The search for alternatives to aircraft power will be critical for meeting future carbon-free goals
By Dan Booth
Although longer-range aircraft will likely continue to rely on burning up some kind of combustible fuel for the near future, airlines have been investing in the idea of fielding electric-powered flight solutions for some time. The vehicles are known as eVTOLs – electric vertical take-off and landing vehicles, or flying taxis, and they have the potential to revolutionize shorter haul operations.
Most recently, United Airlines announced a $15 million investment in a company called Eve Air Mobility and has agreed to buy 200 of the Eve Air’s four-seat electric aircraft with options for 200 more. With expected delivery as early as 2026, the news marks another step forward in the development of air travel powered by sources other than fossil fuels.
Leading aerospace companies such as Airbus, Boeing and Embraer, along with a number of startups, are working to develop eVTOL aircraft, attracting investment dollars and orders from airlines like United. The carrier also has deals going with Archer Aviation that includes a fleet of 200 of the battery-powered short-haul electric aircraft targeting a launch of consumer flights in 2024, and a conditional agreement with Swedish startup Heart Aerospace for 100 of its 19-seaters which could reach the market as early as 2026.
Eve Air Mobility has also signed Halo Aviation Ltd., a provider of helicopter and private urban air mobility travel services in the US and the UK, as its launch customer. The deal includes a firm order for 200 eVTOL aircraft with an expected delivery date of 2026.
Other significant developments in the eVTOL field include a $1 billion deal between Brazilian domestic carrier Azul and electric aircraft manufacturer Lilium Air Mobility for 220 seven-seater Lilium Jets beginning in 2025. And American Airlines is making a $25 million investment in eVTOL developers Vertical Aerospace. American expects to make a $1 billion pre-order of up to 250 aircraft, with an additional 100-plane option.
Batterys Not Required Another zero-carbon strategy involves electric flight powered by hydrogen. Both American and United have invested in ZeroAvia, a developer of hydrogen-electric engines designed to power regional jet aircraft. The British/American firm is developing aircraft engines that use electricity created in a fuel cell to power an electric motor. Since no fossil fuels are burned, there are no emissions.
ZeroAvia is currently working to achieve certifications for the engines to be incorporated into the regional jet market as early as the late 2020s.
In addition to American’s investment, a memorandum of understanding provides the carrier with the opportunity to order up to 100 engines from ZeroAvia’s hydrogen-electric powertrain development program. For its part, United’s equity stake would see the carrier purchase up to 100 of ZeroAvia’s zero-emission engines, which could be retrofitted to United Express’ CRJ-550 aircraft as early as 2028.
Meanwhile, other technologies offer the promise of using existing jet engines burning non-fossil fuel renewable energy. Lufthansa Group is collaborating with technology startups in Europe to develop power-to-liquid processes that use renewably generated electricity, water and CO2 to create synthetic crude oil that can be refined into jet fuel. The airline group is a partner and pilot customer of one of the world's first plants for the production of PtL crude oil in Werlte, Germany, operated by atmosfair, a climate protection organization. The Lufthansa Group has agreed to purchase at least 6,600 gallons of PtL fuel annually and make it available to clients.
A second pilot is underway with ETH Zurich spinoff Synhelion to develop technology to produce SAF from renewable energy sources. The process is similar, using concentrated solar heat to manufacture a syngas from CO2 and water that can then be turned into jet fuel. When the fuel is burned, it will only produce as much CO2 as was used in its manufacture. Lufthansa Group Airline SWISS is set to become the first customer for the solar kerosene in 2023.