The debate about the green credentials of electric cars has been reignited, with new research claiming a rise in electric vehicles could create a shortage in natural resources and further damage to the planet unless we find more sustainable ways to source the metals required to construct battery packs and wiring.
The new study, conducted by a coalition of Canadian researchers, says the transition away from fossil fuels is increasing demand for base metals, with shortages in nickel, cobalt and copper predicted to emerge as early as 2025.
The solution, it says, could lie in the deep sea mining of certain underwater rock concretions that can provide the materials used in electric car battery production without any of the toxic waste.
The study was commissioned by deep sea mining company DeepGreen, which has a vested interest in the proposed method.
According to the research, an electric car with a 75KWh battery and NMC 811 (nickel-manganese-cobalt) chemistry needs 56kg of nickel, 7kg of manganese, 7kg of cobalt and 85 kg of copper for electric wiring.
The problem is, the study claims, these land ores have limited yield and conventional land mining processes produce billions of tonnes of waste while leaking deadly toxins into soil and water.
"The good news is, metals are recyclable and over time, as we build up enough metal stock-in-use to cover our needs, we should be able to cycle and recycle the same stock through the system," the study says.
However, in the meantime, researchers point to a shortfall in metal stock as a potential problem.
The solution, researchers say, is an alternate source of metals known as 'polymetallic nodules' taken deep from the seafloor of the Pacific Ocean.
Also called 'ocean nodules', these rock masses contain high concentrations of nickel, cobalt and manganese and have been described as "effectively an EV battery in a rock".
Above: Ocean nodules.
Unlike their land-ore counterparts, ocean nodules contain no toxic levels of harmful elements and mining them has the potential to generate almost zero solid waste.
Compared with mining the land, ocean nodules deliver 70 per cent smaller carbon footprint, a 100 per cent reduction in solid waste, 94 per cent less land use and 93 per cent less wildlife at risk.
Additionally, they offer lower unit costs compared with land ores, which are more expensive due to smaller supplies and the energy- and personnel-intensive mining requirements they demand.
However, researchers acknowledge the ocean-sourced metals will provide fewer jobs than the traditional land-ore mining industry, but contend these jobs will be "safer and higher-quality".
DeepGreen's research isn't the first of its kind to point to deep sea mining as a way to ensure electric cars remain a viable environmental solution.
According to the BBC, a 2019 European investigation found that meeting the UK's targets for electric cars by 2050 "would require nearly twice the world's current output of cobalt".
"It's readily available on the seafloor, it's almost like potato harvesting only 5km deep in the ocean," EU project head Laurens de Jonge told the BBC.
Behyad Jafari, CEO of Australia's Electric Vehicle Council, says concerns around electric vehicles' impact on resources and the environment have been raised before and work is already being done to circumvent future issues.
"The development of batteries is where EVs have, in the past, been shot in the arm – a few environmental and ethical issues have been raised," Mr Jafari told CarAdvice.
"When it comes to the supply chain of metals there have been questions before about who's digging them up and how, but now that large OEMs and reputable businesses have been put into this domain they've made sure they are reputable sources and are working to provide transparency in that market."
Mr Jafari says studies investigating resource shortages often only account for present-day supply of these metals, which he says does not predict supply in the future. In fact, he says, supplies are likely to increase rather than decline.
"If we look at the pipeline of investment going into making more of those metals, that's actually been scaled back due to concerns of over-supply, not of under-supply," he explained.
While Mr Jafari couldn't speak to the efficacy of ocean nodules as a solution to resource issues, he said the development of electric vehicles will ideally become more environmentally sound as time goes on.
"It's a journey of good, better, best," he said. "You'll hear detractors saying there are still emissions associated with EVs, but compared to what we have today with ICEs, we'll still be in a better position."
MORE: Electric car news