Power corporation relying less on diesel in the N.W.T.'s North Slave this year

The Northwest Territories Power Corporation says people living in the North Slave region will be getting a lot more of their electricity from hydro power this winter.

Extremely low water levels on the Snare River have been forcing the power corporation to lean heavily on diesel to produce power for Yellowknife, Behchoko, Dettah, and N'dilo since the fall of 2022.

Doug Prendergast, a spokesperson for the Northwest Territories Power Corporation (NTPC), said he expects that by the end of March it will have generated 72 per cent of power for the North Slave region from hydro, and 28 per cent from diesel. That is based, in part, on projections for the upcoming winter that Prendergast said he's "cautiously optimistic" about. 

The Snare system is a series of four hydro plants that usually generates about 98 per cent of the region's power. Electricity generated by burning diesel at Yellowknife's Jackfish power plant is what makes up the difference. 

NTPC says nearly half of the region's power in 2022-23 was generated by diesel. 

Prendergast said NTPC measures different things to get a sense of how much power will come from hydro and diesel in the year ahead. That includes the snow pack around the Snare River in the spring, and the amount of water running into the river at a few different locations, as well as precipitation as the summer draws to a close. 

Those measurements are showing "all sorts of positive signs of rising water levels in the Snare River," he said. He's also hopeful that next year will be even better, and that the North Slave will get back to normal water levels. 

But what the future has in store, amidst a changing climate, is uncertain. 

Robert Sexton, the territory's director of energy, said that's one of the reasons why the government is looking for a firm to update a 2016 study done on hydrology in the North Slave. The initial study used historical data, he said, and found that low water levels happen about once every ten years. He said the territory wants to add the last ten years of data — and with models of different climate scenarios that may unfold.

"The hydrology might change in the North Slave due to climate change," he said. "There's no predicting the future, but we're going to look a little deeper this time."

If climate change continues to bring low water conditions to the N.W.T., Sexton said the territory does have options. Expanding the Taltson hydro system, a project the territory has long been trying to make happen, would connect the North and South Slave power systems and allow each one to serve as a backup for the other. 

Sexton said the territory can also look at expanding hydro generation in other places, using liquid natural gas, or developing a long-term rider — basically, collecting a small amount of more money from customers — that could be used to ease the shock of occasional low water levels if they happen every decade or so. 

Communities in the South Slave have also been relying on diesel-generated power since the spring of 2023. That's because the Taltson hydro facility that serves that region is being overhauled.