Southwest Ontario Bulk Planning
Electricity demand in Southwest Ontario is growing at a rapid pace. This growth is primarily driven by economic development in the agriculture and manufacturing sectors.
The Windsor-Essex and Chatham-Kent areas are the primary drivers of the agriculture growth, which is projected to reach a demand of 2,300 MW by 2035 - the equivalent of adding a city the size of Ottawa to the electricity grid.
To meet this growing demand, the IESO developed electricity plans to support this growth and infrastructure and upgrades that are already underway that include two new sets of transmission lines and a new switching station.
The manufacturing sector is also evolving, with the Volkswagen EV plant siting in St. Thomas and NextStar Energy EV plant in Windsor. The IESO is conducting a Central-West bulk plan to assess the bulk transmission system from Hamilton to Windsor and consider other potential demand growth across southwestern Ontario. Through this, the IESO will undertake extensive electricity planning and engagement with local and regional communities and stakeholders to address current and future electricity needs.
These projects, plus other planned initiatives and ongoing dialogue with communities and stakeholders, will support current and future economic growth in the region.
Southwest Ontario Bulk Planning Initiatives
The IESO has launched a Central-West Bulk Planning engagement to actively involve stakeholders and communities in shaping the future of Ontario's energy transmission system.
The 2022 Annual Planning Outlook indicated a need for a new Central-West Bulk Study in 2024 to assess the bulk transmission system between Hamilton and London in light of potential economic development opportunities emerging in the region. With the Volkswagen EV plant siting in St. Thomas, IESO advanced this work. The scope of the study has also expanded to assess the bulk transmission system from Hamilton to Windsor and consider other potential demand growth across southwestern Ontario in addition to the Volkswagen EV plant.
Engagement meetings will be held to inform interested parties about plan development and solicit feedback. You can view more information on the engagement webpage.
This report examines emerging electricity needs, evaluates options and recommends actions required to reinforce the bulk system in parallel with regional electricity planning for the Windsor Essex and Chatham-Kent/Lambton/Sarnia regions. This new bulk transmission plan outlines recommendations to ensure the adequacy and reliability of supply up to the year 2035, including:
- A new 230 kV transmission line from Lambton to Chatham to be in-service no later than 2028 (see March 2021 news release);
- The continued operation of the Brighton Beach Generating Station to support immediate local need in the near-term until the Lambton to Chatham transmission line is in-service;
- A new 500 kV transmission line from Longwood to Lakeshore to be in-service in 2030; and
- 550 MW of local resources needed by 2035 that can be met by reacquiring resources whose contracts have expired or by acquiring new resources.
Engagement meetings were held to inform interested parties about plan development and solicit feedback. You can view meeting materials, feedback received and the IESO’s responses on the engagement webpage.
Supporting Materials and Resources
- Report: West of London Bulk Planning Report
- Data Tables: West of London Bulk Planning Report
- Webinar Recording: Electricity Planning in the West of London Area (July 2021)
- Webinar Recording: New Transmission Line in Southwest Ontario (March 2021)
- Webinar Recording: Electricity Planning in the West of London Area (November 2020)
A planning study was undertaken to asses the adequacy of the bulk transmission system in the Windsor-Essex Region. This study was triggered by forecast electricity demand growth in the Kingsville-Leamington area, which is expected to double over the next five years. It recommends two transmission reinforcements, a switching station at the Leamington Junction (Lakeshore TS) and a new West of Chatham transmission line (Chatham to Lakeshore line).
A companion Integrated Regional Resource Plan (IRRP) was also completed. It focused on providing customers in the region with adequate line connection, step-down transformation capacity and maintaining a level of reliability consistent with planning standards. Information from the IRRP, such as demand forecasts and plans for new connection facilities, informed this bulk planning study.
The IESO recently completed an addendum study to the Windsor-Essex IRRP focused on meeting the future needs in the Kingsville-Leamington area and will continue to monitor the progress of developments in the area while studying future system needs through subsequent regional planning cycles.
Supporting Materials and Resources
The IESO issued a hand-off letter to Hydro One requesting that they undertake work to establish a new switching station at the Leamington Junction along the Chatham to Windsor transmission corridor. This new station will be located in the Municipality of Lakeshore is expected to be completed as early as 2022. It will help meet electricity needs in the area by supporting additional consumer connections and is an integral part of the reliable long-term plan to improve supply for the Windsor-Essex region.
Supporting Materials and Resources
The IESO issued a hand-off letter to Hydro One requesting that they initiate work, including Environmental Assessment and Leave-to-Construct approvals, for the construction of a new 230 kV transmission line from Chatham to the new Lakeshore TS. This line is expected to be completed prior to the winter of 2025/2026.
Supporting Materials and Resources
- Letter: IESO Hand-Off Letter to Hydro One Regarding Transmission Line from Chatham to Lakeshore
- Hydro One Website: Chatham to Lakeshore Line Project Page
The IESO issued a hand-off letter to Hydro One requesting that they initiate the work associated with developing a new 230 kV transmission line from Lambton to Chatham. This is expected to be in service in 2028 and is one more step that will support rapid agricultural growth in the Windsor-Essex and Chatham areas.
The IESO encourages Hydro One to meaningfully engage with Indigenous communities in Southern Ontario in a way that recognizes the unique interest of each community in this project and to discuss their concerns about potential impacts to their Aboriginal or treaty rights.
Supporting Materials and Resources
The IESO published the West of London bulk report, which recommended a new 500 kV transmission line from Longwood to Lakeshore. This is expected to be in service in 2030 and is one more step to ensure the adequacy and reliability of supply in the area up to the year 2035.
Supporting Materials and Resources