Research and development of electric propulsion systems for aircraft is continuing, in spite of the sector’s financial woes due to Covid-19. Catherine Early reports
Electric aviation achieved a significant milestone in May, when the world’s largest all-electric aircraft successfully completed a test flight over the US state of Washington. The nine-seater Cessna Grand Caravan flew for 30 minutes, powered by a 750-horsepower (560 kW) magni500 propulsion system developed by electric propulsion system designers magniX and aerospace engineering company AeroTEC.
Just a few weeks later, regulators at the European Union Aviation Safety Agency (EASA) granted a two-seater electric aircraft capable of up to 80 minutes of flight worldwide certification to operate, hailing it as a massive step forward in battery-powered flight.
One of the most significant challenges for electrifying aviation is the weight to power ratio of batteries, which means that they are mostly seen as a solution for small aircraft flying short distances, such as island-hopping routes, or regional airports to main city hubs.
But electrification plans are not limited to the two-seater market: UK airline EasyJet has teamed up with startup Wright Electric to develop a 186-seat electric aircraft with a 1.5MW electric motor, a development we previously reported on. Plans to conduct flight tests in 2023 and enter commercial service by 2030 have not been side-tracked by Covid-19, the company said.
It is a development encouraged by airports, which are also looking to reduce their climate impact in response to the flight-shame movement. London’s Heathrow Airport is offering a year’s worth of free landing charges for the first commercial airline to launch an electric plane, and last December began a six-month project to research infrastructure to support aircraft electrification at the airport, such as for charging and electrical power and distribution requirements.
The work is being undertaken with researchers from Cranfield University and the universities of Essex and Reading, and aims to help other airports plan for an increasingly electrically powered future for aviation.
It’s not about whether pure electric or hybrid technologies will win out, it’s a portfolio of solutions that will work for all types of planes
Meanwhile, the Norwegian government and its state-owned airport operator Avinor have committed to the electrification of all flights under 90 minutes by 2040.
However, James Domone, senior aerospace engineer at consultancy Atkins, says that the main market for electric planes will be small aircraft on short routes.
“Battery technology is just not going to be there for larger aircraft, even in a hybrid, to make a huge amount of difference to net-zero. Batteries with the energy capacity to fly for a reasonable distance will be too heavy, and that’s based [on] forecast battery development; existing batteries have even lower energy capacity,” he told The Ethical Corporation.
Domone believes that the aerospace industry would have to make a huge investment to take it further, and even look at new battery chemistry such as sulphur ion or lithium air, which are currently only theoretical.
But Roei Ganzarski, chief executive of magniX, expects investment in battery technology to continue and strengthen. He points out that aircraft have very long lifespans, up to 50 years for small planes on island-hopping routes, so planes being flown now will still be in operation in 2050, the date by which the world will need to reach net-zero carbon emissions in order to keep climate change below dangerous levels.
Electric planes emit less noise and air pollution, and are cheaper in terms of both fuel and maintenance. And with 45% of all flights globally being less than 500 miles, according to aviation data company OAG, it is clear they still have a role to play in decarbonisation.
“We believe that all types of planes could electrify to some extent, says Cory Combs, founder and chief technology officer at US technology company Ampaire. “It’s not about whether pure electric or hybrid technologies will win out, it’s a portfolio of solutions that will work for all types of planes,” he says.
The E-Fan X project being developed by Airbus and Rolls-Royce was dropped in April in the wake of the Covid-19 travel slump
Electrifying systems on planes that are already certified will enable commercial services to be developed far faster, Combs says. Ampaire has developed an electric system for a six-seater hybrid aircraft that is already being used for research and pilot training, and plans to test it on a commercial route in Hawaii once Covid-19 restrictions are lifted.
Meanwhile, magniX, owned by Singapore’s Clermont Group, is working with Canadian seaplane company Harbour Air to gain certification for passenger flights of an electrified version of its de Havilland Beaver plane. It successfully completed a test flight last December, and hopes to start operating on short routes by 2022.
Multiple other research programmes are underway. One of the most widely publicised, the E-Fan X hybrid electric plane, was being developed by UK-based Airbus and Rolls-Royce. A test flight of the 100-seater Bae146 airliner was planned for 2021. But the project was dropped in April, just before Rolls-Royce revealed 9,000 job cuts in the wake of the Covid-19 travel slump.
Airlines are continuing with R&D into electrification, despite the impact of Covid-19. (Credit: Charles Platiau/Reuters)
However, the company has stated that it will continue ground testing associated with the E-Fan X to inform future projects. It is still working on the Accelerating the Electrification of Flight (ACCEL) project – part-funded by the UK government, and also involving the Aerospace Technology Institute (ATI); electric motor and controller manufacturer YASA; and aviation startup Electroflight. Its developers hope that the aircraft will reach a speed of at least 300mph, making it the fastest all-electric plane in history, when it is test flown later this year.
The ATI and Rolls-Royce are also working with Cranfield Aerospace Solutions – part of Cranfield University – on Project Fresson, a £9m 30-month project to design, manufacture and integrate a hybrid-electric propulsion system into a nine-seat Britten-Norman Islander aircraft, which is typically used on short flights such as island-hopping routes.
Meanwhile, Nasa is working on modifying an existing aircraft design with an electric propulsion system. Data from the original model powered by traditional combustion engines can then be compared with data produced by the electrically powered plane to inform certification processes for future planes.
When it comes to electric aircraft, it’s much less doom and gloom than people are saying. We’re doing more projects than prior to Covid
The huge impact of Covid-19 on the bottom line of aviation companies worldwide is not having a negative impact on research and development of electrification, commentators maintain. “Clearly the aviation market is in significant decline for some time to come,” says Mark Scully, head of technology of advanced systems and propulsion at the ATI.
“But companies are all looking to the future in terms of sustainable solutions, and many of them are talking to us about getting involved in that, from large organisations right through to small companies. In many ways, we’re probably seeing even more interest from small innovators in recent months,” he says.
Combs agrees. “When it comes to electric aircraft, it’s much less doom and gloom than people are saying. We’re doing more projects than prior to Covid, there’s a number of government and other programmes that have been initiated recently, so I would say this work is expanding right now,” he says, adding that his company has recently been contacted by governments – predominantly in Europe – interested in electrification projects.
In June, the French government announced a €15bn bailout package for its aviation sector, including €1.5bn to be spent on research and development of alternative fuels, and an aircraft that could be powered by electric-hybrid engines for short-haul journeys.
Electric planes will also need new regulation and certification. The main challenges are excess heat from batteries; onboard capacity; safety of high-voltage systems; and reducing the weight of the aircraft to enable the battery power to go further, Domone of Atkins explains.
Scully of ATI says the European Aviation Safety Agency has already issued guidance on battery systems for electric air vehicles to help engineers and designers.
Electric planes could become even more viable if the model for flying changed to enable a larger number of flights of smaller aircraft departing from local airports, rather than main city hubs, he says. “We’re not just about going green – we really think that electric aviation is going to be so huge as to provide infrastructure-light connectivity across the world,” he asserts.
Catherine Early is a freelance journalist specialising in the environment and sustainability. She writes for Business Green, China Dialogue and the ENDS Report among others. She was a finalist in the Guardian’s International Development Journalism competition.
This article is part of our in-depth Energy Transition briefing. See also: