Power corp says low water levels could extend into third year

After months using diesel to help generate power because of unusually low water levels, the NWT Power Corporation says the same conditions could continue well into 2024.

Doug Prendergast, a spokesperson for the power corporation, said a combination of diesel and hydro has been providing power to Yellowknife, Ndılǫ, Dettah and Behchokǫ̀ since the fall of 2022.

The Snare hydro system usually generates most power for those communities.

While roughly 95 to 98 percent of electricity in the North Slave typically comes from hydro, Prendergast said up to the end of November, around 45 percent of power was being generated by diesel.

“Over the next several months, as demand for electricity increases in Yellowknife and the other communities supported by Snare, we do expect that percentage will change somewhat, and the percentage of diesel generation will increase,” he said.

The NWT has experienced hot and dry conditions since the summer of 2022. The latest territorial government water monitoring bulletin indicated water levels remain extremely low, particularly on Great Slave Lake and the Mackenzie River.

“It is obviously a challenging situation,” Prendergast said.

“Now this looks like it could extend into a third year so, obviously, we’ll be hoping for lots of snow in the area of the Snare basin.”

Prendergast could not say precisely how much diesel the power corporation has used since the fall of 2022, beyond expressing it as a percentage of overall power generation.

Earlier this year, the CBC said the power corporation had used an average of nearly 1.3 million litres of diesel a month between January and September.

Generating electricity using diesel is more expensive than using hydro. Prendergast said the corporation plans to speak with the new territorial government to “identify the best path forward to address the financial impact of low water,” but said it was too early to say what that impact is.

In June, the NWT government said it had given the power corporation $15.2 million to prevent residents’ power rates from soaring as diesel generation increased due to low water levels.

Diesel use also has environmental impacts, Prendergast acknowledged, as it produces more greenhouse gas emissions than hydro.

The power corporation says it is doing its best to maximize hydro generation with the amount of water available.

This summer, NTPC applied to temporarily lower the minimum level of water required at some reservoirs. The corporation has since applied to make that allowance permanent at two reservoirs. A lower minimum water level means the power corporation can keep using hydro for longer in dry conditions.

“Once we recognized … in 2022 that there was going to be a challenge with water levels, we took a lot of time to develop our operating plans,” Prendergast said.

“We invested a lot of time in terms of maintenance on our diesel generators to get them operating as efficiently as possible, which I think has been quite helpful in terms of reliability.”