With Nova Scotia's reliance on coal, are electric vehicles the greenest option?

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Electric vehicles are being hailed by consumers and government as a sustainable alternative to fuel-powered vehicles, and are gaining popularity across the country.

But some energy and climate change experts say the choice may not be as green as some drivers believe, particularly in coal-dependent Nova Scotia.

"When we talk about the electric vehicle, we have to take into account the emissions from the electricity provider," said Larry Hughes, a Dalhousie University engineering professor whose area of expertise includes energy systems and climate change.

Hughes said when comparing a vehicle with a traditional internal combustion engine and an electric vehicle with a battery, one must weigh the indirect emissions from the electricity provider — Nova Scotia Power, for example — with the direct emissions from a tailpipe.

Hughes said when discussing the emissions of electricity providers, the metric is grams per kilowatt hour. Just like an internal combustion vehicle consumes litres of gas per 100 kilometres, electric vehicles consume an amount of kilowatt hours of electricity per 100 kilometres.

"Ideally, you want to have an electric vehicle that consumes a small number of kilowatt hours per hundred kilometres, because you then take into account the emissions from the electricity provider," said Hughes, a founding fellow of the MacEachen Institute for Public Policy and Governance at Dalhousie University,

"And in Nova Scotia Power's case, they're probably around 600 grams per kilowatt hour."

According to the utility, its 2021 power generation mix was 47 per cent coal, 16 per cent natural gas and oil, eight per cent imported energy, and 29 per cent from renewable sources, mainly hydro and wind power.

Jacqueline Foster, a spokesperson for Nova Scotia Power, said in an email the utility believes it will be "near 60 per cent" renewable energy by the end of this year. It hopes less than 30 per cent of the mix will come from coal at that time.

The utility plans to be 80 per cent renewable by 2030.

Hughes said this means electric vehicles trail hybrids and plug-in hybrid electric vehicles in terms of lowest emissions, "but that is changing as Nova Scotia Power changes its energy mix."

A hybrid vehicle is powered by an electric motor paired with an internal combustion engine. The battery is recharged by the gas-powered engine or through regenerative braking, which results in less gasoline being burned. 

Plug-in hybrid electric vehicles are similar, but the electric battery can be charged using a wall outlet.

Changing energy mix

"That same vehicle that you buy today will become more and more efficient and better for the environment as we continue to green our grid," said Kelsey Lane, a climate policy co-ordinator with the Ecology Action Centre.

Even with the current energy grid mix in Nova Scotia, she said electric vehicles are already 50 per cent more efficient than gas-powered vehicles.

Lane also pointed to Smart Grid Nova Scotia, a pilot project by Nova Scotia Power that allowed people to apply to have a smart charging system installed at their home, to draw power at low-demand times. The aim of this is to further reduce the environmental impact charging EVs has on the utility's grid.

Systemic change

Lane said this is a move in the right direction, but she said the bigger picture of "greening" transportation in Nova Scotia involves systemic change.

"Electric vehicles are still vehicles," she said. "For decades, we've been building Nova Scotia in a way that's car-oriented, in a way that communities are only accessible by privately owned vehicles. And we need to rethink that."

Lane said transportation should be equitable and accessible, whether someone owns a vehicle or not.

"If somebody needs to buy a vehicle, that vehicle should be electric," she said. "But if somebody doesn't need to buy a vehicle and we can support shifting to more sustainable modes through transit passes and active transportation networks and car share, then that's certainly the priority."

Lane also pointed to the environmental harm of EV battery production. To create the lithium-ion batteries housed inside most electric vehicles, lithium, cobalt and nickel are mined. 

"I think we need to be really genuine with the fact that mining does have a severe impact on our environment," she said.

She said it's important for the EV industry to explore how batteries can be recycled and repurposed for battery storage.

Hughes said along with battery production and indirect emissions, there are also issues with accessibility and affordability for lower income people, and infrastructure issues with charging ports and road maintenance. 

"There are always issues with any transportation system," Hughes said. "It's just that we should do everything we can to minimize both the impact on society and on the environment."