In the CLEANLIEST project, the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is investigating both the climate impact and economic consequences of hydrogen as an energy carrier. Using a range of scenarios, the project investigates how a hydrogen-based transport economy could develop in Germany and worldwide by the year 2070.
The development of new measurement methods provides a reliable basis for research, and existing research findings from DLR are being consolidated and expanded within the CLEANLIEST framework. Where gaps remain, new methods and models are being developed – for example, to optimise the economic viability of hydrogen-powered vehicles. This will make it easier to estimate how much hydrogen will be needed, what emissions will be produced and their long-term impact on the climate.
The project therefore provides concrete insights for policymakers, industry and scientific research – a foundation for building a sustainable hydrogen economy. The research results can contribute to efficient investment and promotion, the development of infrastructure and the alignment of transport modes with sustainability goals.
Research into hydrogen emissions in the transport sector
CLEANLIEST seeks to comprehensively analyse the effect of hydrogen use in transport on the climate and economy. Key objectives include:
- Developing measurement methods to accurately record hydrogen emissions along the entire process chain.
- Calculating the climate impact of hydrogen in aviation, shipping and land transport. This includes looking at the climate impact of hydrogen escaping – leaking – along the production and transport chain.
- Preparing detailed emission figures for all transport sectors – road, rail, aviation and shipping. This involves systematically recording where emissions are being generated and where hydrogen can be deployed efficiently.
- Conducting global analyses of hydrogen production and distribution, as well as examining transport worldwide and its impact on the climate.
- Quantifying the economic effects of a hydrogen transport economy – for example, carrying out cost comparisons and gauging its impact on transport and the economy, such as effects on demand or savings from avoiding environmental costs.
- Comparing various possible developments in the energy system up to 2070 to assess the competitiveness of hydrogen.
- Developing recommendations for political decision-makers and industry.
Holistic emissions assessment for all major modes of transport
CLEANLIEST takes a holistic view of hydrogen use. It examines the emissions generated across the entire value chain – from production, distribution and storage to the use of hydrogen in transport. Notably, all major modes of transport – aviation, shipping and land transport – are included in the analysis. This cross-sectoral approach enables a comprehensive assessment of the impact of a hydrogen economy on the climate and transport economy. The project draws on the expertise of various DLR institutes with outstanding experience in these fields.
CLEANLIEST – sustainability of an integrated hydrogen economy
- Duration: 1 January 2025 to 31 December 2027
- Lead institute: DLR Institute of Atmospheric Physics
- Project type: DLR impulse project
- Funding body: DLR Programme Directorate for Aviation, Transport, Energy, Security and Space