Insight 19: Powering the Skies – The Rise of Electric and Low-Carbon Aircraft
Summary
The aviation industry is in the early stages of the energy transition, with alternative technologies such as electric and hydrogen, as well as synthetic aviation fuels, under development. With rapid advancements in technology, the electric aircraft market is predicted to grow significantly over the next decade. Battery-powered aircraft are expected to take the largest share of the UK urban and domestic aviation markets by 2050, with synthetic aviation fuels and hydrogen emerging as the key technologies for medium and long-haul aviation. The UK has an opportunity to be at the cutting edge of these developments for all three of these technologies.
Focus of the Insight
This insight outlines the increasing size of the global electric market and explores the different low carbon technologies that could become available for aviation, particularly hydrogen, batteries and SAF. The performance characteristics of battery technology for aviation and proposed actions to develop and support the UK aerospace industry in the transition are also highlighted.
Conclusion
Pressure to reduce carbon emissions from air travel is increasing. While battery technology has a lower energy density than fossil-based fuels, it has the potential to be widely used in short-haul and domestic aviation markets. Even this would fundamentally change aviation since around 15% of global revenue passenger-km and half of the global departures could be served by aircraft with a range of 600 miles.
Battery-electric aircraft have shown to be highly efficient in converting stored energy into propulsion, mainly due to the high proportion of electrical energy used for propulsion. However, substantial research challenges still exist with academic and commercial research needed to overcome the current limitations of electrically propelled aircraft and make them commercially viable.
Enhancements in battery energy density, safety, fast-charging capabilities and thermal management systems are all crucial for the commercial viability of electric planes. Meeting the demands of commercial aviation will require transformative breakthroughs in energy density, materials science and system integration, not just incremental research improvements. The following eight research areas have been identifed by the Argonne National Laboratory to facilitate the development and commercialisation of electric aviation batteries:
- Evaluate high-discharge operation of lithium-ion cells for eVTOL applications;
- Evaluate next-generation lithium-ion (silicon anode, advanced cathode, lithium metal) batteries under aviation conditions;
- Develop solid-state batteries to enable 50-passenger regional electric aircraft;
- Study 3 to 5 times higher energy density systems for large regional and 737-class planes;
- Identify opportunities for different aircraft classes as a function of battery energy density;
- Develop efficient battery pack designs for aircraft;
- Identify failure modes under different operating conditions;
- Connect aircraft propulsion models to battery performance to define battery targets under aviation conditions.
Hydrogen-powered aircraft have the potential to overcome the limitations of batteries for long-haul fights. While hydrogen fuel cell-powered aircraft have lower efficiency than battery-electric aircraft because of energy losses in converting hydrogen fuel to electricity, they offer greater energy density and the potential for longer fights. However, commercial adoption is expected to be slow and lagging the adoption of other SAFs until well after 2050 due to challenges in safe hydrogen storage, fuel cell efficiency and infrastructure development that need to be resolved.
The development of infrastructure and safety standards for SAF, battery and hydrogen-powered aviation will be critical for achieving widespread adoption of these technologies. Infrastructure facilities not only include the development of SAF, battery and hydrogen storage facilities but also the establishment of a comprehensive network of refuelling, recharging and servicing stations. Safe deployment of battery and hydrogen-powered aircraft for passenger travel will also require research and global collaboration to establish common safety standards.
Currently, UK-based aerospace companies face many of the same risks evident in the UK automotive industry. Retaining jobs in the UK will require keeping pace with technological advances to maintain UK competitiveness as the sector decarbonises. However, the UK’s position as a leader in aerospace technology could be at risk without new discoveries from domestic research, which could lead to a decline in the industry’s strength and increased offshoring of current areas of expertise.