Climate explained: why switching to electric transport makes sense even if electricity is not fully renewable


Robert McLachlan, Massey University

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to

I have a question about the charging of electric cars. I understand New Zealand is not 100% self-sufficient in renewable energy (about 80%, supplemented by 20% generally produced by coal-fired stations). If I were to buy an electric vehicle it would add to the load on the national grid. Is the only way we are currently able to add the extra power to burn more coal? Does this not make these vehicles basically “coal fired”?

New Zealand is indeed well supplied with renewable electricity. In recent years, New Zealand has averaged 83% from renewable sources (including 60% hydropower, 17% geothermal, and 5% wind) and 17% from fossil fuels (4% coal and 13% gas).

In addition to being cheap and renewable, hydropower has another great advantage. Its production can ramp up and down very quickly (by turning the turbines on and off) during the day to match demand.

Looking at a typical winter’s day (I’ve taken July 4, 2018), demand at 3am was 3,480 megawatts (MW) and 85% was met by renewable sources. By the early evening peak, demand was up to 5,950MW, but was met by 88% renewable sources. Fossil fuel sources did ramp up, but hydropower ramped up much more.

Flipping the fleet

Even during periods of peak demand, our electricity is very clean. An electric vehicle (EV) charged during the evening would emit about 20 grams of carbon dioxide per kilometre.

Even an EV charged purely on coal- or gas-fired electricity still has lower emissions than a petrol or diesel car, which comes to around 240g CO₂/km (if one includes the emissions needed to extract, refine, and transport the fuel).

An EV run on coal-fired electricity emits around 180g CO₂/km during use, while the figure for gas-fired electricity is about 90g CO₂/km. This is possible because internal combustion engines are less efficient than the turbines used in power stations.

Read more:
Climate explained: the environmental footprint of electric versus fossil cars

Looking longer term, a mass conversion of transport in New Zealand to walking, cycling and electric trains, buses, cars and trucks is one of the best and most urgent strategies to reduce emissions. It will take a few decades, but on balance it may not be too expensive, because of the fuel savings that will accrue (NZ$11 billion of fuel was imported in 2018.)

This conversion will increase electricity use by about a quarter. To meet it we can look at both supply and demand.

More renewable electricity

On the supply side, more renewable electricity is planned – construction of three large wind farms began in 2019, and more are expected. The potential supply is significant, especially considering that, compared to many other countries, we’ve hardly begun to start using solar power.

But at some point, adding too much of these intermittent sources starts to strain the ability of the hydro lakes to balance them. This is at the core of the present debate about whether New Zealand should be aiming for 100% or 95% renewable electricity.

There are various ways of dealing with this, including storage batteries, building more geothermal power stations or “pumped hydro” stations. In pumped hydro, water is pumped uphill into a storage lake when there is an excess of wind and solar electricity available, to be released later. If the lake is large enough, this technology can also address New Zealand’s persistent risk of dry years that can lead to a shortage of hydropower.

Read more:
Climate explained: why don’t we have electric aircraft?

Smarter electricity use

On the demand side, a survey is under way to measure the actual charging patterns of EV drivers. Information available so far suggests that many people charge their EV late at night to take advantage of cheap night rates.

If demand gets too high at certain times, then the cost of both generation and transmission will likely rise. To avoid this, electricity suppliers are exploring smart demand responses, based on the hot water ripple control New Zealand began using in the 1950s. This allows electricity suppliers to remotely turn off hot water heaters for a few hours to limit demand.

In modern versions, consumers or suppliers can moderate demand in response to price signals, either in real time using an app or ahead of time through a contract.

New Zealand’s emissions from land transport continue to rise, up by another 2% in 2018 and almost double on 1990 levels.

To address climate change, we have to stop burning fossil fuels. Passenger cars are among the biggest users and also one of the easiest to change. Fossil fuel cannot be recycled or made clean. In contrast, electricity is getting cleaner all the time, both in New Zealand and in car factories.

If you switch to an EV now, your impact is far greater than just your personal reduction in emissions. Early adopters are vital. The more EVs we have, the more people will get used to them, the easier it will be to counter misinformation, and the more pressure there will be to cater for them.

Many people have found that switching to an electric car has been empowering and has galvanised them to start taking other actions for the climate.The Conversation

Robert McLachlan, Professor in Applied Mathematics, Massey University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Electric car sales tripled last year. Here’s what we can do to keep them growing

Gail Broadbent, UNSW and Graciela Metternicht, UNSW

A total of 6718 electric vehicles were sold in Australia in 2019. That’s three times as many as in 2018, but it’s still small beer. More than a million fossil-fueled light vehicles (including SUVs and utes) were sold in the same period.

The sales figures were published in the wake of UK Prime Minister Boris Johnson’s announcement that sales of petrol or diesel cars will be banned in the UK by 2035. The UK’s isn’t the only right-of-centre government to see the benefits of going electric — in 2016, New Zealand’s Conservative party introduced a wide-ranging program to encourage drivers to get off fossil fuels.

If Australia wants to head in the same direction, we can learn from what others have done.

Why should we go electric? And why don’t we?

The main argument for electric vehicles is often about cutting greenhouse gas emissions. But even leaving those aside, there are plenty of reasons to move away from oil as an energy source for transport, among them energy security, better health outcomes, and spending less money on petrol imports.

Read more:
Don’t trust the environmental hype about electric vehicles? The economic benefits might convince you

Australians have been slow to adopt electric cars, however. Our previous research indicates the top two reasons are the fear of not being able to find a fast recharger on long trips (“range anxiety”), and the higher purchase price of electric cars.

Obstacles are clearing

Range anxiety should be on the decline. Fast rechargers are beginning to be installed on major routes and higher capacity batteries are increasing vehicle range. In any case, the average distance travelled by Australians is just 34.5km per day.

Prices for electric vehicles are also on the way down. Bloomberg has predicted that larger electric and fossil-fueled cars will cost about the same in Europe as soon as 2022.

