This paper describes a real-time energy management system developed for a solar park in the Netherlands using an alkaline electrolyser. The optimization problem is split into a two-step optimization, taking into account the specifications of the electrolyser and allowing the electrolyser to respond to changes in the imbalance market. The first optimization step determines the state of the electrolyser one day in advance. The second optimization step determines the electrolyser power, using the state of the electrolyser as an input. Simulations using data from 2020, 2021 and 2022 show that the use of the electrolyser is limited to a number of days in the year with a lot of solar generation, causing the day-ahead prices to be low. Different scenarios have been tested to get insight into how the use of the electrolyser is influenced by these changes. The type of electrolyser, being able to put the electrolyser on standby and allowing the grid to be used for the electrolyser hardly affected the results. At last, different hydrogen prices are compared. The higher hydrogen prices lead to more use of the electrolyser. This real-time EMS contributes to the ability of an alkaline electrolyser to respond to the sudden changes in the grid and by doing this making it possible to use alkaline electrolysers for balancing the grid and contributes to the use of green hydrogen in the industry for a competitive price.

A major transition became necessary for the maritime industry to meet the IMO’s targets for mitigating the carbon footprint of the sector by at least 50% by 2050. One of the promising methods to lower the emissions is the ship's hybridization. An enormous increase in pilot and demonstration projects for that purpose is being observed. This research was contacted through the involvement of TU Delft in such a project called the Implementation of Ship Hybridisation. The design and optimization of hybrid propulsion systems is a complex and challenging task due to the different power sources involved and the dependence on the energy management and control. The physical system and the control algorithm should be designed in an integrated manner to obtain an optimal system design. This study applies a multi-objective double-layer optimization methodology to optimize the sizing and energy management of a hybrid ship propulsion system to be installed on a Crew transfer vessel. A proposed hybrid topology which combines diesel engines, batteries and fuel cells is considered. The proposed approach incorporates the development of fuels and electricity prices as well as the investment costs of the system’s components as an uncertainty element. The introduction of emission reduction measures such as carbon tax was also considered in the study. Future trajectories for the relevant uncertainties were developed and incorporated in the optimization methodology to provide decision-makers with a more realistic picture of the solution space. The analysis of the optimization results was based on the Total cost of ownership (TCO) and the emission reduction potential of the optimal designs produced by the optimization methodology. The results show that instead of choosing a hybrid propulsion system for the vessel under study, an all-electric propulsion system which is based entirely on batteries and fuel cells is the most economical and environmentally friendly option. Incorporating diesel engines has a negative impact on the operational expenditures of the system in the long term. A fully electric propulsion system would require a larger initial investment from the ship owner, but it would pay off over the course of the ship’s remaining useful life. This research can be used as a reference to base the decision of the stakeholders on choosing a new propulsive system for their vessel. The parameters of the optimization methodology can be easily changed to explore more options and expand the design solution space if this thesis’ results don’t satisfy the shipowner. In addition, it is suggested that a professional user interface designer be involved in the development of a real life decision support tool, incorporating the multi-objective optimization methodology.

Over the coming decades the worldwide fleet of ships will have to change to reduce emissions. Hybridisation of the propulsion system is a stepping stone to full electrification, which is required to reduce emissions of the maritime sector to zero. In hybrid propulsion systems, clutches are used to switch between drive engines when transitioning between operational modes. The operation of clutches is indicated to generate significant disturbances in propulsion systems, however, this impact is overlooked in hybrid propulsion simulation studies in the scientific literature. The identified research gap is addressed in this thesis by simulating propulsion mode transition in a hybrid propulsion system and analysing the impact of clutch operation, using a model developed for this purpose. A hybrid propulsion system is defined by introducing multi disk wet friction clutches in a reference propulsion system consisting of a 9.1 MW diesel engine in parallel with a 3 MW electric motor. A broad scope of impact measures, that includes the electric load on the power system and the temperature development of the clutch, is defined and the system is thoroughly modelled to enable evaluation of these measures. The transmission system is modelled with a higher fidelity than typically applied in propulsion system simulation studies to enable assessment of the basic vibratory behaviour of the transmission system. The considered propulsion modes transitions are between diesel and electric propulsion. To enable these transitions, three transition control approaches with an increasing degree of sophistication are implemented. The developed model is used to perform simulations, from which it is concluded that torsional vibrations, gear hammer and a drop in propeller speed characterise the significant impact of clutch operation on hybrid propulsion systems in propulsion mode transitions. It is also concluded that the impact of clutch operation can be limited by implementing an appropriate propulsion control approach for the transition. A torque controlled handover of drive torque between engines is identified as a suitable approach. However, the induction machine switching from torque to speed control introduces power peaks in the load profile that have the potential to severely disrupt the stability of the ships power system. It is finally concluded that the temperature development of the clutch during the propulsion mode transitions is not significant. It is shown in this thesis that there can be a significant impact on the propulsion system as a result of the operation of clutches in propulsion mode transitions. Therefore, this impact has to be taken into consideration when designing hybrid propulsion systems. The model described in this thesis can be used to predict the impact of clutch operation in the early stages of the design process. Furthermore, the model can be used to develop and evaluate propulsion mode transition control approaches.