Every flight operating in Europe could become on average more than 25 percent “greener” by 2030 while using existing technology, according to a new so-called think paper published by Eurocontrol on Tuesday.
The paper asserts that the aviation industry can make significant progress toward the “perfect green flight” through measures including increased use of sustainable aviation fuel (SAF), more efficient use of airspace, and fleet modernization by airlines. Eurocontrol estimates that such efforts could eliminate 4,268 kg of CO2 emissions by 2030 out of 16,632 kg produced during an average flight in the wider European area.
Better use of fuel-efficient air traffic management improvements could account for 8.6 percent to 11.2 percent (up to 1,863 kg) of those improvements, said the study. Accelerating the transition from the research and development phase to deployment of the Single European Sky ATM Research (SESAR) joint undertaking and improving the functioning and performance of the network to the greatest extent will prove crucial, it added.
The study also concluded that emerging aircraft technologies in the form of hybrid, fully electric, and hydrogen airplanes will “transform” aviation during the 20-year period starting in 2030. By 2050, those new airplanes will prevail on short- to medium-haul routes, while SAF use will predominate in long-haul operations. By then, SAF will account for 83 percent of all fuel burned if efforts to increase production capacity prove successful, regardless of any further technological developments, said Eurocontrol. Today, SAF accounts for less than 0.1 percent of all fuel used by the commercial aviation industry in Europe, according to the paper.
Calling SAF “the most important recent development on the sustainability front,” the Eurocontrol study estimates that a 50 percent blend of such fuel to conventional jet fuel can cut CO2 emissions from aviation by 40 percent. However, given today’s relatively minuscule level of SAF use, the paper stressed the importance of accelerating production of the fuel and increasing its availability at major hubs to reduce their cost, which runs three times the amount of jet-A. According to the European Union’s Destination 2050 report, with “proper” incentives, SAF could account for 6 percent of fuel used by 2030. The International Energy Agency’s Sustainable Development Scenario21 estimates about a 10 percent share in 2030 and 19 percent in 2040, while countries such as Norway and Finland already have set a 30 percent target by 2030.
“A firm policy support target of 10 percent SAF by 2030 could lead to higher demand than initially expected and a faster decarbonization of aviation,” said the Eurocontrol paper. “This would accelerate SAF uptake, leading to higher demand and speeding up aviation decarbonization—permitting more ambitious target setting in the future. Twenty percent SAF use by 2030 would represent a colossal challenge to meet, but would potentially deliver 16 percent in CO2 savings per flight, leading, with the other measures proposed, to 34 percent in CO2 emissions savings per flight.”
Measures needed to meet such goals start with passengers, according to Eurocontrol. Non-transit passengers arriving late to the gate cause small delays that can add complexity to managing departures. Meanwhile, airlines that opt to speed en-route flight to compensate for delays and missed slots increase fuel burn and thus emissions.
Airlines and airports share responsibility for the second set of measures. Powering an aircraft using its own auxiliary power unit (APU) burns far more fuel in most cases than using a mobile ground power unit (GPU) for that purpose, for example. APUs also generate more noise, more pollution, and increase aircraft maintenance costs.
The third set of measures lies with air traffic control (ATC). Each minute taxiing with engine on burns 3 to 10 kg of fuel, so ATC should prioritize minimizing ground delays for aircraft with engines already running and facilitate engine-off taxi solutions, said the report. Some ATC and airport processes significantly influence the performance of the aircraft from the beginning of the flight. Employing best practices for stand allocation, the use of fixed electrical ground power and pre-conditioned air, the flexible use of taxiways to minimize taxi time, the use of Airport Collaborative Decision Making (A-CDM) to avoid long queues at the holding points, and the optimization of runway throughput to avoid delays all can contribute to improvements, added the study. Finally, the use of semi- or fully electrical aircraft towing systems brings immediate environmental benefits; delaying engine start-up can reduce fuel consumption during taxiing by 50 to 85 percent.
Meanwhile, the takeoff phase offers a number of potential improvements air traffic and airlines can effect, of which Continuous Climb Operations (CCO) brings the most important environmental benefit, said the paper. Air traffic controllers should, as far as possible, clear flights to climb, avoid unnecessary level-offs and permit the most fuel-efficient CCOs. Other measures include the use of so-called rolling takeoffs to seamlessly deliver clearances and avoid aircraft stopping on the runway.
Once the airplane gets in the air, cruising accounts for the longest flight phase and the biggest effect on overall CO2 emissions and fuel consumption. “Nevertheless, there are a series of improvements that can be made,” notes the report. On-board systems such as the flight management system ensure that the crew can aim to fly using the optimum values of speed and cruise level, it added. Operators should update those systems with the latest wind and atmospheric condition information, and the crew should fly at a speed corresponding to the best specific range (maximizing the distance flown for a given amount of fuel) on minimal drag configuration whenever possible and try to maintain an optimum altitude.
Finally, upon landing, more efficient taxi-in during ground operations means minimizing the use of engine thrust and brakes, choosing the shortest route, using reduced engine taxi techniques such as using a single engine on arrival, delaying the start of the APU, and shutting it off as soon as possible, the report concluded.