The regional planning cycle for the Windsor-Essex region concluded in September 2019 and an Integrated Regional Resource Plan (IRRP) was released. Further work on the 115 kV sub-system capacity, end-of-life needs, and Leamington load restoration needs was undertaken as an addendum to the IRRP, and the final report and Appendices were posted  in February 2022.

Area Overview

Map of Windsor Essex

The Windsor-Essex region is the most southerly portion of Ontario. It consists of the City of Windsor, the Municipality of Leamington, the Towns of Amherstberg, Essex, Kingsville, Lakeshore, LaSalle, Tecumseh, and the Township of Pelee, as well as the western portion of the Municipality of Chatham-Kent. The Windsor-Essex region includes the Caldwell First Nations.

In addition to ensuring adequate supply to the area as a whole, the IRRP focuses on meeting supply capacity requirements in the Kingsville-Leamington area.

The region is home to approximately 390,000 people and has a peak electricity demand of approximately 800 MW. The urban portion of the region in and around Windsor has a long history of advanced manufacturing, especially in the automotive sector. This sector is experiencing a slow recovery from the 2008/2009 global recession. In the past, these operations constituted a significant portion of the region's overall electricity demand, but since 2008, these requirements have decreased.

While the manufacturing sector continues to face recovery challenges, economic diversification is changing the region's economy and electricity use. This includes a focus on entertainment tourism in the downtown core, including a resort casino.

The rural portion of the region in Essex County supports a combination of manufacturing and agri-business. Essex County contains the largest concentration of greenhouse vegetable production in North America. This sector is expected to experience major growth in the future, with much of the activity taking place in the Kingsville-Leamington area, increasing electricity supply requirements in that part of the region. Essex County is also home to several large food processing operations, and a growing winery sector.

Community Engagement

The IESO engages with local and regional communities to seek input to help inform planning activities. Learn more about engagement on the 2019 planning cycle. Engagement in the next planning cycle is expected to commence in 2024.


Regional Planning Activities in Windsor-Essex

A Scoping Assessment Outcome Report and Terms of Reference for the Windsor-Essex Region IRRP was finalized and posted in March 2018, following a two-week comment period. Feedback received and the Working Group's response can be found in the Key Resources section below.

The IRRP and Appendices for the region were posted on September 3, 2019. Given the significant forecast demand increase in the Kingsville-Leamington area, the IRRP identifies specific investments, both non-wires and wires, some of which are already being implemented as well as further investments recommended. The initiation of some of the recommendations was necessary to ensure that they are in service in time to address the region’s urgent needs. For the near- and mid-term needs in local areas, specific recommendations are identified for capacity, end-of-life and restoration, as appropriate. A series of near-term actions were identified to gather information and lay the groundwork for future options to address projected infrastructure, specifically studying options for an integrated solution that addresses multiple needs, in order to maximize the use of these existing electricity system assets. These actions are intended to be completed before the next IRRP cycle so that their results can inform further discussion at that time.

The IRRP was developed based on a set of planning considerations, including reliability, cost, feasibility, and flexibility.  In particular, associated projects recommended by the companion Windsor-Essex bulk study were integrated into the plan.


Visit Regional Planning Process for more information. See below for past regional planning activities in this region.

Windsor-Essex Technical Working Group

A Technical Working Group will follow the regional planning process to discuss opportunities to identify and meet local electricity needs. For the purposes of this regional planning activity, the Working Group will consist of representatives from the five LDCs in the area - EnWin Utilities, Essex Powerlines Corporation, E.L.K. Energy Inc., Entegrus Powerlines Inc., Hydro One Networks Inc. (also Transmitter), and the IESO.

The Technical Working Group will continue to meet at regular intervals to monitor developments in the sub-region and track progress toward plan deliverables. In particular, the actions and deliverables associated with mid-term 115 kV sub-system capacity, end-of-life needs, and Leamington load restoration needs, will be studied as an addendum to the IRRP to be completed by Q2 of 2020.  Mid- to long-term load growth, industry developments, and regional and bulk system transmission developments will require annual review of system demand, project achievement and asset condition to determine whether recommendations require further review by the Working Group. In the event that underlying assumptions change significantly, local plans may be revisited through an amendment, or by initiating a new regional planning cycle sooner than the OEB-mandated five-year schedule.

Bulk Planning Activities in Windsor-Essex

A Windsor-Essex bulk report was finalized and posted on June 13, 2019 and a new West of London bulk study is underway to examine emerging electricity needs in the broader area. Visit the Southwest Ontario Bulk Planning Initiatives webpage for more information.

Documents referenced on this page, but not posted, can be obtained by contacting with 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

2021 Letter from IESO to Hydro One re Transmission Line from Chatham to Lambton 


2019 Windsor-Essex Integrated Regional Resource Plan (IRRP)


2019 Windsor-Essex IRRP Appendices


2019 Letter from IESO to Hydro One re Leamington switching station


Frequently Asked Questions re IESO letter to Hydro One (Jan. 31/19)


2018 Windsor-Essex Scoping Assessment Outcome Report


2018 Windsor-Essex Scoping Assessment Outcome Report - Responses to Public Comments


2015 Regional Planning Process Outcome

In the near and medium term, demand in the Kingsville-Leamington area has exceeded supply capacity. A large portion of the study area does not currently comply with the prescribed Ontario Resource and Transmission Assessment Criteria (ORTAC) restoration criteria. A recommended plan to build a short transmission line and a new transformer station near Leamington in combination with refurbishment work at the Kingsville and Keith stations will address the needs identified for the area.

No long-term needs were identified at this time. The next regional planning process is scheduled to begin in 2018.

2015 Windsor-Essex Area IRRP

2015 Windsor-Essex Area IRRP - Appendix

Key Resources


Terms of Reference

Planning Process Working Group Report to OEB

Supporting Evidence to Hydro One's Section 92 for SETCR

Supporting Evidence for Recommended Cost Allocation Treatment for SETCR

Hydro One Regional Planning