Nova Scotia Power can make repairs to its Wreck Cove hydroelectric generating station in Cape Breton.
Last week, the Nova Scotia Utility and Review Board released a 29-page decision partially approving the $110-million capital project to refurbish the 42-year-old station, which is carved into a granite mountain south of Cape Breton Highlands National Park in Victoria County.
In its application, Nova Scotia Power stated it needs to modernize the facility to ensure it can provide clean energy to the grid during peak hours and help meet environmental emission goals and renewable energy targets.
While the UARB granted permission to replace the two generator units, overhaul the two turbine units, replace the turbine runners and refurbish the spherical valves, it denied a request to upgrade the floodgate that controls and delivers water to the turbines.
The board cited a report from engineering consultant Midgard that found that the proposed penstock intake work is not supported based on safety, economics, operational efficiency and conformance with industry best practice. Midgard declared NSP could have considered simpler and less-expensive options to address safety concerns.
NSP now has until Dec. 10 to revise the amount of the estimated project cost with the penstock intake gate element of the work by Dec. 10 before the board will issue its final order.
The UARB also directed NSP to provide quarterly reporting beginning March 31 to notify it of any changes to any contingency and scope variation amounts, as well as to describe specific examples of cost minimization efforts during the project.
Midgard also expressed some concern about the project execution plan, noting it is a complex project that has the potential for uncontrolled cost and schedule overruns. In response, NSP stated it had put forward a fully vetted and comprehensive project plan and schedule. NSP also indicated that it will hire an experienced vendor to design, plan and execute the work. The utility also said it will file the proper applications if project scope changes or the project forecast exceeds $250,000, or five per cent, of the approved amount.
The Wreck Cove facility is the largest of the 33 hydroelectric plants in Nova Scotia and produces half of the combined total capacity of 400 megawatts, or enough to power 30,000 homes each year. Chief operating officer Mark Sidebottom previously described Wreck Cove as a “very important player on our electrical grid that provides reliable, renewable energy needed to complement and back up the 600 megawatts of clean — but unpredictable — wind power on our system.”
NSP estimates improvements at the station, which underwent a $13.5-million refurbishment in 2015-16, will extend its operations 40 more years, increase its annual generation to 315 gigawatt hours and save on fuel costs.