Prioritizing Power

The widespread damage caused by the Sept. 29 windstorm knocked out power for up to three days for some Door County residents and forced Wisconsin Public Service (WPS) to put its emergency response plan into service to get the lights back on for 12,500 peninsula residents.

WPS employs about 100 of its own line technicians, but in the case of a severe storm event WPS must rely on a network of state and regional technicians.

“We have a couple of groups that generically are called mutual assistance groups,” said Electric Distribution Manager Otto Marquardt in an email. “WPS belongs to two different ones: the Wisconsin Utilities Association (mainly made up of Wisconsin utilities) and the Midwest Mutual Assistance group (a larger group with many utilities across the Midwest.)”

The windstorm that swept through Door County Sept. 29 devastated trees, power lines and power poles. Wisconsin Public Service said 75 power poles were snapped, and it took up to 12 hours to clear tangled power lines out of trees and debris in some places. Photo by Susan Olson.

The Sept. 29 storm required 168 line technicians, plus additional contractors to clear the hundreds of trees that fell (photo gallery) on transmission lines.

As residents waited for the power to come back on, some found it  hard to understand why one street would get fixed right away, while another right down the road could wait hours or days. Lisa Prunty, spokeswoman for WPS, said prioritization is an inexact science that takes many factors into account.

In general, calls received from 911 emergency centers are given highest priority. Emergency calls are usually about downed wires where safety is a concern. Areas of public necessity like hospitals, emergency services and public works are also taken into consideration.

Prunty says WPS asks how they can get the largest number of people reconnected.

“For example,” she says, “if we can send two crews to repair a transmission or large distribution feeder line, even if it takes several hours, we’ll likely restore several thousand customers all at once. By contrast, sending single crews to restore several small, four-customer outages may only take an hour or two, but doesn’t result in the same customer impact.”

Geography also plays a role in response.

“If we’re unable to get our equipment into areas because roads are blocked, that area is going to have to wait until we can get through. In addition, even though we might have lines down at the far end of a service district, it may be more efficient to have crews remain in an area of smaller outages rather than take all the time to move to the larger outage.”

But if WPS dispatches a crew to a smaller outage and finds several wires down that will take many hours or days to repair, that crew will often make the situation safe and move on to other outages that can be restored more quickly.

“It’s really a combination of art and science,” Prunty said.

And it’s one job she’s glad she doesn’t have. She said she has accompanied crews into the field several times, but never in a severe storm.

“I know I could never do their jobs,” she said. “Our crews work very hard in these storms to restore power. The weather and damage keeping the line technician from doing their job can be frustrating for them, as they realize customers want their power back.”