Even when upfront costs for electric vehicles are higher, ongoing costs are generally much lower. An average Australian car travels 12,600 kilometres in a year, consuming 1360.8 litres of fuel at a cost of about A$2,000 (assuming fuel costs $1.50 per litre). For a typical electric car, the same amount of travel would cost $250 if recharging using off-peak electricity (assuming it costs 11 cents per kilowatt hour), or $567 if recharging with more expensive electricity (at 25 cents per kilowatt hour).

Lessons from New Zealand

In 2016, New Zealand’s Conservative transport minister Simon Bridges introduced a suite of policies to encourage electric, especially for passenger vehicles. Since then, electric vehicle sales have been doubling every 12 months.

In 2019, 6545 light electric vehicles were brought into New Zealand and registered for the first time. That’s not far off Australia’s tally, but in a population of 5 million compared to Australia’s 25 million.

So what did the Conservatives do to encourage motorists to go electric? They took advice from the experts and introduced a multi-faceted group of measures.

Read more:
Australia’s ‘electric car revolution’ won’t happen automatically

These included: exemption from the Road User Charge, worth about $600 per year; government procurement programs; installing a public recharging network; investment in a five-year promotional campaign including TV ads, online information and “ride and drive” events. They also established a leadership group across business and government and a funding scheme to encourage organisations to go electric.

In NZ they have just about thought of everything, even ensuring there is a facility to recycle old batteries.

But possibly the most important factor has been that the government has enabled imports of high-quality secondhand electric cars from Japan. In 2019 they accounted for more than half of electric vehicle sales (4155 used compared to 2390 new).

This measure enables motorists with lower budgets to buy electric vehicles. Our unpublished research shows electric vehicles have been especially popular with multicar families who use their EVs as much as possible as it’s so much cheaper than using petrol or diesel. When those happy customers tell their friends and family about how much better it is to drive electric, it’s an important feedback loop that helps people overcome their fear of change.

Maybe it’s time Australia took a “Leaf” out of the Kiwi book and got on board with some sensible policies and legislation to speed up the transition to electric cars.The Conversation

Gail Broadbent, PhD candidate Faculty of Science UNSW, UNSW and Graciela Metternicht, Professor of Environmental Geography, School of Biological Earth and Environmental Sciences, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Wrong way, go back: a proposed new tax on electric vehicles is a bad idea

Jake Whitehead, The University of Queensland

In recent years, false claims have circulated that electric vehicles are “breaking our roads” because they don’t use fuel and so their drivers don’t pay fuel excise.

Heeding such concerns, both the Victorian and New South Wales governments are reportedly considering a new tax for electric vehicles. It follows a report by Infrastructure Partnerships Australia which recommended a per-kilometre tax for electric vehicles.

Read more:
Don’t trust the environmental hype about electric vehicles? The economic benefits might convince you

But this shortsighted approach risks killing the golden goose of our transport system. Such a tax would limit the economic, health and environmental benefits promised by electric vehicles which, together, far exceed any loss in fuel excise.

Instead, Australia needs a mature public discussion about holistic road tax reform to find a fair and sensible way forward.

Electric vehicle owners do not incur petrol costs.

The problem is structural

Fuel excise is built into petrol and diesel prices, charged at around 40 cents per litre. For more than 20 years – well before the introduction of electric vehicles – net fuel tax revenue has been declining, largely due to improvements in vehicle efficiency, meaning engines use less fuel.

But if we take into account fuel tax credits – subsidies for fuel used in machinery, heavy vehicles and light vehicles on private roads – gross fuel tax revenue has actually increased in recent years.

This suggests the tax suffers from a structural problem. Simply applying a new tax to electric vehicles won’t fix it.

Read more:
Australians could have saved over $1 billion in fuel if car emissions standards were introduced 3 years ago

It’s also worth remembering that while electric vehicle owners don’t pay fuel excise, they generally pay more in purchase taxes such as GST, because their vehicles tend to be more expensive to buy.

The federal government should encourage uptake of electric vehicles.

Benefits of electric vehicles

Electric vehicles help reduce our dependency on foreign oil and save owners over 70% in fuel costs by swapping petrol for electricity. Electric vehicles also lead to cleaner air, resulting in significant savings in health costs. They create new local jobs in mining and local energy, and importantly, are key to meeting global climate change targets.

Read more:
Clean, green machines: the truth about electric vehicle emissions

Comparison of annual road accident fatalities vs premature deaths due to vehicle emissions in NSW.
Asthma Australia/Electric Vehicle Council.

An electric vehicle tax would increase costs for motorists, curb sales and may even encourage the purchase of cheap, fuel-efficient vehicles, driving fuel tax revenue down even further.

Congestion is the bigger problem

The proposed taxes will do nothing to tackle the biggest problem with Australia’s transport system: road congestion.

Sweden, where I lived for several years, offers a possible way forward. In 2006, the city of Stockholm introduced a congestion pricing scheme which charged vehicles for driving in and out of the city centre at peak times.

Read more:
Traffic congestion: is there a miracle cure? (Hint: it’s not roads)

The scheme meant normal weekday traffic was considerably lighter. Low-emission vehicles were also temporarily exempted from the charge to encourage sales.

Unfortunately, despite the proven benefits, Australia is unlikely to introduce such a scheme due to a lack of public and political support.

Towards a sustainable road tax

The transport sector faces massive disruption in the near future, from electrified vehicles, automated vehicles, and the shift to shared vehicles.

Focusing solely on electric vehicles misses the broader point: we need to proactively prepare for the transition to a new transport system. This means ditching our unfair, outdated and unsustainable road tax model while reducing congestion.

Read more:
Utopia or nightmare? The answer lies in how we embrace self-driving, electric and shared vehicles

Instead of simply penalising electric vehicle owners, I suggest an approach where electric vehicle owners could voluntarily opt-in to a new road tax model. Here’s how it would work:

  • the tax would include a low per-kilometre fee for all travel, and an additional fee for inner-city travel during peak weekday periods

  • in exchange for opting in, owners would be exempted from the old road tax system, that is: vehicle registration, stamp duty, import tax, luxury car tax, fringe benefits tax, fuel excise, and road tolls.

  • to ensure a true financial incentive to opt-in to the new road tax model, a significant discount would initially apply. This discount would gradually be phased out as electric vehicle uptake increases, as has occurred with similar overseas schemes

  • the new road tax model could easily be extended in the future to apply to automated vehicles, and to more accurately reflect the burden transport poses in terms of congestion and pollution.

