Analysis: Are EVs really better for the planet?

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Words: Nile Bijoux
2 Jul 2019

Managing the Autocar social channels and editing the news, I’ve noticed one discussion keeps cropping up in the comments section. It’s the debate for and against the environmental impact of electric vehicles, particularly around battery production and what happens to them after they have served their time in an EV.

Let’s start with manufacturing. A common argument negating an EV’s green credentials is that making a battery produces more pollution than building conventional internal combustion engines. While it is true that both extracting and using the rare earth metals required to build batteries produces carbon emissions, it’s also important to look at where the batteries are being manufactured.

The International Council on Clean Transportation (ICCT) published a study last year that found the country of origin for batteries has an impact on emissions. According to the report, Chinese-built batteries produce, on average, up to 60 per cent more CO2 during fabrication than Chinese-built combustion engines. However, if the Chinese adopted American or European manufacturing methods, they could reduce these emissions by as much as 66 per cent, figures backed by a separate article published in Science Direct. That would bring pollution from the extraction and production of batteries down to similar levels emitted during the manufacturing petrol or diesel engines.

There’s also the matter of wastage during battery production. According to a recent report, Panasonic ditches enough material to build half a million batteries each day as a result of manufacturing techniques that result in contaminated and faulty products.

Where the EV gains its green and clean badge is during its usage phase. It’s difficult to deny that electric vehicles put less of a burden on the environment when compared with ICE-powered cars. The ICCT claims that electric vehicles typically have much lower life-cycle greenhouse gas emissions than a typical car in Europe, even when assuming relatively high battery manufacturing emissions. That said, ICE-powered vehicles continue to clean up their act, and thanks to lower prices and more convenient and faster refuelling methods, remain the people’s choice of transport.

According to the ICCT: “An average electric vehicle in Europe produces 50 per cent less life-cycle greenhouse gases over the first 150,000 kilometers of driving, although the relative benefit varies from 28 per cent to 72 per cent, depending on local electricity production.”

As for Japan and South Korea, where the bulk of lithium-ion batteries are produced, between 25 per cent and 40 per cent of their electricity is generated by coal which brings down the net benefit. The top three means for electricity production in the European Union in 2016 were renewables (951.4 terawatt hours), nuclear (839.7tWh) and coal/lignite (691.7tWh).

Meanwhile, New Zealand generates the bulk of its electricity through hydroelectric means. In 2017, NZ produced 42.9tWh of electricity, just over half of this from hydroelectric, the remaining generation coming from a mix of geothermal, wind, gas, coal and other renewables like solar. According to the Ministry of Business, Innovation and Employment, renewable electricity generation rose to 85 per cent in 2017, a 35 year high.

There is another piece to the puzzle. What happens to the batteries when they’re discarded?

Most manufacturers will say their batteries are good for somewhere between 100,000km and 150,000km or around ten years but this is usually a best-case scenario. After this, they not only hold less juice but begin losing charge faster and so need to be replaced. At this point the batteries have around 70 per cent of their original capacity left. That means that while they aren’t fit for vehicular use any more, they can still be used in other areas. Here in New Zealand, members of the Motor Industry Association (MIA) have committed to a code of practice to have suitable systems in place for the use, capture, return, refurbishment, reuse, recycling or disposal of EV and hybrid batteries, with the aim that no batteries end up in landfill.

Unfortunately, this isn’t a global effort and one report estimates that there will be 11 million tonnes of batteries in the world that will require disposal by 2025.

Recycling seems a logical solution, but it’s not a financially sound model at present. Recycling a battery costs around €1 per kg. But the value of raw material reclaimed is only a third of that. Recycling lithium costs five times as much as extracting virgin material. Hence, only five per cent of lithium-ion batteries are recycled in Europe.

As recycling systems become more efficient, these numbers will change, especially as we figure out better ways to power BEVs. Solid state battery technology is nearing, which should reduce the reliance on rare-earth metals like lithium and cobalt.

According to the ICCT report, production of recycled aluminium creates approximately 95 per cent less greenhouse gas emissions compared with producing the same amount from raw materials. A separate report listed several potential battery recycling pathways that could be implemented in the near future and identifies potential net savings of 1–2.5 kg CO2 per kg of battery recycled. This would translate to between a seven and 17 per cent net reduction in battery life-cycle emissions. However, as some recycling processes use substantially more energy, the process and location of recycling will affect the total savings in emissions

So, are battery electric vehicles better for the environment than internal combustion vehicles? Yes, they are.

During their useful life, EVs produce considerably lower emissions than petrol or diesel-powered vehicles even when taking into account electricity generation. One study found that an electric car powered by electricity generated by an exclusively coal-fired grid roughly equalled the carbon emissions of an ICE-powered vehicle. As battery production gets more efficient, pre-vehicle carbon emissions will reduce too, especially as dirtier plants adopt cleaner methods. Even taking into account current practises, higher emissions from battery production are paid off after two years on the road compared with a conventional vehicle.

The final hurdle will be dealing with the incoming wave of used batteries in the next decade or two.

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