Energy in Ontario Generation and Conservation

Ontario’s electricity system involves five key components. The system begins with supplying enough electricity to meet demand on a minute-by-minute basis of all the province’s electricity consumers.

1. Generation

The province has many generators that use diverse and complementary sources to produce reliable and affordable electricity. These sources include:


In 2016, nuclear power provided more than 50% of Ontario’s electricity. Nuclear reactors produce energy through the splitting of uranium atoms. The heat produced from the nuclear reaction is used to heat water into steam and spin a turbine or generator to make electricity. The process does not emit greenhouse gases and makes this power source an effective component of Ontario’s climate change strategies.


Waterpower or hydroelectric electricity generation uses energy from falling or flowing water. Waterpower is the foundation of Ontario’s renewable energy supply and accounts for about 21.3% of the electricity supply. More than 8,400 megawatts (MW) of hydro capacity is held within 250 water power facilities across the province.


Clean and sustainable, wind power is one of the fastest-growing sources of electricity in the world. In Ontario, approximately 4,200 MW of wind energy is connected to the transmission system. This capacity generates about 6% of the province’s electricity supply.  Additionally, about 570 MW of wind energy is connected to the province’s distribution system.


Solar (photovoltaic) PV panels take advantage of the abundant supply of energy provided by the sun. About 330 MW of solar energy is connected to the transmission system, which makes up about 2% of Ontario’s electricity, however, there is also nearly 2,000 MW of solar capacity connected to Ontario’s distribution system.


Bioenergy is a renewable energy source that uses organic materials to generate electricity, including plant and animal waste from agriculture and forestry operations. Biogas is made by allowing organic waste, such as manure, to decompose, which produces methane gas. Biomass, such as wood pellets, can be directly combusted to produce electricity. Bioenergy facilities that are connected to the transmission system make up about 0.4% of Ontario’s electricity. There is also over 100 MW of renewable bioenergy capacity connected to the distribution system.

Natural Gas

Natural gas accounts for about 8% of Ontario’s electricity. This energy source produces lower greenhouse gas emissions than other fossil fuels, such as coal. Natural gas plants can start up quickly when electricity demand increases.

To learn more about Ontario’s power supply check out the Ministry of Energy website and Independent Electricity System Operator website.


2. Transmission

Ontario’s transmission companies deliver electricity at high voltages over long distances, from generation sites to local distribution companies and consumers. From there, the electricity is put through transformers that convert it to low-voltage power and sent out on “distribution lines” from your local electricity provider to your company or home.

3. Distribution

Power moves from your local electricity provider, also known as your local distribution company (LDC), along distribution lines to where you consume it in your home or business. The electricity provider owns and operates these distribution networks. LDCs are also responsible for billing your energy consumption and delivering conservation programs.

If you don’t know who your local electricity provider is, you can search the Save On Energy website here.

4. Consumption

As an electricity consumer, you can actively manage your electricity use and save on your electricity bills. You also have a choice over who you consume electricity from, though the majority of customers choose to buy power from their local distribution company or electricity provider. Some may decide to buy electricity from private for-profit companies that sell electricity under contract.

You can search through the list of licensed natural gas and electricity retailers in Ontario here.

5. Conservation

The Ontario government has committed to put Conservation First when planning for the province’s energy needs, where cost-effective. Conservation and energy efficiency are the cleanest and most cost-effective energy resource, offering consumers a way to manage their energy bills and it reduces the need to build new infrastructure. Historically, for every $1 invested in electricity efficiency programs, Ontarians have avoided about $2 in costs to the electricity system.


Businesses can access a suite of conservation programs under the Conservation First Framework and Demand Side Management Framework, which provide the funding and guidelines for utilities to deliver electricity and natural gas programs to their customers. Additionally, the Province will help businesses transition to a low-carbon future by expanding program offerings through the new Green Ontario Fund.

Terawatt-hour energy conservation programs can help businesses shift their electricity use to periods of lower prices, adopt new technologies to use electricity more efficiently and even install technology allowing them to generate their own – behind the meter – electricity.