Read more:
Here’s why electric cars have plenty of grunt, oomph and torque

This is just one example of a balanced approach that would encourage both local adoption of electric vehicles, and public support for fairer road taxes.

Such holistic reform would enable a future transport system with less road congestion, quicker travel times, cleaner air, lower costs and a sustainable road revenue stream.

Let’s be smart and not miss this golden opportunity.The Conversation

Jake Whitehead, Research Fellow, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate explained: the environmental footprint of electric versus fossil cars

The best way to compare emissions from electric cars is to assess all phases of a life cycle analysis.
from, CC BY-ND

Md Arif Hasan, Victoria University of Wellington and Ralph Brougham Chapman, Victoria University of Wellington


Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to

There is a lot of discussion on the benefits of electric cars versus fossil fuel cars in the context of lithium mining. Please can you tell me which one weighs in better on the environmental impact in terms of global warming and why?

Electric vehicles (EVs) seem very attractive at first sight. But when we look more closely, it becomes clear that they have a substantial carbon footprint and some downsides in terms of the extraction of lithium, cobalt and other metals. And they don’t relieve congestion in crowded cities.

In this response to the question, we touch briefly on the lithium issue, but focus mainly on the carbon footprint of electric cars.

The increasing use of lithium-ion batteries as a major power source in electronic devices, including mobile phones, laptops and electric cars has contributed to a 58% increase in lithium mining in the past decade worldwide. There seems little near-term risk of lithium being mined out, but there is an environmental downside.

The mining process requires extensive amounts of water, which can cause aquifer depletion and adversely affect ecosystems in the Atacama Salt Flat, in Chile, the world’s largest lithium extraction site. But researchers have developed methods to recover lithium from water.

Turning to climate change, it matters whether electric cars emit less carbon than conventional vehicles, and how much less.

Read more:
Climate explained: why don’t we have electric aircraft?

Emissions reduction potential of EVs

The best comparison is based on a life cycle analysis which tries to consider all the emissions of carbon dioxide during vehicle manufacturing, use and recycling. Life cycle estimates are never entirely comprehensive, and emission estimates vary by country, as circumstances differ.

In New Zealand, 82% of energy for electricity generation came from renewable sources in 2017. With these high renewable electricity levels for electric car recharging, compared with say Australia or China, EVs are better suited to New Zealand. But this is only one part of the story. One should not assume that, overall, electric cars in New Zealand have a close-to-zero carbon footprint or are wholly sustainable.

A life cycle analysis of emissions considers three phases: the manufacturing phase (also known as cradle-to-gate), the use phase (well-to-wheel) and the recycling phase (grave-to-cradle).

The manufacturing phase

In this phase, the main processes are ore mining, material transformation, manufacturing of vehicle components and vehicle assembly. A recent study of car emissions in China estimates emissions for cars with internal combustion engines in this phase to be about 10.5 tonnes of carbon dioxide (tCO₂) per car, compared to emissions for an electric car of about 13 tonnes (including the electric car battery manufacturing).

Emissions from the manufacturing of a lithium-nickel-manganese-cobalt-oxide battery alone were estimated to be 3.2 tonnes. If the vehicle life is assumed to be 150,000 kilometres, emissions from the manufacturing phase of an electric car are higher than for fossil-fuelled cars. But for complete life cycle emissions, the study shows that EV emissions are 18% lower than fossil-fuelled cars.

Read more:
How electric cars can help save the grid

The use phase

In the use phase, emissions from an electric car are solely due to its upstream emissions, which depend on how much of the electricity comes from fossil or renewable sources. The emissions from a fossil-fuelled car are due to both upstream emissions and tailpipe emissions.

Upstream emissions of EVs essentially depend on the share of zero or low-carbon sources in the country’s electricity generation mix. To understand how the emissions of electric cars vary with a country’s renewable electricity share, consider Australia and New Zealand.

In 2018, Australia’s share of renewables in electricity generation was about 21% (similar to Greece’s at 22%). In contrast, the share of renewables in New Zealand’s electricity generation mix was about 84% (less than France’s at 90%). Using these data and estimates from a 2018 assessment, electric car upstream emissions (for a battery electric vehicle) in Australia can be estimated to be about 170g of CO₂ per km while upstream emissions in New Zealand are estimated at about 25g of CO₂ per km on average. This shows that using an electric car in New Zealand is likely to be about seven times better in terms of upstream carbon emissions than in Australia.

The above studies show that emissions during the use phase from a fossil-fuelled compact sedan car were about 251g of CO₂ per km. Therefore, the use phase emissions from such a car were about 81g of CO₂ per km higher than those from a grid-recharged EV in Australia, and much worse than the emissions from an electric car in New Zealand.

The recycling phase

The key processes in the recycling phase are vehicle dismantling, vehicle recycling, battery recycling and material recovery. The estimated emissions in this phase, based on a study in China, are about 1.8 tonnes for a fossil-fuelled car and 2.4 tonnes for an electric car (including battery recycling). This difference is mostly due to the emissions from battery recycling which is 0.7 tonnes.

This illustrates that electric cars are responsible for more emissions than their petrol counterparts in the recycling phase. But it’s important to note the recycled vehicle components can be used in the manufacturing of future vehicles, and batteries recycled through direct cathode recycling can be used in subsequent batteries. This could have significant emissions reduction benefits in the future.

So on the basis of recent studies, fossil-fuelled cars generally emit more than electric cars in all phases of a life cycle. The total life cycle emissions from a fossil-fuelled car and an electric car in Australia were 333g of CO₂ per km and 273g of CO₂ per km, respectively. That is, using average grid electricity, EVs come out about 18% better in terms of their carbon footprint.

Likewise, electric cars in New Zealand work out a lot better than fossil-fuelled cars in terms of emissions, with life-cycle emissions at about 333 g of CO₂ per km for fossil-fuelled cars and 128g of CO₂ per km for electric cars. In New Zealand, EVs perform about 62% better than fossil cars in carbon footprint terms.The Conversation

Md Arif Hasan, PhD candidate, Victoria University of Wellington and Ralph Brougham Chapman, Associate Professor , Director Environmental Studies, Victoria University of Wellington

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Clean, green machines: the truth about electric vehicle emissions

Evidence shows electric vehicles have significant economic, social and health benefits.

