This thesis investigates the dynamic behaviour of splash zone lowering operations for large offshore structures, with a particular focus on the effectiveness of additional winch support. The primary objective is to reduce critical response parameters that influence the workability of installation operations. A numerical modelling approach is adopted, combining diffraction-radiation analysis in Ansys AQWA with time-domain simulations in OrcaFlex. The study considers a large installation template with complex geometry and evaluates its behaviour in the splash zone, including internal free-surface effects, under varying draft and wave conditions. The main response parameters of interest are the rigid body motions of the template, the crane offlead and sidelead angles, and the dynamic amplification factor of the crane hook load.
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The structural response and thus the service life of offshore wind turbines is significantly affected by their first natural frequency. However, field measurements from offshore wind farms show that the field response of monopile-founded wind turbines is stiffer than expected, suggesting that improved modelling could lead to optimized cost-efficient structures.

This discrepancy may be associated to conservative foundation modelling. The current industry-standard finite element (FE) approach assumes monopiles as wished-in-place (WIP), thus neglecting installation effects. The goal of this thesis is to calibrate a 3D FE model to better capture the lateral response of impact and vibratory-driven monopiles in predominantly sandy soils under monotonic loading, particularly in the small-strain range that governs the dynamic response of offshore wind turbines, by accounting for installation effects.

PLAXIS 3D is used to model the soil-structure interaction with Hardening Soil elastic-plastic constitutive model that can capture small-strain stiffness (HSsmall). The study has a twofold scope: namely, establishing an interpretation scheme for initial soil properties to model the WIP response and incorporating installation effects through a practical approach that captures the effects of the installation on the soil state, and consequently the lateral capacity, without explicitly simulating the pile installation.

The WIP models, validated against a number of field tests, show that the current modelling approach can accurately predict the lateral response of vibratory driven monopiles, while it underestimates the stiffness of impact driven ones. Therefore, this thesis proposes to artificially incorporate installation effects into the established WIP FE models for impact driven monopiles, by either imposing volumetric strains to the soil plug or by modifying the coefficient of lateral earth pressure at rest. Calibration of these installation parameters is performed against the global monopile response and the post-installation horizontal stress profiles. Both methods lead to increased horizontal stresses around the monopile and result in stiffer global response and improved agreement with the field data.

This thesis offers a comprehensive framework for modelling the lateral response of monotonically loaded monopiles, including installation effects, that could potentially be adopted by industry thanks to its simplicity, computational efficiency and reliance on commonly available data in offshore wind projects.
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Indonesia’s decarbonisation strategy hinges on how quickly the power system can absorb new renewable classes beyond wind and solar, yet the role of marine renewables has rarely been tested atsystem scale across the country’s grid, notably due to cost constraints. This thesis extends the energy system optimization framework by Langer et al. (2024) [1], Calliope-Indonesia, to analyze wave point-absorber and tidal stream resources’ optimal contribution to the national energy system by 2050 under two grid configurations: a Supergrid with inter-island transmission versus today’s fragmented provincial networks.

The methodology integrates new technology definitions, provincial-level resource assessments from ERA5 reanalysis and TPXO tidal data, and hourly generation profiles into the established Calliope model structure. Four research questions examine MRE impacts on storage requirements, transmission expansion priorities, cost competitiveness against established renewables, and optimal system configurations for least-cost decarbonisation. Wave energy uses point-absorber performance matrices calibrated to Indonesian coastal conditions, while tidal analysis applies velocity-power curves for horizontal-axis turbines deployed in high-flow straits.

Results show that transmission architecture controls MRE integration value. Under Supergrid operation, total storage capacity decreases from 135.7 to 125.1 GW with reference MRE costs (−7.8%) and to 120.2 GW under optimistic learning trajectories (−11.4%). Fragmented networks show minimal storage reduction (+0.6 GW), indicating that MRE benefits require coordinated inter-island power flows. Tidal energy displaces storage more efficiently than wave (0.94 versus 0.09 GW per GW installed) due to predictable semidiurnal generation patterns. Grid expansion concentrates in specific high-value corridors rather than uniform network reinforcement: HVDC capacity increases from 97.1 to 137.6 GW, with the Lampung–Banten connection handling disproportionate additional flows.

Cost competitiveness emerges when interconnection enables optimistic learning curves. Under the Supergrid configuration with accelerated cost reduction, tidal energy reaches 66.1 US$/MWh and wave energy 69.5 US$/MWh.This positions both technologies within the competitive renewable band alongside small hydro (67.5 US$/MWh) and geothermal (61.7 US$/MWh). Marine generation reaches 261.4 TWh annually (17.3% of total demand), compared to 122.8 TWh under fragmented operation, showcasing transmission’s role as a primary value driver rather than background infrastructure.

