Skip to content

Alternative Fuels

Image credit: Alex Proimos via Flickr


The aviation industry has long championed biofuels and other alternative fuels as offering a real breakthrough in terms of aviation sustainability, breaking the sector’s dependence on fossil fuels and slashing emissions. To provide an incentive, the use of aviation biofuels under the EU Emissions Trading System has been zero-rated on the basis that the emissions reduced or absorbed through biofuel production (whether using plant material or waste) would match those produced when the fuel was burned. But over time a number of issues have emerged.

Key challenges

Environmental groups have cautioned that many early-generation biofuels have not been produced sustainably, either resulting in deforestation of land which has been cleared for fast-growing crops or displacing farmers who may then clear more forest for food crops. Work is currently under way to promote second (non-food crops or food crops that have already served their purpose) and third (algae) generation biofuels which address some of these concerns, and more focus is being given to the actual life-cycle emissions associated with biofuel production.

Biofuels cannot be assumed to be carbon-neutral. While these fuels have the potential to reduce emissions significantly in comparison to conventional jet fuel, depending on how they are produced, they can in fact increase emissions in some circumstances. Life Cycle Analysis (LCA) quantifies the total emissions impact of a given alternative fuel over the course of its life cycle, providing a means of differentiating between different types of fuels for policy purposes.

Competition with other sectors (similarly keen to reduce emissions) has, however, become significant and the Committee on Climate Change – the official body advising the UK Government on climate issues – has argued that bioenergy is more efficiently used in power stations where it can be combined with carbon capture and storage facilities. The cost of biofuel production has meanwhile made it unattractive to the aviation industry where fuel costs typically account for up to 40% of carriers’ total operating costs.

The CEO of IAG (the International Airlines Group), Willie Walsh, has acknowledged the limited role that the UK’s flagship waste-to-jet fuel plant could play in addressing aviation emissions. As a result, despite highlighting the benefits of biofuel production in its Aviation Policy Framework, the Government now predicts that it is likely to account for only 2.5% of UK aviation fuel by 2050.

IATA, the International Air Transport Association, produces an annual report on the uptake of alternative fuels in the aviation industry globally. The 2013 edition is available here.

AEF position on alternative fuels

We support efforts by the aviation industry to reduce its emissions, including through the use of sustainable biofuels if they can meet the following criteria:

  1. Emissions must be accurately accounted for using LCA and not zero-rated.
  2. Full life-cycle analysis must demonstrate that net emissions are lower than conventional fuels.
  3. Sustainability appraisals must include direct and indirect land-use change.

Biofuels have the same climatic impacts as conventional aviation fossil fuels when combusted, including the net warming from NOx emitted in the upper atmosphere and from contrails, as well as from CO2. This should be reflected in any estimate of the extent to which biofuel use in aircraft can offset aviation’s climate change impact.

Given the significant environmental and economic challenges associated with the production of alternative fuels, it seems unlikely that their use will significantly impact aviation’s overall emissions in the short-to-medium term.