Jake Whitehead, The University of Queensland

Despite the overwhelming evidence that electric vehicle technology can deliver significant economic, environmental and health benefits, misinformation continues to muddy the public debate in Australia.

An article in The Australian recently claimed that on the east coast electric vehicles are responsible for more carbon dioxide emissions than their petrol counterparts.

The findings were largely attributed to Australia’s reliance on coal-fired power to charge electric vehicles. The report on which the article was based has not been publicly released, making it difficult to examine the claim.

So instead, let’s review the available evidence.

Read more:
Here’s why electric cars have plenty of grunt, oomph and torque

First, let’s get the maths right

Vehicles create two types of emissions: greenhouse gases and noxious air pollution.

Petrol and diesel vehicles produce the majority of emissions when they are being driven. These are known as “tank-to-wheel” or exhaust emissions, and contribute to both climate change and poor air quality.

Then-Labor leader Bill Shorten at an event to announce Labor’s electric vehicle policy ahead of the May 2018 federal election.

Traditional vehicles also generate emissions through the production and distribution of their fuel, known as “well-to-tank” or upstream emissions.

To comprehensively measure a vehicle’s total emissions, we combine upstream and exhaust emissions to obtain “well-to-wheel” emissions, otherwise known as the fuel lifecycle emissions.

Read more:
New Zealand poised to introduce clean car standards and incentives to cut emissions

How electric vehicles stack up

Battery electric vehicles have no exhaust emissions. Their emissions are primarily determined by the upstream emissions: that is, from the production and distribution of the energy used to charge them.

A parking spot allocated to electric vehicles.

In a paper I co-authored late last year, we estimated that the typical Australian petrol vehicle generated 355 grams of CO₂-equivalent per kilometre in real-world fuel life cycle emissions.

By comparison, a typical electric vehicle charged using the average Australian electricity grid mix generated about 40% fewer emissions, at 213 grams of CO₂-equivalent per kilometre.

Even with dirty energy, electric cars are greener

Electric vehicle emissions vary depending on how dirty the region’s electricity is. By applying the 2019 National Greenhouse Accounts Factors to the same methodology used in our journal paper, electric vehicle emissions in each of Australia’s electricity grids were calculated (see Table 1, click to zoom).

Table 1: Real-world fuel lifecycle emission estimates for battery electric vehicles, hydrogen fuel cell vehicles and petrol vehicles, calculated using 2019 Greenhouse Account Factors.
Dr Jake Whitehead

Victoria has the most emissions-intensive grid in Australia due to its reliance on brown coal. However, even in that state, the real-world fuel life cycle emissions of a typical electric vehicle would still be 20% lower than a typical petrol vehicle. In Tasmania, which is dominated by renewable energy, electric vehicle emissions would be 88% lower than a comparable petrol vehicle.

Read more:
Why battery-powered vehicles stack up better than hydrogen

Electric vehicles are less polluting than traditional cars, even in Victoria which is heavily reliant on brown coal to produce electricity.

Size doesn’t matter

Table 2: Fuel lifecycle emissions extracted from the Australian Government’s Green Vehicle Guide (GVG).*
Dr Jake Whitehead
Table 3: Comparison between the relative differences in electric vs petrol vehicle fuel lifecycle emissions from the analysis Green Vehicle Guide emissions data (see part of sample in Table 2) and the real-world estimates from our journal article (see Table 1). The consistency in findings supports the robustness of these conclusions.
Dr Jake Whitehead

Let’s examine four different sized electric vehicles in Australia to see how their fuel lifecycle emissions compare to petrol vehicle equivalents (see Table 2, click to zoom).

Even when large electric cars are charged using Victoria’s grid, emissions are 6-7% lower than a petrol vehicle equivalent.

Using both real-world emissions estimates and Green Vehicle Guide data, the shift from petrol to electric vehicles is shown to deliver a reduction in emissions – no matter where vehicles are charged in Australia (see Table 3, click to zoom).

And of course emissions from electric vehicles will fall further as grid electricity continues to become cleaner.

Read more:
Australians could have saved over $1 billion in fuel if car emissions standards were introduced 3 years ago

Anyway, lots of electric cars don’t need the grid

There is clearly a strong relationship between ownership of both electric vehicles and zero-emission rooftop solar.

In 2018 we surveyed more than 150 electric vehicle owners in Australia (representing 2% of the national fleet). We found that 80% of vehicle charging occurred at home, with 73% of respondents owning rooftop solar systems (compared to an average of 21.6% of homes nationally)).

Victoria Police Inspector Stuart Bailey with the first all-electric vehicle in its operational fleet.
Victoria Police

Additionally, 22% of electric vehicle owners surveyed had stationary battery storage attached to their solar rooftop systems, with another 53% planning to install batteries in the near future.

Five more reasons to embrace electric vehicles:

  1. Cost savings: Electric vehicles are 70-90% cheaper to operate, potentially saving households more than A$2,000 per year.

  2. Economic opportunities: The Australian resources sector is well placed to capitalise on demand for minerals in batteries, such as lithium, and support the deployment of this technology globally using cheap, reliable and locally-produced energy.

  3. Fuel security: Australia is heavily dependent on imported fuels and holds reserves far below the International Energy Agency’s obligated 90-day supply. So the more quickly we transition to electric vehicles, the more secure our transport system will be.

Read more:
How electric cars can help save the grid

4) Grid support: Electric vehicles hold enormous potential to support our electricity grid. If Australia’s 14 million-odd cars were electric, the energy stored in their batteries could power the entire nation for at least 24 hours, while still meeting average driving needs.

Vehicle emissions from petrol and diesel cars drives air pollution and associated illnesses such as asthma.

5) Health benefits: Noxious emissions from traditional vehicles also take a massive toll on our health by contributing to rates of asthma and other chronic illnesses. Vehicle pollution causes an estimated 40% to 60% more premature deaths than road accident fatalities in Australia. Electric vehicles provide a pathway to avoid these deaths.

