Why PSE urged Western Washington to conserve energy amid severe cold

Energy utilities in Washington and Oregon asked their customers to curtail gas and electricity usage on Saturday after the Northwest’s largest storehouse of natural gas shut down amid extreme cold temperatures.

A spokesperson for Puget Sound Energy, Washington state’s largest utility, said Sunday afternoon that it will keep asking customers to conserve as long as the region’s unusually cold weather continues.

On Saturday afternoon, Tulsa, Oklahoma-based Williams Companies, operator of the Northwest’s main natural gas pipeline, sent out an emergency notice: “Puget Sound Energy’s Jackson Prairie Storage facility has suffered a complete outage.”

The Jackson Prairie facility, about 10 miles south of Chehalis, Wash., stores more natural gas than any other site in the Pacific Northwest.

In sandstone layers, more than 1,000 feet underground, it holds gas purchased in summer, when prices are low, for pumping into Williams' Northwest Pipeline in winter, when demand and prices are high.

With the need for heat and gas-fired electricity spiking during the region’s coldest temperatures in many years, the volume of gas in the Northwest’s pipeline system on the I-5 corridor was dropping “at a rapid rate,” the company warned customers.

“Northwest requests all customers to take IMMEDIATE action to reduce loads on the system,” Williams’ notice stated.

Just before 7 p.m., Puget Sound Energy asked its customers to conserve gas and power that evening, blaming “extreme cold temperatures” and “higher energy use than forecasted” without mentioning the dwindling supply of gas entering the Northwest Pipeline.

“This evening, we’re asking customers to set their thermostats at a lower setting and limit the use of hot water, such as dishwashing or clothes washing, dryers and other appliances.”

Gas-fired power plants are the leading source of electricity for Puget Sound Energy, followed by hydropower and coal.

Other utilities in Washington and Oregon made similar asks of their customers, though some acknowledged the outage at Jackson Prairie as well as the weather.

In an interview on Sunday, PSE spokesperson Christina Donegan said she did not know how long Jackson Prairie’s output was stopped, but that it was up to 50-70% of capacity later that afternoon and up to full capacity “that evening.”

Donegan said the outage was caused by "redundant" fiber-optic cables that failed, though the cause of that failure was still being investigated.

“We build redundancy into all of our systems, so we have it, but sometimes you can run into an issue with that, especially when it's extremely cold,” Donegan said.

Though some customers complained on social media about being asked to conserve during a cold snap, Donegan said many customers came through and saved energy.

“We saw the load drop correlated with that request to our customers,” Donegan said. “They did an amazing job.”

Donegan said Puget Sound Energy’s liquified-natural gas plant in Tacoma, which mostly fuels ships at the Port of Tacoma but also provides backup supplies to gas users on land during times of peak demand, has been running at “full tilt” to help gas customers in the Tacoma area stay warm.

Utilities including NW Natural, which serves 800,000 customers in Oregon and southwestern Washington, and Cascade Natural Gas, which serves 300,000 customers in Washington and eastern Oregon, told their customers on Sunday the crisis had passed.

“The issue with the natural gas storage facility has been resolved and operating conditions have returned to normal,” Cascade told its customers. “Customers may resume normal usage.”

Puget Sound Energy customers, meanwhile, are still being asked to curtail their energy usage.

“We will be asking customers to continue to conserve into the evening and then tomorrow and really, as long as we're facing these unusually cold temperatures,” Donegan said.

“Extreme cold poses all sorts of problems for the gas system – from reduced supply due to frozen oil and gas wells, to pipeline malfunctions to frozen equipment at gas plants,” Seattle-based fossil-fuel industry critic Caleb Heeringa with the nonprofit Gas Leaks said in an email. “Still alarming that so much of our energy security is dependent on one facility. More geographically distributed solar and battery storage would be helpful during extreme weather events like this.”

Regulators with Washington Utilities and Transportation Commission and the U.S. Pipeline and Hazardous Materials Safety Administration could not be reached for comment Sunday.

Puget Sound Energy serves 1.1 million electric customers and 900,000 gas customers in Washington, with gas the main source of heat for most customers.