The aviation industry's commitment to decarbonisation by 2050 is undoubtedly a titanic challenge. But the good news is that the ambition for a cleaner sky is driving an unprecedented wave of innovation. While sustainable aviation fuels (SAF) represent an important step, the reality is that future fuel demand will be so immense that SAF alone will not be able to supply the entire global air fleet. This is where hydrogen comes into the picture, a promise that is gaining strength every day as the fuel of the future for aviation.
Battery electrification, although viable for cars and some small aircraft, faces an insurmountable barrier in long-distance commercial aviation: weight. Current batteries are simply too heavy to efficiently power large aircraft. That is why the industry has set its sights on hydrogen, a lightweight element with enormous energy potential.
There are two main approaches to using hydrogen in aviation:
. Fuel cells: Hydrogen is used to generate electricity to power electric motors. This technology appears to be the favourite for short- and medium-range aircraft with a capacity of up to 50 passengers. Innovative companies are already developing prototypes and conducting flight tests with promising results.
. Direct combustion in modified engines: Major engine manufacturers such as Rolls-Royce, Safran and Pratt & Whitney are investing heavily in adapting their engines so that they can run directly on hydrogen, either in gaseous or liquid form. Airbus, for its part, has announced its ambitious goal of launching a hydrogen-powered commercial aircraft by 2035.
Liquid hydrogen, although it has a higher energy density, poses significant challenges in terms of its storage and handling. It requires cryogenic systems to maintain it at extremely low temperatures and high pressures, which implies expensive and complex infrastructure. However, the advantage is that it is a relatively well-known technology with a higher degree of maturity. On the other hand, gaseous hydrogen, although easier to handle, requires much larger storage tanks, which impacts the design and aerodynamics of the aircraft.
The race for hydrogen in aviation is in full swing. The next five years will be crucial for testing different configurations and technologies. We will see an increase in test flights, the development of new infrastructures at airports and collaboration between manufacturers, airlines and governments. This period of intense experimentation is essential to pave the way for the certification of new aircraft, a rigorous and extensive process that guarantees the safety of passengers, a non-negotiable value in the aeronautical industry.
The transition to a sustainable air future is not without its challenges. In addition to the technical aspects, there are other important challenges to address:
. Green hydrogen production: For hydrogen to be truly sustainable, it must be produced from renewable sources, such as the electrolysis of water using solar or wind energy. Large-scale green hydrogen production needs to be boosted to meet aviation demand.
. Airport infrastructure: Airports will need to adapt to store, transport and supply hydrogen to aircraft. This involves significant investment in new facilities and the training of specialized personnel.
. Costs: Hydrogen is currently more expensive than fossil fuels. Innovation and economies of scale need to be promoted to reduce production costs and make it competitive.
Despite the obstacles, optimism prevails. The aeronautical industry is demonstrating a real commitment to sustainability. The commitment to hydrogen is firm and investment in research and development is constant. Technological advances are promising and collaboration between the different actors in the sector is increasing.
I found the creation of the Hydrogen in Aviation Alliance Alliance to promote these activities and share experiences very interesting. You can see their website at https://hydrogeninaviation.co.uk/
The road to a green sky is not easy, but every step we take brings us closer to a future in which flying is not only a safe and efficient experience, but also environmentally friendly. Hydrogen will undoubtedly play a fundamental role in this transformation, driving a new era of sustainable aviation.
Let's hope it happens as soon as possible.
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