SPECIAL REPORT / Electric cars are an axiom of clean transport planning - they produce no tailpipe emissions, little localised air pollution and, potentially, no greenhouse gas output. But as their critics point out, they are only as green as the electricity that they use.
A power supply dependent on fossil fuels will produce greenhouse gas emissions from electric vehicles that are less than - but still comparable to - those from automobiles fitted with internal combustion engines (ICE)
One recent study by environmental scientists at the International Council for Clean Transportation (ICCT) projected that by 2015, a fully-electrified Nissan Leaf would emit 20 grams of CO2 (g/km) if driven in nuclear energy-reliant France, but 114 g/km in the decidedly less green fields of the UK.
A separate research paper by the European Association for Battery Electric Vehicles estimated CO2 emissions from a plug-in vehicle charged in coal-dependent Poland or Luxembourg at approximately 130 g/km – the same as the EU standard for cars with ICE in 2015.
But in the US and China, the ICCT estimates that dirty fumes from a leaf would be even worse, at 136 g/km and 182 g/km respectively.
Such figures are not widely understood, said Greg Archer, the clean vehicles spokesman for the Transport and Environment pressure group.
“There has undoubtedly been some hype about the short-term potential of electric vehicles,” he said, “but that is not to say that in the longer term they will not prove to be a very successful technology.”
“If we want to have a European market for electric vehicles then for environmental consistency, we have to have a progressive decarbonisation of the grid across Europe,” he added.
Carbon intensity levels
At current levels of carbon intensity, a typical European electric car would generate around 80 g/km according to long-standing figures from Eurelectric, Europe’s electricity industry association.
This is around 55-60% below the average emissions from an internal combustion engine but still more than the standard for an average US car in 2025.
However, EurActiv understands that more up-to-date but so far internal back-of-the-envelope calculations by Eurelectric suggest that with technological advances, the current carbon intensity figure for European electric cars may be closer to 62 g/km.
“Obviously no car based on an internal combustion engine will beat this figure,” Gunnar Lorenz, head of Eurelectric’s networks unit, told EurActiv.
“At the moment we only see a very few electric cars [on the roads] but the take off will come later, in 2020 and increase from there. By then, we will have an electricity sector 35% [powered by] renewables."
By 2030, assuming that renewables spur the EU’s energy mix to a carbon intensity of 130 g/kWh, electric vehicles will be emitting less than 30 g/km, Eurelectric believes.
In the meantime, “even the most energy-efficient Opel Astra emits 100 g/km,” said Sophie Tielemans, a policy officer at Eurelectric. “But it is tricky because it is theoretical and very much depends on real driving behaviour.”
Driving in a ‘sporty’ style on a motorway will emit more carbon dioxide, she noted.
“Our key point is that in the long term, as the electricity mix increasingly decarbonises, electric vehicles will only be a win-win situation,” Tielemens said.
Windmills in Barcelona
Last month, to try and bridge the gap between present and future decarbonisation, the first integrated wind-powered electric vehicle charging station was launched in Barcelona.
Built using GE electric vehicle charging technology and UGE wind turbines, more ‘Sanya Skypump’s are expected to be installed in Australia and the United States later this year.
But some environmental scientists say that such schemes may be more successful in meeting marketing needs than environmental ones.
“It doesn’t matter if the windmill is directly next to your charging station,” the ICCT’s Peter Mock told EurActiv. The origin of the electricity being used was more important, and that depended finally on the amount of renewables in the grid, he said.
From the ICCT’s perspective, a more pressing priority is the EU’s alleged bias against considering vehicle size in its carbon dioxide measurements, contrary to practice in the US.
As car manufacturers run out of ‘low hanging fruit’ to tighten their fuel efficiency standards on the way to 2025, size will increasingly loom as an issue, Mock argues, and the issue is pertinent for electric vehicles.
“Electric vehicles are heavier because of their batteries,” he said. Heavier batteries increase energy consumption and, because the space for propulsion systems is limited, restrict the overall energy economy of electric vehicles.
This is exacerbated by a tendency among manufacturers to build heavier batteries as a counter-point to ‘range anxiety’ among electric car users – a fear that their cars may run out of electricity without the possibility of refuelling at a recharging station.
Because of this, Mock argues that the lobby against size-based measurement of CO2 performance is “short-sighted”.
“Reducing the weight of your vehicle would allow you to have a smaller battery - and they are the most expensive part of the current electric vehicle - so in the long run those companies would benefit,” he said.
- By end of 2012: DG Move to publish clean transport communication
- 2013: Review of 2020 target expected to wrap up
- 31 Dec. 2014: EU expected to complete review of targets for 2020 and 2025
- 1 Jan. 2015: 130 grams of CO2 per km target to be enforced across Europe
- 2016: US to introduce 35 mpg standard for all new passenger cars
- 2020: 95 grams of CO2 per km target expected to enter force across Europe
- 2025: European Commission could impose another milestone on the road to decarbonsiation by 2050
- 2025: US to introduce 54.5 mpg standard for all new passenger cars
- 2030: European Commission could impose another milestone on the road to decarbonsiation by 2050