Nalcor V-P explains why hiccups in the system cause blackouts in your home
It’s a new addition to the vocabulary of a lot of people in Newfoundland in the past couple weeks: “trip.”
The Holyrood generating station at dusk Tuesday. — Photo by Joe Gibbons/The Telegram
Along with being an excursion to a faraway place, and an accidental moment where you lose your footing, apparently “trip” means electrical problems, blackouts and cold houses.
Four times in the past two weeks, a trip at the Holyrood power plant has turned out the lights for tens of thousands of people as utility managers struggled to run a fragile power grid and protect their infrastructure.
On Friday night, a compressor motor failed at Holyrood, which led to a unit tripping offline.
On Sunday, as workers were bringing another unit up to full operation after fixing a broken fan motor, that unit tripped and went offline.
On Jan. 5, a breaker in the switchyard outside Holyrood failed, causing one of the units to trip and shut down.
In each case, people across the province noticed the problem when the lights went off.
Rob Henderson, vice-president of Newfoundland and Labrador Hydro, sat down with The Telegram to talk about the recent hiccups and explain why there have been so many trips and blackouts in the past couple of weeks.
For starters, he said, these things happen fairly regularly — probably five to eight times per year — and its just a fact of life when running very, complicated electrical systems.
“With Holyrood, with a thermal plant, it’s a complex plant,” he said. “It’s a huge, complex machine with a lot of high-pressure steam, high temperatures, a lot of pumps and motors running to keep the whole plant running well.”
Essentially, if something goes wrong with one of these big systems, they can do a lot of damage to themselves, so they’re designed to automatically shut down in the event of a problem.
When that happens, it puts a strain on the whole system.
The people who run the power grid always need to maintain absolute balance between the total demand on the system, and how much electricity they’re generating.
When people turn on the lights and turn up the heat, NL Hydro operators respond by putting a bit more water on the turbines at the hydro dams, and putting a bit more fuel in the generators at Holyrood.
But when there’s a problem — for example, a compressor motor fails on one of the units at Holyrood, and the whole thing shuts down — then the system automatically cuts power to a few neighbourhoods to compensate and maintain balance on the system.
Less generating supply needs to be compensated with less demand — blacked-out customers — or else things could start breaking.
“This all happens very fast. This is within seconds when a generator trips off,” Henderson said.
If a random trip happened in March or June, a few people would patiently wait in the dark for half an hour until the lights came back on. Behind the scenes, the people controlling the electrical system would ramp up output at some of the hydroelectric dams, bring the customers back onto the grid and everything would go back to normal.
But Henderson said right now, because of the rolling blackouts, broken infrastructure and calls for energy conservation, everyone is hyper-aware of everything about the electrical system.
The good news is that the weather is warmer, which decreases demand, and, for the first time in weeks, all three units at Holyrood are working properly, so the critical situation is over.
Henderson said once the links to Nova Scotia and Labrador are built as part of the Muskrat Falls project, trips at individual power plants won’t mean blackouts anymore.
Because the province will be connected to such a big system, Newfoundland will instead just pull a tiny bit of power from the mainland grid to maintain the balance, and the lights will stay on.