OPG advancing refurbishment of R.H. Saunders GS, Ontario’s second-largest hydro station

At a glance

• OPG is investing more than $600 million to execute a multi-year, 16-unit refurbishment of the R.H. Saunders hydro station in Cornwall.
• The project is part of OPG's overall commitment to refurbish generating units across its expansive hydroelectric fleet.
• The Saunders refurbishment will help secure decades more clean, reliable power from Ontario's second-largest hydro station.

On the St. Lawrence River, OPG continues to advance an extensive, multi-year refurbishment of the R.H. Saunders Generating Station (GS), Ontario's second-largest hydroelectric station.

[Link]OPG's R.H. Saunders Generating Station in Cornwall is undergoing a refurbishment of its 16 units.

The company is investing more than $600 million to refurbish 16 generating units at the 1,045-megawatt hydro giant, which is located in Cornwall and forms part of the larger Moses-Saunders Power Dam shared with the U.S.

Once completed in the early 2040s, this major infrastructure program will secure up to 160 gigawatt-hours of additional clean electricity each year, the equivalent to powering more than 19,000 homes, to help meet increasing demand from electrification and fuel Ontario's growth.

The project will also create hundreds of highly skilled jobs and create lasting economic benefits for local and Indigenous communities.

This initiative is part of OPG's overall commitment to invest and revamp turbine-generator units across its fleet of 66 hydroelectric stations in Ontario.

Since it went into service on July 5, 1958, R.H. Saunders GS has tirelessly produced enough electricity to power more than 800,000 homes annually, meeting up to 5% of Ontario's power needs in recent years.

The first unit to undergo refurbishment, G9, is expected to be completed and returned to service later this year.

[Link]The massive turbine runner is pulled up from R.H. Saunders GS's G9 unit, the first of the station's 16 units to be refurbished.

Each unit refurbishment will include major rehabilitation of generating equipment through civil, electrical, and mechanical improvements.

This work includes hoisting out and replacing the massive, 62-ton turbine runner, which includes the steel blades that help convert rushing water into electricity. The old runners will be replaced with newer, more efficient designs that will require less water to generate clean power.

To prepare for the refurbishment program, R.H. Saunders GS underwent several significant equipment and station upgrades.

This included the replacement of the 300-ton powerhouse gantry crane, which support lifting major components found in each generating unit, the replacement of headworks and tailrace cranes used to help block water for any unit while work is being performed, and ongoing refurbishment of the station's main output transformers.

A unique clean power partnership

Since the early 20th century, OPG's predecessor company, Ontario Hydro, had sought to harness the St. Lawrence River's tremendous hydroelectric potential, in partnership with the U.S.

[Link]An employee is seen at OPG's R.H. Saunders Generating Station. The second-largest hydro station in Ontario meets about 5% of the province's power needs.

After years of studies and political setbacks, shovels were finally placed in the ground in 1954 to begin construction of the Moses-Saunders Power Dam. Development was jointly undertaken by Ontario Hydro and its cross-border counterpart, the New York Power Authority (NYPA).

Ultimately, the construction of R.H. Saunders GS and the Moses-Saunders Power Dam were completed ahead of schedule. A friendship monument was unveiled at the centre of the dam on June 27, 1959, in an opening ceremony attended by Queen Elizabeth II and U.S. Vice President Richard Nixon to celebrate the partnership between the U.S. and Canada.

Since the dam went into service, OPG and NYPA have worked closely under a Joint Works Agreement to not only share the hydroelectric potential of the St. Lawrence River (at the International Rapids Section of the river between Cornwall and Iroquois), but also maintenance practices, safety experiences, and common operational costs and duties, all while producing power independently at two separate generating stations.