Technology potentials for optimised hydrogen provision

The use of green hydrogen (H₂) in aviation requires its provision in liquid form (LH₂) (see Fig. 1). Centralised production and liquefaction of H₂ at suitable locations favoured by cost-effectively accessible renewable energies and economies of scale, necessitates the transport of LH₂ in cryogenic tanks to airports. Given the cross-sectoral transition towards a hydrogen economy and the planned Europe-wide distribution of gaseous hydrogen (GH₂) through repurposed and new pipelines, Bauhaus Luftfahrt has analysed technology perspectives for LH₂ and GH₂ transport, with a focus on energy requirements and capacity.

Transporting LH₂ over long distances proved to be more energy-efficient, especially with future use of boil-off gas for propulsion. For shorter distances, GH2 transport may be more advantageous, depending on the technology mix and the extent of the more energy intensive land transport compared to sea transport. A key finding was that repurposed pipelines, while cheaper than new ones, substantially reduce the break-even distance (see Fig. 2). The thermodynamic analysis showed that the rougher inner surface of the pipes significantly increases the energy requirement for recompressing GH₂ to compensate for friction losses. However, a moderate reduction in the transport quantity can compensate for this additional energy consumption, but always at the expense of the total costs.