The analysis identifies targeted deployment strategies: wave clusters positioned behind reinforced transmission gateways on high-resource coasts, and tidal installations near demand centres where network access maximizes predictability benefits. However, single-year operational modeling, coarse nearshore resource resolution, and incomplete spatial exclusions limit precision in site-specific assessments. Despite these constraints, the evidence indicates that MRE technologies can contribute meaningfully to Indonesia’s 2050 power system under cost-optimistic assumptions (CAPEX: 986,000 US$(2023)/MW, OPEX: 50,000 US$(2023)/MW) and remain viable even under reference cost scenarios (CAPEX: 1.76 million US$(2023)/MW, OPEX: 88,000 US$(2023)/MW) when supported by strategic interconnection investments and disciplined resource targeting. ... Read more

Pre-operational site comparison studies for Wave Energy Converters (WECs) typically do not account for potential dependencies between site selection criteria. This study addressed this gap by developing a novel copula-based site comparison framework that evaluated the trade-off between extreme loads and power production while incorporating their dependency. The results showed that dependencies may exist between these criteria and that accounting for them could improve conventional site comparison approaches. Additionally, the study was extended to an operational context, enabling operators to anticipate future operational periods with relatively high or low probabilities of failure... ... Read more

This thesis dives into the collision dynamics between an ice ridge and a moored point absorber-type wave energy converter. The collision dynamics in this case encompass the ice–structure interaction forces, the resulting mooring line tensions, and the point absorber’s behaviour after impact.

For this research a 3D-model was developed using DualSPHysics, complemented by MoorDyn for mooring line dynamics and Project Chrono for collision dynamics. This research examined collisions between ice ridges modelled as rigid structures with typical subarctic dimensions and a moored buoy representing the point absorber. Various simulations were run with variations in ice ridge size, surface roughness of the ice ridge and different failure mechanisms for the mooring lines.

Key findings indicated that mooring line failures at a tension limit of 5 MN predominantly resulted from entanglement with rough keel surfaces rather than direct impact forces alone when ice crushing was neglected. Smooth-surfaced ridges allowed mooring lines to withstand tensions up to approximately 2.2 MN. Additionally, reducing ridge dimensions significantly decreased maximum tensions and horizontal contact forces, highlighting the critical role of ridge size and surface roughness in collision dynamics.

From this study it becomes clear that the highest uncertainty lies within ice crushing during the interaction with the ice ridge keel structure, it is expected to happen when the point absorber slides against the ice ridge, which can lead to entanglement of the point absorber within the ridge itself. This study contributes critical insights and provides a computational SPH-model for preliminary testing and analysis of moored point absorbers under ice ridge collision scenarios.
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The transition to a low carbon energy system is focusing attention on the synergies between large scale offshore wind and green hydrogen production. These synergies can have system-wide benefits for the integration of wind farms to the power system, whilst improving their economic performance. Offshore wind investments face multiple uncertainties: commodity prices fluctuate and impact turbine cost, vessel rates required to install the turbines are dynamic and the electricity price fluctuates daily. Additionally, to realize wind-hydrogen synergies (hybrid powerplants) the electrolyzer is an additional source of cost uncertainty. On the contrary, the revenue uncertainty of the wind farm is expected to be mitigated through the use of Hydrogen Purchase Agreements. To take informed investment decisions regarding wind-hydrogen synergies, Vattenfall, a leading European utility, is interested in analyzing the trade-off between increased cost uncertainty and reduced revenue uncertainty.

This thesis investigates how integrating a 400 MW onshore electrolyzer with a 2 GW bottom-fixed wind farm affects the project’s economic uncertainty. To answer the question, a three-step methodology is applied. Firstly, the economics of the offshore wind farm and hybrid powerplant are modelled without the presence of uncertainty, using Vattenfall’s techno-economic model. This model considers investment and operation costs, along with the revenues of the wind farm from electricity sales on the power market. For the revenues of the hybrid powerplant, an optimization algorithm deciding when it is optimal to produce hydrogen or electricity is employed. Secondly, the uncertainties in key commodities (steel, aluminum, copper and shipping fuel oil), vessel day-rates, electricity prices and electrolyzer costs, are defined. Thirdly, the uncertainties are sampled through a Monte Carlo simulation to create 10,000 different realizations of the project, covering the entire range of possible outcomes. By combining the techno-economic model, the dispatch algorithm and the Monte Carlo approach, the uncertainties of the offshore farm and hybrid powerplant can be quantified, and their impact on the project economics can be evaluated.

The methodology allows to compare the effect of hydrogen integration in the business case uncertainty of an offshore wind farm. On a deterministic comparison, the two projects perform similarly. For the considered wind farm, the inclusion of the electrolyzer adds an additional e94 M
in cost uncertainty, while it reduces revenue uncertainty by e18 M. These results hold true for the considered offshore farm, given projected conditions and modelling assumptions. For this case, the offshore wind farm is marginally more certain in terms of economic returns. Given the two projects produce similar investment returns, accepting the increased uncertainty of the hybrid powerplant is non-economical.

