Our mission, vision & values

As Ontario’s largest clean electricity generator, see how our focus is on generating safe, efficient, and reliable energy.

About

Our subsidiaries
Our subsidiaries & partnerships are helping us improve electricity generation, storage, and distribution technology to electrify life in one generation.
Who we are
Powering Ontario
Ontario’s need for power never takes a rest and neither does OPG — we’re on the job 24 hours a day, seven days a week, powering Ontario.
What we do
Public safety
We maintain a long-term commitment to the health, safety and energy needs of Ontarians, and it shows in everything we do.
Our commitments in action
Code of Business Conduct
We operate according to a Code of Business Conduct that ensures safety, integrity and efficiency for Ontario.
Governance & regulation

Workers in hard hats look out from the top of an open stairway before a huge Canadian flag in a nuclear plant.

Our role in the system

Our role is to help build a stronger Ontario by investing in clean, affordable power and energy solutions that help grow Ontario's economy.

Power generation

Nuclear power
Nuclear power plays an important role in Ontario and OPG’s energy mix, and its critical to helping us achieving our net-zero goals.
Our power
Educational resources
We support students and educators by providing learning resources developed specifically for teachers, young people and schools.
Our role in the system
Nuclear safety and emergency preparedness
We build safety into every step of our energy production and about our comprehensive emergency preparedness plans for Ontarians.
Our commitment to safety
- Nuclear safety and emergency preparedness
- Water safety

An aerial view of the Darlington Nuclear Generating Station.

Darlington refurbishment project

Our mission, vision & valuesAs Ontario’s largest clean electricity generator, see how our focus is on generating safe, efficient, and reliable energy.Learn MoreAbout Our ...

Projects & services

Darlington SMR
The Darlington site is the only location in Canada licenced for new nuclear with a completed and accepted Environmental Assessment.
Our projects
Clean energy credits
With an extensive portfolio of clean energy generation across North America, OPG can offer environmental credits in both Canada and the US.
Our services
- Electrification services
- Clean energy credits

Community investment

The Power for Change Project was designed to give back to Ontario and to the communities where we operate, to help build a cleaner, more sustainable future for generations to come.

Ouimet Canyon Provincial Park, Thunder Bay, Ontario

Territorial acknowledgement

We respectfully acknowledge that our facilities are located within the traditional and treaty territory of Indigenous Nations and communities.

Communities

Territorial Acknowledgement
- Territorial Acknowledgement
  OPG respectfully acknowledges that the lands on which its generating stations and other assets are located are within the traditional and treaty territory of many Indigenous communities. Click to read more.
Central Ontario
- Central Ontario
  Central Ontario is home to 20 of our hydroelectric facilities, some of which, like our Sills Island Generating Station, have been part of their community for more than one hundred years.
Eastern Ontario
- Eastern Ontario
  Eastern Ontario is host to one gas-fired generating station and 15 of our hydroelectric generating stations on the St. Lawrence, Ottawa and Madawaska Rivers.
Northeastern Ontario
- Northeastern Ontario
  Northeastern Ontario contains 14 of our hydroelectric stations, including several we built or redeveloped through key partnerships with local Indigenous communities.
Northwestern Ontario
- Northwestern Ontario
  Northwestern Ontario hosts 11 of our hydroelectric stations as well as a former coal generating station that we converted to use biomass as fuel.
Southern Ontario - Durham Region
- Southern Ontario - Durham Region
  The golden horseshoe of Southern Ontario is home to key operations including our Darlington and Pickering nuclear stations in Clarington and Pickering.
Southern Ontario - Niagara Region
- Southern Ontario - Niagara Region
  The golden horseshoe of Southern Ontario is home to key operations including our iconic Sir Adam Beck hydroelectric stations in Niagara Falls.
Southwestern Ontario
- Southwestern Ontario
  Southwestern Ontario is host to our NSS - Western Waste Management Facility in Bruce County, our Eugenia hydroelectric station near Meaford, and our Nanticoke Solar Facility on the site of the former Nanticoke coal station.

Hydroelectric Water Portal (water.opg.com)

Find water level and flow information from gauges on rivers where OPG operates hydroelectric stations in Ontario.

News & resources

Watt’s New
In our revamped e-newsletter, find out how we're helping electrify Ontario while strengthening its economy, communities, and the environment.
Newsroom
WattNext.ca
Ontario Science Centre, Ontario Tech University and OPG's energy education program aims to educate, inform, and connect Ontarians with energy careers.
Educational resources
Hydroelectric Water Portal (water.opg.com)

Careers
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Reports
OPG Websites
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March 17, 2026

7 min read

Darlington Nuclear Performance Report – Q4 2025 Results

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Performance update

As part of our commitment to keep you informed, this report tracks performance for Ontario Power Generation’s (OPG) Darlington Nuclear in the areas of safety, operational and environmental performance, and significant accomplishments during the fourth quarter of 2025.

21.6 TWh

Electricity production

The electrical energy generated, minus station needs

OPG’s nuclear electricity generation for Q4 of 2025 totaled 8.7 terawatt hours (TWh).

In Q4 2025, Darlington Nuclear produced 4.9 TWh of electricity, which was 11.6 per cent of the electricity produced in Ontario. By the end of Q4 2025, Darlington Nuclear generated a total of 21.6 TWh of electricity for the 2025 calendar year.

95.69% UCF

Reliability

Unit capability factor

By the end of Q4 2025, Darlington’s Unit Capability Factor (UCF) this year to date is higher (95.69) than in Q4 2024, primarily as a result of a decrease in the number of days the station has been shut down for maintenance outages.

1 spill

Environment

Spills to the environment

During Q4 2025, there was one spill to the environment at Darlington Nuclear reportable to a regulatory authority.

0.08 TRIF

Safety

Total Recordable Injury Frequency

Total Recordable Injury Frequency (TRIF) measures the number of injuries involving OPG employees that result in a fatality, lost time, requiring restricted work and requiring medical treatment per 200,000 hours. By the end of Q4 2025, the 12-month rolling average TRIF was 0.08 injuries per 200,000 hours worked.

About OPG’s Nuclear Generating Stations

OPG owns and operates the Pickering and Darlington Nuclear Generating Stations. The two stations have a combined generating capacity of about 4,698 megawatts with Darlington Unit 4 currently on refurbishment. Accounting for 20.5% of the electricity produced in Ontario in Q4, OPG’s nuclear units generated 8.7 TWh.

Questions?

Please contact Jennifer Knox, Director - Nuclear Stakeholder Relations, through the form below.

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Territorial Acknowledgement

Central Ontario

Eastern Ontario

Northeastern Ontario

Northwestern Ontario

Southern Ontario - Durham Region

Southern Ontario - Niagara Region

Southwestern Ontario

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