Project Overview

The former Ontario Power Authority (OPA), which has now been integrated with the Independent Electricity System Operator (IESO), has recommended that Hydro One build a new transformer station due to the upcoming retirement of the Pickering Nuclear Generating Station (NGS).


The IESO has advised that the Pickering NGS will be retired by 2024 removing approximately 3,000 MW of generation. This electricity must be replaced by a corresponding amount of power through the transmission system. Clarington Transformer Station (TS) is required to ensure an adequate, safe, and reliable supply of power to support the growing communities in the eastern part of the Greater Toronto Area by the 2018 timeframe. Upon completion, Clarington TS will be a 500/230 kilovolt (kV) transformer station and will connect to the existing 230 kV and 500 kV transmission lines in the area.

image of Transmission towers in a corridor strung with high-voltage powerlines

Project Timeline

  • JUL2014-SEP2015
  • Site preparation activities including the relocation of 230kV and 500 kV lines


  • JUL2015-FEB/MAR2017
  • Clarington TS Construction

  • NOV2015-AUG2017
  • 230 kV & 500 kV Lines Connection Preparation

  • AuG/SEP2016-Aug2017
  • ​Station Equipment Testing and Commissioning

  • AUG2017-MAR/APR2018
  • ​230 kV & 500 kV Lines Connection​

  • MAR-APR2018
  • Clarington TS - In-Service​​​

  • APR/May2016-May/JUN2019
  • ​Habitat Creation and Visual Screening

Project Approvals

Learn more about the Environmental Study Report (ESR) we completed to support the Clarington Transformer Station project.

Project Approvals
Public Consultation

Learn more about the Public Information Centres (PICs) we conducted to support this project.

Public Consultation

Project Resources

View maps, diagrams, and resources related to this project.

Project Resources
Community Liaison Committee

Learn more about the committee we established to support and encourage community participation on this project.

Community Liaison Committee

Contact Us


For more information or to be added to the project contact list, please contact:

Denise Jamal / Dana Gardner
Community Relations
Hydro One Networks Inc.

Tel:  416-345-6799 or 1-877-345-6799

Fax: 416-345-6984