Electricity Terms

Here we will try to explain some of the terminology used in the utility world.

Term  Description
Ampere The basic unit of electrical current in the International System of Units (SI), equivalent to one coulomb per second, formally defined to be the constant current which if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed one meter apart in vacuum, would produce between these conductors a force equal to 2 × 10 −7 newton per meter of length.
Cogeneration Production of heat energy and electrical or mechanical power from the same fuel in the same facility.
Coulomb The coulomb is a unit of electric charge. One coulomb is the amount of electric charge carried by a current of 1 ampere flowing for 1 second.
Demand The level at which electricity is delivered to users at a given point in time. Electric demand is measured in kilowatts.
Distribution When moving electricity from the generation source to your home, it goes through a series of transformers that step-down the voltage to lower level. Line loss is lower with a higher voltage, but most electrical equipment would be damaged. NOTL Hydro receives electricity from Hydro One Transmission lines at 500 kVA and ultimately brings it to a home at a 120/240 voltage. This process of receiving from transmission and delivering it to the end user is distribution.
Distributed Generation This is the generation of electricity from local sources involving smaller scale generation such as solar, wind power and smaller hydro installations.
Grid The electric generation, transmission and distribution system that links power plants to customers connected loads (refrigerators, light bulbs, etc).
Kelvin Kelvin is used when describing the colour emitted from a light bulb. As it is also referred to in climate terminology, the colour is also known as temperature.
Kilo-volt Ampere – kVA A kilo-volt ampere is a unit of apparent power. It is the total electricity available to a building. Due to losses from power factor, processes often need to draw additional power from the grid.
Kilowatt – kW A kilowatt is the rate at which energy is being generated or consumed.  It is equivalent to 1,000 watts.
Kilowatt Hour – kWh A kilowatt hour is the total electricity used over the course of one hour. If you use ten lamps using 100W bulbs for 30 minutes, you would consume 0.5 kWh.
LED Standing for Light-emitting diode, this is the term used for the technology being LED lighting.  LED light bulbs last longer and are much more efficient than traditional incandescent lighting. Although CFL technology is comparable in efficiency, LEDs have a better power factor and do not contain mercury.
Line Loss Line loss is energy waste from the transmission and distribution of electricity across power lines. It is often lost due to heat and electromagnetic energy.
Lumens Lumen is a standard measurement of light. Where many people equate the wattage of a light bulb as an indicator of the amount of light it produces, a Lumen is the term that will be used in the future. Historically a 60W incandescent bulb would produce 800 lumens of light.
Megawatt – MW  A megawatt is a measure of electricity and is equivalent to 1,000 kilowatts.
Ohm – Resistance An ohm refers to a unit of electrical resistance.
Power Factor Power factor is the ratio between the kW and the kVA drawn by an electrical load where the kW is the actual load power and the kVA is the apparent load power.

In other words, it is a measure of how efficiently the load current is being converted into useful work output. A power factor of 1 means that the power entering the building is being used at full efficiency. Motors, pumps and fluorescent lighting will lower a building’s power factor.

Smart Grid Is an electric grid that incorporates technology to allow for two-way communication. This communication can be with distributors and consumers or just between the distributor and technology in the field so we can isolate outage faults.
Transmission Transmission is the transfer of generated electricity directly from the generator to the local distribution company. Ontario’s transmission uses 115 kilovolt, 230 kV and 500kV lines.
Volt It’s more than just an electric vehicle. The volt is the unit of pressure, i.e., the volt is the amount of electromotive force required to push a current of one ampere through a conductor with a resistance of one ohm
Watt A watt is a unit of power defined as 1 joule per second.