Expanding and Upgrading Our Bay d’Espoir Facility
June 14, 2025
At our Bay d’Espoir hydroelectric generating facility, our Major Projects team has begun to execute our multi-year plan to upgrade and refurbish various components of the facility, as well as further develop the site to increasing our energy capacity and safeguard reliability of service to our customers.
Penstock 1 Refurbishment and Replacement
Penstock 1, one of three original penstocks built in the 1960s*, channels water from the reservoir to the powerhouse turbines. This year, it’s undergoing a major refurbishment to extend its operational life and ensure reliability into the future.
(Middle) Hydro lines crew assisted in transportation of Penstock sections to site.
(Right) Penstock Steel sections or “Cans” shipped and ready for installation at the BDE site.
More than 1,100 ft of the penstock will be removed and replaced with newly fabricated sections. The new sections have started to arrive from the fabrication site via an onloading site in Nova Scotia, shipped by barge into Bay d’Espoir where they’re offloaded and trucked to site. Meanwhile, the remaining 2,600 ft will be refurbished.
The project is anticipated to be completed by the end of this year.
Penstock 2 & 3 Refurbishment
Penstocks 2 and 3 are also being reviewed for partial replacement and repair, prompted by recurring weld seam issues. A feasibility and front-end planning study is currently underway for Penstock 3, with the goal of submitting a PUB application in the end of 2025, with work to be completed in 2027. While the work for Penstock 2 is slated to be completed in 2030. No environmental assessment is required.
Unit 1 & 2 Overhaul
Two of the seven generating units at the Bay d’Espoir hydroelectric station is in the middle of a scheduled overhaul.
Photo taken by Alex Chaulk.
These major inspections are completed approximately every six years and will include the partial dismantling of the Units 1&2 to complete the cleaning and testing of several components, as well as bushing replacement. Any operational issues and seal leaks on the Spherical Valves for both units will also be addressed and a condition assessment will be completed to provide recommendations for future maintenance.
(Middle) Alex Chaulk, Mechanical Graduate Engineer, standing next to disassembled Unit 1 turbine runner and shaft assembly in preparation for inspection.
(Right) Unit 1 wicket gates prepped for shipment to be refurbished.
Did you know? The rotor for this unit weighs approximately 160 tons and spins at up to 300 revolutions per minute during operation!
Unit 7 Life Extension
Unit 7 located in Powerhouse 2 in Bay d’Espoir (BDE) was commissioned in 1977 and provides 154.4 MW of generation capacity to the Island Interconnected System and produces an average 835 GWh of energy annually (five-year average 2020-2024). Many critical components have typical service life of 40-55 years.
To ensure the continued reliable operation of Unit 7, the project will include life extension activities to extend the reliable service life by at least 25 years through inspection, refurbishment, and replacement of components. This will include replacement of the runner, bottom ring, stator windings, and re-insulation of rotor poles. The project is expected to be submitted to the PUB in mid 2025 and execute in BDE in 2028.
Unit 8 New Build
Plans are also underway to expand the existing Bay d’Espoir station capacity by adding an eighth generating unit. This development has long been recognized as a practical and efficient way to increase firm energy capacity for the island. In fact, when Powerhouse 2 was originally constructed in the 1970s, Unit 8 was already envisioned as a potential future expansion, and Hydro proactively planned and completed initial civil works for Unit 8 at that time. This foresight now provides significant efficiencies as we proceed with the Unit 8 build.
When Powerhouse 2 was built in the 1970s, Hydro proactively included initial civil works for Unit 8 as part of the long-term expansion strategy. These works were not just conceptual—they were physically constructed to accommodate a future generating unit. This included:
- Certain Structural provisions within the powerhouse.
- Concrete and foundations in the draft tube area to support future mechanical and electrical installations.
- Penstock alignment and space allocation, ensuring that future hydraulic connections could be made without major structural rework.
This foresight now provides significant efficiencies as we proceed with the Unit 8 build.
Our build application to Public Utilities Board was submitted in March of this year. In April, our Early Works Application was approved, enabling our teams to begin initial procurement and other activities within 2025. The Unit 8 project is expected to take approximately six years from the start of construction through to final close-out.
There’s a lot of exciting progress underway at Bay d’Espoir as we continue to invest in the long-term reliability of this vital facility and build for the future energy needs of our province!
*Penstock 4 was built in the mid-1970s.