A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Access:
The legal right to use an electrical or gas transmission and /or distribution system to transfer electrical energy or natural gas.

Availability:
Unit of measure for the actual time a transmission line or generating unit is capable of providing service, if called upon.

Average Annual Energy:
The total energy generated annually by a power station, averaged over a period of time of full operation or since the start of full operation, if less, measured in gigawatt hours (GWh).

Average Inflow:
The average water flow available for power generation measured in cubic feet per second (cfs).

Average Revenue per Kilowatt-hour:
Calculated by dividing the total revenue in any given period by the corresponding total KWh sales.

Base Load:
The minimum amount of electric power or natural gas delivered or required over a given period of time at a steady rate. The minimum continuous load or demand in a power system over a given period of time usually not temperature sensitive.

Black Start:
A rapid start-up of an off-line, idle, non-spinning electric generation source.

Blackout:
The emergency loss of the source of electricity serving an area caused by failure of the generation, transmission, or distribution system.

British Thermal Unit (BTU):
The amount of heat energy necessary to raise the temperature of one pound of water one degree Fahrenheit.

Brownout:
The partial reduction of electrical voltages caused by customer demand, which is higher than anticipated, or by the failure of the generation, transmission, or distribution system. A brownout results in lights dimming and the slow down of motor-driven devices slowing down.

Capacity (Electric):
The maximum volume of power that can be produced or delivered under specified conditions by a generator or system, measured on an instantaneous basis, usually expressed in megawatts.

Capacity Factor:
Ratio of average generation to the capacity rating of an electric generating unit for a specific period (expressed in percentage).

Capacity Peaking:
The capacity of facilities or equipment normally used to supply incremental gas or electricity under extreme demand conditions. Peaking capacity is generally available for a limited number of hours per day at a maximum rate.

Cogeneration:
The use of a single prime fuel source to generate both electrical and thermal energy to optimize fuel efficiency. The dominant demand for energy is usually thermal with excess electrical energy, if any, transmitted into the local power supply companies' lines.

Cogenerator:
A generation facility that produces electricity and another form of useful thermal energy (such as heat or steam), for industrial, commercial, heating, or cooling purposes.

Combustion Turbine (CT):
A fuel-fired turbine engine used to drive an electric generator.

Conductor:
A wire, cable, or busbar, that allows a current of electricity to pass continuously along it.

Connection:
The physical junction (e.g., transmission lines, transformers, switch gear, etc.) between two electric systems permitting the transfer of electric energy.

Cubic Feet per Second (CFS):
A measurement of water flow representing one cubic foot of water moving past a given point in one second.

Demand:
The rate at which electric energy or natural gas is delivered to or by a system at a given instant or averaged over a designated period, usually expressed in kilowatts or megawatts (electric).

Dispatchable Generation:
Generation available (contractually or physically) to respond to changes in system demand or to respond to transmission security constraints.

Distribution (Electrical):
The system of lines, transformers and switches that connect the transmission network and customer load. The transport of electricity to ultimate use points such as homes and businesses.

FERC:
The Federal Energy Regulatory Commission in the United States.

Forced Outage:
An unplanned component failure (immediate, delayed, postponed, startup failure) or other condition that requires a unit to be removed from service.

Forced Outage Rate:
The rate of shutdown of a generating unit, transmission line, or other facility, for emergency reasons or a condition in which the generating equipment is unavailable for load because of unanticipated breakdown.

Generation:
The process of producing electric energy by transforming or connecting other forms of energy such as steam, heat or falling water.

Gigawatt (GW):
One billion watts.

Gigawatt Hour:
One gigawatt hour (GWh) equals one million kilowatt hours. A kilowatt hour (KWh) is equivalent to the energy consumed by a 100 watt light bulb burning for 10 hours.

Green Power:
Electricity generation considered to be less intrusive environmentally than traditional generation. Green power sources include wind, water landfill gas, solar, and others.

Greenfield Development:
Development of a new power generating facility.

Grid:
A synchronized transmission network that delivers electricity from generating stations to local distributors and other large users at high voltage.

Hourly Peak:
The maximum demand for energy from a transmission or distribution system in any hourly period of time.

Hydroelectric Plant:
A plant in which the turbine generators are driven by falling water.

Independent Electricity Market Operator (IMO):
An independent entity with no commercial interest in market transactions that directs the operation of the Ontario bulk power system as well as the institutional framework of the electricity marketplace, performing both system operator and market operator functions.

