In its 2024 financial results report, Ontario Power Generation (OPG) announced that it has Ontario’s support to move forward with plans to refurbish and expand a number of hydroelectric generating stations across Northern Ontario over the next decade.

When complete, this work will secure up to 830 megawatts (MW) of electricity in the North, OPG said. This is part of OPG’s plan to refurbish and redevelop hydroelectric generating stations across the province to maintain reliable and efficient operations and increase production of renewable energy.

“Many of our hydroelectric stations have been in service, generating the electricity Ontarians need, for decades and, in some cases, more than a century,” said Nicolle Butcher, OPG president and CEO. “The work we are doing now and over the next number of years to renew our hydroelectric fleet will ensure those same stations reliably produce power for future generations to come.”

OPG has commenced the execution of three projects to redevelop existing hydroelectric generating stations in Ontario that are approaching the end of their operational lives. The redevelopments will generally involve construction of new powerhouses or powerhouse extensions, replacement of turbine and generator units and supporting systems, and replacement or rehabilitation of other structures at the stations. The redevelopments are expected to ensure continued safe and reliable operations of the assets for approximately an additional 80 to 90 years, OPG said.

In November 2024, OPG initiated the execution phase of a project to redevelop the 118-year-old Kakabeka Falls GS, the second oldest generating station in OPG’s Ontario-based hydroelectric fleet, located along the Kaministiquia River in northwestern Ontario. The project will involve construction of a new powerhouse extension, replacement of the surge system, and replacement of the penstocks. The redeveloped station is expected to have a generating capacity of approximately 27 MW. The project’s expected in-service date is 2028, with an approved budget of $519 million.

The new powerhouse will house two new modern turbine-generating units capable of generating approximately 27 MW of clean electricity, about three MW more than the plant’s current capacity, or a 13% increase. The four existing generating units and ancillary equipment will also be removed from the current powerhouse, which will be maintained in its original location. The four existing penstocks will be removed and replaced with new penstocks. Finally, the project will replace the plant’s surge tank, which is used to manage abrupt changes in water pressure.

Kakabeka Falls GS went into operation in 1906 with a single unit. A third unit was added in 1911 and a fourth unit was installed in 1914. Ontario Hydro, OPG’s predecessor company, purchased the station in 1949.

During the fourth quarter of 2024, OPG also initiated the execution phase of a project to redevelop the Coniston and Stinson hydroelectric generating stations, located along the Wanapitei River east of Sudbury, Ontario. The redeveloped stations are expected to have a combined generating capacity of approximately 12 MW. The project’s expected in-service date is 2027, with a combined approved budget of $178 million.

In its end-of-year results, OPG also provided insight into the performance of its hydroelectric generators. Electricity generation from OPG’s regulated hydroelectric generation business segment increased by 1.1 TWh during 2024, compared to 2023, mainly due to higher electricity generation at the hydroelectric facilities in the Niagara region reflecting higher electricity demand, and higher water flows across most of Ontario.

On the other hand, electricity generation from the contracted hydroelectric and other generation business segment in 2024 was comparable to 2023. Availability of the hydroelectric stations in the segment for 2024 was 80.8%, compared to 85.9% for 2023. The decrease was primarily due to higher planned outages at the Lower Mattagami hydroelectric generating stations.