All forecasts point to dramatic growth in aviation over the coming decades – but can more flights and more passengers be accommodated without a significant increase in CO2 emissions?

A grouping of UK industry players including manufacturers, airlines, airports and air navigation service providers believe this is possible – but only if the government takes steps to support the development of biofuels.

Launching a consultation paper at July’s Farnborough air show on the role of carbon-neutral fuels in achieving the UK’s ambitions for carbon reduction, industry group Sustainable Aviation stressed that the technology is promising. However, that potential cannot be realised without active government support and a clear policy framework to “stimulate production and investment in sustainable aviation fuels”.

In the group’s latest analysis, its 2008 assumption that sustainable, carbon0neutral fuels have the potential to cut UK aviation carbon emissions by 9% by 2050 turned out to be wrong. Now, they are confident that 18% is possible.

A study by energy consultancy E4tech, commissioned by Sustainable Aviation, estimates that global sustainable aviation fuel supplies could reach 13 million tonnes in 2030. This would create greenhouse gas emissions savings of 35 million tonnes of CO2 equivalent.

Moreover, says E4tech, UK production could be 640,000 tonnes, which translates to about 12 sustainable fuel plants that would produce both aviation and road transport fuels. Such an industry would create some 4,400 full-time jobs, give the economy a £480 million ($800 million) boost and improving energy security. Getting to that stage would also provide a foundation for scaling up production.

And, all of that should be possible without diverting crop production from food or carving out farmland by tropical deforestation.

British airways London City 640

BA will fly synfuels from London City (Rex)

Significant steps are already being taken. British Airways and fuel specialist Solena earlier this year identified a site in Essex for the landfill waste-to-jet kerosene conversion plant they are planning, which will produce enough fuel to power BA's flights from London City airport "twice over", according to the carrier. Virgin Atlantic plans within two to three years to be flying Shanghai and New Delhi to London Heathrow with a synthetic fuel derived from waste carbon it has developed with New Zealand firm LanzaTech.

However, Keith Bushell, Airbus’s UK stakeholder manager for environmental affairs, says the investment needed to get to serious volume will only be available if the government moves to reduce investor risk.

It could do this by actively supporting technology development so new fuels can be brought to market. In the medium term, that means “stimulating the market” while production costs are high.

The UK’s approach to sustainable fuels so far, he says, has been to prioritise research and investment on road fuels – which is a lost opportunity. While road transport is the biggest polluter, road vehicles have many fuel options.

Aviation relies on so-called “drop-in” fuels, which are molecularly identical to jet kerosene – and thus can be blended with traditional, certificated fossil fuels.

Such fuels exist. Certificated biomass-to-liquid fuels can be made by the Fischer-Tropsch chemical process. Likewise, using the HEFA process waste oils can be converted to fuel much as crude oil is refined.

Also, so-called SIP (renewable synthesized iso-paraffinic) fuel is produced from processed sugars, and can be blended up to 10% with fossil kerosene.

Unfortunately, all of these alternatives cost around three times as much as fossil fuels. Thus, adds Bushell, the government should long ago have introduced the sort of incentives to develop aviation biofuel that have existed for road fuel development.

As a result, Sustainable Aviation wants a “level playing field” for subsidies.

Specifically, the group is calling on the government to articulate long-term goals for sustainable aviation fuels and establish a suitable incentive framework. The group would like to see a public-private sector task force assigned to spell out a plan, and suggests this be modelled on existing initiatives such as the Commercial Aviation Alternative Fuels Initiative (CAAFI) in the USA.

Jet fuel suppliers, says Sustainable Aviation, should be eligible for the same market incentives – in the form of renewable transport fuel certificates – as are available to road transport fuels. That scheme effectively reduces production costs by giving investors and suppliers confidence to invest in and produce fuels that would otherwise be cost-prohibitive.

As things stand, that incentive is worth some $200-300 per tonne of fuel. However, as it is not yet available to aviation fuel suppliers, this imbalance acts as a disincentive to sustainable jet fuel production.

Critically, however, Sustainable Aviation says jet fuel suppliers have to be exempt from the obligation, which applies to road fuels, to blend all supplies with sustainable fuels. The result of such an obligation applied to all jet fuel uplifted in the UK, says the group, would be to put UK-based carriers at a cost disadvantage compared to foreign rivals. Sustainable Aviation points to the success of that no-obligation approach in the USA and the Netherlands.

Also, the group says the UK should look to the example of the US defence department, which has created market demand by pursuing development of synthetic fuels for use by military aircraft.

Sustainable Aviation takes a UK-focused approach to the problem, but Bushell notes that E4tech’s research considers the global market.

One indication of the challenge of achieving widespread use of sustainable aviation fuel is the fact that aircraft need to be able to fill up anywhere. This means there will have to be a wide range of fuel technologies brought to commercial fruition.

He says that in the UK, the only viable feedstock for sustainable fuel is waste. There is no prospect of massive algae farms in the desert, for example – a source of fuel that may prove valuable in many parts of the world.

Sustainable Aviation is considering the issue from all angles. Bushell points to new engine technologies, higher seating density, reduced aircraft weight and improved air traffic control that enables so-called “perfect flights” – routes which fly straighter paths and spend more time at altitude for maximum efficiency.

To achieve UK and EU greenhouse gas emissions targets – and the aviation industry’s own goal of halving absolute CO2 emissions by 2050 – all of these techniques, along with sustainable fuels, will have to be employed aggressively.

“If there was a magic bullet, we’d put it in place,” Bushell says.