substations linking generation stations to one another and to customers throughout a utility’s service area. Excludes isolated customers who are connected to stand-alone or remote generating plants.
Independent System Operator An Independent System Operator (ISO) is functionally separated from other electricity market participants, such as generators, transmission companies and marketers, and makes non-discriminatory access available to users of the transmission system.
Interruptible Power or Energy Power made available under an agreement that permits curtailment or interruption of delivery at anytime at the option of the supplier.
Industrial Sector The industrial sector is generally defined as manufacturing, construction, mining, and forestry products producers. From an electrical utility’s perspective, industrial customers are often defined as those that can accept and use electricity at transmission voltages, 60,000 volts and higher.
Investor Owned Utility (IOU) An investor-owned utility (IOU) is privately owned electricity serving the general public whose stock can be publicly traded. An IOU’s electricity rates are usually regulated to achieve an allowed rate of return, as determined by a provincial or state energy regulator.
Kilowatt (kW) A unit of electricity, which is 1,000 watts, without reference to the duration (number of hours) of the electricity consumption. See Units of Electric Measure at the end of this section
Kilowatt hour A commercial measure of electric energy. A kWh is the basic billing measure of electricity usage, equivalent to consuming 100 watts over 10 hours. See Units of Electric Measure at the end of this section.
Load The amount of electricity required by a customer or group of customers.
Load Centre An area with a significant number of electricity customers, which makes it an important point for power delivery (e.g. Lower Mainland).
Load Displacement A reduction in electricity sales, due to electricity conservation or customer self-generation.
Load Factor The ratio of the average demand supplied during a given period to the peak demand occurring during the same period.
Load Forecast The expected load requirements that an electricity system will have to meet in future years.
Load Management Management of load patterns to make better use of system facilities, generally by shifting load from peak periods to other periods of the day or year.
Load Profile The pattern of electricity supply or demand over a time period. For example, a one-day hourly load profile for a customer shows hourly consumption over a 24-hour period.
Long Term Acquisition Plan BC Hydro's Long Term Acquisition Plan (LTAP) is a plan of resource development actions over the next 10 years to meet customer demands.
Marginal Cost The cost of the last unit (of electricity) produced.
Natural Monopoly An industry characterized by sufficiently large economies of scale, whereby one firm can most efficiently produce the output to supply market demand.
National Energy Board (NEB) A Canadian federal agency that regulates several aspects of the energy industry, such as the construction and operation of interprovincial and international pipelines and international power lines.
North American Electric Reliability
Council (NERC) NERC’s mission is to ensure that the bulk electric system in North America is reliable, adequate and secure. NERC sets standards for the reliable operation and planning of the bulk electric system and monitors and enforces compliance with reliability standards. NERC is working closely with industry stakeholders, FERC, and regulators to create an electric reliability organization with mandatory reliability standards.
Net Metering A program that allows customers with their own generation facility to “bank” their surplus electricity with the electric utility. This banked surplus is then applied against the amount of electricity supplied by the utility
Open Access Non-discriminatory access to electricity transmission lines.
Peak Demand The maximum coincident demand over in a stated period, usually indicated as an instantaneous load, which the system must meet. In B.C., the peak demand usually occurs in the winter due to heating requirements. In the southern U.S., it usually occurs in the peak cooling months in the summer.
Power Smart BC Hydro’s demand-side management (DSM) initiative to encourage energy efficiency by its customers. Launched in 1989, Power Smart includes a full range of DSM programs aimed at BC Hydro’s residential, commercial and industrial customers.
Power Sense FortisBC’s demand-side management (DSM) initiative to encourage energy efficiency by its customers. Launched in 1989 by West Kootenay Light and Power.
Photovoltaic (PV) Direct conversion of light into electricity by semi-conductor diodes called photovoltaic cells, especially using sunlight.
Power When energy is being transferred or changed from one form to another, the term “power” is used to mean the amount of energy transferred per unit time. The metric unit of power is the watt (W), defined as one joule per second.
Rate The price charged for a commodity or service. Rates may be subject to regulatory approval or may be set by the market.
Reliability The degree of performance of the elements of the bulk electricity system that results in electricity being delivered to customers within accepted standards and in the amounts desired.
Renewable Energy Energy sources that are capable of being renewed by the energy within the natural ecosystem (e.g., wind, biomass, solar).
Reserve Margin The amount of unused available capacity of an electric power system at peak load as a percentage of total capacity.
Residential Sector Private household establishments that consume energy primarily for space heating, water heating, air conditioning, lighting, refrigeration, cooking and clothes drying.
Resource Smart BC Hydro's program of improvements to existing power generation facilities to increase supply-side efficiency through physical and operational modifications.
Retail Access A market in which electricity or other energy services are sold directly to consumers by competing suppliers.
Self-Generation Generation of electricity by an industry or commercial enterprise whose principal product is not electricity. Self-generation can reduce the amount of electricity purchased from the utility, or surplus electricity may be sold to the utility as a supply-side resource.
Simple Cycle A combustion turbine that burns natural gas (or some other fuel) to drive a turbine, which in turn drives a generator to produce electricity, without utilization of waste energy.
Spot Market Market where actual commodities or financial instruments are bought and sold for instant delivery. The spot market contrasts with the futures market, in which contracts are completed at a specified time in the future.
Steam Turbine A generating plant that uses a fuel or other source of heat to boil water and produce steam to drive a steam turbine connected to a generator.
Storage The volume available in a reservoir to hold water for power generation or flood control.
Streamflow The rate at which flowing water passes a given point, usually measured in cubic metres per second (m3/s).
Tariff Terms and conditions under which a service or product will be provided, including the rates or charges that users of a service or product must pay. Tariffs are usually proposed by the service or commodity provider, and are subject to regulatory approval.
Thermal Generation Electric Generation using a steam turbine or combustion turbine driven by heat for combustion of biomass, fossil fuels or nuclear power.
Time-of-Use Rates Rates that are based on the time of day when the electricity is actually used. These rates allow consumers to pay less for electricity used during ‘off-peak’ or low demand periods, while electricity used during ‘on-peak’ hours is more costly.
Transmission The movement or transfer of electric energy over power lines, 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 reduced in voltage for distribution.
Vertically-Integrated Utility A utility that provides all the functions of generation, transmission and distribution.
Volt The basic unit of measurement of electromotive force, the force required to change the random motion of electrons into an electric current.
Watt The basic unit of measurement of electric power, indicating the rate at which electric energy is generated or consumed. (1 watt = 1 joule per second.)
Western Electrical Coordinating
Council (WECC) Western Electrical Coordinating Council is the body that sets electricity system operating performance and reliability standards for members in Western Canada and the Western United States.
Wheeling The transmission of electric power from one system to another system through a third party, usually the owner or operator of the transmission facilities. Retail wheeling involves the wheeling of power from electricity suppliers direct to customers. Wholesale wheeling refers to the wheeling of power from electricity suppliers to utilities (wholesalers).
Wholesale Access A distributor of power has the option to buy its power from a variety of power producers on a wholesale basis for resale on a retail level.
