Dynamic modelling of a high-power electrolyser: A study of green hydrogen generation from an offshore wind turbine and a wave energy converter

The energy transition is pushing towards a future powered by zero-emission energy systems, in which renewable energies can play a key role. Photovoltaic solar systems, wind power plants, wave energy converters are some of the protagonists involved in the energy revolution that humanity is experiencing. These systems are intermittent sources of energy due to the strict dependence on resource availability, such as solar radiation or wind. Electrolysers can help address the problem of intermittent energy production by making these systems more flexible and providing strength to electricity networks. Surplus renewable energy can be used to power electrolysers with the purpose of generating hydrogen, which can be stored as gas compressed, liquefied, or even absorbed/adsorbed and then converted directly to electricity, by means of fuel cells. Moreover, hydrogen can be exploited in other sectors as well, including automotive, heavy-duty, chemical and hard to decarbonise industries, making its production even more interesting from a technological perspective. In this context, the aim of the thesis, developed in collaboration with Mondragon Unibertsitatea (Basque Country, Spain), is to implement a one-dimensional (1D) mathematical model of a proton exchange membrane (PEM) water electrolyser in the Simulink environment and to test green hydrogen production from an offshore wind turbine and a wave energy converter. The model, composed of an electrochemical, thermal and mass transport submodels linked together, is able to predict the hydrogen production, heat flux generation, as well as water and energy consumption in dynamic conditions. In fact, in addition to model validation, a sensitivity analysis has been carried out, thus providing remarkable results on the electrolyser response to temperature and pressure gradients.