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12/01/2022

12/01/2022

Charging ahead: how to make sure the electric vehicle transition is sustainable and just
Electric vehicles (EVs) are hitting the roads in ever greater numbers. Global EV sales were up by 168% in the first half of 2021 compared to 2020, and are expected to cost the same as – or even less than – combustion (petrol and diesel) cars by 2028 at the latest. Accompanied by proposed government bans on the sale of combustion vehicles in many countries, EVs will be increasingly commonplace over the next decade.

But EV uptake brings its own set of challenges. While the UK’s national energy provider has assured consumers that there is “definitely enough energy” to facilitate mass EV adoption, the problem lies in how to sustainably and cheaply supply cars with power.

Our local networks were not designed to charge millions of cars with energy simultaneously and, as we move towards a zero-carbon electricity system with variable wind and solar generation, the energy may not be there when we need it most.

The key to handling this lies in ensuring EVs are able to affordably charge when there is plenty of wind and sun-driven energy available. Coordinating this requires significant planning and government investment into a smart charging network.

How to charge
When we decide how to charge an EV, a key consideration is the vehicle’s “dwell time” at its charging location.

If the driver is at home for the night or at work for the day – and therefore in no rush to charge – they can use a seven kW charger, a standard home charger in the UK, to charge their car for a week’s driving (about 250km) in an eight hour session. But if the driver decides to charge their car on the same charger while they pop to the supermarket for just 45 minutes, they’ll only get around 30km of extra range: barely enough for a day’s driving.

Dwell times and charging speeds

A chart showing EV dwell times and charging speeds
How long cars parked at different chargers need to power up. Author provided
In the latter situation, a “DC Rapid” charger – which typically provides between 50 to 150kW – is more appropriate. While they are far more expensive – typically at least ten times the cost of a standard home charger – you get what you pay for: using these chargers will provide roughly a week’s driving in just 45 minutes.

The problem with these rapid charges is that, as well as being expensive, they place large demands on electricity infrastructure which could lead to local blackouts. Since, on average, cars spend about 95% of their time parked, you’d ideally want them to be slowly charging from excess renewable energy during that time, with rapid charges reserved for long road trips and occasional emergency charges.

The dashboard seen from inside an electric car at sunset
The Honda e, a new fully electric car, is an example of EV models hitting the market. EVClicks
In future, cars might also help support their local electricity grid by discharging power at times of high demand when renewable generation is low – a technology known as “vehicle-to-grid”. To enable this technology, communication between chargers and cars needs to be a two-way street, allowing drivers to simultaneously charge up and support the grid.

Energy inequality
Access to power is also a financial issue. For those with off-street parking at home, staying plugged in is easy, but many don’t have that option. That means plugged-in households will have access to low-cost travel, whilst those without home charging will face higher costs due to expensive street charging. In the UK, around 7 million households, many on lower incomes, fall into the latter group.

We must widen access to charging not just to help the grid, but also to reduce social inequity. Street chargers could be automatically assigned to the car owner’s account when they plug in, enabling those without home charging to access a full range of services for the same cost as someone with a home charger.

An electric car charges outside a home
Charger availability for EVs could lead to increased inequality. EVClicks
In the UK, we’d need about 750,000 street chargers to ensure that those without home chargers can charge once a week. If we want to make use of the energy storage in those cars to help balance production and consumption from the grid – and to achieve the UK’s net zero target – I’d estimate we’d need up to 5 million chargers. That would require 500 new street chargers to be installed every day between now and 2050.

Using our cars to help balance our grid will likely be cheaper than energy storage alternatives like pumped-storage hydroelectricity or liquid air storage, since we already have some of the infrastructure we need. But to make this happen, car manufacturers, network operators and energy suppliers – and the UK government – must coordinate to put the right chargers in the right places at the right time

12/01/2022

We analysed 100 million bike trips to reveal where in the world cyclists are most likely to brave rain and cold
Hopping on your bike when it’s raining, or snowing, might seem unappealing. But our research has found inclement weather conditions deter some cyclists more than others.

In the first analysis of its kind, we captured eight years of data from 40 bike-sharing schemes around the world, across a range of climate zones, totalling 100 million trips. We then linked this data to fine-grained historical weather information.

We found weather patterns affect people’s willingness to cycle in different ways. For example, people in Melbourne are more likely to avoid cycling in the rain or snow than people in Dublin. And female cyclists are more put off by rain and snow than male cyclists.

These differences are important. Personal decisions on how and when to travel can affect overall traffic congestion, environmental pollution and travel experience. So understanding how outdoor conditions affect cycling is crucial to effective transport planning and more sustainable cities.

cyclist rides past row of cars
Cycling can ease traffic congestion. Shutterstock
Insights from ‘big data’
Obviously, cycling behaviour is more affected by bad weather than most other forms of transport. Previous research has confirmed this; however, the data has been patchy and limited. Bike-share schemes, which digitally record every trip taken, mean excellent “big data” is now available.

