Charging ahead with electric vehicles

Amidst the optimistic growth prospects of renewable energy, it is important to recap that electricity is but a subset of overall energy consumption, instead of accounting for the latter in its entirety. “Greening” electricity generation alone is hence insufficient to mitigate global warming if other components of energy consumption remain heavily reliant on fossil-fuels, most notably in the transport sector which comprises almost one-quarter of all energy-related CO2 emissions (6.7 GtCO2). Given its disproportionate size, the remainder of this blog will focus on understanding how the road transport subsector can contribute towards a global clean energy transition, beginning with electric vehicles (EVs).

EVs were featured across global media outlets less than 2 weeks ago, when UK Prime Minister Boris Johnson announced that selling new petrol and diesel cars in Britain would be banned by 2030. This came as the latest prominent episode amongst numerous EV-related developments this year, following Tesla recording its first annual profit and Hyundai’s official announcement to manufacture EVs in Singapore. As the popularity of EVs continues rising across the globe (video below), it seems appropriate to examine their environmental costs more closely, in response to criticisms which have surfaced.

Although allegations of higher greenhouse gas emissions (GHG) during the EV production phase are scientifically accurate, a more holistic approach would utilize the life-cycle assessment (LCA) to account for overall GHG emissions across its production, operational and disposal stages. LCA conducted for EVs in Europe (illustrated below) portray them far more favourably. Even the worst-case scenario, which assumes lithium-ion batteries (LIBs) produced in China alongside EVs being operated in Poland (amongst the European Union’s most carbon-intensive electricity sources), yields a 22% decrease in lifetime CO2 emissions compared to diesel vehicles. Another LCA conducted in China, which remains heavily-dependent on coal for electricity generation, concluded that life-cycle GHG emissions of EVs are ~18% lower than conventional Internal Combustion Engine Vehicles (ICEV). Most of these improvements stem from the higher efficiency of EVs compared to ICEVs (video below) alongside reduced need for EV maintenance due to fewer moving parts, allowing EVs to have significantly lower GHG emissions during its operational phase even if electricity is generated from fossil-fuels. Vehicle electrification hence proves beneficial for mitigating global warming in most areas studied.

Source: Transport & Environment, 2020: 2

On the flipside, EVs can also harm the environment in several ways. Since producing LIBs requires substantial volumes of rare metals like lithium, cobalt and nickel as inputs, toxic chemicals used during extraction and processing can pollute surrounding land and water bodies if not properly handled, destroying neighbouring ecosystems while poisoning humans. Lithium processing using brine solutions also necessitates large volumes of water loss through evaporation, potentially aggravating water scarcity in dry regions especially when groundwater is overexploited. An overview of environmental impacts from mining is illustrated below. Furthermore, the prevalence of child labour and harsh working conditions in artisanal mines brings the ethics of EVs into question – are environmental problems merely being shifted to the socioeconomically disadvantaged, under the guise of sustainable development?

Source: Sovacool et al., 2020

For their effectiveness in reducing GHG emissions, the negative implications of LIBs dampens my enthusiasm for EVs. Fortunately, EV researchers have demonstrated commendable foresight in targeting these challenges, through technological developments ranging from synthesis of alternative cobalt‐free cathodes for LIBs to extracting lithium from seawater. Alongside rising interest in recycling LIB components beyond high-value metals, I am optimistic that environmental costs of EVs will gradually diminish over time, presenting a clearer choice over ICEVs. Synergies between EVs and renewable energy growth make these prospects exciting indeed!