Hydrogen Demand

To begin with the case study for the use of hydrogen in ferries, the focus has been decided to be on one that would represent a substantial fuel consumption, since the proposal of a new offshore wind farm to power electrolysers would only be feasible if there was enough constant demand of all the hydrogen produced when they are deployed. 

  

In Shetland there are two passenger ferries that run every day between Lerwick, Kirkwall and Aberdeen, which are identical in terms of engine power. So, it means that, although the focus here is just on one ferry, we assume that if we understand the requirements for the one, it would be easier to adapt the size of the project to attend both in future projects, due their similarity.  

 

Between Lerwick and Kirkwall, two sisters passenger ferries are operated by NorthLink. According to the European emission report, the ferry MV Hrossey produced a total amount of 30,873 tonnes CO₂ in 2018 [1] from the use of fossil fuels. This gives a value of 226.7 kg of CO₂/km, and taking into account that there were 122 passengers per journey [1], the emissions per passenger were estimated as 1.8 kg CO₂/km/passenger. Therefore, it currently emits over 16 times compared to the emissions an average plane would produce on the same distance for one passenger (Figure 1).  

 

Therefore, it can be estimated that MV Hrossey alone is responsible for 0.52% of the UK domestic shipping yearly carbon emissions, as the Clean Maritime Plan (2019) reported [2].  For this reason, this specific ferry was chosen to be studied, as it is potential candidate for switching from HFO to LH2.