Despite being better for the planet and our wallets than a petrol or diesel option, EVs are still a long way from being fully zero carbon. Automakers are starting to tackle the remaining challenges with the goal of making a truly carbon-free car, writes Olivia Wannan.
READ MORE:
* The hidden carbon footprint of electric cars
* Fuel your car for 40 cents ‘per litre’ by going electric, says Transpower
* Young Kiwis choose not to drive to reduce greenhouse gases
NEW PETROL CAR: 40.8 tonnes of emissions
For a new petrol car, more than a quarter of its carbon footprint will be produced before it drives out of the sales yard, according to research led by Victoria University PhD grad Arif Hasan. But its time on the road will contribute nearly all of the rest.
FUEL: 26.8 tonnes of emissions
Petrol contributes just under two-thirds of a car’s lifetime impact.
Traditional combustion engines are inefficient, with only a fraction of the energy actually moving the car. The process creates a lot of planet-heating carbon dioxide: for every 50-litre tank of petrol you buy, your car will produce just over 0.1 tonnes of emissions.
Petrol and diesel also contribute greenhouse gas during the extraction and refining processes.
Today: Switch to electric. (Save 23.7 tonnes – but add 2.8 tonnes in manufacturing = 20.9 tonnes saved)
Electric power will halve a vehicle’s total climate effect in a country such as ours with predominantly renewable electricity. Research has also measured the impact in countries with much dirtier grids, Hasan says. “Even there, electric cars have environmental benefits in the long run.”
Although dry years and peak demand can increase the amount of coal burned to generate electricity, the country’s grid is expected to get greener as new solar and wind farms are built and geothermal power stations start to reinject their emissions.
Because they’re much more efficient, an electric car also saves cash. The cheaper running costs of an EV more than make up for the higher upfront purchase price – even without government subsidies, Hasan says. “A used electric car has the biggest benefit, saving the most money.”
On the horizon: biofuel blends. (Save 1.1 tonnes of carbon)
From next year, the Government wants petrol and diesel stations to mix in a blend of lower-carbon biofuels. Oil companies will need to reduce the average carbon footprint of their fuel by 1.2% in 2023, rising to a proposed 7.4% by 2033.
Across the entire fleet of more than 5 million cars, the policy could save up to 1.1m tonnes of emissions by 2025, according to government estimates. But for an individual vehicle purchased today, biofuel blends aren’t going to make a big dent.
STEEL: 3.4 tonnes
More than 50 per cent of our car is steel – and once fuel is out of the equation, this metal contributes a hefty portion of the remaining carbon footprint.
Metal-making is a dirty business. The iron ore mined from the ground – using fossil-fuelled heavy machinery – must be refined. In ore, iron and oxygen are bonded together, along with impurities. Steel factories burn coal for two reasons: to heat the furnaces above 1500C and to create carbon monoxide. This gas effectively steals oxygen molecules away from the metal, leaving it pure and ready to be made into steel – but in doing so forms planet-heating carbon dioxide.
RICKY WILSON
Steelmaking factories are a notable contributor to national – and global – carbon dioxide emissions.
All up, 553 iron and steelmaking factories – making metal for cars, building materials and containers – contribute around 3 billion tonnes of carbon dioxide each year, or roughly 9 per cent of global emissions. That’s more than the collective footprint of India’s 1.4 billion people.
Today: Switch to recycled steel. (Save up to 1.7 tonnes)
Typically, a new car contains about 25% recycled steel. Reusing steel reduces the emissions associated with mining and shipping the metal. Steel recycling factories use electric arc furnaces – and these recycling ovens require less energy and can be powered by renewable power generation.
BMW promised to boost the amount of recycled steel it uses in its new vehicles – from about a quarter today to half by 2030. Its recycled steel will be made in European factories powered by renewable electricity.
On the horizon: zero-carbon steel
The German automaker is also investing in zero-carbon virgin steel. A number of other European carmakers are also investing in this.
Swedish-born carmarker Polestar is aiming to make a climate-neutral car by 2030. As part of this, it’s paired with a company that last year produced the world’s first fossil fuel-free steel prototype.
Instead of using coal and carbon monoxide to steal the oxygen atoms, steelmaker SSAB used hydrogen gas – which can be made from water and electricity. The company is also converting to electric arc furnaces, and hopes to be selling its green steel to customers including Polestar from 2026.
EV BATTERY: 3.0 tonnes
The lead-acid starter battery in a traditional petrol car is a tiny fraction of the carbon footprint of the lithium-ion version powering an EV. Lot of energy is consumed extracting minerals and manufacturing them at high temperatures.
