August 30, 2022

Ontario Energy Resources

There are several energy resources that power Ontario’s electricity grid. The province continues to evolve its mix of generation sources with a focus on green, safe, and reliable energy.

In fact, the IESO reports that using these resources combined with investments in conservation, demand response and transmission have reduced greenhouse gas emissions in Ontario’s electricity sector by more than 80 per cent.

Ontario Energy Resources

Solar Photovoltaic

Solar power is energy generated by the sun. This is done using solar panels made with photovoltaic (PV) cells that absorb the solar energy and convert it into electricity.

Solar power is a renewable energy source and is considered a variable resource as it relies on the weather, the time of year and time of day. It makes sense that the summer months are the most important for generating this type of energy, as peak demand occurs midday when solar panels reach their height of production.

The solar panels range in size, from small-scale generation with from homeowners, farmers, and community groups to large “solar farms” spanning acres of land and connected to the transmission grid.

Wind Power

Wind power is energy generated by the wind, and like solar power, is a renewable energy source. Using large wind turbines equipped with propeller-like blades, the wind passing through the turbines moves the blades to turn a rotor connected to a generator to create electricity. The amount of energy generated is determined by the wind speed, which is usually the highest during the winter, but can also vary by geography.


Hydro is another renewable energy source, using falling or moving water to produce electricity. Also referred to as hydroelectric or waterpower, most hydroelectric generating stations use rapids, waterfalls or dams that create a driving force of water to turn the blades of a turbine connected to a generator to create electricity.

Hydro is a major supplier of energy for Ontario, with hundreds of hydro-generating stations found across the province’s many waterways.


Nuclear power production uses fission, a process of splitting uranium atoms, to create heat and steam that drives turbines to create electricity. Nuclear power is a critical supplier of energy in Ontario, representing 13,000 MW with three nuclear facilities producing about 60 percent of the province’s electricity. Nuclear power generation operates 24 hours a day at a relatively consistent output level.

Natural Gas

Natural gas as a source of electricity generation has increased in Ontario in recent years as coal-fired generation has been phased out. There are several ways natural gas can be used to generate electricity.

Many of the new natural gas power plants are known as “combined-cycle” units which use both gas and steam to produce electricity. The gas is used as fuel to rotate a turbine to generate energy. The heat from the gas turbine is then used by the steam turbine to create electricity. This process is more efficient as it reuses the exhaust heat, rather than releasing it through the exhaust stack.

Natural gas makes up approximately 10,000 MW of Ontario’s installed capacity and is often used to ensure a reliable power supply during periods of higher demand and pressure on the power system.


Bioenergy is a form of renewable energy that is derived from organic materials (biomass) to produce electricity. Biomass matter such as agricultural and animal waste are burned to generate electricity. Biogas, which is derived from biomass, produces methane which is combusted to create electrical energy. This process is considered carbon neutral. Ontario has almost 500 MW in bioenergy capacity.

Source: Independent Electricity System Operator (IESO) Energy Resources: How They Work (