We used data from 40 public bike sharing programs in 40 cities across 16 countries. The programs spanned five climate zones, ranging from hot to frosty.

The cycling habits of people who own their bike may differ from those who use bike-sharing schemes. But bad weather can cause all cyclists to delay trips or change transport modes, so most of our findings are likely to apply broadly.

Read more: Australian cycling boom? Nope - it's a myth

Bad weather can cause all cyclists to delay trips. Flickr
What we found
Prior studies have shown rain and snow are among the worst deterrents for cycling. But our analysis reveals a more nuanced picture.

In cities such as Melbourne (Australia), Chicago (the United States) and Vancouver (Canada), people are more likely to avoid cycling when it rains or snows.

In the top 5% rainiest hours of the year in Dublin (Ireland), people use bike share at 81% of the average usage rate. In Seville and Valencia these figures are 79% and 74%, respectively.

In Brisbane this figure drops to 68%, while in Melbourne it’s 46%.

Past research has assumed this trend is due to people in cooler cities being more accustomed to rain and snow, while people in hot climes are accustomed to the sun. But while Dublin is notoriously rainy, Seville and Valencia are rather dry.

Various factors may affect willingness to cycle in the rain. For example, high-quality cycling infrastructure may spur people to get on their bikes even in inclement weather. Seville and Valencia have large bike-share systems and safe cycling networks, whereas Melbourne’s was small and not particularly useful for commuting.

Other factors can push bike-share use up or down. They include lengthening opening hours, increasing prices or changing public transport arrangements – for example, Melbourne’s free tram zone.

We found female cyclists are put off by rain and snow more than male cyclists. Not all bike-share systems record the gender of subscribers, and so this effect could only be studied in New York City and Chicago.

This may suggest a greater risk aversion among women, often the product of socialisation in patriarchal cultures where women are taught from childhood to take fewer risks.

Read more: Too wet? Too cold? Too hot? This is how weather affects the trips we make

woman rides bike near water
The research found female cyclists were more deterred by inclement weather than male cyclists. James Ross/AAP
Goldilocks temperatures
Unsurprisingly, people cycle when it’s not too hot or too cold. We found the sweet spot is around 27-28℃, and bike usage declines when it gets hotter or colder.

But what’s considered too hot or too cold to cycle is not closely connected to the climate zone.

For example, cyclists in Trondheim (Norway) and Ljubljana (Slovenia) are sensitive to lower temperatures even though the first is a cold city and the second is less so. And cyclists in chilly Dublin (Ireland) and tropical Kaohsiung (Taiwan) are less sensitive to lower temperatures, even though these two cities also have vastly different climates.

This finding is surprising because, as with rain and snow, it was previously assumed people in the tropics could tolerate more heat while people in temperate climates were more tolerant of cooler temperatures.

Read more: Cycling and walking are short-changed when it comes to transport funding in Australia

Silhouette of cyclists against sun and water
What’s considered too hot or cold to cycle is not closely connected to the climate zone. Steen Saphore/AAP
On your bike
In Australia, bicycle travel accounts for only about 1% of journeys. Obviously, we can’t control the weather – but we can transform our institutional and political environments to remove barriers to cycling.

This includes creating safe, weatherproof infrastructure separated from high-speed motor vehicles. And cycling should become an integral part of transport planning and receive a fair share of funding.

Such changes will require public support to implement. Planning officials and cycling advocates must do better at motivating people to cycle. This might include positioning cycling as a “normal” pursuit, or framing it as a source of pleasure and well-being.

Improving cycling rates offers huge potential benefits. It would lower health-care costs, ease traffic congestion, lower greenhouse gas emissions and, importantly, make our cities more liveable places.

12/01/2022

Blue-sky thinking: net-zero aviation is more than a flight of fantasy
As international air travel rebounds after COVID-19 restrictions, greenhouse gas emissions from aviation are expected to rise dramatically – and with it, scrutiny of the industry’s environmental credentials.

Aviation emissions have almost doubled since 2000 and in 2018 reached one billion tonnes. Climate Action Tracker rates the industry’s climate performance as critically insufficient.

As the climate change threat rapidly worsens, can aviation make the transition to a low-carbon future – and perhaps even reach net-zero emissions? The significant technological and energy disruption on the horizon for the industry suggests such a future is possible.

But significant challenges remain. Achieving a net-zero aviation sector will require a huge collaborative effort from industry and government – and consumers can also play their part.

Build back better
The aviation sector’s progress in cutting emissions has been disappointing to date. For example, in February last year, research on the world’s largest 58 airlines found even the best-performing ones were not doing anywhere near enough to cut emissions.

