Electric cars could boost CO2 emissions in some provinces

Trying to go green by replacing your gas guzzler with an electric car? In some provinces, that may actually be worse for the environment, a University of Toronto researcher says.

In Alberta, Saskatchewan and Nova Scotia, electric cars generate more carbon over their lifetimes than gas-powered cars, said Chris Kennedy, a professor of civil engineering at the University of Toronto, in an interview with CBC's The Current Tuesday.

The Current24:59Switching to an electric car isn't always good for the environment - March 24, 2015

Powering an electric car may be just be an electrical socket away but electricity as fuel may actually be more laden with green house gases than filling up at a gas station. And in some provinces research shows electricity is dirtier than oil.

• Hear the full interview on The Current

That's because those provinces generate much of their electricity by burning coal, so consuming more electricity – by charging your electric car battery, for instance – significantly boosts carbon emissions.

"So… literally, if you're living in Alberta, Saskatchewan or Nova Scotia, an electric car does not make you green?" asked Anna Maria Tremonti, host of The Current. "You're better off filling up at the pump?"

"You're better off filling up at the pump," Kennedy agreed. "Or if you really want to go for something greener, you should be buying a conventional hybrid car."

However, in the rest of Canada, driving an electric car is the greener choice, he found.

He figured that out by looking at the carbon emissions generated by gas and electric cars over their entire life cycle, taking into account the source of electricity used to charge their batteries and how the gas used to fuel a conventional car is produced in different parts of the world.

The carbon emissions from electricity generation are measured in tonnes of CO2 emitted per gigawatt hour of electricity produced. That ranges from:

• Close to 0 for hydroelectric, nuclear and renewable energy.
• 500 to 600 for natural gas power plants.
• 1,000 for coal-fired power plants.

For a given country or province, if average emissions were under 600 tonnes of CO2 per gigawatt hour, then switching from conventional to electric cars, buses and trucks will lead to a reduction in carbon emissions, Kennedy reported in a study published in the journal Nature Climate Change earlier this month.

In some Canadian provinces, that reduction in emissions can be quite dramatic – B.C., Quebec, Manitoba, and Newfoundland all produce less than 20 tonnes of CO2 per gigawatt hour of electricity, so driving an electric car can reduce emissions to close to zero.

Ultimately, however, the study's goal isn't to help consumers make decisions about what car to buy, Kennedy said.

The take-home message is actually for governments in some Canadian provinces and other countries: That they need to get their average emissions below the 600-tonne threshold so they can benefit from technology like electric cars.

"Electrification," he said, "is the most pivotal strategy for reducing greenhouse gas emissions worldwide."