CO2 impact of plug-in vehicles questioned

The sometimes marginal CO2 advantage of electrified vehicles over those with conventional internal combustion engine (ICE) drivetrains has been amplified by two recent studies.

Swedish-Chinese EV manufacturer Polestar has revealed that its first electric vehicle (EV), the Polestar 2, has a bigger CO2 footprint in its production phase than an equivalent ICE vehicle and will take at least 50,000km to redress the balance.

Meanwhile, analysis compiled by British pressure groups Greenpeace and Transport and Environment has questioned the environmental benefit of plug-in hybrid vehicles (PHEVs).

They claimed PHEVs can emit as much as two-and-a-half times more CO2 than official tests.

They found PHEVs emit a real-world average of 120g/km of CO2 – or about two-thirds the average orthodox petrol or diesel vehicle – rather than the claimed 44g CO2g/km figure based on lab testing.

The results were based on ‘real world’ data collected from around 20,000 PHEVs in Europe. Their drivers either recorded fuel consumption themselves or it was recorded automatically because they are company or leased vehicles.

Critically, the analysis found some PHEV drivers relied heavily on the ICE powertrain and didn’t recharge the electric motor, negating the 20-40km of emissions-free running it could provide.

The British motor industry criticised the analysis because it uses emissions data that is two years old.

Greenpeace described PHEVs as "the car industry's wolf in sheep's clothing".

"They may seem a much more environmentally friendly choice," Rebecca Newsom, the pressure group's head of politics told the BBC, "but false claims of lower emissions are a ploy by car manufacturers to go on producing SUVs and petrol and diesel engines."

Polestar, meanwhile, has revealed its newest EV generates a 26-tonne carbon footprint compared to the XC40’s 14 tonnes in the manufacturing phase, mainly due to the energy-intensive battery production process.

Once the Polestar 2 reaches customers, if charged with green energy, further carbon-dioxide equivalent emissions (CO2e) are negligible. After 50,000 km of driving, the fossil fuelled car surpass the EV in total CO2e emissions.

However, that’s a best-case scenario based on using wind power. On what Polestar calls a global power mix, the CO2e breakeven is 112,000km and on a European power mix it’s 78,000km.

Australia’s coal-biased power grid would presumably make its CO2e, a term describing different greenhouse gases in a common unit, much greater.

As of this week Polestar has started publicly revealing a headline number that shows the climate impact of EVs as they leave the production line and the total climate impact of its cars over their lifecycle.

At the same time, Polestar called on the rest of the automotive industry to join it in publishing the full climate impact of their vehicles.

“Car manufacturers have not been clear in the past with consumers on the environmental impact of their products,” said Thomas Ingenlath, Polestar CEO.

“That’s not good enough. We need to be honest, even if it makes for uncomfortable reading.”

The five-door Polestar 2 fastback is now on sale in North America priced from $US59,900 and will also become available in Australia.