Sustainable flights thanks to green hydrogen: the aviation challenge

The challenge of decarbonization of the aviation sector can also be won with thehydrogen. Several experts are convinced of this, but they do not intend to use it only as an alternative fuel for the aircraft of the future: for some of them, it would be preferable to use it to produce e-fuela synthetic form of the Saf fuels – acronym of Sustainable aviation fuel – for use in current propulsion systems without the need for major modifications to the engines. During a panel held during the European Business Aviation Convention & Exhibition, Frank Moestasenior vp of strategy at Rolls-Royce, he explained that this would be an easier route to take than developing new vehicles with completely different engines. “To be honest, I’m not a big fan of the option of fueling an aircraft with hydrogen,” commented Moesta whose company, which specializes in the production of aircraft engines, is busy developing a new hydrogen propulsion system in collaboration with Easyjet.

Hydrogen-powered aircraft

According to a study by the consulting firm McKinsey, battery- and hydrogen-powered aircraft could make up between 21 and 38% of all aircraft by 2050, and thus be responsible for 15% to 34% of the energy needs of the entire sector. These alternative propulsion systems could require between 600 and 1700 TWh of clean energy by 2050, the equivalent of the energy generated by about 10-25% of the largest wind farms in the world: most of it would be used for fuel hydrogen aircraft, while between 4 and 11% would go to battery-powered aircraft.

With the gradual diffusion of these systems, the airports they will need more energy to carry out some operations, such as the liquefaction of hydrogen and the recharging of electric batteries. In the case of large hubs, the energy consumption to carry out these activities, including those relating to terminals and ground support, could fluctuate between 1,250 and 2,450 GWh per year, i.e. a value 5 to 10 times higher electricity consumed by London Heathrow Airport today.

How e-fuel works

This synthetic fuel is produced by combining thecarbon dioxide captured by the atmosphere with thegreen hydrogen: it is a type of hydrogen made in a sustainable way thanks to the electrolysis process, which allows a water molecule to be divided into hydrogen and oxygen using electricity from renewable sources. As reported by the FutureFlight website, Moesta explained that e-fuel is more accessible than Saf derived from agricultural waste, because it can be produced locally in a simpler way. The problem according to Moesta is that ordinary alternative fuels today are made in few plants in the world. Furthermore, even if large airports will probably have the infrastructure to fly hydrogen-powered or SAF-powered aircraft in the future, there will be thousands of small airports that will not be able to do so due to lack of funds.

There remains a major obstacle to overcome to promote the diffusion of e-fuel, and it is the price of green hydrogen. In fact, producing it costs about 4 dollars per kilogram: second Erik Lindberghco-founder and executive chairman of VerdeGo Aero, as well as president of the Lindbergh Foundation, the cost is expected to come down to one dollar per kilogram.

Meanwhile, some companies are working on this solution. One example is the joint venture announced last year between the German P2X-Europe and the Portuguese The Navigator Company to produce synthetic kerosene from green hydrogen and carbon dioxide. The goal of the agreement was to build 80,000 tons to power 500 Airbus A320s. P2X-Europe has also signed an agreement with the Spanish company Greenalia to start a project to develop sustainable fuels for aviation: according to estimates, a production of over 11,000 tons of green hydrogen per year is expected which, combined with biogenic CO2 capture, should allow the production of 20,000 tons of synthetic hydrocarbons ready to be refined.