This Pilar bridge, Spanish airports are experiencing frenetic activity, with thousands of travelers taking advantage of the days of rest to travel, mainly, to European cities. In a society that seeks to cross long distances quickly and comfortably, there is no doubt that in the future human beings will continue to fly. Let's take a recent example: in July 2023, the largest number of flights in history was recorded in Spain, with an average of almost 7,200 planes per day that took off or landed in our country. And demand continues to grow: there are currently 37,100 active aircraft and more than 15,000 on order, according to the CAPA Fleet Database.
As explained by Abel Jiménez, Chief Engineer of Decarbonization Projects at the aeronautical engine manufacturer ITP Aero, the airplanes, to become profitable, “are in service for between 20 and 25 years.” With this data and the objective of achieving decarbonization within the indicated period, the industry needs to incorporate new ways of propelling aircraft.
The challenge is important, however, we already have alternatives to accelerate the energy transition of the sector. One of the most advanced is SAF (Sustainable Aviation Fuels), or in other words, renewable aviation fuels. Precisely, this week the EU approved the 'Refuel EU' regulation, which establishes an increase in the use of these fuels from 2025.
These fuels made from organic waste emit up to 80% less CO₂ than kerosene, while maintaining similar properties. “They can be used in current engines, without modifications or the need to invest to create a new supply infrastructure,” says Francisco Lucas, Senior Manager of Sustainable Aviation at Repsol.
SAF is already being produced from raw materials such as used cooking oil, remains from the agri-food industry or agricultural waste. In 2022, 300 million liters of SAF were obtained globally and the goal for 2050 is to reach 449 billion liters annually. To achieve this, explains Francisco Lucas, it will be necessary to “build new industrial plants or transform current ones.” The first steps are already being taken. At the end of 2023, the first plant of this type in Spain will begin operating, built by Repsol in the Cartagena industrial complex and where a production capacity of 250,000 tons of renewable fuels per year will be reached.
Furthermore, the SAF is positioned as an economic opportunity. A study commissioned by Iberia and Vueling to PwC estimates that the commitment to this industry could generate 270,000 jobs until 2050 in Spain, with a contribution to the GDP of 56,000 million euros.
Reducing emissions from air transport also requires other types of measures. One of the main ones is to manufacture more efficient devices. “The performance of the new generations of commercial aircraft,” says Jiménez, “offers an improvement in efficiency of between 15 and 20%” compared to generations from decades ago. A notable fact, although the ambition is greater.
An example is the UltraFan engine. Developed by a consortium led by Rolls Royce, it will offer “a 10% fuel saving over the current most efficient engine,” according to Jiménez.
Lightening the weight of aircraft is also key. In this sense, the largest manufacturer in the world, Airbus, is introducing advances in the design of its latest aircraft, the A350, which manage to reduce fuel consumption and CO₂ emissions by 25%.
Another less costly measure with immediate effect is the improvement of air traffic management. Today pilots fly on airways predefined decades ago. Current satellite navigation technology already allows this to be done following straighter trajectories. Thanks to its work, Enaire - responsible for managing air traffic in Spain - promises to save 9.8 million kilometers between 2021 and 2025, which is equivalent to 246 trips around the Earth. In the EU, the full development of the so-called Single European Sky, created to overcome the fragmentation of airspace marked by borders, would bring an average reduction of more than 11 minutes in intra-European flights and savings of between 8% and 10 % in CO₂ emissions.
The use of hydrogen as an aviation fuel is positioned as an advantage since, if it is generated with electricity of renewable origin, it does not produce CO₂ emissions, but it has a great difficulty: its use implies substantial changes in the design of the airplanes.
Because? Hydrogen has a lower energy density than kerosene and requires up to four times more volume, so larger and heavier tanks will be needed. Furthermore, the use of hydrogen will imply changes in airports, since "it entails a new adapted supply and storage infrastructure," says Francisco Lucas. Despite the difficulties, Airbus is already working on new models, called ZEROe, with the aim of launch the first commercial aircraft powered by this fuel on the market in 2035.
It is not an easy path, but the truth is that aeronautical decarbonization is advancing steadily. New technologies are the key to reducing emissions. Some will be available in the short term, like the SAF; others will be extended over time, such as the design of new airplanes or the use of hydrogen. What is clear is that the entire sector knows the objective and is committed to achieving it.
