March 11, 2021 OPG REPORTS STRONG OPERATING PERFORMANCE FOR 2020 Commits to Net-Zero Carbon Goal and Continues to Advance Safe and Successful Execution of Darlington Refurbishment [Toronto]: – Ontario Power Generation Inc. (OPG or Company) today reported its financial and operating results for 2020, with net income attributable to the Shareholder of $1,361 million for 2020, compared to $1,126 million in 2019. OPG’s financial results for 2020 reflected its continued generation of electricity to meet the needs of Ontario during a year challenged by the pandemic, with increased revenues resulting from higher regulated prices previously approved by the Ontario Energy Board for the Company’s nuclear generating assets and from the assets acquired in 2020. “OPG provides an essential service, producing more than half of the power used by Ontarians every day. Since the beginning of the pandemic, we have taken strong action to protect the health and safety of our workers and communities, while ensuring continued reliability of our generating facilities,” said Ken Hartwick, OPG President and CEO. “As an energy sector leader, we also remain focused on delivering projects and investing in innovation as part of our commitment to action on climate change.” OPG released its Climate Change Plan in November 2020. The Climate Change Plan commits OPG to being a net-zero carbon company by 2040 and taking action to drive efficient, economy-wide carbon reduction in Ontario and beyond. Under the plan, OPG will continue to maximize the decarbonizing potential of its existing assets, while advancing electrification of the transportation sector and technologies that can make a further meaningful and immediate impact on climate change, such as nuclear small modular reactors (SMRs). The Company will also continue to pursue other opportunities to add new clean generating capacity. In addition to reducing carbon emissions, OPG’s plan will help create new jobs, nurture new industries, strengthen the economy, and protect the environment. “OPG is leading the way on the development and deployment of the next generation of nuclear power in Canada,” said Hartwick. “Our plan to build an on-grid SMR at the Darlington site by the end of this decade will benefit all Ontarians while further bolstering Durham Region and Ontario as the clean energy capital of the world.” In November 2020, OPG announced the resumption of planning activities for future nuclear power generation at the Darlington site, to host a nuclear SMR, subject to the Shareholder’s concurrence and the Canadian Nuclear Safety Commission’s approvals including renewal of the Company’s existing site preparation licence. 1 The refurbishment of the Darlington nuclear generating station (Darlington GS), one of Canada’s largest clean energy infrastructure projects, is critical to enabling OPG’s Climate Change Plan through a continued supply of carbon-free power to the province. “Throughout the pandemic, OPG and our project partners have maintained strong protective measures and have continued working diligently and safely, ensuring the $12.8 billion Darlington Refurbishment project remains on track,” said Hartwick. “Thanks to the expertise and commitment of our project partners, hundreds of suppliers and thousands of workers, we have successfully returned Unit 2 to service and are advancing project work on Unit 3.” Generating and Operating Performance Electricity generated in 2020 was 82.1 terawatt hours (TWh) compared to 77.8 TWh in 2019. The increase in generation was primarily due to higher electricity from the Contracted Hydroelectric and Other Generation and Contracted Gas Generation business segments. Regulated – Nuclear Generation Segment Electricity generation from the regulated nuclear stations increased by 0.3 TWh in 2020 compared to 2019. This was primarily due to electricity generated from Unit 2 of the Darlington GS following its return to service on June 4, 2020 and until the shutdown of Unit 3 of the Darlington GS on July 30, 2020, and fewer planned and unplanned outage days at the Darlington GS. The increase in electricity generation from the Darlington GS was largely offset by a higher number of cyclical maintenance planned outage days at the Pickering nuclear generating station (Pickering GS). The unit capability factor at the Darlington GS increased from 87.4 per cent for 2019 to 93.1 per cent for 2020 reflecting fewer planned and unplanned outage days. The unit capability factor at the Pickering GS decreased from 87.6 per cent for 2019 to 76.3 per cent for 2020 due to the higher number of planned outage days. Regulated – Hydroelectric Generation Segment Electricity generation from the regulated hydroelectric stations decreased by 0.2 TWh during 2020 compared to 2019, primarily due to lower electricity demand in Ontario. The availability of 88.2 per cent at these stations for 2020 was higher than 86.6 per cent for 2019. The increase in availability was largely due to fewer planned outage days as the Company