Most recently, at the COP26 climate change summit in Glasgow, the industry merely reasserted a commitment to a plan known as the Carbon Offsetting and Reduction Scheme for International Aviation.

The scheme relies on carbon offsetting, which essentially pays another actor to reduce emissions on its behalf at lowest cost, and doesn’t lead to absolute emissions reduction in aviation. The scheme also encourages alternative cleaner fuels, but the level of emissions reduction between fuels varies considerably.

Read more: Major airlines say they're acting on climate change. Our research reveals how little they've achieved

Governments have generally failed to provide strong leadership to help the aviation sector to reduce emissions. This in part is because pollution from international aviation is not counted in the emissions ledger of any country, leaving little incentive for governments to act. Aviation is also a complex policy space to navigate, involving multiple actors around the world. However, COVID-19 has significantly jolted the aviation and travel sector, presenting an opportunity to build back better – and differently.

Griffith University recently held a webinar series on decarbonising aviation, involving industry, academic and government experts. The sessions explored the most promising policy and practical developments for net-zero aviation, as well as the most significant hurdles.

passengers queue at airport
COVID-19 has significantly jolted the aviation sector. Steven Senne/AP
Nations soaring ahead
Some governments are leading the way in driving change in the aviation industry. For example, as a result of government policy to make Sweden climate-neutral by 2045, the Swedish aviation industry developed a roadmap for fossil-free domestic flights by 2030, and for all flights originating from Sweden to be fossil-free by 2045.

Achieving fossil-free flights requires replacing jet fuel with alternatives such as sustainable fuels or electric and hydrogen propulsion.

The European Union plans to end current tax exemptions for jet fuel and introduce measures to accelerate the uptake of sustainable fuels.

The United Kingdom is finalising its strategy for net-zero aviation by 2050 and a public body known as UK Research and Innovation is supporting the development of new aviation technologies, including hybrid-electric regional aircraft.

Australia lacks a strategic framework or emissions reduction targets to help transition the aviation industry. The Emerging Aviation Technology Program seeks to reduce carbon emissions, among other goals. However, it appears to have a strong focus on freight-carrying drones and urban air vehicles, rather than fixed wing aircraft.

Read more: How a 1940s treaty set airlines on a path to high emissions and low regulation

plane taking off
Some governments are leading the way in driving change in the aviation industry. Zhao Xiaojun/AP
Building tomorrow’s aircraft
Low-emissions aircraft technology has developed substantially in the last five years. Advancements include electric and hybrid aircraft (powered by hydrogen or a battery) – such as that being developed by Airbus, Rolls Royce and Zero Avia – as well as sustainable aviation fuels.

Each of these technologies can reduce carbon emissions, but only battery and hydrogen electric options significantly reduce non-CO₂ climate impacts such as oxides of nitrogen (NOx), soot particles, oxidised sulphur species, and water vapour.

For electric aircraft to be net-zero emissions, they must be powered by renewable energy sources. As well as being better for the planet, electric and hydrogen aircraft are likely to have lower energy and maintenance costs than conventional aircraft.

This decade, we expect a rapid emergence of electric and hybrid aircraft for short-haul, commuter, air taxi, helicopter and general flights. Increased use of sustainable aviation fuel is also likely.

Although electric planes are flying, commercial operations are not expected until at least 2023 as the aircraft must undergo rigorous testing, safety and certification.

A solar powered aircraft prototype flies in mountainous terrain
Electric planes exist, but the route to commercialisation is long. Pictured: a solar powered aircraft prototype flies near the France-Italy border. Laurent Gillieron/EPA
Overcoming turbulence
Despite real efforts by some industry leaders and governments towards making aviation a net-zero industry, significant strategic and practical challenges remain. Conversion to the commercial mainstream is not happening quickly enough.

To help decarbonise aviation in Australia, industry and government should develop a clear strategy for emissions reduction with interim targets for 2030 and 2040. This would keep the industry competitive and on track for net-zero emissions by 2050.

Strategic attention and action is also needed to:

advance aircraft and fuel innovation and development

update regulatory and certification processes for new types of aircraft

enhance production and deployment of new aviation fuels and technologies

reduce fuel demand through efficiencies in route and air traffic management

create “greener” airport operations and infrastructure

build capability with pilots and aerospace engineers.

The emissions created by flights and itineraries can vary substantially. Consumers can do their part by opting for the lowest-impact option, and offsetting the emissions their flight creates via a credible program. Consumers can also choose to fly only with airlines and operators that have committed to net-zero emissions.

Net-zero aviation need not remain a flight of fantasy, but to make it a reality, emissions reduction must be at the heart of aviation’s pandemic bounce-back.

12/01/2022

12/01/2022