Even international bank BNP Paribas sees the writing on the wall. In advice to investors last month it outlined that thanks to electric vehicles, the economics of oil for transport was “in relentless and irreversible decline, with far-reaching implications for both policymakers and the oil majors.”

*Note: The Green Vehicle Guide figures in Table 2 are based on a 1997 drive cycle – the New European Drive Cycle or NEDC – which significantly underestimates real-world emissions and efficiency. As a result, Green Vehicle Guide values for all vehicles are lower than the real-world emissions estimates we published in our 2018 paper. Despite this, the relative difference in emissions between electric and petrol vehicles is largely consistent with our estimates – see Table 3 – and therefore these figures are still useful for comparing different vehicles.The Conversation

Jake Whitehead, Research Fellow, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Here’s why electric cars have plenty of grunt, oomph and torque

File 20190414 76846 1zcq5u.png?ixlib=rb 1.1
Nobuteru Taniguc drifting a Tesla Model S in Tokyo, Japan.

Jake Whitehead, The University of Queensland

Australian politicians, including Prime Minister Scott Morrison, have raised the question of electric vehicles’ capacity for “grunt”.

Now I’m by no means a “grunt” expert, but when it comes to performance, electric cars are far from lacking. In fact, Australian electric car owners have ranked performance as the top reason for their purchase choice.

The V8, fuel-guzzling, rev-heads, who are supposedly worried that electric cars mean they will be left driving around golf buggies, should first check out this drag race between a Tesla and a Holden V8 Supercar.

SPOILER ALERT: The Tesla wins, and by a fair amount. Tesla Model S v Holden V8 Supercar v Walkinshaw HSV GTS Drag Race.

Read more:
Don’t trust the environmental hype about electric vehicles? The economic benefits might convince you

Internal combustion engine vs electric motor

Internal combustion engines and electric motors are very different. In an internal combustion engine, as the name suggests, small amounts of fuel are mixed with air, and are exploded to drive a series of pistons. These pistons drive a crankshaft, which is then connected to a gearbox, and eventually the wheels.

This is a rather simplified overview, but there are literally hundreds of moving parts in a combustion engine. The engine must be “revved-up” to a high number of revolutions in order to reach peak efficiency. The gearbox attempts to keep the engine running close to this peak efficiency across a wide range of speeds.

All of this complexity leads to a significant amount of energy being lost, mostly through friction (heat). This is why combustion engine cars are very energy inefficient.

Read more:
Why battery-powered vehicles stack up better than hydrogen

So how are electric motors different? Electric motors are actually pretty simple, consisting of a central rotor, typically connected to a single gear. The rotor is turned by a surrounding magnetic field, which is generated using electricity. The added benefit of this design is that it can operate in reverse, acting as a generator to charge the batteries while slowing down the vehicle (this is called regenerative braking).

On the other hand, the electric motor reacts instantly as soon as the accelerator is pushed. Given the minimal moving parts, electric motors are also highly reliable and require little to no maintenance. Their simplicity also means that almost no energy is lost in friction between moving parts, making them far more efficient than internal combustion engines.

Does simplicity translate to more or less grunt?

Combustion engines need to be “revved-up” to reach peak power and torque. Torque is a measure of how much rotational force can be produced, whereas power is a measure of how hard an engine has to work to produce the rotational force.

As shown below, the power and torque characteristics of a combustion engine means that although a conventional car might have a top capacity of 120 kW of power and 250 Newton metres of torque, this is only when the engine is running at high speeds.

Power and torque characteristics of a typical internal combustion engine.
Victor Barreto

In contrast, an electric motor provides full torque from zero kilometres an hour, with a linear relationship between how fast the motor is spinning and the power required. These characteristics translate to a vehicle that is extremely fast at accelerating, with the ability to push you back into your seat.

Power and torque characteristics of a typical electric motor.
Victor Barreto

What about pulling power?

For over a decade electric motors have been used in mining trucks, sometimes with a capacity greater than 100 tonnes, due to their powerful, instant torque and ability to pull large loads at slow speeds.

While most of these vehicles have been diesel-hybrids, fully electric mining trucks are now being introduced due to their high power-to-weight ratio, low operating costs, and ability to use regenerative braking to – in some cases – fully recharge their batteries on each mine descent.

A 590 kW, 9,500 N.m electric mining dumper truck, known as the eDumper, uses 30 kWh to travel uphill (unloaded, and can regenerate 40 kWh of electricity when driving back downhill fully loaded.
Andreas Sutter/eMining AG

Electric motors are also increasingly being used in shipping, again because of their ability to push large loads. In Europe, a number of short-haul electric ships are currently in use. One example is the Tycho Brahe, a 111 metre-long, 8,414 tonne electric passenger and vehicle ferry that operates between Helsingborg, Sweden and Helsingør, Denmark.

Tycho Brahe – an electric vehicle and passenger ferry with 4,000 kWh of batteries.

The future of grunt

The global transition to electric vehicles is underway. Australians must decide whether we want to capture the enormous benefits this technology can bring, or remain a global laggard, literally being killed by our current vehicle emissions.

A Mitsubishi Outlander PHEV (Plug-in Hybrid Electric Vehicle).
Jake Whitehead

While long-distance towing in fully electric vehicles is currently a challenge, in the near future this will no longer be the case with the introduction of long-range electric utes like the Rivian R1T and Tesla Pickup.

In the interim, alternatives also exist, like my own plug-in hybrid electric vehicle. It can tow, drive on the beach, and drive up to 50 kilometres on electricity alone. Charged using my home solar system or The University of Queensland’s fast-charger, it means that more than 90% of my trips are zero-emission.

It is clear that electric cars can provide plenty of grunt for Australians, so let’s make sure we are ready for an electric performance future.

An earlier version of this article stated the electric passenger and vehicle ferry Tycho Brahe was 238 metres long. The article has been updated with the correct length of 111 metres.The Conversation

Jake Whitehead, Research Fellow, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Electric cars can clean up the mining industry – here’s how

File 20190416 147514 1952tye.jpg?ixlib=rb 1.1
Electric vehicles and renewable energy must mine more responsibly.

