The Clean Sky 2 TRANSCEND (Technology Review of Alternative and Novel Sources of Clean Energy with Next-generation Drivetrains) Coordination and Support Action identifies what alternative energy sources for aviation and novel aircraft propulsion can contribute to mitigating climate change and achieving the environmental goals for 2050. In addition roadmaps for alternative energy sources and novel propulsion towards 2050 will be developed.


The European Commission has recently published the European Green Deal – a roadmap with actions for making the EU’s economy sustainable. The actions include a proposal on a European “Climate Law”, scheduled for March 2020, enshrining the 2050 climate neutrality objective.

In the time frame 2014-2023 the Clean Sky 2 (CS2) programme is taking large steps in novel propulsion (and aircraft) technologies and their integration into aircraft towards achieving the environmental objectives for air transport in 2050. The environmental progress of each demonstration platform in Clean Sky 2 will be monitored by the Technology Evaluator (TE) of CS2.

In various other programs and projects, complementary developments are taken up as well, also for alternative energy sources for aviation.

The objectives of TRANSCEND are:

  • To evaluate the environmental impact of novel propulsion technologies and alternative energy sources in 2035-2050 based on the state-of-the-art knowledge, complementary to the TE Core evaluation Clean Sky 2 innovations;
  • To shape the future of green aviation propulsion in 2050, by preparing roadmaps for novel propulsion technology and for availability and viability of alternative energy sources to achieve the evaluated reduction of environmental impact.

TRANSCEND infographic


Project partners

TRANSCEND is led by the Royal Netherlands Aerospace Centre with the Technical University Delft (Applied Sciences/Biotechnology ) as partner.


Collaborative methodology

TRANSCEND’ seeks wide involvement of experts through expert workshops and interviews.

In addition, TRANSCEND investigates exploitation routes for the roadmaps in interaction with its Advisory Board, which encompasses various policy makers at European and national levels (with link to ICAO) and industries in alternative aviation fuels, propulsion, and aircraft.


Workshop on Sustainable Aviation Fuels, held on 15 October 2020.

Six promising sustainable aviation fuels and associated low-to-zero carbon propulsion concepts selected, with literature study and ecological balance sheets.

Workshop on Hydrogen-powered propulsion for aircraft, held on 7 October 2021.

This project has received funding from the European Union’s Clean Sky 2 Innovation Action programme under grant agreement No 864089

The TRANSCEND website reflects only the author’s view. The JU is not responsible for any use that may be made of the information it contains.