Electric Vs Hydrogen – What’s The Future Of Aviation?

Many industries are looking for ways to reduce their carbon footprint in the future. The aviation sector is no exception. Technology changes may take time, but many companies are now looking at electric and hydrogen-powered aircraft possibilities. This article explores the two options.

British Airways, Carbon zero, Hydrogen
British Airways and ZeroAvia are working on hydrogen-powered flight. Photo: British Airways

Electric planes

There has been a lot of talk and progress in recent years about electric-powered vehicles. Electric cars are, of course, now a reality and growing in popularity and ability. Moving to aircraft, though, there are issues with battery capacity. Much more power is needed, and a battery would end up unfeasibly large (and heavy).

The energy density of a battery is much lower than that of aviation fuel. And to make it worse, an empty battery weighs the same as a full one, so there is no reduction in weight as the flight progresses as there is with fuel.

Several companies are working on electric aircraft, and there have been smaller aircraft built and flown. The Pipistrel Alpha Electro seats two people and has a range of around 139 kilometers (75 NM), for example.

Pipistrel Alpha trainer
The Pipistrel Alpha Electro. Photo: New York-air via Wikimedia

But current battery technology significantly limits the possibilities, especially for larger aircraft. Simple Flying followed a discussion at a conference in November 2019 that looked at this issue. Estimates are that a battery for an ATR aircraft, for example, would weigh around 20 tonnes, about the same as its MTOW.

Manufacturer Eviation is developing a nine-seater electric aircraft with a range of just over 440 NM and hopes to conduct test flights later this year. But for any larger aircraft or better ranges, there need to be some significant technological advances.

DHL Express Eviation Alice
The ‘Alice’ from Eviation recently secured orders from DHL for cargo variants. Photo: DHL

Airbus was working on a hybrid-electric aircraft, the E-fan X, but the manufacturer canceled this project in April 2020. This would have seen a BAe 146 aircraft with one engine switched to electric power.

Andreas Klöckner, Coordinator of Electric Flying Program Strategy Aeronautics at the German Aerospace Center (DLR), has estimated that it would be at least 2040 before a working electric large aircraft is developed.

Hydrogen-powered aircraft

Hydrogen power is a popular possibility in many industries, with an abundant supply. No carbon dioxide is produced as a by-product of combustion.

An aircraft would use compressed liquid hydrogen as fuel. This could either be burned in a jet engine (with no carbon dioxide produced) or generate electricity using a fuel cell. As well as lowering emissions, a hydrogen-powered engine would also be a lot quieter, another significant appeal for the aviation industry with ever busier airports and longer operating hours.

Manufacturers have started to look at designing hydrogen-powered aircraft. Boeing has built a Fuel Cell Demonstrator, a small aircraft powered by a hydrogen fuel cell. And Airbus has carried out extensive studies, together with several European countries, and looked at the possibility of using hydrogen in a hybrid aircraft. Other smaller companies have developed prototypes too. The first hydrogen-powered passenger plane took flight in 2016, a four-seat light aircraft designed by Pipistrel and equipped with the DLR Institute of Engineering Thermodynamics fuel cell system.

HY4 hydrogen aircraft
The HY4 hydrogen aircraft produced by Pipistrel and DLR. Photo: DLR, CC-BY 3.0 via Wikimedia

Fuel infrastructure will limit hydrogen

There is a second, significant challenge, though, with hydrogen. As well as developing hydrogen-powered aircraft, there would need to be substantial changes to fuel supply and airport infrastructure. All airports are equipped to store and supply kerosene aviation fuel, which would have to change on a large scale for workable aircraft operations. If aircraft were severely limited to refuel, it would be hard to make hydrogen work.

This is starting, but it is early days. There are currently plans underway to develop Europe’s first commercial plant for hydrogen-based aviation fuel. Norsk e-Fuel is leading the development of a plant, which should offer a maximum capacity of 10 million liters of hydrogen-based jet fuel within three years.

jet fuel price
Replacing standard jet fuel will be a challenge. Photo: Getty Images

Which will we see first?

Both electric and hydrogen-powered aircraft are feasible, but both have their challenges. With the need for a significant change in airport infrastructure globally, it is likely to be some time before we see hydrogen-powered aircraft operating on a considerable scale. For manufacturers and airlines to commit to making it work, there would need to be a shift from the whole industry.

Battery power has its limits, too, with significant advances in battery technology and the size needed for large aircraft. Hybrid aircraft can be developed in the interim, though, which should help with emissions reduction and research and development. But don’t expect to be boarding a fully electric or hydrogen-powered aircraft any time soon!

What do you think of battery technology for aircraft or hydrogen as a fuel source? Which do you think will be most successful or appropriate for aircraft? Let us know your thoughts in the comments.