Elsa Dominish, University of Technology Sydney and Nick Florin, University of Technology Sydney

Growing demand for electric vehicles is important to help cut transport emissions, but it will also lead to new mining. Without a careful approach, we could create new environmental damage while trying to solve an environmental problem.

Like solar panels, wind turbines and battery storage technologies, electric vehicles require a complex mix of metals, many of which have only been previously mined in small amounts.

These include cobalt, nickel and lithium for batteries used for electric vehicles and storage; rare earth metals for permanent magnets in electric vehicles and some wind turbines; and silver for solar panels.

Read more:
Time for a global agreement on minerals to fuel the clean energy transition

Our new research (commissioned by Earthworks) at the Institute of Sustainable Futures found that under a 100% renewable energy scenario, demand for metals for electric vehicles and renewable energy technologies could exceed reserves for cobalt, lithium and nickel.

To ensure the transition to renewables does not increase the already significant environmental and human impacts of mining, greater rates of recycling and responsible sourcing are essential.

Greater uptake of electric vehicles will translate to more mining of metals such as cobalt.

Recycling can offset demand for new mining

Electric vehicles are only a very small share of the global vehicle market, but their uptake is expected to accelerate rapidly as costs reduce. This global shift is the main driver of demand for lithium, cobalt and rare earths, which all have a big effect on the environment.

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Although electric vehicles clearly help us by reducing transport emissions, the electric vehicle and battery industries face the urgent challenge of improving the environmental effects of their supply chains.

Our research shows recycling metals can significantly reduce primary demand for electric vehicle batteries. If 90% of cobalt from electric vehicle and energy storage batteries was recycled, for instance, the cumulative demand for cobalt would reduce by half by 2050.

So what happens to the supply when recycling can’t fully meet the demand? New mining is inevitable, particularly in the short term.

In fact, we are already seeing new mines linked to the increasing demand for renewable technologies.

Clean energy is not so clean

Without responsible management, greater clean energy uptake has the potential to create new environmental and social problems. Heavy metals, for instance, could contaminate water and agricultural soils, leading to health issues for surrounding communities and workers.

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Dirty deeds: how to stop Australian miners abroad being linked to death and destruction

Most of the world’s cobalt is mined in the Democratic Republic of Congo, and around 20% of this is from artisanal and small-scale miners who work in dangerous conditions in hand-dug mines.

This includes an estimated 40,000 children under 15.

Rare earths processing requires large amounts of harmful chemicals and produces large volumes of solid waste, gas and wastewater, which have contaminated villages in China.

Copper mining has led to pollution of large areas through tailings dam failures, including in the US and Canada. A tailings dam is typically an earth-filled embankment dam used to store mining byproducts.

A tailings dam.

When supply cannot be met by recycling, we argue companies should responsibly source these metals through verified certification schemes, such as the IRMA Standard for Responsible Mining.

What would a sustainable electric vehicle system look like?

A sustainable renewable energy and transport system would focus on improving practices for recycling and responsible sourcing.

Many electric vehicle and battery manufacturers have been proactively establishing recycling initiatives and investigating new options, such as reusing electric vehicle batteries as energy storage once they are no longer efficient enough for vehicles.

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Treasure from trash: how mining waste can be mined a second time

But there is still potential to improve recycling rates. Not all types of metals are currently being recovered in the recycling process. For example, often only higher value cobalt and nickel are recovered, whereas lithium and manganese are not.

And while electric vehicle manufacturers are beginning to engage in responsible sourcing, many are concerned about the ability to secure enough supply from responsibly sourced mines.

If the auto industry makes public commitments to responsible sourcing, it will have a flow-on effect. More mines would be encouraged to engage with responsible practices and certification schemes.

These responsible sourcing practices need to ensure they do not lead to unintended negative consequences, such as increasing poverty, by avoiding sourcing from countries with poorer governance.

Focusing on supporting responsible operations in these countries will have a better long-term impact than avoiding those nations altogether.

What does this mean for Australia?

The Australian government has committed to supporting industry in better managing batteries and solar panels at the end of their life.

But stronger policies will be needed to ensure reuse and recycling if the industry does not establish effective schemes on their own, and quickly.

Australia is already the largest supplier of lithium, but most of this is exported unprocessed to China. However, this may change as the battery industry expands.

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For example, lithium processing facilities are under development in Western Australia. Mining company Lithium Australia already own a battery component manufacturer in Australia, and recently announced they acquired significant shares in battery recycling company Envirostream.

This could help to close the loop on battery materials and create more employment within the sector.

Human rights must not be sidelined

The renewable energy transition will only be sustainable if human rights are made a top priority in the communities where mining takes place and along the supply chain.

The makers of electric cars have the opportunity to lead these industries, driving change up the supply chain, and influence their suppliers to adopt responsible practices.

Governments and industry must also urgently invest in recycling and reuse schemes to ensure the valuable metals used in these technologies are recovered, so only what is necessary is mined.The Conversation

Elsa Dominish, Senior Research Consultant, Institute for Sustainable Futures, University of Technology Sydney and Nick Florin, Research Director, Institute for Sustainable Futures, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia’s electricity grid can easily support electric cars – if we get smart

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Smart meters can help share the load of charging electric cars.
Chris Hunkeler/Flickr, CC BY-SA

Marcus Brazil, University of Melbourne

Following opposition leader Bill Shorten’s policy announcement that 50% of new cars will be electric by 2030, questions have been raised about the ability of the electricity grid to cope with the increased demand associated with a substantial increase in the use of electric vehicles.

Read more:
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These concerns are not completely unfounded. Modelling and research at the University of Melbourne, conducted as part of a project led by Professor Iven Mareels, has shown that in Victoria even fairly modest rates of electric vehicle uptake could have a major impact on the electricity distribution grid.

However, these problems would be caused by uncoordinated charging, with battery recharging occurring as soon as the driver returns home and plugs in the car. With some simple coordination – perhaps using smart meters – Australia’s grid can easily support far more electric vehicles for decades to come.

The problems

It’s helpful to first understand the challenges to the grid posed by a high number of electric vehicles. The focus here is on the low voltage electricity distribution network, by which we mean the part of the grid “downstream” from local transformers that directly supply electricity to homes and businesses.

