The IESO operates the province’s electricity grid 24/7, ensuring electricity will be available to all Ontarians when and where they need it. Achieving a reliable and cost-effective system depends on forecasting and monitoring demand for electricity through comprehensive planning processes that consider near-, medium- and long-term electricity needs, as well as coordinating the resources and services required to meet those needs.


Every calendar quarter the IESO publishes the Reliability Outlook, which reports on the adequacy and security of resources and transmission to meet Ontario's forecast demand. The summer and winter versions look five years forward, while the spring and fall versions look 18 months forward. To conduct its assessment, the IESO collects information from market participants such as plans for new or modified facilities and any planned outages over the study period.

The IESO’s Annual Planning Outlook provides a 20-year forecast for Ontario's electricity system. The outlook includes projected electricity demand, a resource adequacy assessment, transmission considerations, and performance indicators, such as an emissions outlook. It also identifies the province's energy and capacity needs.

The Annual Acquisition Report translates planning and operational information into a series of procurement requirements. Looking at the province’s needs over a variety of timeframes, it will provide specific targets in the case of near-term Capacity Auctions, but also offer increasing granularity around longer-term needs.