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Image credit: Bryan Goff, Unsplash

Freezing temperatures and low water levels in lakes, the source of hydropower for Ketchikan Public Utilities’ electric division, have maxed out power production.

The utility is asking customers to throttle back their electrical usage to cope with the situation.

A 30MW demand is putting stress on the system during peak hours. The utility is also juggling repairs, sending power to northern communities and dealing with Alaska Department of Environmental Conservation permit limitations, said electric division manager Andy Donato.

“I don’t know if it’s a real big challenge,” Donato said. “It may be a fun one, you know. Depends how you want to look at this.”

Peak usage rates are from 6 a.m. to 9 a.m. and 8 p.m. to 9:30 p.m.

“These mornings we’ve broke 30MWh,” Donato said. “And when we get up to around 31, we get close to the extreme (where) we don’t have any more generation.”

The utility suggests lower temperatures on thermostats, turning off lights and taking shorter showers.

“I just think that if more people are cognisant, we can diminish those peaks in those two periods and we’ll get through this tight time.” Donato said.

KPU is encouraging local businesses that have alternative fuel options to change over. The utility might shave another MW off demand if they do, he said.

Hydropower facilities around Ketchikan are producing about 12MW. Diesel generators power the other 18MW.

KPU is not using hydropower generation at Whitman Lake because of its low water level.

Meanwhile, a generator is in need of repair and the utility has turned to rentals.

A state air quality permit bans the grouping of too many generators for too long. KPU workers recently unhooked rental diesels from the Bailey Powerhouse and transported them offsite.

With cold weather forecast to continue another week, challenges remain. The air permit has hour limitations on the generators based on their particulate emissions, Donato said.

“This has really become a challenge on how we balance various generators, to optimise the time remaining and utilise the larger ones for peak,” he said.

The situation doesn’t just affect Ketchikan. Last month, at the direction of the Southeast Alaska Power Association, KPU began transmitting power from Swan Lake to the Tyee Lake hydro facility. The intention was to help Wrangell and Petersburg, which also face low lake levels.

“We’re kind of in this together — Ketchikan, Wrangell and Petersburg,” Donato said. “And we realise with this weather it’s going to be around here for a couple more weeks. We want to figure out what’s the best strategy to get all of us to pull through it.