Taltson hydro plant back online once more after corrosion repair

After a years-long overhaul and unexpected repair work that jointly cost about $155 million, the South Slave’s Taltson hydro plant is back in service.

The NWT Power Corporation said on Friday it had restored communities in the region to power from the dam rather than diesel generators.

Tens of millions of dollars has been spent on diesel since Taltson, which is 60 years old, was first shut down for a major refurbishment in May 2023.

That work took about four times longer than planned, in part because of a wildfire raging through the site and a series of equipment issues. Then, NTPC found a corrosion problem that was more serious than first thought.

The federal government has supplied $18 million to offset a small portion of the overall cost.

Usually, customers are ultimately expected to bear the cost of this kind of work. The NWT government is subsidizing some power rates for at least the next two years to try to limit a price spike that is, in part, associated with the Taltson work.

“Despite the extended shutdowns over the past several years, the investments made in the hydro unit and supporting infrastructure will ensure that South Slave communities and customers will have access to clean hydropower for decades to come,” NTPC president Cory Strang was quoted as saying in a Friday news release.

Taltson’s return comes as oil costs worldwide are soaring as a result of the United States’ war with Iran.

“At a time of fast-rising diesel prices, the return to hydro is extremely helpful in keeping generation costs as low as possible,” Strang added.

Separately, Prime Minister Mark Carney said this week he was referring the Taltson hydro expansion to the Major Projects Office.

That project would allow Taltson to power parts of the North Slave, including potential future mines. The cost, which includes a power line below the surface of Great Slave Lake, runs into the billions.

Taltson itself also needs a further upgrade before it can distribute its maximum generation capacity of 22 megawatts.