The latest aviation innovation is under way. The first transatlantic passenger flight using only sustainable aviation fuel, or SAF, took off from London Heathrow airport, destination New York, shortly before 12 noon on Tuesday 28 November.
The Boeing 787, “Lucy in the Sky”, had to be specially certified by the aviation authorities in the UK, Ireland, Canada and the US, the nations it is flying over. No paying customers were on board – instead, around 100 invited guests made the 3,500-mile journey.
Ahead of departure, Virgin Atlantic’s chief executive, Shai Weiss, told The Independent:“This is a proof-of-concept of what can be done and what should be done.”
But environmentalists dispute some of the claims made for SAF, and say the only real solution to the impact of aviation on the planet is to reduce the amount of flying. These are the key questions and answers.
What’s the big idea?
The aviation industry says that sustainable aviation fuel, or SAF, can reduce overall emissions by 70 per cent – and the aim of this flight is to show that if the world gets to the point where it can make enough of SAF, there would be no need for oil-based fuel.
Unlike any previous transatlantic flight, this one used zero fossil fuel – instead flying mainly on a mix of recycled vegetable oil, animal fat and household waste.
The two Rolls-Royce engines are mainly fuelled by processed waste fats, known as HEFA (hydroprocessed esters and fatty acids). But 12 per cent of plant-based synthetic aromatic kerosene (SAK) is added to provide the necessary mix for the engines to function normally.
So zero emissions?
Far from it. The amount of fuel burnt (about 45 tons) and carbon dioxide generated by the seven-hour Virgin Atlantic Flight 100 is exactly the same as if normal Jet A1 kerosene had been used.
The difference is: over the lifecycle of the fuel, the net amount of greenhouse gases generated is much lower. For example, by converting household waste to SAF, it won’t end up generating methane as landfill.
Another example is with plant-based fuel: while those plants are growing, they absorb CO2 from the atmosphere – and then, when burnt an aircraft engine, they release it back.
Which, says the aviation industry, is a pretty good example of moving towards net zero. But they are desperate for wider availability of affordable SAF.
Rania Georgoutsakou, managing director of Airlines for Europe, says: “Today’s transatlantic trailblazing trip is an exciting glimpse into the future of flying but if we want to move from it being a one-off stunt to a daily reality, we need action now.
“Across Europe there is enormous airline appetite for sustainable aviation fuels combined with ambitious mandates for SAF use under new EU rules. But we are starting from a low base.
“However, with the right level of government incentives and support we could supercharge supply in Europe – adding 30 sustainable fuel factories across the continent by 2030 – and truly transform our industry.”
Does everyone agree?
Far from it. Anna Hughes, director of Flight Free UK, says: “This relies on the emissions-savings-claims from SAF being accurate. There is no difference in emissions when the fuel is burned; any ‘savings’ come from the life-cycle of the product.
“But converting these to aircraft-grade fuel is very energy-intensive, meaning that on balance, you might as well just use kerosene.”
Campaigners also say that growing crops specifically to be converted to fuel can damage biodiversity and cause deforestation – making it worse than using fossil fuels.
The Royal Society calculates that the energy crops considered – rapeseed, miscanthus, and poplar wood – would require more than 50 per cent of the UK’s available agricultural land to replace aviation fuel.
The UK government is keen to champion the processing of waste into SAF, saying: “Repurposing waste products into jet fuel to cut emissions provides the most immediate solution to help decarbonise our skies.”
But the Royal Society says: “‘Waste’ feedstocks including sewage, solid municipal waste, or forestry residues, could contribute towards net zero fuel demand, but there is competition from established markets for these feedstocks and significant investment in fuel production and collection infrastructure is required.”
In terms of inedible animal fat, T&E (Transport and Environment), Europe’s leading NGO campaigning for cleaner transport, calculates: “A flight from Paris to New York needs 8,800 dead pigs.”
Should we simply fly less?
Anna Hughes of Flight Free UK thinks so. She fears some passengers may be soothed into believing there is a simple and painless solution to the impact of aviation on the planet.
“This is a seminal moment for the industry and government, allowing them to pretend that we can continue to fly as much as we like with no harm to the environment.
“The reality is that we still haven’t worked out how to meaningfully reduce the environmental harms of flying, so the short-term answer must be that we need to do it a lot less.
“While it sounds promising that a flight can be fuelled with 100 per cent SAF, we are many years away from seeing so-called ‘sustainable’ fuels in widespread use. The reality is that in order to reliably bring down flight emissions, we need to be flying less, which is certainly not what the industry wants to hear.”
Helen Coffey, the travel editor of The Independent, agrees: “The branding of this type of fuel has been, I’ll admit, extremely clever. The seductive words ‘sustainable aviation fuels’ suggest they produce fewer emissions than regular jet fuel when the plane is airborne; this simply isn’t the case.”
But Virgin Atlantic’s boss, Shai Weiss, told The Independent: “Flying is something that island nations need. We need to do business, we need to do science, we need to visit friends and family.
“To think that we can magic up elimination of flying, I think is naive to an extreme.”
Earlier this year, the UK government made domestic air travel significantly more attractive by halving Air Passenger Duty.
When will passengers fly routinely in SAF-powered planes?
They are already – but using only a fraction of SAF alongside normal fuel. And that highlights the real problem: SAF is in very short supply worldwide, and consequently costs a fortune.
The aviation industry says governments must come to the rescue, and support this nascent industry – to enable the goal of net zero aviation in 2050 to be achieved.
What about other solutions?
Electric aviation using batteries or hydrogen is zero emission. But the Transport Select Committee says: “Electric batteries are unlikely to become small or light enough to make them suitable for anything beyond short-haul flights.
“Hydrogen is likely to demand large amounts of storage space and is highly flammable.”