Clean Sky

Clean sky 2 logo

Clean Sky 2 (2014-2024), which is part of the EU Horizon 2020 programme, has a combined public and private budget of just under €4 billion. It aims to develop, demonstrate, and accelerate the integration of technologies capable of reducing CO2, NOX and Noise emissions by 20 to 30% compared to state-of-the-art aircraft in 2014, with a market deployment within the decade after the programme’s end in 2024.

The benefits and potential impact from Clean Sky 2 research are evaluated through a dedicated Technology Evaluator function with key assessment and reporting duties. Inputs for this assessment include criteria such as fuel saving, weight saving, maintenance or production improvement, overall aircraft system improvement, and noise reduction. The Technology Evaluator provides integral reports encompassing forecast performance of the Clean Sky 2 technological solutions at the aircraft, airport, and fleet level in terms of their contribution to Clean Sky’s high level environmental objectives for CO2, NOX, and noise. An interim assessment by the Technology Evaluator was performed in 2021 [26] and concluded that good progress had been made towards the programme’s objectives ( Table 3.2 ) resulting in a reduction of CO2 and NOX emissions of about 15% and 31% per seat kilometre as compared to a 2050 global traffic scenario incorporating only 2014 reference technology.

Clean aviation logo

Building on Clean Sky 2, the new Clean Aviation Joint Undertaking was established in November 2021 and will pave the way towards the EU’s ambition of climate neutrality by 2050. This new programme will focus research and demonstration in three areas that are expected to drive future energy efficiency and potential emissions reduction of future aircraft, including:

  • Hybrid electric and full electric architectures – Research on novel electrical power architectures and their integration. Maturing technologies towards the demonstration of novel configurations, on-board energy concepts and flight control.
  • Ultra-efficient aircraft architectures – Short, medium, and long-range aircraft architectures making use of highly integrated, ultra-efficient thermal propulsion systems to support the transition to low/zero emission energy sources (e.g. synthetic fuels, hydrogen).
  • Disruptive technologies to enable hydrogen-powered aircraft – Enable aircraft and engines to exploit the potential of hydrogen as a non-drop-in alternative zero carbon fuel.

The programme will focus on early adoption and market deployment in the 2035 timeframe within the key market segments of regional, short, and short/ medium range aircraft that cover over half of global aviation emissions. The targeted performance levels are summarised in Table 3.3 .

Aircraft in the hangar