Terms you should know
Get plugged into the terminology used on this web site, and in the electricity market in Ontario.
Capacity
is the maximum load – or amount of electricity – supplied by a generator or utility, typically measured in megawatts (MW).
Convergence
partnerships between electricity retailers and other service providers, such as natural gas, water, cable and long distance, to provide a package of services in an integrated manner.
Distribution
is the process of moving lower voltage electricity from major substations to customers’ homes and businesses. This is the responsibility of Local Distribution Companies (LDCs), such as London Hydro.
Full Retail Access
a fully competitive market where customers have the ability to purchase power from electricity retailers.
Kilowatt-hour (kWh)
Most common unit of electrical energy consumption. On average, Ontario consumers use nearly 1,000 kWh a month. London Hydro customers consume 750 kWh per month on average.
Load
is the total demand on electricity supply at any given time.
Marketers
are companies that operate by buying and reselling electrical power, but don’t own generating or transmission facilities.
Megawatt (MW)
electricity produced by generating stations is measured in megawatts, which is one million watts, or 1,000 kilowatts.
Spot market
much like an auction, the market price of electricity is determined each day according to the demand for it and the supply of electricity that’s available at that time. This daily wholesale electricity auction is known as the spot market, and it is run by the Independent Market Operator (IMO).
Substation
is the facility where incoming and outgoing voltage is changed and controlled.
Transmission system
is the system of delivering electricity over long distances at higher voltages from generating facilities to local distribution centres.
Suppliers And Agencies
Independent Electricity Market Operator (IMO)
is a non-profit, regulated corporation that is responsible for the day-to-day operation of Ontario’s electrical system and, in general terms, directs the flow of electricity from those that generate it to those that use it.
Ontario Energy Board
is a regulatory agency of the Ontario Government that licenses market participants, sets market rules, approves transmission and distribution charges, and investigates consumer complaints.
Ontario Hydro Services Company
is responsible for the transmission and distribution of electricity. Also provides retail services.
Ontario Power Generation
is the largest generator of electricity in Ontario. It currently produces around 75% of the electricity for the province, but reduction, to 35% by 2012 has been mandated through the deregulation process.
Energy sources
Cogeneration
is the co-production of electrical and thermal energy, also called combined heat and power (CHP), which is then used for industrial processes or to heat buildings.
Hydroelectric plants
generate electricity through turbines that are powered by flowing water. Produce nearly one-quarter of our electricity.
Power plants
generate electricity by burning coal, oil or natural gas, or by using uranium. Power plants produce nearly three-quarters of Ontario’s electricity.

