Germany is the leading automotive market in Europe with the biggest fleet of innovative vehicles and applications. Aside from the electricity sector, the federal government seeks today intensively for possibilities to implement the transformation of the energy system ("Energiewende") in the final energy sectors. Especially the transport secotr shall be addressed.

In the road transport, electro mobility is seen from many actors as "the" clean and sustainable future option. It is therefore opposed to internal combustion engines (ICE), although they are in a continuous optimisation process and battery technology still faces disadvantages, at the current point of time.

Fuel cell vehicles fuelled with hydrogen offer aside from efficient internal combustion engines and electric vehicles an additional relevant alternative for future mobility. The focused implementation of hydrogen as fuel is to be seen in the context of potentials for hydrogen in the overall energy system and finally a question of the implementation of a hydrogen economy.

Aside the innovative field of "power-to-x", hydrogen is even today used in diverse industrial plants and processes - and occurs in some processes as side product, that can be partly used for other, energetic but as well material uses. So the utilisation as chemical, as for hydrogenation in refinery processes or at the production of fertilizer is of some relevance.

The state of knowledge about hydrogen as fuel and the resulting advantages and disadvantages as well as the effects to the overall system is in wide circles of economy, politics and society relatively low. The here presented projects therefore aims at working up the actual knowledge, addressing especially the following aspects:

• What properties does hydrogen as fuel possess, what advantages and disadvantages compared to other fuels?
• How and from what sources can hydrogen be produced in the short, but especially in the mid- to long-term?
• In what technologies and vehicles is hydrogen as fuel used? What competitions of use exist and have to be accounted for regarding the utilisation of hydrogen in other sectors?
• How can a hydrogen infrastructure be built up, considering technical, economic and safety aspects and implement them in a skilful way?
• What ecological effects on climate and environment protection are bound to the use of hydrogen as fuel, compared to other fuels and drive trains?
• How can a scenario look like, if hydrogen as fuel contributes in a relevant way to the future sustainable energy system?

As a result, the facts about hydrogen as fuel are extensively worked up from different perspectives, in order to offer stakeholders and decision makers a valid and broad picture of the option as part of a future sustainable mobility.