Reality check: Will Calgary’s ebuses stress electrical grid?

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Reality check: Will Calgary’s ebuses stress electrical grid?
WATCH: Calgary city council is moving forward with a plan to electrify 259 transit buses. But there are questions about how the electrification will impact the local power grid. Adam MacVicar reports – Dec 20, 2022

As Calgary councillors consider the city’s bus electrification strategy on Tuesday, there are some that have questioned whether the city’s electrical grid can manage.

The bus electrification strategy aims to replace up to 250 diesel buses with zero- and low-emission vehicles at the end of their life cycle starting in 2023.

A pilot project would first be conducted to determine the feasibility of the electric buses. Around 44 buses will be deployed during the pilot, said city staff.

The bus electrification strategy is part of the city’s climate strategy and will cost $491 million. City staff said they have filed an application to the Canada Infrastructure Bank for a $168 million loan, along with a $223 million grant from Canada Zero Emission Transit Fund (ZETF). The city will fund the remaining $100 million, staff said

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“We are working on a fleet transition plan that looks at many different technologies. Right now, the technology for zero-emission buses is an electric bus,” said Karen Alm, the city’s manager of transit service vehicles.

“We have looked at our route design and we’re confident that these vehicles will be a good addition to our Calgary Transit fleet.”

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But many Calgarians are concerned about the stress the buses will have on the city’s electrical grid.

Albertans were asked to reduce their electricity consumption earlier this month after the Alberta Electric System Operator issued a grid alert. Grid alerts are issued when the power system is under stress and the province prepares to use emergency reserves to meet demand.

But Werner Antweiler, an associate professor at the University of British Columbia’s Sauder School of Business, said the electric buses will not stress the city’s electrical grid.

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According to Antweiler, Calgary’s proposed electrical bus fleet will increase Alberta’s total generating capacity by about 1 per cent. Antweiler’s calculations assumes each electric bus consumes between 1.24 to 2.84 kilowatt-hour per kilometre and only 70 per cent of Calgary’s total fleet is deployed at a given time.

The calculations also assume Calgary uses 50 chargers that all charge at 350 kilowatt-hour.

“It’s not nothing, but it’s not looking like it will overload Calgary’s grid. It takes about 20-30 years to gradually replace the fleet. Plenty of time to upgrade Calgary’s electric infrastructure along the way,” Antweiler said.

Antweiler also said the transition will be taken place gradually, which will help ease the burden on the province’s electrical grid.

“In Calgary, when all the diesel buses reach the end of their life, they will be replaced by electric buses. It’s a very gradual transition. It’s not happening all at once.”

Shahab Nejad, a PhD candidate in transportation engineering at the University of Calgary, said the city must carefully think about its transition strategy.

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“If the city analyzes its deployment strategy and how they buy and sell their electricity supply, the province can plan for an increase in demand on the grid. It shouldn’t be a surprise,” Nejad said.

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Cold temperatures in Alberta strain energy grid

Nejad also said significant infrastructure upgrades are needed in Calgary if the city wants to bring in more than 200 electric buses. The city will need to invest in charging stations and new technology to upgrade bus shelters, roads and existing electric buses when they break down.

However, these infrastructure upgrades are not expected to overload the system if rolled out over time.

“The city needs some investment in infrastructure long term. They are so beneficial,” Nejad said.

“I think the main concern is whether or not the infrastructure will be durable. Is there technology to make sure the buses and stations last at least 50 years?”

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Antweiler said these capital investments will be spread out over time, which may be cheaper for Calgary in the long run.

“Alberta also makes most of its money from delivering its oil to other jurisdiction… Does it make a difference to Alberta’s oil economy if Calgary or Edmonton electrify their fleets? The answer is no,” the economics professor said.

“For every diesel bus that’s being replaced, the capital cost is spread out over a long period of time. And as the cost for batteries become cheaper over time due to innovation and scaling up of production, we’re not looking at a very significant increase in cost.”

Chinta Puxley, senior communications advisor for Enmax, said the company is continually investing in the electric grid to make sure it is safe and reliable.

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“At ENMAX, we are continually investing in our grid – it’s part of our ongoing commitment to ensuring Calgary’s transmission and distribution system is safe, reliable and positioned to meet customer needs, now and into the future,” Puxley said.

“We are working with The City of Calgary on advancing electrification and ensuring the grid can support their needs. ”

Electric buses not a perfect zero-emission solution

However, electric buses are not the perfect zero-emission system according to Nejad. The city will have to dispose of the batteries once they break down, which is part of Calgary’s carbon footprint. A lot of greenhouse gases are generated when batteries are manufactured and recycled.

“That’s not a good number at the moment with current technology, but the good thing is that developed countries are funding more research in improving battery technology,” Nejad said.

“The carbon footprint of batteries have roughly decreased by 30 to 40 per cent in the last 12 years.”

Then there are concerns about winter. Electric buses will need to use more energy to heat their cabins in the winter, which will reduce their capacity to drive further.

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“It takes a lot of battery power to power the cabin of the vehicle. There’s a bit of uncertainty about the battery drainage rates of electric vehicles,” the PhD candidate said.

“Phone manufacturers added an element around your battery so it drains part of its energy to warm the battery, but that’s not a solution for electric vehicle manufacturers because they don’t want to lose their capacity… Unfortunately, the technology isn’t there.”

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