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Gas Phase-Out Impact Assessment

Forecasting and Planning

The future of gas generation in Ontario has become a focus of discussion for a number of municipalities as they consider efforts to tackle climate change, raising questions and concerns from stakeholders about the challenges and opportunities these discussions have raised. The electricity system would undergo significant impacts if natural gas was taken out of the supply mix. Such an undertaking would require a comprehensive plan to develop and invest in suitable replacement supply and reorient the system around the new supply mix in order to maintain the reliability of the system. 

The IESO is looking to inform future discussion about the implications of a phase out of natural gas generation in Ontario. This will be done by launching this engagement that will result in the development of an assessment that outlines the implications of lowering emissions by reducing the reliance on natural gas generation.  More specifically, the assessment will outline the current role natural gas plays in maintaining a reliable electricity supply across Ontario as well as provide an assessment on the reliability, cost, operability and timing issues that would need to be addressed should the phase out of natural gas be considered. Stakeholders will have an opportunity to provide feedback on the scope of the assessment. The publication of the assessment with the conclusions of the assessment will be issued later this year.

The IESO encourages all interested parties to participate in this engagement through the public webinars and written feedback. 

To be added to the email list for communications related to this engagement or to submit comments and enquiries, please email


Related Information

Schedule of Activities

Date Engagement Activity Expected Actions

May 16, 2022

Final Summary Engagement Report


October 21, 2021

Engagement webinar

The IESO released an assessment of the impacts of phasing-out natural gas generation by 2030. Stakeholders are welcome to participate in an engagement webinar on October 21 where the IESO will provide a briefing of the report and answer stakeholder questions pertaining to the assessment.

Recorded Presentation

This webinar was presented during the IESO's October stakeholder engagement sessions, see full agenda for more information.

October 14, 2021

IESO response to stakeholder feedback


October 7, 2021

Assessment Posted



Development of assessment


June 24, 2021

Engagement webinar

Stakeholders will be provided an overview of the current role that natural gas generation plays in Ontario, the proposed assessment approach as well as an overview of early feedback submitted by stakeholders.

Presentation - May 27, 2021

Feedback form - May 27, 2021

Stakeholder feedback
due June 17

Recorded Presentation

This webinar was presented during the IESO's June stakeholder engagement sessions, see full agenda for more information.

June 17, 2021

The IESO has received a high volume of submissions for this stakeholder engagement and is working to post all feedback as soon as possible.


Stakeholder feedback due on May 27 materials

Organization Feedback
Resident Feedback
Date Engagement Activity Expected Actions

May 27, 2021

Engagement webinar - postponed until June 2021 

April 29, 2021

Gas Phase-Out Impact Assessment engagement launched