Grid operator says all but one plant back in service
By Dan Healing, Calgary Herald July 10, 2012
CALGARY — With all but one plant back pumping electricity onto the grid Tuesday morning, the director of market operations for the Alberta Electric System Operator said chances are “pretty slim” Monday’s power outages will be repeated today.
But he couldn’t rule it out.
“Today we’re in much better shape, we have an additional 1,200 megawatts,” Doug Simpson told the Herald in a morning interview.
“That said, if we have a number of forced outages again, then I guess we could end up in that condition again.”
Lights went out all over Alberta on Monday as utility companies were ordered by the AESO to implement rolling blackouts because demand was exceeding electricity supply.
One coal-fired plant, TransAlta Utilities’ 362-megawatt Sundance 3, went down on Friday but came back on as scheduled at about 3 p.m. Monday.
But by then, four other plants had gone dark and Alberta’s backup power source, the wind generators centred mainly in southern Alberta, were becalmed, producing as little as six MW.
Simpson said Alberta moved to import power from B.C., taking 550 MW, the maximum the import line will hold, and picked up another 50 MW from Saskatchewan, the maximum that province could spare.
Meanwhile, the demand side was headed for the highest summer level on record, spiking at 9,885 MW, 300 MW higher than the previous record of 9,552 set last summer.
Simpson said wind power grew as the afternoon went on, peaking at 180 MW and helping restore the system to balance.
Paul Wright, vice-president of finance for ATCO Power, said Tuesday morning that the 385-MW Battle River 5 coal-fired unit, which went off-line Monday morning, remains dark and will likely stay that way until Thursday until mechanical issues are repaired.
Spot electricity prices spiked at the maximum $1,000 per megawatt-hour on Monday afternoon after trading as low as $11 earlier in the day.
Wright conceded that his company does see a financial gain from those prices, as would all of the generators, but he said speculation by critics that generators worked in concert is not true.
“Our situation is that it was an issue at the plant, it wasn’t anything other than that,” he said. “I can’t comment on other people’s speculation.”
In quick succession in early afternoon Monday, plant outages were experienced at TransAlta’s 406-MW Keephills 1, Capital Power’s 400-MW Genesee 2 and ATCO Power’s 385-MW Joffre CT201.
Capital Power said its plant had an instrument malfunction and automatically shut down, but was restarted quickly and back fully on line by 5:15 p.m.
At Keephills 1, a generator cooling temperature sensor was aggravated by the daytime heat and automatically shut down the unit, according to TransAlta.
Simpson said one other plant, a gas-fired generator at Balzac, also went out late Monday but that happened after the crisis was over and it was a brief outage.