Wind power is making an increasingly important contribution to the UK’s energy system and the governments legal commitment to reach Net Zero carbon emissions by 2050. However, wind generation is intermittent, so energy storage technologies are necessary to ensure a secure supply of energy. One option is hydrogen, which has applicability for seasonal energy storage and as fuel for heavy duty transport. Combining wind power with renewables with different generation profiles, such as tidal power, can reduce energy storage requirements. This research envisions that Orkney’s ferry service has converted to hydrogen, and finds the optimal plant capacity and fuel cost in several scenarios. Here we show that tidal power can increase hydrogen cost due to its expensive electricity. However, it can reduce costs when grid electricity is not used, by reducing minimum plant capacities. This shows the importance of choosing favourable business models and plant operation strategies when developing proposals.