Power

In the last 40 years, aircraft fuel burn and CO2 emissions have been cut by more than 70 per cent.  Now it’s time for something a little bit alternative.

Aviation currently represents 2 per cent of total manmade CO2 emissions, 80 per cent of which is from flights over 1,500 km. for which there is no practical alternative. Along with developments in aircraft design and technology and improvements in air traffic management, sustainable alternative fuels are a promising solution to minimising CO2 emissions.

They also are produced from renewable resources such as biomass.  When burnt, their emissions are the same as fossil fuels – but they emit 50-80 per cent less CO2 over their entire lifecycle.

The benefits are clear, clean and proven in the skies above.  Over 1,500 commercial flights worldwide have been flown on biofuels to date. So the burning question is, when will sustainable biofuels become the industry standard?

As challenges remain in scaling up production and providing competitive pricing, governments and industry stakeholders will need to develop and implement policy frameworks and necessary investments to facilitate this.

Moreover, it’s imperative that development does not adversely impact the food chain, fresh water supply or deforestation. So robust sustainability standards are crucial. Sustainable feedstock could come from a number of sources, such as: algae, woodchip waste, camelina, jatropha, halophytes such as salicornia (plants growing in salt water), waste produce or other microorganisms.

Unlike other forms of transport and industries, aviation will have to rely on fuels as its main energy source in the short to medium term, making critical the prioritisation and support for development of sustainable alternative fuels for aviation. Assuming this is the case, some 30 per cent of aviation fuels are expected to come from these and other alternative sustainable sources by 2030.  Looking ahead to 2050, we can aim even higher.

Renewable energy could be regionally-sourced from plantations or farms on or near airports to feed both future aircraft and infrastructure needs. And other energy sources – including solar panels, fuel cells that transform the energy in hydrogen into electricity with the only by-product being water, and even "harvesting" passenger body heat – might power some systems on-board or on the ground.

How does it work?

The potential benefits of this solution to the long-term availability and affordability of fuel means it’s fast becoming a very real and viable option.  50/50 blend biofuels already are certified for commercial flights.  The ultimate goal is to achieve the approval of 100 per cent blends for commercial aircraft.

Airbus is acting as a catalyst for sustainable biofuels through an ambitious programme to form regional biofuel "value chains" in every continent, using the Roundtable on Sustainable Biofuels criteria to guarantee sustainability.  Five such value chains already have been established, in Australia, Brazil, Middle East, Romania and Spain.

While it’s not foreseeable that fuel cells would be used for commercial aircraft propulsion, they are one of the most promising "step change" technologies to power cabin operations.  As hydrogen is combined with oxygen in a "cold" combustion, the only by-product is water.  This could be used for the aircraft’s water and waste system, saving water, weight and – in turn – fuel consumption and emissions.