Although the electric airplane market is in its infancy, it is off to a surprisingly strong start, according to IDTechEx. To the best of IDTechEx's knowledge, there is only one example of an electric airplane for sale today: the Pipistrel Velis Electro. From IDTechEx's perspective, it has had a stellar start, with a surprising number of deliveries since its first in 2020.

Electric powertrains fit small general aviation planes well, helping to drive a predicted 35.7% CAGR in electric general aviation airplanes between 2025 and 2035. This is just the beginning of a new era of aviation, with the new IDTechEx report “Sustainable Future Aviation 2025-2045: Trends, Technologies, Forecasts” finding that electric and hydrogen-powered airplanes can contribute to a decarbonized aerospace industry across a spectrum of aircraft.

From the smallest two-seaters like the Velis Electro, to the largest planes on the market, such as the Boeing 777, electric and hydrogen power can provide value and reduce GHG contribution.

Emissions of a Boeing are 777-9 per hour compared to a theoretical electric alternative of the same size. Source: IDTechEx

Despite the success of batteries in the automotive industry, and the technological improvements they have shown, it will be almost impossible for battery-electric aircraft to achieve the ranges of existing jet fuel airplanes. The batteries will simply be too heavy, especially for commercial airliners, which need to burn tens of tonnes of fuel before landing to hit their maximum landing weights. T

his weight limit leaves scarcely a few tonnes of wiggle room for batteries to occupy. A narrow-body airplane like the Boeing 737-10 requires around 100MWh to get its full range. A battery this size would weigh hundreds of tonnes. Even future battery technologies such as silicon-anode, metal-anode, or aluminum air will likely be too heavy. As such, full range with battery power alone is a near impossibility, according to IDTechEx.

The key to the success of battery-powered commercial airliners is to deploy them strategically. Some of the most popular, highest-volume routes flown today are less than 1,000 km. Routes such as LAX to SFO (Los Angeles to San Francisco) and LHR to FRA (London to Frankfurt) are only 540 km and 655 km respectively. This is not easily electrifiable today, but there are some avenues open that could help get there, such as:

• Improved battery technologies

• Improved plane design with better flight efficiency

• Higher maximum landing weights to carry more batteries

Hydrogen has great promise due to its gravimetric energy density. At 39.3kWh/kg, it is three times as energy-dense as jet fuel and more than 100 times as energy-dense as today’s lithium-ion batteries. This can be exciting until volumetric limitations are understood. Even in liquid form, hydrogen occupies nearly four times the volume of jet fuel for the same energy. The limiting factor is getting enough storage volume on the airplane to make it useful. It is also limited by the need to be cryogenically cooled to remain a liquid, or pressurized to have useful volumetric energy density as a gas. Despite these limitations, the IDTechEx report explains how hydrogen can be used strategically to fulfill significant air travel demand.

A key challenge for hydrogen will be balancing fuel costs with carbon credentials. Green hydrogen, from renewable water electrolysis, is the greenest, but also the most expensive way of producing hydrogen. Blue hydrogen, produced from natural gas with carbon capture and storage (CCS), is significantly cheaper but does not provide 100% CO₂ removal. Conventional grey hydrogen on the other hand can be made very cheaply, and a grey hydrogen-powered fuel cell airplane would be much cheaper to fuel than jet fuel. However, grey hydrogen emits around 10 kg of CO₂ for every kg of hydrogen. The report shows the expected net emissions for each hydrogen production type highlighting which can produce a benefit compared to traditional fossil fuels.

IDTechEx believes that the technology exists today to build a hydrogen airplane, the industry is just in the process of demonstrating the technology, certifying, scaling etc. The process will take many years. However, even if hydrogen and electric planes were ready today, the industry would still need SAF to decarbonize by 2050.

There is currently a fleet of around 25,000 commercial airliners in use today, and some of them will still be around in 30 years, such is the long life of these airplanes. Business jets and general aviation are even worse. This report finds there are planes in use today in the US that were built more than 80 years ago. The only realistic option to fully decarbonize by 2050 is to adopt SAF for airframes that are built today, but still be in use then.

In addition to aging airframes, there will still be other factors necessitating SAF. The maximum range of planes today is unlikely to be reachable with hydrogen, meaning some routes will be confined to kerosene-like fuels indefinitely. Additionally, some airports simply won’t be able to afford new electric and hydrogen fuelling infrastructure and will have to take SAF as a drop-in alternative.