This includes most of the grid infrastructure that we see around us every day, such as residential power lines and pole-mounted transformers. Electric vehicle charging can affect this infrastructure in a number of different ways.

Power demand

An electric car with a typical daily commute of 40km requires roughly 6–8 kilowatt hours of energy to recharge, which is equivalent to the daily needs of a small household. In other words, if you purchase an electric vehicle, the impact on the local electricity network is about the same as adding a small house to the neighbourhood.

And in an unregulated environment most electric vehicle owners are likely to plug in and begin charging when they arrive home, around 6 to 7 pm, which is the time residential electricity networks experience peak demand. This can lead to network failures, or component overload where assets such as distribution transformers and the utility lines run beyond their nominal current ratings and capacity limits, substantially shortening their lifetimes.

Voltage drop

Voltage can be thought of as the “electrical pressure” in the network. Each utility line in the distribution network has an associated impedance, meaning that the voltage at each house in the network decreases the further it is from the distribution transformer. As more current is drawn through the lines due to the charging of electric vehicles, this decrease in voltage is exacerbated. If the voltage in some houses falls below regulated limits, household appliances may fail or suffer.

Phase unbalance and power quality

Electricity distribution networks in Australia are generally three-phase, meaning there are three lines carrying the current, each a third of a cycle out of phase with the others. Most houses connect to only one of these phases. If a disproportionate number of households with electric vehicles all happen to be connected to the same phase, then that phase can get out of balance with the others, leading to a significant loss of efficiency in the network. Mass electric vehicle charging could also affect the overall quality of the power in the network, for example by distorting the shape of the 50Hz waveform that carries the current.

Modelling and simulations, based on real Australian data, have shown these negative impacts on the grid can occur at fairly low rates of electric vehicle ownership. For example, in a study based on an area in Melbourne it was shown that an electric vehicle penetration of only 10% can lead to network failures in an unregulated environment.

Getting smart

The good news is that all of these problems can be prevented by implementing a smart charging framework: shifting electric vehicle demand away from peak times.

Electric vehicles are among the most flexible loads in the grid. Unlike showering, cooking and heating our homes, we can shift the demand to other times, such as overnight, when there is more capacity in the network. The trade-off, of course, is that it takes longer until the vehicle is fully charged.

However, most owners are unlikely to notice this, as long as the car is charged and ready to go by the time they need to leave for work. Furthermore a standard commute will generally mean there is enough spare battery capacity to allow the car to be taken out for an emergency late-night run, even if it is not yet fully charged.

Shifting electric vehicle load. If vehicle charging is not controlled, there is a significant increase in peak demand. If the vehicle charging load is shifted to times when there is more capacity, there is no increase in peak load.

Setting up such a charging system would not be particularly difficult or expensive. One suggested scenario is for each residence with an electric vehicle to acquire a home charging terminal that the car plugs into, which receives instructions from the utility operator via the household smart meter. This allows the operator to control vehicle charging across the network based on the current network conditions and demand.

If the charging of electric vehicles can be controlled in this manner, then our existing networks will be able to sustain high uptake rates, without any additional investment into grid infrastructure.

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Detailed simulations have shown that the same network that started to fail at a 10% uptake with uncontrolled charging is able to sustain more than an 80% uptake when vehicle charging is shifted, using simple optimisation algorithms. Through this sort of demand management, most of our existing networks should be able to handle electric vehicles for decades to come.The Conversation

Marcus Brazil, Associate Professor and Reader in Engineering, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Don’t trust the environmental hype about electric vehicles? The economic benefits might convince you

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There are plenty of economic reasons to change our gas-guzzling habits.

Gail Broadbent, UNSW and Graciela Metternicht, UNSW

With electric cars back in the headlines, it’s time to remember why we should bother making the transition away from oil.

In our recent research looking at attitudes towards electric vehicle uptake, we pointed to some of the factors making the case for change. We need to remind ourselves that burning oil, a finite resource, to energise motor vehicles will not only cost the environment, but also the economy.

A critical factor is carbon emissions. The transport sector is the fastest growing contributor of greenhouse gases.

The transport sector contributes some 18% of Australia’s total greenhouse gas pollution and Australia is ranked second worst in an international scorecard for transport energy efficiency.

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Costly, toxic and slow to charge? Busting electric car myths

But even if you don’t believe this is an urgent issue, there are plenty of economic reasons to change our gas-guzzling habits.

A matter of money

In just one year (2017-18), Australia’s imports of refined petroleum cost A$21.7 billion.

Crude petroleum cost us a further A$11.7 billion – that’s more than A$33 billion going to overseas companies who may pay limited tax to Australia.

The argument that electric vehicle motorists, who do pay GST on their electricity, may not pay any fuel tax is really a distraction asking taxpayers to look somewhere else instead of the big companies.

What’s more, the A$18 billion fuel tax goes to general revenue and isn’t pledged to road building.

Unsteady fuel reserves

Policies minimising Australia’s reliance on oil imports could bring significant benefits to businesses and families, and even to public sector agencies with fleet operations.

Around 90% of the oil Australia consumes is imported and road transport is almost entirely dependent on it. The bulk of our automotive gasoline comes from Singapore and South Korea, and in the event of geopolitical imbalance, the supply of our fuel could potentially be jeopardised.

And our fuel stockpiles are very low. Australia has only about 21 days’ supply in stock, rather than the recommended 90 days.

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Australia’s fuel stockpile is perilously low, and it may be too late for a refill

Health risks

Potential geopolitical imbalances affecting the national supply are important, but the health costs associated with fossil fuels are in the scale of billions of dollars in Australia.

This includes premature death, hospital and medical costs, and loss of productivity that arise from toxic air pollution from internal combustion engine vehicles.

It has also been found pollution from burning fossil fuels can cause respiratory illnesses like asthma and neurodevelopmental disorders in children It’s a high price to pay to continue burning fossil fuels.

And noise pollution from traffic can cause health problems, for instance, by elevating blood pressure, or creating cognitive development problems for children, who have noise-related sleep disturbance.

Conventional cars are inefficient

Electric vehicles convert about 60% of their energy to propulsion. Conventional cars, on the other hand, are very inefficient.

