Low-carbon aviation fuels

This POSTnote reviews the main types of low-carbon aviation fuels and their potential for use, as well as associated challenges and opportunities. It supplements POSTnote 615: Climate Change and Aviation.

Key points

• Low-carbon aviation fuels could reduce UK aviation CO₂ emissions by 5-30% by 2050.
• Biofuels vary by the inputs and processes used to produce them. They face environmental sustainability challenges around land use and overall emissions.
• Electro-chemical fuels have significant technical potential but are currently costly.
• Hydrogen is being investigated as a fuel for short-haul aircraft but faces significant challenges due to its low energy density.
• Policy mechanisms such as incentives and targets for uptake can accelerate the phase-in of low-carbon aviation fuels.

Low-carbon aviation fuels can replace conventional aircraft fuel (jet fuel) to reduce greenhouse gas emissions from flights. Estimates suggest that they could mitigate between 5% and 30% of carbon dioxide (CO₂) emissions from UK aviation by 2050. These fuels do not require major changes to aircraft or airports and could in theory be implemented immediately. They can be used in long-haul flights, where other options for mitigating emissions are limited. Several airlines have invested in these fuels, seven airports supply them and six production methods are currently certified, with more under review.

However, the uptake of low-carbon aviation fuels has been low. In 2017, 0.002% of total fuel consumption by aircraft was from low-carbon fuels. The main barriers are the high production costs and high levels of required upfront capital investment. Aviation fuels need to be very energy dense, and safety requirements are strict, mean that timelines for developing and certifying fuels are long. Aviation also competes for low-carbon fuel technologies and for the use of biomass with the road transport sector electricity production sector.

POSTnote 615: Climate Change and Aviation is available online.

Acknowledgements

POSTnotes are based on literature reviews and interviews with a range of stakeholders, and are externally peer reviewed. POST would like to thank interviewees and peer reviewers for kindly giving up their time during the preparation of this briefing, including:

• ADS Group*
• Dr Simon Weeks, Aerospace Technology Institute
• Sarabpal Singh Bhatia, Airbus
• Aviation Environment Federation
• Boeing
• Leigh Hudson, British Airways*
• Carbon Engineering*
• Dr Stuart Capstick, Centre for Climate Change and Social Transformation, Cardiff University
• Steve Westlake, Cardiff University
• Civil Aviation Authority
• Owen Bellamy , Committee on Climate Change*
• Ian Poll, Cranfield University
• Department for Business, Energy and Industrial Strategy – Aerospace division
• Department for Business, Energy and Industrial Strategy – Emissions Trading division
• Department for Transport
• Government Office for Science
• Greenpeace
• John Andresen, Heriot-Watt University*
• Mercedes Maroto-Valer, Heriot-Watt University*
• Bing Xu, Heriot-Watt University*
• Peter Bearman, Department of Aeronautics, Imperial College London
• Emile Greenhalgh, Composites Centre, Imperial College London
• Dr Marc Stettler, Centre for Transport Studies, Imperial College London
• International Air Transport Association
• Jonathon Counsell, International Airlines Group
• Dan Rutherford, International Council on Clean Transportation
• International Emissions Trading Association
• David Lee, Centre for Aviation, Transport and the Environment, Manchester Metropolitan University
• Natural Resources Canada
• Leo Murray, Possible
• Robert Thomson, Roland Berger Ltd
• Rolls-Royce
• Dr John Green, Royal Aeronautical Society
• Dr Matt Watson, Sheffield University
• Dr Andy Jefferson, Sustainable Aviation
• Bill Hemmings, Transport & Environment
• UK Research and Innovation Future Flight Challenge
• Andreas Schafer, Energy Institute, University College London
• Dr Simon Blakey, Department of Mechanical Engineering, University of Birmingham
• Piers Forster, Priestley International Centre for Climate, University of Leeds
• Alice Larkin, Department of Mechanical, Aerospace & Civil Engineering, University of Manchester
• Dr Emma Harvey, Virgin Atlantic and Virgin Holidays

(*denotes contributors who externally reviewed the POSTnote)