The electrification of transportation has reached a level where it increasingly feels like it is a matter of when rather than if battery-powered vehicles will become the majority of transportation solutions, leaving fossil fuel-powered cars as a legacy option.

The first electric passenger train was showcased in 1879 and transformed the railway network by enabling the safe use of huge tunnels.

Meanwhile, after a century of false starts, electric cars and vehicles started selling in significant numbers, starting with the Nissan Leaf in 2009. In the 2020s, they reached a point of critical mass where it seems extremely likely that the market will sustain itself and grow even larger.

With trains and automobiles going electric, that only leaves planes, but given the challenges involved in electric flight, as well as some rather notable recent events, will we see a battery-powered jumbo jet anytime soon?

Trip The Flight Fantastic

Developing a feasible aircraft is an extremely complicated balance of power and weight, with much higher stakes than a car or a train.

Trains can use electrified rails augmented with batteries, whilst if a car runs out of battery, the worst thing that can happen is that it will coast to a stop and require a tow. According to The AA, even that is remarkably rare.

With aircraft, however, running out of power can effectively be a death sentence, which makes fuel management one of the most critical tasks of any aircraft operator; too little fuel is dangerous, but too much fuel makes the plane heavier than it needs to be and can eat into profit margins.

This has historically made developing an electric plane extremely difficult outside of UAV drones, and barely over 100 aircraft powered by electric motors have been created, all of which are prototypes at this stage.

The first crewed flight by an electric aeroplane was the Militky MB-E1 in 1973, a modified motor glider with a 10kW electric motor and Ni-Cd batteries that provided a maximum altitude of 380m for a total of 12 minutes.

The big difficulty with electric aircraft is battery technology, to an even greater degree than has historically been seen with electric cars.

Energy density has always been the limiting factor for aircraft, as it is impossible to simply make bigger batteries as the overall weight of the plane reaches a tipping point where the extra energy of the plane is not enough to offset this.

A jumbo jet the size of an Airbus A320 would require a power pack that delivers 2000 Wh/kg. At present, experimental batteries that can even reach half that are exceptionally uncommon, and until that changes, electric aircraft will be limited to low-range, small-capacity air taxis.

A major complication to this is the bankruptcy of Northvolt, which according to FlightGlobal had links to several electric aircraft startups, and has had a ripple effect across the battery market in general.

To what extent remains to be seen and will likely depend on the conclusion of their restructuring, as the downfall of Northvolt, despite some reporting to the contrary, was the result of Northvolt’s overly-ambitious expansion and is largely unrelated to the electric battery market as a whole.

The biggest effect this has had is on Heart Aerospace, a Swedish startup that had plans to make a 30-seater electric aircraft, although it did also note that the ES-30 experimental aircraft they are currently developing does not use Northvolt batteries, but instead was focused on compatibility.

Another complexity is operating temperatures. Electric vehicle drivers have known for a while that lithium-ion batteries tend to lose performance in colder temperatures, with dramatic drops in range noticed with temperatures below freezing.

Calculating the temperature of the hull whilst at cruising altitude can depend on a wide variety of factors, but it is significantly below freezing, which means that efficient systems will need to be in place to keep the batteries warm that do not themselves drain too much of the battery.

The advent of other battery technologies such as solid-state, lithium-air and sodium-ion could potentially fix this issue, as well as avoid the potential volatility issues at higher heats that can happen on landing approaches.

A final, rather unusual factor that electric aircraft need to bear in mind is that the weight of the plane in flight will be constant. This is different to jetliners, which get progressively lighter as the flight continues.

This affects some structural elements, which often need to be reinforced for electric planes in ways that would not be required for those powered by jet fuel.

However, with battery capacities constantly improving, there is a chance that a breakthrough will turn an electric aircraft from impossible to the way of the future extremely quickly.