Modern Australian
Men's Weekly

.

why don't we have electric aircraft?

  • Written by Dries Verstraete, Senior Lecturer in Aerospace Design and Propulsion, University of Sydney
why don't we have electric aircraft? 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 Electric cars, trains, trams and boats already exist. That logically leads to the question: why are we not seeing large electric aircraft? And will we see them any time soon? Why do we have electric cars and trains, but few electric planes? The main reason is that it’s much simpler to radically modify a car or train, even if they look very similar to traditional fossil-fuel vehicles on the outside. Land vehicles can easily cope with the extra mass from electricity storage or electrical propulsion systems, but aircraft are much more sensitive. Read more: Zero-carbon electric transport is already in reach for small islands For instance, increasing the mass of a car by 35% leads to an increase in energy use of 13-20%. But for a plane, energy use is directly proportional to mass: increasing its mass by 35% means it needs 35% more energy (all other things being equal). But that is only part of the story. Aircraft also travel much further than ground vehicles, which means a flight requires far more energy than an average road trip. Aircraft must store onboard all the energy needed to move its mass for each flight (unlike a train connected to an electrical grid). Using a heavy energy source thus means more energy is needed for a flight, which leads to extra mass, and so on and on. For an aircraft, mass is crucial, which is why airlines fastidiously weigh luggage. Electric planes need batteries with enough energy per kilogram of battery, or the mass penalty means they simply can’t fly long distances. Read more: Why battery-powered vehicles stack up better than hydrogen Short-range planes Despite this, electric aircraft are on the horizon – but you won’t be seeing electric 747s any time soon. Today’s best available lithium ion battery packs provide around 200 watt-hours (Wh) per kilogram, about 60 times less than current aircraft fuel. This type of battery can power small electric air taxis with up to four passengers over a distance of around 100km. For longer trips, more energy-dense cells are needed. why don't we have electric aircraft? An experimental flying taxi, with a vertical take-off-and-landing, was unveiled in 2019 show in Las Vegas. It is powered by a hybrid-electric system. Bell/Cover Images Short-range electric commuter aircraft that carry up to 30 people for less than 800km, for instance, specifically require between 750 and 2,000Wh/kg, which is some 6-17% of kerosene-based jet fuel’s energy content. Even larger aircraft require increasingly lighter batteries. For example, a plane carrying 140 passengers for 1,500km consumes about 30kg of kerosene per passenger. With current battery technology, almost 1,000kg of batteries is needed per passenger. To make regional commuter aircraft fully electric requires a four- to tenfold reduction in battery weight. The long-term historical rate of improvement in battery energy has been around 3-4% per year, doubling roughly every two decades. Based on a continuation of this historical trend, the fourfold improvement needed for a fully electric commuter aircraft could potentially be reached around mid-century. While this may seem an incredibly long wait, this is consistent with the timescale of change in the aviation industry for both the infrastructure and aircraft design lifecycles. A new aircraft takes around 5-10 years to design, and will then remain in service for two to three decades. Some aircraft are still flying 50 years after their first flight. Read more: We can't expand airports after declaring a climate emergency – let's shift to low-carbon transport instead Here come the hybrids Does this mean long-distance flying will always rely on fossil fuels? Not necessarily. While fully electric large aircraft require a major, yet-to-be-invented shift in energy storage, there are other ways to reduce the environmental impact of flying. Hybrid-electric aircraft combine fuels with electric propulsion. This class of aircraft includes design without batteries, where the electric propulsion system serves to improve the thrust efficiency, reducing the amount of fuel needed. Hybrid-electric aircraft with batteries are also in development, where the batteries may provide extra power in specific circumstances. Batteries can then, for instance, provide clean take-off and landing to reduce emissions near airports. Electric planes are also not the only way to reduce the direct carbon footprint of flying. Alternative fuels, such as biofuels and hydrogen, are also being investigated. Biofuels, which are fuels derived from plants or algae, were first used on a commercial flight in 2008 and several airlines have performed trials with them. While not widely adopted, significant research is currently investigating sustainable biofuels that do not impact freshwater sources or food production. Read more: Explainer: what are biofuels? While biofuels do still produce CO₂, they don’t require significant changes to existing aircraft or airport infrastructure. Hydrogen, on the other hand, requires a complete redesign of the fuelling infrastructure of the airport and also has a significant impact on the design of the aircraft itself. While hydrogen is very light – hydrogen contains three times more energy per kilogram than kerosene – its density is very low, even when stored as a liquid at -250℃. This means that fuel can no longer be stored in the wing but needs to be moved to relatively heavy and bulky tanks inside the fuselage. Despite these drawbacks, hydrogen-fuelled long-distance flights can consume up to 12% less energy than kerosene. why don't we have electric aircraft? This article is part of The Covering Climate Now series This is a concerted effort among news organisations to put the climate crisis at the forefront of our coverage. This article is published under a Creative Commons licence and can be reproduced for free – just hit the “Republish this article” button on the page to copy the full HTML coding. The Conversation also runs Imagine, a newsletter in which academics explore how the world can rise to the challenge of climate change. Sign up here.

