Problems at Holyrood, unavailable generators, push island system past limit
An early winter cold snap, trouble at the Holyrood power plant and two unavailable backup generators led to rolling blackouts in Newfoundland Thursday night.
The Holyrood power generating station. Nalcor has been increasing its spending in its quest to keep the province’s energy facilities in good running order. — Telegram file photo
The result was no lights inside chilled homes, with traffic snarls outside, accidents and reports
of people getting trapped in
elevators in St. John’s office buildings.
The purposeful power outages started about 4 p.m., as the island grid began to hit one of two periods of peak energy usage for the day.
The peaks in energy demand typically run daily from 7-10 a.m. as people wake up and prepare for the day, and 4-8 p.m. as large numbers of people get home from work, make dinner, turn on the lights and turn up the heat.
Blackouts became necessary as there was more demand for power than there was power to be supplied.
The outages are likely to be necessary again during the peak period this morning, according to Newfoundland Power and Newfoundland and Labrador Hydro.
The root of the problem
The problem started with unexpectedly cold temperatures.
“We’ve had a very cold December,” said Dawn Dalley, vice-president of corporate relations with Nalcor Energy.
Nalcor is the parent company of Newfoundland and Labrador Hydro.
“We hit a system peak on Dec. 14 — I think it was 1,496 megawatts. And that was the highest we’ve seen since 2004.”
On Thursday, power usage was 200 megawatts higher than the highest demand recorded for the same day over the last five years, Dalley said.
According to Environment Canada, the temperature in St. John’s moved between -14 C and -17 C, running to -30 C with the windchill. The resulting demand for heat was met with troubles in supply.
As an energy supplier — the main one for Newfoundland Power — Hydro fell short.
To start, one of three generators at the Holyrood power plant, Unit 3, experienced a failure on a fan motor, meaning the unit could not be run at maximum capacity.
It is something Dalley called a “low-probability event.”
“What that means is the unit is still operational, but it’s been de-rated. So rather than be able to generate 150 megawatts, we’re only able to generate 50 (megawatts),” she said.
Hydro also happened to have two backup turbines down for maintenance. The turbines are typically used to deal with peaks in the power demand during the winter.
They are also used when the Holyrood plant is shut down during the summer for maintenance. It means Hydro has to conduct maintenance on the turbines in the “shoulder season” — between the heavy summer and winter demand periods.
“And the Hardwoods (turbines) ... we needed a three-month window for that and the first opportunity started in October,” Dalley said.
The maintenance schedule would have worked out, but the cold came early and cut deep.
As the power shortage became apparent, Hydro began with the normal steps. It asked Newfoundland Power to contribute as much generation as it could from its own, smaller turbines. It also asked that utility to see if load from some of its larger, industrial customers might be curtailed.
Hydro asked the same — power generation, with less usage — from Corner Brook Pulp and Paper.
Everyone contributed. “But the load is so high today, we thought it was prudent to make a call to the public to curb (power usage),” Dalley said.
With the decision made, both Newfoundland Power and Newfoundland and Labrador Hydro staff took to traditional and social media in an attempt to get out an immediate call for energy conservation. They asked people to turn off Christmas lights, not wash laundry or dishes during peak demand periods, not use clothes dryers and reduce the temperature in their homes by a degree or two if possible.
Blackouts were still required.
Newfoundland Power spokeswoman Michelle Coughlin said the rolling blackouts are to be employed at peak periods as needed and continue as long as the island’s power demand exceeds its available supply.
“Those power outages are expected to last anywhere from a half-hour to an hour and then we’ll rotate to the next group of customers based on what the demand on the system is,” she said.
Prior to The Telegram’s deadline, some customers were on social media stating their outages were running longer.
The fallout begins
Any real security in the system is unlikely to be achieved until Hydro has the capability of producing more power as required.
It is expected to be two to three weeks before Holyrood is back online at 100 per cent and all of Hydro’s backup turbines are available.
That said, temperatures are supposed to warm this afternoon, with the hope being energy demand will drop as temperatures go up.
There is no estimate available yet on the potential costs associated with the outages or, for Newfoundland and Labrador Hydro, the repair of the unit at Holyrood.
The cold temperatures also had Hydro Quebec asking its customers to conserve energy in peak periods.