Ontario’s Electricity System

Ontario needs a reliable, efficient and clean electricity system that comes from a number of sources. Learn where your energy comes from and how the province is building a cleaner energy future in Ontario’s Long-Term Energy Plan.

Ontario's Electricity System: Inforgraphic showing the components of Generation, Transmission, Distribution, Consumers and Conservation. Select image for a longer description.

In general, the only time we sit up and take notice of the electricity we use happens when the utility bill comes in the mail or on the rare occasion when there is a power outage.

Frequently Asked Questions on Ontario’s Electricity System


Nuclear energy is part of Ontario’s balanced plan to make sure we have safe, clean, reliable and affordable electricity for years to come.

Nuclear reactors, which produce heat by splitting uranium atoms, do the same job as typical power sources. They produce heat to change water into steam. The steam spins a turbine or generator to make electricity. Instead of coal, oil or natural gas, Ontario’s nuclear reactors use natural uranium in CANDU reactors.

Natural Gas

Natural gas is a mix of methane and other gases found underground. Ontario has a small amount of natural gas Most of the province’s supply comes from Saskatchewan, Alberta and British Columbia.

You can use natural gas for many things. In Ontario we commonly use it to heat our homes and businesses. You can also make electricity from natural gas.

Renewables: Hydroelectricity, Wind, Solar, Bioenergy


Hydroelectricity also called water power, uses energy made from falling or flowing water. It is a reliable, clean, local and naturally recurring source of energy.

Water power has been helping to fuel Ontario’s growth for over 100 years and is the backbone of our renewable energy supply. Water power accounts for about 26 per cent of the province’s electricity supply. There are about 250 water power facilities province-wide with a total installed capacity of more than 8,400 megawatts.

Wind Power

Wind power is one of the fastest-growing sources of electricity in the world. It is a completely sustainable and clean form of energy. It has the potential to provide a large amount of Ontario’s energy needs.

Using the wind for local power generation is not new. In the 1930s more than 600,000 windmills were used in rural areas. These windmills made electricity and pumped water on farms across Canada and the United States.

Solar Energy

Solar energy is free and there is an endless supply. Only a small amount of the energy from the sun hits Earth but it’s enough to provide lots of power. This clean source of energy is a good addition to normal and non-renewable sources of energy such as coal, oil and natural gas.

Solar photovoltaic technology converts the sun’s rays into electricity. It uses silicon, the semiconductor used in computers, to generate electricity.


Bioenergy is a form of renewable energy that uses organic and waste products from farming to make heat and create electrical energy.

Biomass uses organic materials such as plants and animal waste. These products can be burned in their original forms or in pellets.

Biogas is made by fermenting organic materials such as manure and other agricultural wastes.

Learn More

What Is a Kilowatt Hour?

How does electricity get to me?

How is electricity made?