For every litre of fuel burned, only about 17 to 21% of the energy is converted to forward motion, the rest is lost as heat and noise. The waste heat collectively warms up urban areas, causing more use of air conditioning in buildings in summer.

And buildings located near heavily trafficked roads may be exposed to high air and noise pollution, so windows may not generally be used for ventilation. This also places demand on air conditioning and electricity.

Renewable energy is cheaper and faster

An important point in the ongoing debate about electric vehicles is that they’re only as clean as the electricity they use. A widespread adoption of electric vehicles means the electricity supply will need to be increased.

And Australia’s current energy supply is notoriously one of the dirtiest in the world.

But the demand for new electricity to supply future electric vehicle uptake will be met by installing renewables because they’re cheaper and faster than installing new coal fired power stations.

Read more:
How electric cars can help save the grid

The bottom line on this ongoing debate is really about changing our mindset about transport – let’s not get stuck in the past, let’s join the modern world and charge ahead.The Conversation

Gail Broadbent, PhD candidate Faculty of Science UNSW, UNSW and Graciela Metternicht, Professor of Environmental Geography, School of Biological Earth and Environmental Sciences, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Why battery-powered vehicles stack up better than hydrogen

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A battery electric vehicle in The University of Queensland’s vehicle fleet.

Jake Whitehead, The University of Queensland; Robin Smit, The University of Queensland, and Simon Washington, The University of Queensland

Low energy efficiency is already a major problem for petrol and diesel vehicles. Typically, only 20% of the overall well-to-wheel energy is actually used to power these vehicles. The other 80% is lost through oil extraction, refinement, transport, evaporation, and engine heat. This low energy efficiency is the primary reason why fossil fuel vehicles are emissions-intensive, and relatively expensive to run.

With this in mind, we set out to understand the energy efficiency of electric and hydrogen vehicles as part of a recent paper published in the Air Quality and Climate Change Journal.

Electric vehicles stack up best

Based on a wide scan of studies globally, we found that battery electric vehicles have significantly lower energy losses compared to other vehicle technologies. Interestingly, however, the well-to-wheel losses of hydrogen fuel cell vehicles were found to be almost as high as fossil fuel vehicles.

Average well-to-wheel energy losses from different vehicle drivetrain technologies, showing typical values and ranges. Note: these figures account for production, transport and propulsion, but do not capture manufacturing energy requirements, which are currently marginally higher for electric and hydrogen fuel cell vehicles compared to fossil fuel vehicles.

At first, this significant efficiency difference may seem surprising, given the recent attention on using hydrogen for transport.

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How hydrogen power can help us cut emissions, boost exports, and even drive further between refills

While most hydrogen today (and for the foreseeable future) is produced from fossil fuels, a zero-emission pathway is possible if renewable energy is used to:

Herein lies one of the significant challenges in harnessing hydrogen for transport: there are many more steps in the energy life cycle process, compared with the simpler, direct use of electricity in battery electric vehicles.

Each step in the process incurs an energy penalty, and therefore an efficiency loss. The sum of these losses ultimately explains why hydrogen fuel cell vehicles, on average, require three to four times more energy than battery electric vehicles, per kilometre travelled.

Electricity grid impacts

The future significance of low energy efficiency is made clearer upon examination of the potential electricity grid impacts. If Australia’s existing 14 million light vehicles were electric, they would need about 37 terawatt-hours (TWh) of electricity per year — a 15% increase in national electricity generation (roughly equivalent to Australia’s existing annual renewable generation).

But if this same fleet was converted to run on hydrogen, it would need more than four times the electricity: roughly 157 TWh a year. This would entail a 63% increase in national electricity generation.

A recent Infrastructure Victoria report reached a similar conclusion. It calculated that a full transition to hydrogen in 2046 – for both light and heavy vehicles – would require 64 TWh of electricity, the equivalent of a 147% increase in Victoria’s annual electricity consumption. Battery electric vehicles, meanwhile, would require roughly one third the amount (22 TWh).

Read more:
How electric cars can help save the grid

Some may argue that energy efficiency will no longer be important in the future given some forecasts suggest Australia could reach 100% renewable energy as soon as the 2030s. While the current political climate suggests this will be challenging, even as the transition occurs, there will be competing demands for renewable energy between sectors, stressing the continuing importance of energy efficiency.

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At its current rate, Australia is on track for 50% renewable electricity in 2025

It should also be recognised that higher energy requirements translate to higher energy prices. Even if hydrogen reached price parity with petrol or diesel in the future, electric vehicles would remain 70-90% cheaper to run, because of their higher energy efficiency. This would save the average Australian household more than A$2,000 per year.

Pragmatic plan for the future

Despite the clear energy efficiency advantages of electric vehicles over hydrogen vehicles, the truth is there is no silver bullet. Both technologies face differing challenges in terms of infrastructure, consumer acceptance, grid impacts, technology maturity and reliability, and driving range (the volume needed for sufficient hydrogen compared with the battery energy density for electric vehicles).

Battery electric vehicles are not yet a suitable replacement for every vehicle on our roads. But based on the technology available today, it is clear that a significant proportion of the current fleet could transition to be battery electric, including many cars, buses, and short-haul trucks.

Such a transition represents a sensible, robust and cost-efficient approach for delivering the significant transport emission reductions required within the short time frames outlined by the Intergovernmental Panel on Climate Change’s recent report on restraining global warming to 1.5℃, while also reducing transport costs.

Together with other energy-efficient technologies, such as the direct export of renewable electricity overseas, battery electric vehicles will ensure that the renewable energy we generate over the coming decades is used to reduce the greatest amount of emissions, as quickly as possible.

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Meanwhile, research should continue into energy efficient options for long-distance trucks, shipping and aircraft, as well as the broader role for both hydrogen and electrification in reducing emissions across other sectors of the economy.

With the Federal Senate Select Committee on Electric Vehicles set to deliver its final report on December 4, let’s hope the continuing importance of energy efficiency in transport has not been forgotten.The Conversation

Jake Whitehead, Research Fellow, The University of Queensland; Robin Smit, Adjunct professor, The University of Queensland, and Simon Washington, Professor and Head of School of Civil Engineering, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.