How Green are Electric Vehicles?

More and more people are into electric vehicles, reported by the Federal Chamber of Automobile Industries. Over the past five years, the number of sales of electric vehicles has increased slowly but steadily as Australian consumers perceive electric cars to be greener and more environmentally friendly than cars fuelled by petrol, diesel or other traditional fuels.

It is true that electric vehicles have zero emissions on-road, whereas conventionally fuelled cars emit carbon dioxide when fuel is combusted in their combustion engine. For example, a car with a fuel economy of 10L/100 km requires 10 litres of petrol to travel 100 km, which will emit around 23 kg of carbon dioxide, as combustion per litre of petrol emits about 2.3 kg of carbon dioxide.

Although electric vehicles have zero tailpipe CO₂ emissions, the electricity they use to power the vehicle must be generated somewhere, and this will cause CO₂ emissions. The Green Car Guide gives data on fuel lifecycle emissions for all types of vehicles, and measures emissions from both production and combustion of fuel. Not only does fuel lifecycle emissions take into account the direct tailpipe emissions, it also considers emissions from fuel extraction, refining and transportation. Therefore, this approach more accurately estimates the environmental impact of a car, giving a fairer, more consistent comparison across vehicle types.

From a fuel lifecycle emissions perspective, an electric vehicle may not be the greenest choice. A conventional small car, say Toyota Corolla (2L 4cyl Petrol 91RON, 1 Spd CVT, 4-door 5-seat Hatch, 2WD, Released: 2018), has a fuel lifecycle emission of 163 g/km CO₂, whereas a small electric car, say BNM i3 (BMW I01 i3 i3s BEV 120Ah Pure Electric, 1 Spd Other, 4-door 4-seat Sedan, 2WD, Released: 2019), has fuel lifecycle emissions of up to 130 g/km CO₂, according to the Green Vehicle Guide. A hybrid Toyota Corolla (1.8L 4cyl Electric/Petrol 91RON, 1 Spd CVT, 4-door 5-seat Hatch, 2WD, Released: 2018), however, has the lowest fuel lifecycle emissions among the three types, at only 101 g/km.

In fact, the fuel lifecycle emissions for electric vehicles differ from state to state since the emissions intensity of electricity production varies across states. According to the National Greenhouse Gas Accounts Factors, on average, Australia electricity generation has a greenhouse gas factor of 0.90. New South Wales has a factor of 0.92 kg CO₂ -e/kWh, showing that per kWh generated emits 0.92 kg CO₂ equivalent. The value of the factor ranges from 0.22 (Tasmania) to 1.36 (Northern Territory) across states. The reason the greenhouse gas factor for Tasmania is low is because over 90 per cent of Tasmania’s electricity comes from hydro-electric generation. This suggests that riding an electric car is more environmentally friendly in Tasmania than in New South Wales because the electricity is cleaner in Tassie than in NSW, where over 80 per cent of the electricity is generated by coal.

From 2006 to 2016, the greenhouse gas factor has dropped from 1.03 to 0.90 in Australia. In the next twenty years, if we take decisive steps to transfer from a coal-fuelled economy to a renewables-fuelled economy, electric vehicles will indeed be greener to drive. There might be one day when electric vehicles have truly zero emissions at a life span, but all depends on the electricity generation process.

There are various impacts of the fuel-efficient cars on consumers’ choices, government revenues and, consequently, the environment. The annual fuel costs associated with these three vehicles, Toyota Corolla, BMW i3 and Toyota Corolla Hybrid are $828, $629 and $1,338, respectively. Apparently, consumers pay least if they drive electric cars because in this way the drivers avoid paying fuel excises. Consequently, government gains less revenue from drivers. It might be fairer if the government could tax electric vehicle drivers according to their road usage because they cause as much congestion when driving on busy roads during rush hours as conventional cars and, at the same time, cause negative environmental impacts.

Many European countries, such as Austria, Croatia, Luxembourg, Portugal and Sweden use renewables to generate over 50 per cent of their electricity for home and industrial use. Utilising renewable energy makes electric cars a greener transport alternative in those countries than in Australia. As Australia is committed to reducing carbon dioxide emissions by 50 per cent per capita by 2030 (compared to 2005), electric vehicles will play an important role in achieving this goal if the electricity production becomes progressively cleaner.