Bulk Planning

Bulk electricity planning is the level of electricity planning that works to ensure Ontario’s high-voltage transmission system can deliver reliable, affordable, and sustainable electricity where and when it is needed. As demand grows across the province, bulk planning helps ensure the system has the infrastructure and resources required to support economic development and electrification across the province.

Electricity planning in Ontario is undertaken at three levels, each with a specific focus, however they are interconnected:

• Bulk electricity planning is led by the IESO to look at the high-voltage transmission system that spans the province, flowing electricity from where it’s generated to where it’s needed. Bulk planning initiatives typically stem from the IESO’s Annual Planning Outlook. Any recommended actions stemming from bulk planning are considered as part of regional planning to determine any impacts to local reliability and future growth needs.
• Regional electricity planning is led by the IESO in collaboration with the lead transmitter and local electricity distributors within a specific region. It assesses the individual power requirements within the IESO’s 21 regional electricity planning zones and are re-evaluated on an ongoing basis. It is an essential link between bulk and local planning activities. This cyclical process was established and formalized by the Ontario Energy Board and must be undertaken every five years at a minimum. Findings and outcomes from regional planning may indicate a need for larger bulk system upgrades.
• Local electricity planning is done by the more than the 50 Local Distribution Companies (LDCs) that are actively involved in forecasting and planning for their respective communities’ energy needs. Local planning determines how local distribution systems connect to and benefit from any actions on the transmission system stemming from bulk and/or regional planning.

Related Information

• Explore current engagement opportunities
• View planning initiatives
• Review the Annual Planning Outlook
• Read the Integrated Bulk Power System Planning Process - High-Level Design Overview for details on the high-level design of the bulk system planning process
• Discover how the IESO powers progress across Ontario by exploring our Digital Guides.
• Subscribe to receive updates on a variety of the IESO’s activities

Major Projects Identification Committees Process

To support planning activities, the IESO requires visibility into emerging major projects and development activity that may impact the electricity system. The IESO has established a Major Projects Identification Committees (MPIC) process to support the early identification of major projects and to strengthen electricity demand forecasting and system planning. Communities are encouraged to work with their Local Distribution Company to share information about future developments that may increase electricity demand.