Southwest Ontario Bulk Planning Initiatives

A bulk transmission plan for the Windsor-Essex region was completed and development work is underway for two bulk transmission projects in the Kingsville-Leamington area including:

These projects will reinforce the existing West of Chatham interface (the 230 kV transmission path from Chatham to Lakeshore) to ensure that adequate electricity supply is available to meet the Windsor-Essex region’s growing electricity needs and support economic growth in the area. However, there are still transmission limitations in the areas east of Chatham.

A new plan, Need for Bulk System Reinforcements West of London, was developed to address transmission limitations impacting the connection of load growth in Kingsville, Leamington, Lakeshore and Dresden.

West of London Map

West of London Map

West of London Bulk Report

This report examines emerging electricity needs, evaluates options, and recommends actions required to reinforce the bulk system in parallel with on-going regional electricity planning for the Windsor-Essex addendum study and new cycle in Chatham-Kent/Lambton/Sarnia that began in Q3 2021. This new bulk transmission plan outlines recommendations to ensure the adequacy and reliability of supply up to the year 205 such as:

  • A new 230 kV double-circuit line from Lambton southwards to Chatham (Lambton South) to be in-service no later than 2028 (announced in March 2021);
  • The continued operation of the Brighton Beach Generating Station to support the immediate localized need in the near-term until the Lambton to Chatham line is in-service; and
  • A new single 500 kV transmission line from Longwood to Lakeshore to be in-service in 2030, and 550 MW of local resources 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. View meeting materials, feedback received, and IESO responses on the engagement webpage.

Windsor-Essex Bulk Report

This report documents the outcomes of a planning study that assessed the adequacy of the bulk transmission system in the Windsor-Essex Region. It recommends two transmission reinforcements to meet the identified near- and mid-term needs: a switching station at the Leamington Junction and the West of Chatham transmission line.

This bulk planning study was triggered by recent unprecedented growth in forecast electricity usage for the greenhouse sector in the Kingsville-Leamington area. As a result, the region’s electrical demand is expected to double over the next five years.

A companion integrated regional resource plan (“IRRP”) for the Windsor-Essex Region was also completed. It focused on providing customers in the region with adequate line connection and step-down transformation capacity, and maintaining a level of reliability consistent with accepted planning standards. Information from the IRRP, such as demand forecasts and plans for new connection facilities inform this bulk planning study.

Recommended solutions from both have been integrated as they impact bulk and regional needs.

The IESO will continue to monitor the progress of load and generation developments in the area while studying future system needs east of Chatham through the on-going Windsor-Essex addendum study. Future stages of system reinforcement will be triggered as required.

Switching Station at Leamington Junction (Lakeshore TS)

On January 31, 2019, the IESO issued a hand-off letter to Hydro One requesting that they undertake work to establish a new switching station on the existing 230 kV transmission corridor between Chatham and Windsor at the Leamington Junction (Lakeshore TS). This station 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 Windsor-Essex region.

Transmission Line from Chatham to Lakeshore (North of Leamington)

On June 13, 2019, the IESO issued a hand-off letter to Hydro One requesting that they initiate the work and activities, including seeking Environmental Assessment and Leave-to-Construct approvals, for the construction of a new 230 kV double-circuit line from Chatham to the site of the new switching station north of Leamington. This line is expected to be completed prior to the winter of 2025/2026.

The approximate locations of these proposed electricity transmission facilities are shown in the map below for illustrative purposes only. Specific sites and/or routes have not yet been determined.

Hydro One will begin development work in the coming months, and opportunities for public involvement, including municipalities and Indigenous communities, will be available.

Transmission Line from Lambton to Chatham to (Lambton South)

On March 26, 2021, the IESO issued a hand-off letter to Hydro One requesting that they initiate the work, engagement and activities associated with developing a new 230 kV double-circuit line from Lambton to Chatham. This new 230 kilovolt double-circuit transmission line will connect from the Chatham transformer station to the Lambton switching station with an expected in-service date of 2028. This is one more step that will support the rapid agricultural growth in the Windsor-Essex and Chatham areas.

The approximate locations of these proposed electricity transmission facilities are shown in the map below for illustrative purposes only. Specific sites and/or routes have not yet been determined.

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.

 

Map showing transmission lines and switching station in Southwest Ontario


Documents referenced on this page, but not posted, can be obtained by contacting customer.relations@ieso.ca. Provide a link to the web page that lists the document and advise whether it needs to be provided in an accessible format. Please allow a minimum of one business day for a response.


Key Resources

West of London Bulk Report

Need for Bulk System Reinforcements West of London

Need for Bulk System Reinforcements West of London Data Tables

Transmission Line from Chatham to Lambton

IESO Letter to Hydro One re Transmission Line from Chatham to Lambton 

News Release

Backgrounder

Windsor-Essex Bulk Report

Need for Bulk Transmission Reinforcement in the Windsor-Essex Region

Switching Station at Leamington Junction (Lakeshore TS)

IESO Letter to Hydro One re Leamington Switching Station

Hydro One Lakeshore Transformer Station Project

Transmission Line from Chatham to Lakeshore (North of Leamington)

IESO Letter to Hydro One re Transmission Line from Chatham to Lakeshore

Chatham to North Leamington Transmission Backgrounder