One of the interesting aspects when first observing a battery electric vehicle (BEV) is the absence of an exhaust pipe. This notable exclusion is an obvious clue as to why they offer significant environmental benefits compared to internal combustion engine (ICE) cars: they do not emit CO2 or other noxious substances that pollute the atmosphere and impact public health.
However, ‘tailpipe’ emissions are only part of the answer. Let's look at the key issues and discover why moving to electric vehicles will be a significant benefit to the environment, including how EVs in Australia emit considerably less greenhouse gases than ICE vehicles, even if charged on the current electricity grid.
Why is this important?
The NRMA supports the reduction of Australia’s emissions through the electrification of our transport sector because EVs can limit ecological damage, reduce smog and improve public health.
Emissions have risen sharply over the past three decades in the transport sector, making up about 20 per cent of total emissions, with light vehicles accounting for about half of that. As motorists, our choices play a key role in reducing these emissions.
Since 2018, the proportion of Australians who would consider buying an EV as their next car has stayed at about 50 per cent, according to annual surveys commissioned by the Electric Vehicle Council and the NRMA. This is not surprising given how environmentally conscious Australians are in their daily lives.
The 2021 Clean Energy Australia report, which provides a comprehensive overview of the Australian clean energy sector, notes that one in four households now have solar panels – the highest rate in the world.
If the grid is powered by fossil fuels, how are EVs cleaner?
In Australia, our electricity grid is currently heavily reliant on coal for generation. Despite this, driving a BEV off the current grid is still much less polluting than driving an ICE vehicle.
According to modelling by the NRMA and PwC Australia, an average new ICE vehicle emits around 185 gCO2/km compared to an average new BEV which emits around 98 gCO2/km if charged via the grid. As renewable energy represents an increasing proportion of the electricity mix and battery capacity improves, BEV emissions are estimated to fall to 58 gCO2/km.
Plus, there remains the option of charging off-grid; when charged solely via renewable energy sources (e.g. solar), BEVs emit zero emissions.
Do BEVs produce any emissions while running?
Unlike ICE vehicles that emit a range of particulates, contaminants and gases as a result of the combustion process, at a vehicle level, BEVs only emit heat.
However, they use the same compounds in their tyres and brake pads as other vehicles and these will expel some particles into the environment through normal wear and tear.
What about the manufacturing process?
Like ICE cars, EVs use metals, rubbers, plastics and glass in their construction, which contribute similar levels of pollution during manufacture.
Unlike ICE cars, EVs generally rely on rechargeable lithium-ion batteries to run. The process of making those batteries — from mining raw materials like cobalt and lithium, to production in factories and transportation — is energy-intensive, and one of the biggest sources of carbon emissions from EVs.
Recent studies, including from the Massachusetts Institute of Technology Energy Initiative, have found that while whole-of-life emissions (including production) are still significantly lower for EVs, battery manufacture currently dictates that emissions are greater during vehicle production (between 50 and 75 per cent greater for a mid-size, dedicated BEV compared to an equivalent petrol vehicle).
What about an EV's battery lifecycle?
For end-of-life lithium-ion batteries, reuse recycling is currently possible. Consistent with NRMA policy, leading carmakers and other entities are developing strategic alliances to create a second life market for used EV batteries. Recently, the focus has been on developing large-scale energy storage systems to make use of the capacity that remains in batteries after their use in vehicles.
There appear to be significant, environmentally friendly opportunities ahead. Companies around the world are in a race to improve the efficiency and effectiveness of battery recycling and to craft the next-generation electric vehicle battery that could leapfrog the current lithium-ion battery, improving battery density and efficiency while lessening reliance on rare earth materials.
Energy storage capacity potential
Looking to the future, as more EVs — like the recently reviewed 2021 Nissan Leaf e+ — become capable of bidirectional charging (vehicle to grid technology), the opportunity for EVs to become a dynamic, flexible new energy storage source will eventuate.
In this instance, energy service providers could encourage EV owners to charge up from excess, intermittent sources like solar and wind, and then use the energy stored to power their houses when they need it or sell it back to the grid to support grid efficiency and reliability.
Looking forward, electric vehicles can play a positive role in the energy sector and help to put downward pressure on vehicle running costs and electricity prices.
