Road transport in the UK generates a quarter of the country’s greenhouse gas (GHG) emissions, a carbon flow attributed to conventional internal combustion engine vehicles (CVs). The international transport sector as a whole also consumes 48% of global oil extractions. If goals for global emissions as outlined by the Paris treaty (a 2016 agreement between 195 nations to agreeing to mitigate GHG emissions) are to be met, an alternative to fossil-fuel powered transport is a necessity.
As electric vehicles begin to gain traction in the British automobile market (a steady increase to 6% of the current market share), this nascent trend has faced early criticism due to the excess greenhouse gas emissions associated with EV production — bringing the climate benefits of EVs into question.
Hailed as zero-emission vehicles, manufacturers claim that electric and hybrid vehicles (EVs) provide a solution to the excessive emissions created by CVs in the road transport sector. However, EVs require manufacturing energy and in many countries still run on electricity that is generated primarily from fossil fuels.
As such, a vehicles’ cumulative life-cycle emissions must be considered to assess the carbon footprint of that vehicle accurately. In this regard, although there are aspects of EV manufacturing and fuel-cycle that can be further refined and optimized to make them more environmentally beneficial, they are certainly an impetus in reducing transport sector emissions.
Lithium-ion Battery Production
The critical aspect to EVs so-called zero-emissions is their reliance on a lithium-ion battery for power. Indeed, this system produces zero tailpipe emissions. The cost of this, however, is manifested in manufacturing these batteries.
Producing lithium-ion batteries requires the energy-intensive processes of extraction and refinement of rare-earth metals. In a 2018 study, The ICCT (International Council for Clean Transport) quantified the impact that lithium-ion battery production has on the total emissions associated with EV production.
The study showed that assuming a vehicle is driven 92,000 miles in its lifetime, EVs produce double the emissions during their production relative to conventional cars (45 grams/mile for the electric vehicle vs 23.5 grams per mile for a standard car).
It is these comparatively high emissions associated with EV manufacture that has brought EV manufacturers the likes of Tesla, Kia and Hyundai under public scrutiny. While it is true that lithium-ion batteries add a high manufacturing cost to EVs, this life-cycle stage of these vehicles is being refined and optimized. Instead of using the traditional fossil fuels, EV battery gigafactories such as the Tesla factory in Nevada, US and a proposed JLR battery factory in the UK utilize renewable primary energy sources such as solar energy to power production. This adaptation, along with reusing the batteries in stationary domestic applications and recycling their rare earth components all serve to reduce the manufacturing emissions of EVs.
Using alternative methods to generate the electricity necessary to power lithium-ion batteries will serve to reduce EV life-cycle GHG emissions further. As nations realign their primary power production methods with the Paris agreement and begin to use renewable energy sources such as hydroelectric, solar or nuclear power, the fuel-cycle costs associated with EVs will diminish, if not altogether vanish.
By conservative estimates, even charging from carbon-intensive electricity grids, EVs offset their higher manufacturing emissions within twenty-four months of driving - and continue to outperform CVs until their disposal.
Fuel-cycle and Use
The cleanliness of an EVs electricity is entirely dependant on the country in which it charges its’ battery. As countries produce electricity with different primary sources, the emissions produced in an EVs’ fuel-cycle directly correlates to the respective countries’ energy production method.
For instance, EVs driven in Norway have zero fuel-cycle emissions, as Norwegian energy is generated primarily by zero-carbon hydroelectric. EVs that charge in France create only 7 grams/mile emissions as France uses nuclear power to produce most of its’ electricity.
Contrastingly, EVs charging in Germany, a nation whose primary energy source is coal, produce 70grams/mile emissions. While the UK is moving towards renewable energy sources, EVs using British power, garnered primarily from burning natural gas, produce 32 grams/mile emissions.
Fundamentally, CVs’s fuel-cycles are limited in the fact that they rely on fossil fuels. The complete CV fuel cycle involves drilling to obtain the crude oil, transporting the raw product to a refinery, purifying the crude oil into petroleum and finally shipping to gas stations for distribution to the public. All taken into account, this fuel-cycle process generates 29 grams/mile for the average European CV to fill its tank with petrol. Whereas fuel efficiency of CV motors will always be fossil-fuel dependent, increasingly clean electricity grids mean the climate emissions of EVs can only decrease.
Another advantage of EVs is that they decouple energy production and use. By doing so, smog and air pollution in vehicle-dense areas can be significantly reduced, thus addressing health issues and microclimates caused by local pollution. This is not to say that electricity generation using fossil fuels becomes any better or worse for the environment, however.
Clearly, with the near-global concession to realign industry and energy production within more environmentally guidelines, the environmental burden posed by EVs will only be reduced, whereas CV fuel cycling will always depend on finite fossil fuels.
Disposal of the vehicles generates similar amounts of GHG emissions. Again, where EVs can potentially outperform CVs lie in the potential to reuse the lithium-ion EV battery in different, less energy-intensive applications such as domestic use or even recycling the rare-earth elements to use in new batteries.
With the impacts associated with a rising global temperature ever more prominent, the decision falls mainly to consumers to change their behaviour to stem the flow of carbon produced by human beings. As EV production and electricity grids move towards renewable, cleaner energy, opting for an electric-hybrid vehicle over a traditional combustion engine car can significantly reduce an individual’s carbon footprint.