Independent Power Producer (IPP):
A generator other than an electricity utility.

Installed Capacity:
The measure of a power station’s electric generating capacity at full production, usually measured in megawatts (MW).

Interconnected System:
A system which has two or more power systems normally operating in synchronism with connecting tie lines.

Intertie:
A transmission line that links two or more regional electric power systems.

Kilowatt (kW):
A unit of electrical power equal to one thousand watts.

Kilowatt-hour (kWh):
A unit of electrical energy, which is equivalent to one kilowatt of power, used for one hour. One kilowatt-hour is equal to 1,000 watt- hours. An average household will use between 800 - 1300 kWh per month depending upon geographical area.

Load:
The amount of electric power delivered or required at any specific point or points on a system and usually measured in megawatts(MW). The load of an electric utility system is affected by many factors and changes on a daily, seasonal, and annual basis, typically following a pattern.

Load Factor:
Ratio of the amount of electricity used during a specific time period to the maximum possible use during that period, expressed as a percentage.

Megawatt (MW):
One megawatt equals one thousand kilowatts. A kilowatt is the electrical energy required to turn on ten 100 watt light bulbs and is equivalent to 1.34 horsepower.

Megawatt-hour (MWh):
One million watt-hours of electric energy. A unit of electrical energy which equals one megawatt of power used for one hour.

On-Peak Energy:
Electricity supplied during a period of high system demands as specified by the supplier.

Ontario Energy Board (OEB):
A regulatory tribunal that has regulatory oversight of natural gas and electricity matters in the province of Ontario and also provides advice on energy matters referred to it by the Government of Ontario.

Operating Head:
The vertical distance that water drops to the tailrace to generate hydroelectric power, measured in feet.

Outage:
A planned or unplanned operational interruption of part of a power system (e.g. generating unit, transmission or distribution lines).

Peak Demand:
The maximum load during a specified period of high demand.

Planned Outage:
The removal of a unit from service to perform scheduled work on specific components for a predetermined duration (e.g., annual overhaul, inspections, testing).

Power:
A term usually meant to imply both capacity and energy.

Pumped-Storage Hydroelectric Plant:
A plant that generates electric energy by using water pumped by reversible pump-turbines during off-peak periods into an elevated storage reservoir. At peak periods, when additional generating capacity is needed, the water is released from the elevated storage reservoir down to the turbine generators in the plant at a lower elevation.

Rate Base:
The value of assets upon which a utility is given the opportunity to earn a specified rate of return as established by a regulatory authority.

Renewable Resource:
A power source that is continuously or cyclically renewed by nature, i.e. solar, wind, hydroelectric, geothermal, biomass or similar sources of energy.

Reserve Capacity:
Capacity in excess of what is required to carry peak load, available to meet unanticipated demands for power or to generate power in the event of loss of generation.

Reservoir:
A lake or body of water used to store water for later use in the production of electricity.

Retailer:
In electricity markets, an entity that purchases electricity in bulk for resale to end-use consumers or that acts as an agent or broker for a consumer or another retailer in the sale of electricity.

Run-of-River Plant:
A hydroelectric plant which utilizes the flow of a river or stream for generation. This differs from a storage project, which has river capacity available to store water.

Storage Capacity:
The temporary holding capacity available to store water for later use in electricity generation, measured in cubic feet per second days (cfs days).

System:
A combination of generation transmission and distribution components comprising an electric utility or group of utilities.

Terawatt hours (TWh):
One thousand Gigawatt hours.

Thermal Generation:
The production of electricity from plants that convert heat energy into electrical energy. The heat in thermal plants can be produced from a number of sources such as coal, oil, gas or nuclear fuel.

Transmission:
The network of high voltage wires, transformers and switches used to move electrical power from generators to the distribution system. Also utilized to interconnect different utility systems and independent power producers together into a synchronized network. Transmission is considered to end when the energy is transformed for distribution to the consumer.

Transmission Grid:
An interconnected system of electric transmission lines and associated equipment for the transfer of electric energy between points of supply and points of demand.

Unbundled Services:
The selling and pricing of energy services separately as opposed to offering services "bundled" into packages with a single price for the whole package. With unbundling, separate fees are charged for each service, based upon only the costs of providing that service. (i.e., transportation, storage, generation, uplift, etc.).