Markets and Related Programs

In the IESO-administered markets, there are more than 600 market participants playing a variety of different roles.

Dispatchable generators

Dispatchable generators submit offers to supply electricity in specific quantities and prices into the Day-Ahead Market for each hour of the day. In the Real-Time Market, they are able to adjust the amount of electricity they generate in response to dispatch instructions issued as often as every five minutes by the IESO.

Most resources participating in the real-time market before when the DAM schedule is released each afternoon.

Dispatchable loads

Large energy consumers registered as dispatchable loads can submit bids to purchase electricity in the DAM. Dispatchable loads are able to adjust their power consumption in response to instructions arriving as often as every five minutes from the IESO. If the real-time Ontario energy price is greater than the price they are willing to pay, the dispatchable load will receive dispatch instructions to reduce their consumption.

The IESO also offers another option for consumers who want to respond to price. Price Responsive Loads can take advantage of local prices by locking in day-ahead but still have the flexibility to consume energy without being required to be dispatchable.

See the various options for large energy consumers in the Ontario’s wholesale markets

Importers and Exporters

The Ontario electricity market is interconnected with five other jurisdictions: Manitoba, Minnesota, Michigan, New York and Quebec, allowing market participants access to markets throughout eastern North America. Market participants can import energy from another jurisdiction into Ontario, as well as export energy from Ontario. Participants can also move energy through Ontario from one jurisdiction to another in a type of transaction called a linked wheel.

To complete an import transaction, a participant will simultaneously make an offer to import and bid in another jurisdiction to export. An import offer is accepted and scheduled hourly to flow if it is economical in comparison to other supply options and it can be physically accommodated by the intertie and the IESO-controlled grid.

In order to export energy, a participant will simultaneously make a bid to purchase energy and offer to import into another jurisdiction. An export will be scheduled hourly if the bid is economical at the intertie and the IESO-controlled grid can physically accommodate the transaction.

A new market participant category – virtual traders - participate in the market with the view of finding arbitrage opportunities based on the difference between DAM prices and real-time market prices.

Wholesalers and Retailers

Both wholesalers and retailers re-sell electricity. They do not need to have physical facilities that produce or consume electricity to participate in Ontario's day-ahead, real-time and financial markets. Wholesalers buy energy in the wholesale market and sell energy and services to other customers. Retailers sell energy and services to consumers at the retail level.

Non-dispatchable participants

Producers and consumers of electricity who are not able to respond to five-minute signals in the market are called non-dispatchable.

Non-dispatchable generators submit forecasts to the IESO of their expected energy production. Non-dispatchable generators are paid in the same manner as dispatchable generators. That is, they are settled using their day-ahead and real-time locational prices. Non-dispatchable loads or consumers draw electricity from the IESO-controlled grid to meet their needs, without the need to follow dispatch instructions. A local distribution company is an example of a non-dispatchable load. These consumers pay the Ontario Price which is calculated using the Day-Ahead Ontario Zonal Price and the Load Forecast Deviation Adjustment. The LFDA accounts for the cost of differences between day-ahead schedules and real-time needs.