deferred certain planned maintenance and project activities in response to the onset of the COVID-19 pandemic in the second quarter of 2020, as well as fewer overall unplanned outage days across the regulated hydroelectric fleet. Contracted Hydroelectric and Other Generation Segment Higher electricity generation from the Contracted Hydroelectric and Other Generation business segment of 2.2 TWh during 2020 compared to 2019 was largely due to a full year of electricity generation from hydroelectric facilities in the United States acquired in October 2019. The availability of the Ontario-based hydroelectric stations in the segment increased from 77.0 per cent for 2019 to 86.2 per cent for 2020. The increase in availability was 2 primarily due to fewer planned outage days at the contracted hydroelectric facilities in northeastern Ontario, including from the deferral of certain planned maintenance and project activities in response to the onset of the COVID-19 pandemic in the second quarter of 2020. Contracted Gas Generation Segment Electricity generation from the Contracted Gas Generation business segment increased by 2.0 TWh 2020 compared to 2019. The increase was primarily due to electricity generation from the portfolio of natural gas-fired plants in Ontario acquired in April 2020. The earnings from these facilities contributed to an increase in net income in 2020 compared to 2019. Total Generating Cost The Enterprise Total Generating Cost (TGC) per megawatt hour (MWh) was $50.56 for 2020, compared to $50.82 for 2019. The Enterprise TGC per MWh in 2020 was comparable to 2019, with the impact of higher electricity generation from Ontario-based facilities, net of an increase in fuel expense, largely offset by a planned increase in sustaining capital expenditures in support of OPG’s digital strategy and for regulated hydroelectric asset overhaul programs. Generation Development OPG is undertaking a number of generation development and other major projects in support of Ontario’s electricity system. The Company continues to execute on these projects while maintaining enhanced safety measures in response to the pandemic. Significant developments during 2020 included the following: Darlington Refurbishment The Darlington Refurbishment project will extend the operating life of the four-unit Darlington GS by at least 30 years. OPG successfully returned to service Unit 2 of the Darlington GS from refurbishment on June 4, 2020, reconnecting it to Ontario’s electricity grid. Unit 2 has been operating reliability since returning to service. The refurbishment of the second unit, Unit 3, commenced on September 3, 2020. Defueling of the reactor was completed in the fourth quarter of 2020 and the separation of Unit 3 from the three operating units was successfully completed in January 2021. Unit 3 refurbishment has entered the disassembly segment and is progressing as planned. Once refurbished, Unit 3 is scheduled to be returned to service in the first quarter of 2024. Planning and pre-requisite activities for the refurbishment of the subsequent units, Unit 1 and Unit 4, are progressing as planned. OPG continues to assess and seek ways to manage the impact of the COVID-19 pandemic on the total cost of the project, which is otherwise continuing to track to the $12.8 billion budget. 3 Little Long Dam Safety Project OPG continues to execute on a project to improve dam safety along the Lower Mattagami River in northeastern Ontario, primarily through the Little Long Dam Safety project. The project will increase the discharge capacity and make other improvements at the Little Long Main Dam, helping the Company comply with updated Provincial dam safety requirements. During 2020, the project progressed rock excavation activities below the Adam Creek spillway structure on the Little Long Reservoir and, in the fourth quarter, commenced concrete placement of the new bays adjacent to the sluicegates and construction of the barge landing. The project is expected to be placed in service in 2023 and is tracking within its $650 million budget. The Little Long Dam supports OPG’s contracted hydroelectric generating stations. Sir Adam Beck I Hydroelectric GS Units G1 and G2 Replacement OPG is continuing to execute on the replacement of two previously decommissioned generating units at the ten-unit Sir Adam Beck I GS in Niagara Falls, Ontario, which will add approximately 125 MW of incremental peaking generation capacity and provide decades of cost effective, clean power from one of the Company’s flagship hydroelectric stations. In the fourth quarter of 2020, the project completed the removal of 100-year old embedded turbine scroll cases from the G2 unit and in February 2021, completed the removal of the G1 unit scroll cases. The installation of new scroll cases for the G2 unit is underway. The project is expected to be placed in service in 2022, and is tracking on budget of $128 million. The Sir Adam Beck I GS is reported in the Regulated – Hydroelectric Generation business segment.