Currently, more than three-quarters of all EV battery factories are in China, where high-polluting coal is a major energy source.
On the horizon: cleaner assembly
To supply the growing demand for electric cars, European automakers are putting billions into battery-assembling factories closer to home. BMW is helping to build a gigafactory in Skellefteå, Sweden to be powered entirely with wind and hydro generation.
Volkswagen is setting up similar factories in Germany and Spain, and estimates green power could reduce a battery’s total emissions by about 40%. The car giant is also investing in battery recycling in Europe, estimating 90% of materials could be re-used.
GLASS: 0.04 tonnes
Like metal, virgin glass has a double carbon footprint. Fossil fuels often power the furnaces, producing the very high temperatures required. The chemical reactions between the ingredients are another source of carbon dioxide.
In theory, glass can be recycled endlessly. But practically that’s harder to do. Most glass in our day-to-day lives contains a minority of virgin material.
Vehicle glass also must meet performance standards. To protect occupants, windscreens are made out of safety glass. This material is typically heated and cooled in a particular way to toughen it, and is laminated with plastic to help prevent it from shattering.
It’s challenging to separate materials and get rid of all the impurities when sorting used glass – that’s not such a problem when you’re producing beer bottles but is far more of an issue when you’re making windows for a brand-new car.
On the horizon: carbon-neutral glass
Earlier this year, a French glassmaker created the first zero-carbon glass, made from 100% recycled material and powered by 100% renewable electricity.
The company, Saint-Gobain, has paired up with automaker Audi to see if it can do the same thing with cracked car windows. The carmaker will collect unrepairable windows, via its dealerships. A sorter will then separate the glass from the plastic laminate, plus the associated metal and built-in antenna wires, leaving ultra-pure glass sand. Saint-Gobain will then use the sand to make new windows for Audi’s electric cars.
SHIPPING: 0.3 tonnes
Since the death of the domestic car-making industry, all of our vehicles are delivered by fossil-fuel-burning freighters.
Sea freight is a relatively efficient form of transport. A solitary person flying from Japan – where the largest share of our new and used cars come from – to Aotearoa produces the equivalent of nearly 1.7 tonnes of carbon dioxide. The journey for a 1500kg vehicle by sea creates less than a fifth of that.
Even so, the shipping sector produces more than 1 billion tonnes of greenhouse emissions every year, nearly 3% of the world’s emissions footprint. Ships typically run on a low-grade sludge known as fuel oil – when burnt, the fuel produces greenhouse gases carbon dioxide and nitrous oxide.
Sean Gallup/Getty Images
Because all new cars are imported into New Zealand, shipping adds to the vehicles’ lifetime footprints.
No country takes responsibility for the emissions associated with international shipping. Instead, the International Maritime Organisation aims to reduce the average per-kilometre emissions by 40% by 2030.
Electricity may be a viable low-carbon fuel for ferries – but batteries cannot yet store enough power for cargo ships that spend weeks at sea (though they can make these journeys more efficient).
Already, it’s possible to build freighters capable of running on zero-carbon fuels such as ammonia and methanol. But these fuels simply aren’t available: no one has an economic way to mass produce, transport and store them.
There is one current solution: slow steaming. Ships that slow down by between 10 and 20% can reduce their emissions by roughly one-third.
Today: Buy an ebike. (Save at least 18.8 tonnes)
Smaller is better when it comes to emissions. With a larger battery, plus more steel and glass, electric SUVs and utes will have a larger impact than an e-hatchback.
For the same reason, it’s worth considering Aotearoa’s most popular electric vehicle: the bike.
Per kilometre, an ebike produces one-twentieth of the emissions of a petrol car, according to one study.
Ebike owners may still keep their car for longer journeys or rainy days. But even if a new e-cyclist only rides recreationally, they’ll still reduce their climate impact by nearly half, the researchers calculated. The carbon savings increase the more the bike is used, the research found.
MARTIN DE RUYTER/STUFF
Frank Witowski produces carbon fibre e-bikes powered by solar panels at his company’s Nelson base.
Bikes manufactured locally – with Aotearoa’s greener electricity – would have an even greater impact, says Ralph Sims, a co-author of the study. Cargo and covered ebikes should resolve many people’s lingering doubts about carrying bags and staying dry(ish).
With ebikes in the shed, city residents will increasingly replace their private cars with car-sharing memberships, Sims says.
“Why would anybody want to own a car? They are expensive, when you pay your registration and insurance,” he adds. “You could just borrow one when you wanted them, and then re-park them… Nobody should need to own a car.”
The figures were calculated by Stuff, based on published research and emissions factor data and are intended to illustrate key concepts.
