Are electric vehicles cleaner than petrol, diesel when run from coal grid?

A particular point of misinformation commonly bandied about by electric vehicle naysayers is that there is no point investing in an EV to reduce carbon emissions if you charge it off a coal-powered grid.

Statements like these muddy the argument for clean transport and confuse the public about a transition that could have a significant impact on carbon emissions, considering that transport accounts for nearly one-fifth of carbon emissions in Australia.

But more importantly, they are also completely wrong.

A recent study published by researcher Ryan Cornell of Harvard University shows that electric vehicles emit less carbon emissions than internal combustion engine (ICE) vehicles even when charged off a largely coal-powered grid.

Using the Argonne full lifecycle model, which accounts for battery and vehicle manufacturing as well as a standardised 150,000 miles (about 240,000km) life, an average ICE vehicle will emit around 69 metric tonnes in its lifetime.

But an EV, in a state like Wyoming which is almost completely powered by coal, will only produce 66 metric tonnes if the vehicle is made by a manufacturer using a grid that is 13% renewables (the US national average).

And of course, the more renewables the better.

According to the abstract from Cornell’s study, “the lifecycle EV carbon emissions for a vehicle powered by the 2016 US grid is 30.82 metric tons, while the emissions for an EV powered by 100 percent renewable energy is 6.3 metric tons.”

And if an EV is made on a 100% renewable grid and charged in a state such as Wyoming, its lifecycle carbon emissions would be around 56 metric tonnes, says offshore wind power and EV expert Professor Willett Kempton.

Kempton, who hails from the University of Delaware, aggregated the data from Cornell’s study into a chart to show the difference between EVs and ICE on different grid mixes (see below).

Comparing Cornell’s data to Australia’s own electricity grid’s state by state, that means that even in NSW, Victoria and Queensland where some 80-90% of electricity is still generated from coal and gas, EVs only emit half the carbon dioxide of ICE vehicles over their entire lifecycle.

Australians are still hesitant to make the switch to electric vehicles, largely because of the higher prices compared to ICE cars, due to high costs of batteries according to recent research from LEK Consulting.

Battery prices are tipped to fall substantially in coming years, but as long as there is confusion about whether EVs will make a difference to carbon emissions, electric vehicles may still struggle to gain popularity in Australia.

One would hope that data like this can help turn misconceptions about electric vehicles around.