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 http://www.shutterstock.com, CC BY-ND

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


CC BY-ND

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 climate.change@stuff.co.nz

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.




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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.




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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.




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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.
AAP

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.




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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.
AAP

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.




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

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.




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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.




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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.
AAP

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



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Nobuteru Taniguc drifting a Tesla Model S in Tokyo, Japan.
MASUDA

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.

CarAdvice.com: Tesla Model S v Holden V8 Supercar v Walkinshaw HSV GTS Drag Race.



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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.




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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.
Forsea

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



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Electric vehicles and renewable energy must mine more responsibly.
Ioanac/Shutterstock

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.




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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.
Shutterstock

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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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.
Edvision/Shutterstock

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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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.




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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.
Shutterstock

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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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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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



File 20181114 194500 iw2c1a.jpg?ixlib=rb 1.1
A battery electric vehicle in The University of Queensland’s vehicle fleet.
CC BY-ND

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.




Read more:
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.




Read more:
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.




Read more:
The north’s future is electrifying: powering Asia with renewables


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.