Authors: Dries Verstraete, Senior Lecturer in Aerospace Design and Propulsion, University of Sydney

Read more http://theconversation.com/climate-explained-why-dont-we-have-electric-aircraft-123910

How To Keep Vase Flowers Fresh Through Australia’s Coldest Months

Winter flowers develop slowly, which gives them stronger structure and longer vase life Heat from indoor environments is the biggest threat to th...

Artificial Intelligence is Powering the Growth of Australian Telehealth Services

Many Australians have traditionally experienced difficulties in accessing timely and quality healthcare, especially those who live in rural or remot...

Powering Shepparton’s Businesses: Expert Commercial Electrical Services You Can Count On

When it comes to running a successful business, having reliable, compliant, and efficient electrical systems is non-negotiable. From small retail ou...

Maximise Efficiency: Cleaner Solar Panels for Optimal Performance

Solar panels are a smart investment in energy efficiency, sustainability, and long-term savings—especially here in Cairns, where the tropical sun ...

7 Common Air Conditioner Issues in Melbourne – And How to Fix Them

Image by freepik Living in Melbourne, we all know how unpredictable the weather can be. One moment it’s cold and windy, the next it’s a scorchin...

Powering Palm QLD with Reliable Electrical Solutions

Image by pvproductions on Freepik When it comes to finding a trustworthy electrician Palm QLD locals can count on, the team at East Coast Sparkies s...

The Smart Way to Grow Online: SEO Management Sydney Businesses Can Rely On

If you’re a Sydney-based business owner, you already know the digital space is crowded. But with the right strategy, you don’t need to shout the...

What Your Car Says About You: The Personality Behind the Vehicle

You can tell a lot about someone by the car they drive—or at least, that’s what people think. True Blue Mobile Mechanics reckon the car says a l...

The Confidence Curve: Why Boudoir Photography Is the Empowerment Trend You Didn’t Know You Needed

Boudoir photography has been quietly taking over social feeds, Pinterest boards, and personal milestones—and for good reason. It’s not just abou...

Understanding Level 2 Electricians: Why Sydney Residents Need Licenced Experts for Complex Electrical Work

When it comes to electrical work around the home or business, not all electricians are created equal. In Sydney, particularly when you're dealing wi...

Retirement Anchored in Model Boat Building for Waterford’s Doug Unsold

WATERFORD — When Doug Unsold sees his ship come in, it’s usually one he’s crafted with his own hands. The 67-year-old retiree from Waterford ...

The Science Behind Alarm Clocks and Your Circadian Rhythm

Waking up on time isn’t just about setting an alarm—it’s about working with your body, not against it. At the heart of every restful night and...

How to Use Plants to Create a Calming Atmosphere in Your Home

In today’s fast-paced world, cultivating a calm, soothing environment at home has never been more important. Whether you live in a busy urban apar...

How Maths Tutoring Can Help Students Master Maths

Mathematics can be a daunting subject for many students, often causing stress and frustration. However, maths tutoring has proven to be an effective...

Refurbished iPads Are Better Than New Ones (Here's Why)

Image by rawpixel.com on Freepik Apple's refurbished iPad program has quietly become one of the best deals in tech. While everyone obsesses over the ...

Your Guide to Finding the Right GP: What Perth City Doctors Offer Today

Choosing a General Practitioner (GP) is one of the most important health decisions you’ll make. Luckily, Perth’s vibrant CBD now hosts a new ge...

Why Every Mining Operation Needs a Robust Safety Management System

Mining is one of the backbones of the Australian economy, particularly in Western Australia. Back in 2019-20, mining contributed 10.4% of Australia...

Australian Classic Literature Enjoys Resurgence

Welcome back to the good old days of storytelling! As the modern world becomes increasingly more demanding, returning to childhood favourites offers...