This question was addressed by asking 12 bus operators to carry out design studies into hydrogen refuelling systems which could provide hydrogen for the very large fleets of buses which they may use in future. These operators worked with experts in the production and handling of hydrogen for transport applications to develop the design studies. In each location dedicated design teams were formed to produce detailed engineering designs, together with costs and assessment of the performance of the stations. The designs were carried out to comply with today’s codes and standards around hydrogen systems and also meet the needs of the operators. The results of the design studies were analysed by the project partners (WP3) and then aggregated and anonymised to produce publishable findings from the project which can help influence future developments of hydrogen bus depots.
The high level conclusion of the project is very positive. In each location, it was possible to produce a design which met the local specification for refuelling capacity, refuelling speeds, reliability and did so within the local regulatory conditions. This is an important result is it proves the technical viability of the hydrogen option. Furthermore environmental analysis demonstrates a number of routes to ultra-low carbon hydrogen using these systems (depending on the production option used).
The prices of hydrogen assessed varied widely between sites, which demonstrates the fact that hydrogen price is likely to be fairly site specific and dependent on the local cost of energy, as well as proximity to other sources of hydrogen. The project demonstrated that with the scale implied by these large bus depots prices for hydrogen ranged from below €5 to just over €10/kg. Four stations showed prices of hydrogen below €6/kg which was the target to achieve parity with the cost of fuel for diesel buses.
The other issue identified on a number of sites related to the footprint of the stations, which tended to be significant. Whilst low footprint solutions were identified (generally based on liquid hydrogen), the options involving production of hydrogen on site did lead to large land takes which will be problematic in dense urban depots. This suggests a research need for more work on making hydrogen systems more compact particularly for these large scale systems.
Many more technical and practical conclusions were drawn on the project and are summarised in the project’s two main public reports. These reports have been circulated widely via the project website, dedicated presentations at bus and hydrogen industry events and via targeted outreach to groups with an active interest in hydrogen buses.