Hydrogen used as a fuel has emerged as an alternative fuel with multiple benefits. It is commonly used in its gaseous form to power a fuel cell, generating electricity, where it is completely emission free at point of use, with zero tailpipe emissions. Fuel cells are especially useful in-vehicle applications where the energy and power density of batteries is not sufficient, with also the advantage of low refuelling times.
In urban transport, there are some vehicle categories that benefit the most with the use of hydrogen, it being mostly related to the need for long autonomy, or the need for fast refuelling, as compared to the longer recharging times for battery powered vehicles. Such is the case for buses, waste collection trucks, taxi fleets, delivery trucks and inland waterway vessels in which BEVs encounter challenges and FCEVs show great promise.
The successful deployment of hydrogen-powered transport for the reduction of emissions in cities depends on some factors. Firstly, the market availability of mature, efficient, and less costly technology related to hydrogen/fuel cell-powered vehicles and vessel technology is essential. Moreover, the availability of hydrogen refuelling stations, with high safety standards and reliability, is necessary to enable refuelling of fleets. Finally, the way that hydrogen is produced determines its environmental impact. Fossil-based hydrogen is mainly produced from natural gas, emits CO2 during its production, and thus is not environmentally friendly. This production method can be more environmental friendly if it is combined with carbon capture techniques, known as fossil-based hydrogen with carbon capture. Finally, renewable hydrogen is produced by water electrolysis with renewable energy.
In the EU, the majority of research was carried out under the Fuel Cells & Hydrogen (FCH) Joint Undertaking I and II (for the 7th Framework Programme and Horizon 2020), which is followed by the Clean Hydrogen Joint Undertaking for Horizon Europe (1).
Hydrogen lacks infrastructure and sustainable large production on-site in ports and at the refuelling stations. Depending on the type of waterborne transport different solutions are necessary . In road freight transport, for light and medium trucks, an extensive use of batteries is possible, whereas heavy trucks rely most on the development of hydrogen fuel cells. Hydrogen cars and buses are already available, such as Toyota or Hyundai, or solaris for buses. In waterborne transport, Hydrogen is usually used in short-sea shipping (like in Norway). Long-distance trips need several weeks of autonomy, therefore, are going to use for now internal combustion engines operating in sustainable fuels, with a potential transition towards fuel cells using hydrogen .
The maturity of hydrogen technologies varies depending on the transport mode and technology associated with it. For fuel cell road vehicles (both light duty and heavy duty), the technology is already available on the market, in its early stages (TRL 8 and 9), while vessels powered by fuel cells are still under development, with TRL around 5 to 7 (5).
For refuelling technologies, there are already market ready solutions for hydrogen refuelling stations, while there is still research to improve the efficiency and advancing the technologies to a next stage, such as in the COSMHYC DEMO (c), NewBusFuel (f) and H2REF (k) projects.