The omnipresent topic of the last months and years remains climate change and what course must be set to counteract it. Time and again, aviation has come under fire here – because flying is not at all climate-friendly.
The industry’s ambitious goal is to halve CO² emissions by 2050, despite a tripling of passenger numbers, and thus avoid a comprehensive crisis. Current research into new propulsion technologies should help make this vision a reality. Whether electric, solar or hydrogen propulsion – the wealth of ideas of engineers, scientists and designers with regard to the aviation of the future knows hardly any limits.
Against the backdrop of the European Union’s 1.5 degree target and dwindling fossil fuels, the question of aircraft propulsion of the future is becoming ever more pressing. Every day, the approximately 35,000 aircraft (excluding smaller planes and helicopters) burn about one billion litres of paraffin. But that’s not the only thing that harms our environment; aircraft noise also needs to be reduced – by 2050, this should fall by around two thirds.
The first fully electric passenger aircraft took off in Canada last year, and the German Aerospace Center (DLR) is also striving for the first passenger e-plane in Germany.
According to the coordinator for electric flying at DLR, it is possible at this stage to convert mainly small aircraft to e-propulsion or fuel cells. For large long-haul jets, this is much more complicated. Currently, the electrification of aircraft fails mainly because of the low power density and the high weight of batteries. However, the development of electric propulsion systems is being pushed forward and will play a decisive role in the future of aviation. A hybrid solution is conceivable at the present time, for example, in which the energy-intensive take-offs and landings take place electrically.
In the long term, the battery problem could be solved by burning hydrogen in a fuel cell. In 2016, the prototype of a seven-metre-long fuel cell aircraft with four seats took off from Stuttgart Airport. A combination of hydrogen storage, fuel cell and high-performance battery for take-off and climb enables a remarkable range of 1,500 km and a maximum speed of around 200 km/h. If the hydrogen is produced by electrolysis with the help of regenerative energies, this combination could even make it possible to fly completely emission-free.
The electrification of aviation is still in its infancy, but holds great potential for the sustainable propulsion of aircraft. Experts expect profound changes by the year 2050. The answer as to how these developments can be reconciled with current efforts to bring supersonic jets back into service is still to be found beyond the 10,000 metre mark at this point in time.
Experts assume that the potential for developing lower-emission aircraft will be exploited first. Besides increasing engine efficiency, the use of alternative fuels also offers a lot of potential for the future of aviation in terms of reducing CO2 or soot emissions. DLR has already produced initial results in this area as well. One example is aviation fuel, which can be produced using biomass or renewable electricity and no longer has to be made from fossil oil. This synthetic paraffin is not only CO2-neutral, but also more efficient as a fuel and significantly less harmful to the environment overall.
Another advantage is that aircraft do not have to be modified for this purpose; only the tank filling changes. Measurements showed that not only CO² emissions were reduced, but also particulate matter was reduced by 50%.
A further possibility for a climate-friendly future of the aviation industry, which is, however, also still far from mass production, is solar propulsion. The spectacular circumnavigation of the world by the Swiss Bertrand Piccard in the solar-powered plane “Solar Impulse 2” shows that this works.
The new propulsion technologies should also help to master the conflict of interest between climate protection and increasing capacity needs. Low prices and an ever-expanding route network make it possible: 9 billion passengers are expected in the air by 2050. Thus, the passenger volume in aviation of the future will more than double compared to the current level. This development is additionally favoured by the production stop of the Airbus A380 and the change of course from wide-body aircraft to medium-haul jets. This will inevitably lead to growing aircraft fleets and even more air traffic in the skies.
Increasing globalisation is also causing the demand for freight transport to skyrocket. As early as 2030, the DLR expects 7.3 million tonnes of loaded cargo in Germany in its aviation report – more than three times as much as in 2014 – and this trend is not expected to decline 20 years later.
Propulsion technologies and aircraft size are only two aspects of aviation in 2050. Aircraft manufacturers – first and foremost the top dogs Boeing and Airbus – are also coming up with a lot in terms of interiors. In a video, the American aircraft manufacturer Boeing presents its ideas of the aircraft cabin of the future: the creativity of the designers ranges from projections of the sky on the ceiling to oversized, rounded screens.
Competitor Airbus goes one step further and integrates common rooms with interactive employment opportunities, conference rooms, ergonomically adjustable seats and ceilings made of glass into its vision of the future. Despite all the progress, however, the space problem will remain – at least for economy travellers – in the coming years.
Visions of “flying cities” with boundless space for shopping, sunbathing and fun do exist, but are still very ambitious even for the year 2050.
By contrast, the establishment of so-called “all-wings ” aircraft with a smooth transition between fuselage and wings in air traffic is somewhat more realistic. This design is currently predominantly used in the military sector, but is also being considered by Boeing for civil aviation. Thanks to the significantly greater use of space, the amount of space available in the aircraft could be significantly improved by “all-wings”.
Congested roads, kilometre-long traffic jams and collapsing local transport systems in metropolises demand innovative solutions. Established aviation companies as well as start-ups from all over the world are therefore researching flying devices that shift local transport from the road to the air. Electrically powered “air taxis” could solve two problems at once: by dispensing with fossil fuels, particulate matter and CO² emissions can be significantly reduced, and by shifting local traffic to air transport, the roads are relieved.
What sounds like a distant vision of the aviation future is already technically feasible today. Already in 2017, Volocopter completed a maiden flight and is considered a pioneer for electrified individual transport in the air.
Other start-ups are taking a similar approach: the electrically powered Lilium Jet from Munich is said to be able to fly 300km for an hour and can take off and land vertically. The five-seater air taxi could start operating as early as 2025 and pick up passengers on the roofs of buildings.
Industry giants such as Airbus and Siemens are also working flat out on aircraft for urban use, underlining the importance of this new sector for aviation. If current developments continue, air travel by air taxi will be just as much a part of everyday life as travelling on the underground in 2050.