Bury the wires? Trim the trees? What Hydro-Qubec could do to prevent another mass outage

One week after freezing rain began accumulating on tree branches, breaking them and leaving hundreds of thousands of Montrealers without power, some 4,000 Hydro-Qubec customers still didn't have electricity on the island.

On Tuesday, in Beaconsfield, a city inMontreal's West Island,tree limbs lay strewn across lawns and residents who still lacked power expressed frustration with the delays.

Georges Bourelle, the mayor of Beaconsfield, surveyed the damage.

"It's way, way too long," he said. "Five or six days is far too long. Now we're at the point where we need to look at the distribution model."

Hydro-Qubec saysthe ice storm crippled its network in some areas, but, unlike during the 1998 ice storm, when the company's large steel transportation structures were toppled by the weight of freezing rain, this time, those structures remained standing.

It was, instead, the neighbourhood-level electrical poles and wires that failed, mainly beneath the weight of falling or sagging branches.

There were thousands of power failures some affecting just a few customers.

One of those customers, Dany Kattar, a Dorval resident whose power was out for nearly a week, sayshe haslost faith in Hydro-Qubec's ability to maintain its network.

"I'm not going to trust Hydro or the government on that," he said. "Promises, promises. I will have a backup, a generator. Imagine this happened in January. It would have been catastrophic, basically."

The ice storm has called into question Hydro-Qubec's ability to withstand future storms even as experts warn that climate change could make such events more frequent.

But how can the state-owned energy provider make its network more resilient?

WATCH| Beaconsfield Mayor Georges Bourelle it's time for change:

This Quebec mayor says it's time to protect the grid from future storms

1 year ago

Duration 4:18

'We have lots of power, but we cannot distribute it,' said Georges Bourelle, the mayor of Beaconsfield, Que. Bourelle said Hydro-Qubec needs to rethink its systems to be more reliable for when storms inevitably hit the province.

Burying wires

The most obvious way to prevent a future ice storm from damagingelectrical wires and breaking distribution poles is to put the infrastructure underground.

Buried electrical wires are, obviously, immune to damage from falling branches and other risks like strong winds.

But it's an expensive process.

Premier Franois Legault said the cost of doing so would be prohibitively high.

"We're talking about $100 billion," Legault said. "We have to be realistic. Maybe for some places, yes, but we have to be realistic."

But Normand Mousseau, the scientific director of the Institut de l'nergie Trottier at Polytechnique Montral, said Quebec should move ahead with the investment by slowly burying the wires, bit by bit.

"Clearly these lines should have been buried and we should have started that 50 years ago," he said. "We open the street all the time [for other repairs]. Burying the lines there would be natural."

Mousseau also suggested passing on the cost of burying wires to builders working on new developments.

But Sylvain Audette, a professor at HEC Montral with expertise in energy policy, warned that such a move could increase the cost of housing at new developments.

"Nobody wants the rate increase, no one wants to pay more income taxes, no one wants to pay more for housing," he said. "Someone has to pay."

Legault said in discussions with Hydro-Qubec, executives had brought up other ways to strengthen the network without burying the wires.

New equipment

In December, Quebec's auditor general's annual report held some prescient information about Hydro-Qubec's preparedness for the type of storm that knocked out power last week.

The report found that power outages had become more common in Quebec over the last decadeand were lasting longer than ever.

The increases were due in part to the failure of aging infrastructure.

Hydro-Qubec acknowledged the problem in a statement at the time, saying that its aging infrastructure was becoming more vulnerable to inclement weather like freezing rain.

In its climate change adaptation plan, released in November, Hydro-Qubec pledged to reinforce some of its transmission lines and to replace wooden poles with stronger composite poles in some areas.

"If you have a fragile network then of course a branch will have more impact than if you have something sturdy," Mousseau said.

Legault said Hydro-Qubec executives suggested one easy way of reinforcing the existing network would be to string additional wires overtop of the current system intended to bear the load of any falling branches.

Cutting trees

The auditor general also flagged that Hydro-Qubec was falling behind on its plans to prune tree branches near its wires.

One way to ensure the reliability of the electrical distribution network would be to remove trees from near Hydro-Qubec wires in general.

But that's not feasible, according to Christian Messier, the Natural Sciences and Engineering Research Council of Canada/Hydro-Qubec research chair on the control of tree growth, because, in a city like Montreal, trees are everywhere.

That may be bad news for the vulnerability of power wires, but Messier said it's a good thing, overall.

"Trees are important for people in cities," he said. "Trees give us shade, obviously They filter the air, they collect water, they prevent flooding, and we know that greenery in cities improves our health."

But Messier and his colleagues are trying to find a way to have trees coexist alongside electrical wires.

That could happen by intervening early in the life of a tree growing near power lines to ensure its branches are divertedaway from the wires.

Messier said he hopesto develop a computer modelling system to map the branches that are growing near wires and identify those that were more likely to break so that workers could be more surgical with what they cut.