By Tim Kalinowski on January 15, 2021.
Lethbridge experienced winds up to 125 km/h during Wednesday’s storm event, but City crews were able to respond effectively to restore power as quickly as possible, said Tracy Brason, Compliance and Controls manager with the City of Lethbridge.
“The biggest part is trying to co-ordinate,” he confirmed. “External entities had some issues as well across southern Alberta. So trying to figure out where the issues were was the biggest problem.”
Lethbridge Electric Utility experienced back-to-back transmission circuit outages just after 9 a.m. as a result of high winds, said Brason. The wind knocked out two major transmission lines coming into the city from the provincial power grid connections at one of its six electrical supply substations, affecting about 25 per cent of the city, primarily the downtown core.
There were numerous reports of downed trees and line failures as a result of the storm throughout the city and in neighbouring municipalities and communities.
The City’s follow-up investigation verified that equipment operated correctly, but due to the extreme gusting winds the power lines simply snapped altogether causing power flow swings.
Brason confirmed the grid is designed to always be able to survive the loss of a single circuit, but in this case could not adjust to the loss of two key lines almost simultaneously. He said these types of extreme wind events seem to be occurring more often in recent years, and the City will be taking all the information learned from this event to help come up with a strategy to shore up the grid when future storms of this nature happen.
“This was like hurricane level winds temporarily,” Brason confirmed. “I have been around a few decades myself, and sustained events, whether it is downpours of rain or high winds, they do seem like the come up more often now.”
Brason said the fact City crews were able to get the power up in about two hours after such a major outage is a great testament to their skills, abilities, and dedication to the citizens of Lethbridge.
“To see the expertise we have working,” he said, “is kind of like when we (say) ‘Good sailors are not made on smooth waters.’ It is was great to see the guys in action, and the pretty confident bunch we have throughout the organization.”
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