Two university professors have confirmed what most people in the Sault already suspect – Algoma Steel’s electric arc furnace could cause residents’ lights to flicker and power outages, but it’s not the only cause.
“What's happening doesn't sound that surprising given that electric arc furnaces . . . they tend to be very very hard on grids,” said Zeb Tate, an associate professor in electrical and computer engineering at the University of Toronto, in an interview with SooToday.
“Their power consumption changes very fast.”
He compared it to turning on a powerful device in your home.
“I don't know if you've ever noticed when your air conditioner turns on, you may notice slight dimming of the lights in your house.
“That's the same kind of phenomenon but at a much larger scale.”
At a recent council meeting, Robert Brewer, president of PUC Services, said Algoma Steel gets 105 to 110 megawatts of power from a gas plant and 30 megawatts through Hydro One.
Tate said the 30 megawatts would be enough to cause fluctuations in the power that PUC receives from Hydro One.
“The total load in the region looks to be around 250 megawatts, so Algoma's EAF would constitute a significant proportion of the total regional load,” he said.
"It's an interesting illustration how . . . if you're trying to increase sustainability of a operation it can have secondary impacts on others right on the grid," Tate added.
Algoma Steel began using the first of two electric arc furnaces last summer, to significantly reduce carbon emissions and modernize the plant's production capacity.
It replaced the blast furnace technology and coke ovens used to produce steel in Sault Ste. Marie for 124 years.
The electric arc furnace is currently shut down due to issues with Lake Superior Power, the company's gas plant.
In a statement, Hydro One said they continue "to work with Algoma Steel, the Independent Electricity System Operator and PUC Services Inc. to monitor the grid, investigate reported flicker events and support mitigation measures where possible."
SooToday reached out to Algoma Steel on Aug. 10 and yesterday with questions on the electric arc furnace and the company's power usage. No response came in by deadline.
Tate said voltage stability problems in the area could also be a contributing factor to power outages and flickering lights.
He sent SooToday a slide show from a June meeting of the Independent Electricity System Operator working group that described the issues.
“The Sault Ste. Marie 115 kV interface experiences voltage stability issues when both autotransformers at Third Line TS are out of service,” the document says.
There are also issues with power in the region.
“Under certain contingency conditions, thermal overloads may occur at the Algoma interface and are currently managed using a Remedial Action Scheme.
“However, the existing scheme rejects more load than permitted under planning criteria, and under high growth conditions, this issue would evolve into a broader supply capacity need,“ the IESO document says.
John Simpson-Porco, an associate professor in electrical and computer engineering at University of Toronto, said a number of factors could cause flickering lights and power outages.
“I think the specific number 30 megawatts is not very important. It is probably quoted as a peak power that can be drawn directly from the high-voltage system.
“If that is what is agreed to, Hydro One has made sure they can provide it. It does not tell us anything about flickering or outages being more or less likely,” he said.
Outages are almost never caused by just one thing, so they are difficult to assess from the outside, he said.
“The system is well-protected against all of the most probable dangers that could cause a major outage. You usually need two or more factors combining to produce an outage, so absent some other interacting problem, flicker alone is unlikely to result in an outage.”
He said an electrical arc furnace can cause flicker because the power consumption can vary a lot and can change quickly.
“This can be mitigated by having special voltage control equipment, including capacitor banks, Static VAR compensators, and STATCOMs.
“These devices act like shock absorbers, and oppose the fluctuations. So the important question is, what voltage control equipment is currently in service, and is it performing adequately?” Simpson-Porco said.
The IESO report also said electricity demand is expected to grow significantly in the East Lake Superior area, increasing by approximately 140 per cent in summer and 110 per cent in winter over the next five years.
“This growth is primarily driven by industrial developments and broader electrification,” the report said.
