Government support for Sustainable Aviation Fuels and Heathrow expansion

In this guest blog, Neil Spurrier from Teddington Action Group navigates us through what is meant by “sustainable aviation fuels” and why they are not the silver bullet to Heathrow expansion as the Airport claims.

Heathrow expansion is still approved government policy through the Airports National Policy Statement, which is still valid. Now the UK Government is supporting the creation of Sustainable Aviation Fuel in an initiative it calls “a revenue certainty scheme”. This is defined as a “a scheme whose purpose is to give producers of sustainable aviation fuel greater certainty than they otherwise would have about the revenue that they will earn from sustainable aviation fuel that they produce.” Effectively taxpayers’ money will be used to subsidize such fuels to provide certainty to manufacturers of the revenue that they will receive. As yet, there is no detail on the form of the scheme, but the Secretary of State for Transport is obliged to open a consultation on how this might work. The Government had previously confirmed its support for a revenue certainty scheme and its publication is at https://www.gov.uk/government/news/new-measures-to-support-sustainable-aviation-fuel-industry.

So; what is “Sustainable Aviation Fuel”? BP defines Sustainable Aviation Fuel (SAF) as “produced from sustainable feedstocks and is very similar in its chemistry to traditional fossil jet fuel. Some typical feedstocks used are cooking oil and other non-palm waste oils from animals or plants; solid waste from homes and businesses, such as packaging, paper, textiles, and food scraps that would otherwise go to landfill or incineration. Other potential sources include forestry waste, such as waste wood, and energy crops, including fast growing plants and algae. Air bp’s SAF is currently made from used cooking oil and animal waste fat.”

Most right-thinking people now recognize that fuels made directly from crops growing are not sustainable. They are either taken from crops that would otherwise have been grown for food, or, in the case of deforestation like extraction of palm oil, involve destruction of carbon absorbing trees and destruction of natural habitats. Even the Government in its proposed Sustainable Aviation Fuel “Mandate” say that there will be “Land Criteria” “to ensure any land use impacts resulting from the harvesting of the principal crop and/or collection of the resultant waste are appropriately managed”.

Waste resources, or “second generation” fuels as they are sometimes known, might save some net greenhouse gas emissions. The industry makes some very wacky claims for these fuels made from vegetable waste like used cooking oils or oil extracted from other waste products or waste wood and forestry. BP, along with many others in the industry, state that SAF “has the potential to provide a lifecycle carbon reduction of up to 80% compared to the traditional jet fuel it replaces”.

 So-called “Drop-in” sustainable aviation fuel is  carbon based and will therefore emit CO2 on combustion. There is therefore no advantage on combustion. The advantage comes from an offset from the CO2 that the crop or waste has previously absorbed through its natural growth prior to its conversion into fuel. Another SAF is Hydrogen (which is not a drop-in fuel but requires a substantial rethink in the construction of the aircraft), which does not produce any CO2 on combustion so that looks even better. The problem with hydrogen is that it produces large quantities of Nitrous Oxide (NOx) on combustion. NOx is itself a greenhouse gas and therefore burning hydrogen is not the proverbial silver bullet. You may have noticed that some hydrogen fueled vehicles such as buses use “hydrogen fuel cells”. Here, hydrogen is mixed with air via an electric current to produce energy, thus avoiding combustion and the emission of NOx. Whether an aircraft could be made to work on a hydrogen fuel cell is a moot point.

This claimed 80% reduction is all very nice but what is a “lifecycle carbon reduction” when it comes to a sustainable aviation fuel? It is surprisingly difficult to find a definition – and maybe the industry intends this. A well-known firm of property consultants describes the carbon savings that can be achieved by best-practice design and choice of materials used in building construction. Efficient buildings with low energy and water use can give an emissions saving over the lifecycle of the building meaning “the building’s lifespan” -  which could be say 100 years. Transposing this to aviation fuel made from waste, we are looking at the typical lifespan of the waste and its breakdown. This could be say 25 years. We are thus comparing the carbon emission from aviation fuel burn over an 8-hour flight being offset against the degradation time of 25 years if the waste were left unused.

This is the crux of the greenwashing. The industry washes the emissions on combustion over say an 8-hour flight against the slow degradation over 25 years. The Government have simply swallowed this. 8 hours set off against 25 years……

We have not considered the energy consumed in converting the waste into fuel. This can be very considerable and could itself emit large quantities of greenhouse gas. Some claim that the conversion will use “green” hydrogen made from renewable energy. However, this renewable energy itself is limited, and may have to be taken away from other uses like domestic heating. None of this has been properly factored into the calculations. The Aviation Environment Federation provides some interesting articles on its website.

In truth, we do need to reuse waste, but we also need to reduce our flying. This is stated by the Committee on Climate Change. There is no 80% saving on CO2 emissions by using SAF in the aircraft. CO2 will still be emitted from the aircraft, just as it would from a fossil fueled aircraft. CO2 will still be emitted in the making of the SAF – just like fossil fuel. The offset then will not be completed for some 25 years – by which time there will have been billions more flights emitting CO2!

The truth is that we need to follow the advice of the experts. The Government’s own Committee on Climate Change says we should fly less, thus emitting fewer greenhouse gases. The sad truth is that flying emits large quantities of greenhouse gases and SAFs are not going to stop that. The Committee on Climate Change has repeatedly stated that airport expansion should be tightly controlled. In its June 2023 Report to Parliament, it went so far as to say “There has been continued airport expansion in recent years, counter to our assessment that there should be no net airport expansion across the UK. No airport expansions should proceed until a UK-wide capacity management framework is in place to assess annually and, if required, control sector CO2 emissions and non-CO2 effects”.

Quite simply Heathrow should not expand – let alone construct a third runway. The Airports National Policy Statement should be withdrawn. SAFs are not the silver bullet claimed and taxpayers’ money is much better spent elsewhere.