Overview
Planning is essential to a reliable, sustainable electricity future. The IESO plans and prepares for Ontario's electricity needs by assessing energy requirements for the power system of today and tomorrow, to ensure electricity will be available when and where it is needed. The responsibility includes broad engagement with stakeholders and communities across the province. It is an iterative process that must consider short-, medium- and long-range electricity needs as well as impacts on cost, reliability, the environment and others.
Forecasting Ontario's Electricity Needs
Forecasting electricity demand is a complex exercise that identifies future system needs and the factors that influence them. It also provides insights into electricity system changes that will be required to meet Ontario’s future needs and ensure the continued reliability of the provincial grid.
The IESO’s outlooks are grounded in data analysis and consider the impacts of many variables on demand, including:
- The day of the week – including special events and holidays
- Weather impacts
- The grid’s ability to make - and deliver - enough power to Ontario’s communities
- Sources of demand, such as the opening of new manufacturing plants and electric vehicle uptake
- Government policies and conservation efforts
- Historical energy use patterns
Reports
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 over the upcoming 18 months. 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(APO) provides a forecast of Ontario’s electricity demand out to 2050. The APO includes a supply and transmission outlook and identifies the province’s energy and capacity needs. It also sets out upcoming procurement activities and targets.
Bulk system planning
Bulk system planning focuses on the electricity resources that transmit energy from the generation source to local distribution companies across the province. The IESO’s bulk system planning processes address provincial electricity needs and consider the impacts of various factors on the electricity system, including policy directions, the supply/demand balance, operability requirements and others. See the status of ongoing Bulk Planning studies: East Ontario Bulk Planning, Southwest Ontario Bulk Planning, Northeast Ontario Bulk Planning, Northwest Ontario Bulk Planning.
Regional planning
Regional planning considers local electricity priorities within each of the province’s 21 electricity planning regions. This process considers each region’s unique needs, priorities and preferences. Options to satisfy local demand may include generation, transmission and distribution, and/or other innovative resources or solutions.