Aligned with the objective ofaddressing the urgent need to achieve environmental sustainability, the aeronautical industry, in close collaboration with international bodies, is demonstrating a firm commitment to reducing emissions and achieving completely emission-free aviation by 2050. This is the conclusion that can be drawn from the Report on Sustainability in the Aeronautical Sector 2022 prepared by the Official College of Aeronautical Engineers of Spain (COIAE).
With this report, the Association wants to counteract the frequent messages that point to aviation as the main cause of pollution in the transport sector. Aviation is one of the sectors that generates a lower volume of global emissions compared to other modes of transport. Specifically, in the year 2019 busiest year so far, aviation was responsible for 13.4% of emissions in the transport sector in the European Union, while road transport was responsible for 71.7% and maritime for 14% (data “EU Emissions Inventory 2019”).
The aim of the Report prepared by COIAE is, in addition to updating information on the state of the art in this area, seeks to raise awareness of the challenges and needs of the environmental issues that aviation faces. In general terms, although the impact of air transport on climate change is lower than that of other existing modes of transport, the commitment and willingness of the sector in terms of sustainability is not. All these issues will be the subject of the different tables at the ‘III Climate Summit in the aviation sector’ on December 11, 2023, in which different experts from the aviation sector will participate.
Commitments and treaties
Already in the COIAE Sustainability Report issued in 2020 there is a recapitulation on the milestones achieved and the state of the art to date. With regard to 2022, some agreements stood out, such as, for example, the Toulouse Declaration, in which 37 European countries and nearly 150 private entities committed to achieving net carbon neutrality for aviation by 2050, in addition to meeting certain intermediate targets.
At the policy level, programs such as CORSIA and the EU ETS scheme have been reviewed and updated. These play a crucial role in regulating and offsetting aviation emissions.
On the private side, both manufacturers and airlines have approved initiatives of various kinds with the aim of developing and implementing disruptive technologies in the future, such as Embraer’s Energia program (focusing on electric and hydrogen cell-based propulsion), or improving conventional solutions leading to cleaner solutions in the short to medium term, such as Rolls Royce’s UltraFan turbofan engine (whose high bypass ratio reduces the specific consumption and noise emitted by the aircraft). The range of initiatives is broad, ranging from progressive improvements to current technologies to long-term revolutionary proposals that aim to completely change the paradigm of air transport in the world.
Technologies and innovation
The airline industry is leading the search for innovative solutions, including the improvement of existing technologies as well as the development of new disruptive concepts for the ambitious goal of ‘zero emissions’ by 2050. Some of the ideas put forward that resonate most at present are:
Numerous possible solutions and combinations have been put forward for the progressive introduction of electric energy as a power source for various systems, mainly aircraft propulsion. The strategies range from recovering energy from the engines to power other systems to propelling the aircraft entirely with electric motors, either powered by batteries or hydrogen cells.
Although electric batteries currently have a “low energy density” compared to fossil fuels, which greatly limits the range and autonomy of an aircraft, some manufacturers are already implementing electric propulsion on small scales and in experimental models (Pratt & Whitney Canada plans to test its Dash 8-100 hybrid model, powered by thermal and electric motors).
It should be noted that, in any technological solution, and especially in electricity (as an energy vector), it is necessary to analyze the entire life cycle to ensure that the principles of sustainability are complied with both in production and in the useful life of each product.
To highlight that 2022 saw the first flight of a commercial aircraft with battery electric propulsion (Eviation Alice) and in January of this year the first flight powered by hydrogen fuel cells (ZeroAvia).
-Hydrogen and Sustainable Fuels (SAF)
Hydrogen as a fuel is one of the great hopes for sustainable transport in the future (not only in aeronautics) due to its energy power comparable to traditional fuels and its almost total ‘cleanliness’ in terms of pollutant emissions. The challenges facing manufacturers are essentially the difficulty of storage/transport and its low energy density (much more storage capacity is required to store hydrogen than the energy equivalent in fossil fuels).
Until this option becomes technologically feasible, the least costly strategy, requiring fewer modifications to existing aircraft and infrastructure, is to rely on sustainable fuels (or SAFs). While SAFs were already being introduced in blends with fossil fuels, the goal is to achieve 100% compatibility of thermal engines with SAFs. Of particular note is the test Airbus conducted on its A380 in 2021 with an engine running exclusively on PBS.
-Efficiency and design improvements
At present, manufacturers continue to implement improvements in aircraft efficiency involving reductions in fuel consumption (improving energy efficiency) both in propulsion plants and others: new wing designs, weight reduction, active wing control, etc. For their part, air traffic control agencies and airlines are seeking to implement more efficient aircraft routes and operations that will also reduce fuel consumption and, therefore, polluting emissions.
The path towards sustainable aviation, so necessary in our time of climate emergency, is undoubtedly irreversible, as demonstrated by the firm commitments reached in 2022, both within the industry and at the governmental and international level. Emissions awareness (especially CO2) and offsetting is at the heart of the strategy, along with the implementation of policies and regulations that actively promote sustainable aviation. Collaboration between industry, governments and society is highlighted as a key factor in achieving these goals.
The aviation industry has always been a leader in innovation, exporting much of its progress to other industries, and the challenge of sustainable transport will follow suit.
Despite the notable advances, it is recognized that there are challenges in scaling up production and implementing these initiatives. However, there remains a solid hope for a greener and cleaner future in aviation, backed by continued innovation and a collective commitment to sustainability.