For Mid-sized and Large Businesses

Businesses with a peak demand of 50 kilowatts or more pay the wholesale price for electricity.

The wholesale price is determined by matching supply with Ontario's demand for electricity in the real-time market operated by the IESO. In Ontario, all electricity rates reflect the wholesale electricity price in some way. The wholesale price of electricity is dynamic − changing hourly based on demand and the availability of supply. Factors impacting demand include consumer behaviour, weather, time of day, day of the week, as well as economic conditions.

Businesses pay the wholesale price, also referred to as the Hourly Ontario Energy Price, in one of three ways:

  • Businesses with an interval meter pay the Hourly Ontario Energy Price
  • Businesses without interval meters are charged a weighted average hourly price based on consumption patterns of similar consumers in their service territory 
  • Businesses may choose to enter a fixed-price contract with an electricity retailer

The wholesale price is only one part of the total commodity cost for electricity. Businesses also pay the global adjustment rate on their consumption for the month.

Learn more about global adjustment and how it impacts your electricity bill.

Note all Ontario consumers pay global adjustment, however residential and small business consumers have the global adjustment costs incorporated into the time-of-use and tiered rates and will not see it as a separate line item on their electricity bills.

Other charges on your electricity bill

See this sample bill for other charges that are paid by wholesale price electricity consumers.

Manage your electricity costs

The commodity price for electricity changes throughout the day, week and season, providing businesses an opportunity to adjust their energy use to take advantage of lower prices. For example, shifting operations to cheaper times of the day, or running operations overnight will help to reduce your business’ energy costs.

For more energy management ideas, see IESO’s brochure: The Bottom Line on Energy Management for useful information to help your business control its energy usage and its costs, including managing the global adjustment.


Save on Energy programs offer financial support and technical expertise to help Ontario businesses reach their energy management goals. Save on Energy programs are powered by the IESO, delivered through local distribution companies and provide information and tools to invest in energy-saving techniques, projects and capabilities.


In addition to cost savings, businesses that invest in energy-efficient technology may be able to benefit financially by providing demand response in the IESO’s electricity market. Read how large companies and aggregators who represent groups of commercial energy consumers are able to participate in the IESO’s demand response auction.

Participating directly in the electricity market

Large consumers that are directly connected to the transmission grid buy electricity through the IESO-administered market. These customers may also opt to become dispatchable loads – this means they can adjust their energy use in response to five minute dispatch instructions from the IESO. Dispatchable loads can also provide operating reserve to the system, agreeing to be on-call to reduce demand should there be an unexpected loss of generation. These market incentives allow users to reduce their own costs and also generate a new revenue stream.

Learn more about participating in Ontario's real-time or operating reserve market.

Further, eligible transmission-connected companies can receive financial incentives for investment in energy efficiency projects such as innovative process changes and equipment retrofits. For more information, see Industrial Accelerator Program.