Frozen Oregon Tree

A frozen tree in an Oregon field. Hundreds of thousands of Portland General Electric customers lost power this week due to wintry conditions.

A series of winter storms over Valentine's Day weekend caused "catastrophic damage" to Portland General Electric's system and left hundreds of thousands of Oregonians without power for several days.

The first of a trio of storms packing a blustery mix of ice and snow hit Oregon the evening of Feb. 12; the next day, Gov. Kate Brown declared a state of emergency as nearly half of PGE's retail customers were impacted by the storms.

On the morning of Feb. 15, PGE reported 350,000 customer accounts were without power, and by Feb. 18 about 100,000 customers were still out. About 15,000 customers in the hardest-hit areas likely won't have their power restored until the week of Feb. 21, Maria Pope, PGE president and CEO, said during a virtual media briefing on Feb. 18.

Pope said about 567,000 of PGE's customers were affected by the storms.

The utility lost power to 20 substations during the storms and had to replace sections of 29 transmission lines, totaling 300 miles of line. An additional 230 distribution lines needed to be restored. The utility reported stringing 222,544 feet of new wires.

Stretches of Interstate 5 and Interstate 84 had to be shut down during the week to repair transmission poles that had failed, PGE said.

Most of the damage was caused by trees and tree limbs falling onto power lines, Pope said. She defended the utility's vegetation-management program during the media briefing, saying much of the damage was caused by trees outside of the utility's tree-trimming right of way.

"This is a one-in-40-year storm," she said. "We could trim and take more trees out in the future, but that will require discussion with stakeholders."

PGE said it deployed 300 crews in the field—1,100 line personnel—to restore power. The recovery was aided by crews from Avista Utilities, Seattle City Light, Snohomish County Public Utility District, Central Lincoln PUD, Eugene Water and Electric Board, Puget Sound Energy, Clark Public Utilities, Clatskanie PUD, Columbia River PUD, Salem Electric and Bonneville Power Administration.

"In the Northwest, BPA is very much a part of the larger community, and we believe it's our duty to help one another in times of distress," John Lahti, vice president of transmission field services at BPA, said in a prepared statement. "This time it was PGE who had the need. Next week, it might be the City of Minidoka in Idaho. It doesn't matter the size of the customer. In return, they help us when the need arises. It's how we take care of each other."

As of the afternoon of Feb. 18, PGE did not have an estimate on the total cost to restore power, but a spokesperson for the utility said "it was a massive event, with multiple waves of ice, snow and wind that did catastrophic damage to our system."

It's always difficult to compare storms, especially with historical data, Steven Corson, spokesman for PGE, told California Energy Markets in an email.

"This is certainly high on the list of the very worst," he said. "It appears this may have affected the largest number of PGE customers ever, although the 1962 Columbus Day Storm affected a larger percentage of our then-smaller customer base."

Pacific Power's service territory was also impacted, but not nearly to the extent of PGE's service area.

At the peak of the storm activity, about 80,000 Pacific Power customers were in the dark. Most of those outages were reported in the mid-Willamette Valley, Drew Hanson, spokesman for utility parent company PacifiCorp, told CEM.

Hanson said the utility's distribution system was hit the hardest. Damage in the Portland area was mostly from trees falling into wires, but it was more extensive farther south into the Willamette Valley, where the utility had to replace more poles and broken crossarms.

Pacific Power's restoration efforts were aided by crews from its sister utilities Rocky Mountain Power, NV Energy and MidAmerican Energy, Hanson said.

By the afternoon of Feb. 18, power had been restored to 96 percent of Pacific Power's customers, Hanson said.

BPA reported numerous line outages from falling trees, but said weather forecasts gave the agency plenty of time to reschedule planned generation outages and to prepare lower Columbia River hydroelectric projects to increase generation.

"BPA was well positioned to serve the region during this significant weather event," John Hairston, administrator and CEO of BPA, said in a prepared statement. "In instances where off right-of-way trees fell on our lines, our transmission crews, substation operators and dispatchers were able to quickly address the problem and safely restore service to our customers."

Overnight on Feb. 12, the first wave of the storms took out 11 different BPA transmission lines. BPA lost 20 MW of load it served to Consumers Power Inc. and the City of Monmouth, southwest of Salem, Oregon, as well as 5 MW of load to PGE on a line it owns coming out of the Oregon City Substation. BPA restored those loads by the afternoon of Feb. 13, the agency said in a statement.

A tree took out a feeder line on the morning of Feb. 13 that resulted in the loss of the Chehalis 69-kV bus and interrupted 164 MW of BPA load to Lewis County PUD and the City of Centralia in Washington. But the situation was resolved within about two hours, BPA said.

On Feb. 15, BPA said, four more transmission lines went down in its southern service area that included 8 MW of lost generation at Cougar Dam and 40 MW of lost generation at EWEB's Carmen Smith hydroelectric project. BPA also experienced a loss of 15 MW of load to Tillamook PUD and a loss of service to Columbia River PUD during this period. All customer generation and load were restored by the afternoon of Feb. 15, Bonneville said.

Washington missed the brunt of the storms, but heavy snow and wind caused power outages to about 17,000 PSE customers, mostly in King and Thurston counties on the morning of Feb. 13, the utility reported.

The majority of those PSE customers had power restored by the afternoon of Feb. 13, with the last remaining customers restored by the morning of Feb. 14. Ultimately, PSE reported that a total of 36,500 customers had been affected and restored.

Editor - Clearing Up

Steve began covering energy policy and resource development in the Pacific Northwest in 1999. He’s been editor of Clearing Up since 2003, and has been a fellow at the Institute for Journalism and Natural Resources and University of Texas.