| 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.
Back
Up Protection Equipment :
or system which is intended to operate when a system fault is
not cleared in due time because of failure or inability of the
main protection to operate or in case of failure to operate
a circuit-breaker other than the associated circuit-breaker
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.
Biomass:
Biologically
derived material that can be used as a fuel - e.g. naturally
growing wood, plant or animal residues or specially grown energy
crops.
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..
Energy
Watch:
The trading name of the Gas and Electricity
Consumer Council.
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.
Grid:
A synchronized transmission network that delivers electricity
from generating stations to local distributors and other large
users at high voltage.
High
Voltage:
A voltage exceeding 650 volts. It is the
rated voltage above 1kV and medium voltage and is commonly used
for distribution systems, with rated voltages above 1kV and
generally applied up to and including 52kV.
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
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. or equivalent
to energy consumption at a rate of 1000 joules per second .
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 3000 - 3,600
kWh per year 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.
Ofgem
:
The regulatory body for the gas ad electricity
markets in England, Wales and Scotlan , Ofgem
is the regulator for Britain's gas and electricity industries.
Its role is to protect and advance the interests of consumers
by promoting competition where possible, and through regulation
only where necessary. Ofgem's work focuses on the following
areas:
-
making
gas and electricity markets work effectively;
- regulating monopoly businesses intelligently;
- securing Britain's gas and electricity supplies; &
- meeting its increased social and environmental responsibilities.
Ofgem
operates under the direction and governance of the Gas and Electricity
Markets Authority, which makes all major decisions and sets
policy priorities for Ofgem. The authority's role in the management
of Ofgem is set out in its rules of procedure.
Ofgem's
powers are provided for under the Gas Act 1986, the Electricity
Act 1989, as amended by the Utilities Act 2000 and the Energy
Act 2004. It also has enforcement powers under the Competition
Act 1998.
Offreg
:
The regulatory body for the gas and electricity
markets in Northern Ireland.
On-Peak Energy:
Electricity supplied during a period of high system demands
as specified by the supplier.
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.
Supplier
:
same as Retailer
Terawatt hours (TWh): One thousand
Gigawatt hours , or one million kilowatt-hours, 1TWh is equivalent
to the total electricity typically used by 250,000 homes in
one year.
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.).
Watt : a unit equivalent to 1 joule
per second or .0013404 horsepower - measures electrical power
in terms of capacity or demand at a point in time.
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