Much of the province was left without power on Tuesday, and the source of that outage was transmission lines in southern Saskatchewan weighed down by heavy frost accumulations.
Between 175,000 and 200,000 SaskPower customers across the province were left without power when Units 3-6 at the Boundary Dam Power Station, the one unit at the Shand Power Station, all of which are in the Estevan area, and the two units at the Poplar River Power Station tripped.
SaskPower has pinpointed the cause to the rime frost that started to accumulate on power lines late last week due to foggy and misty conditions. That frost had caused power outages, but nothing remotely close to what was experienced on Tuesday.
“The frost built up on our transmission lines, it built up on our distribution lines and all of our equipment, and in a lot of cases, caused some pretty serious damage out there (before Tuesday),” said Jordan Jackle, a consultant for media relations and issues management in SaskPower’s corporate and regulatory affairs. “We had increasing amounts of lines tripping as time went on. Monday night there were transmission lines tripping on and off, pretty steadily throughout the night.”
The lights went off in Estevan just before 9 a.m. While the power in the Energy City was restored just before 9:30, other communities, including most of Regina, were without power for much of the day.
“We lost two very important transmission lines in the southeast, which caused the outage,” said Jackle. “The level of the grid instability caused by that transmission loss is what caused our power stations – Poplar River, Boundary Dam and Shand – to go down. They tripped off. That actually happens when a power station senses that instability on the system.”
If the power units didn’t trip off, they would have been producing power, but the power wouldn’t have been able to go anywhere without the transmission lines.
The issues with those units stemmed from their location, Jackle said, and not because they use coal to produce power.
SaskPower crews worked to restore power throughout the day. Oxbow and Carnduff were the last communities in Saskatchewan to have their power restored at 10 p.m. Tuesday. SaskPower had previously stated that those areas might not have had their power restored until Wednesday.
In an interview with Lifestyles Wednesday morning, Jackle said there might have been a few farm customers without power. Those who were without electricity were asked to call SaskPower.
“There could be a more isolated problem with a distribution line or something to that effect. But for the bulk of everyone that was affected by the large outage yesterday, they were back online by about 10 o’clock (Tuesday night).”
The measures that SaskPower took for this outage are similar to the ones they take with any other outage, except this one was much greater.
“It starts with an assessment, so we’re out in the field doing an assessment of the kind of damage that was done. We had crews in the sky and helicopters. We had crews on the ground getting a good sense of the state of things out there, what needed to be fixed and making those decisions … to restore power to as many people as possible.”
On the generation side, SaskPower worked to get the units back online. Some were ready to go, but SaskPower did not have the transmission infrastructure in place, and fixed to the point to move the power.
An update on the condition of the Shand Power Station and Units 3-6 at Boundary Dam was not available at press time.
SaskPower also wants its crews to avoid fatigue, so they don’t cause safety issues for themselves or anyone else. While people were working throughout the day to get power restored, they did so on a rotating basis.
Jackle said this was one of the biggest power failures, if not the biggest power failure, since 1981, when the entire province was left without power for some time.
There was still a risk for power failures on Wednesday, he said, because the power lines were still weighed down by the frost that has accumulated. There was an outage in the southeast corner of the province on Wednesday afternoon that affected several communities and lasted for hours.
“We need the sun to come out and really start burning off some of that frost out there,” said Jackle.
Better weather would also allow SaskPower to focus on more permanent fixes for the issue.
Customers have been very patient throughout the process. Some of the major industrial customers asked SaskPower to get the residential customers up first, and to tend to the industrial customers later.
“That really gave us the ability and the flexibility to work on getting people’s homes back on,” said Jackle.
But SaskPower still received about 45,000 total calls to its outage centre. About 33,000 of those came in the first three hours of the outage, which was more calls than they received in all of November.