The results of the thesis do not favor an investment in hybrid project in terms of uncertainties. However, this result is true for the project investigated and as conditions change and hydrogen technology matures, the analysis can shift in favor of hydrogen. Specifically, hydrogen is a large
scale infrastructure with the first full scale projects currently under development. With more project-experience gained, the uncertainty in costs can be reduced, favoring the hybrid projects. With increased support for large scale hydrogen production, the proposed framework for continuous analysis can be leveraged to keep pace with the external macroeconomic changes. The methodology can be extended and applied to other hybrid solutions, such as hybrid projects with batteries. ... Read more

The global energy landscape is undergoing a significant transformation, marked by the increasing fragility of conventional energy systems and a decisive shift towards electrification to meet climate objectives. This transition elevates energy security and resilience to core priorities for governments and industries. Offshore artificial energy islands are emerging as pivotal strategic infrastructures, particularly in regions like the North Sea, designed to expand renewable energy capacity, alleviate grid congestion, and facilitate power exchange, thereby supporting overarching climate and energy security goals. This thesis investigates how integrating multiple functionalities, specifically energy generation and port logistics, within a single offshore island could enhance financial feasibility. The central research problem addresses how to assess the techno-economic viability of such multi-functional offshore islands, with the Princess Elisabeth Island (PEI) in the Belgian North Sea serving as a representative case study. Current assessment methodologies often fall short in comprehensively evaluating the intertwined financial and operational aspects of combining distinct energy and port functionalities on a unified offshore platform, creating a notable research gap. The primary objective of this research is, therefore, to develop and apply a standardized, transparent Techno-Economic Analysis (TEA) framework tailored for these complex, integrated systems.

The methodological approach is rooted in a TEA framework, systematically applied to the PEI case. This involves a physical breakdown of systems, detailed financial analysis including CAPEX, OPEX, revenue projections, and cash flow modeling, and performance analysis using key metrics such as Levelized Cost of Energy (LCOE), Net Present Value (NPV), and payback periods. The PEI project, planned for 3.5 GW of offshore wind connected via an artificial island housing AC and HVDC substations, formed the initial focus. The base case analysis for PEI as a standalone wind energy hub revealed significant financial challenges: amedian LCOE of 224 =C/MWh, substantially exceeding recent offshore wind strike prices, and a consistently negative NPV. This financial vulnerability is largely attributed to the dramatic increase in transmission infrastructure costs, which now account for nearly 50% of the total project CAPEX, a sharp rise from approximately 18% in 2020. Sensitivity analyses indicated that the LCOE is highly susceptible to project delays, ranging from 200 to 260 =C/MWh, and noted a cooling investor appetite in the European offshore wind sector. Enhanced base case considerations for the wind system showed that an AC-only configuration could reduce the LCOE to 182 =C/MWh, while incorporating HVDC as an interconnector, despite potential arbitrage revenues, increased the LCOE to 237 =C/MWh, illustrating a trade-off between strategic energy security benefits and immediate financial viability... ... Read more

Floating offshore wind farms enable wind energy deployment in deeper waters, where bottom-fixed turbines are not viable. However, integrating mooring systems and dynamic cables introduces additional challenges in cable routing, increasing design constraints and costs. While research on cable optimization for bottom-fixed wind farms is well-developed, studies focused on floating wind farms remain limited.
This thesis presents an optimization framework that minimizes inter-array cable length while ensuring compliance with mooring system constraints and loop topology requirements. A Mixed-Integer Linear Programming model is used to enforce spatial and technical constraints, structured into three phases: preprocessing, optimization, and postprocessing. Preprocessing defines feasible cable connections while preventing crossings with mooring lines. To manage complexity, turbines are grouped into clusters with defined boundaries to separate routing areas. The optimization phase determines the best cable layout while ensuring loop connectivity and balanced electrical loads. Postprocessing checks compliance with industry standards, identifying clearance violations and refining layouts for feasibility.
A case study of the London Array wind farm demonstrates the model’s effectiveness, achieving a 1.1% reduction in total cable length while maintaining the original layout structure. When adapted for floating wind, spatial constraints from mooring systems cause clearance conflicts, which are mostly resolved by scaling the layout. Minor turbine adjustments eliminate remaining issues. The study highlights that increasing the number of loops and reducing loop size creates more routing conflicts, particularly near the offshore substation and at cluster boundaries. It also finds that centrally positioned substations significantly reduce clearance violations compared to those at the field boundary.
This research provides practical insights into the spatial constraints of floating wind farms and offers a structured, computationally feasible approach to optimizing inter-array cable routing for large-scale farms. ... Read more

The global transition toward low-carbon energy systems has intensified interest in offshore renewable energy (ORE), particularly floating offshore wind turbines (FOWTs) and wave energy converters (WECs). As competition for offshore space increases, integrating multiple technologies within a single multi-use energy park has emerged as a promising strategy to enhance spatial efficiency while potentially reducing environmental impacts. However, existing research largely evaluates these technologies in isolation, leaving the environmental implications of shared infrastructure underexplored. This thesis addresses this gap by assessing the life cycle environmental performance of co-located offshore wind and wave energy systems compared with standalone deployments.

This study conducts a cradle-to-grave Life Cycle Assessment (LCA) using both the EF 3.1 and IMPACT World+ methodologies. Three 180 MW scenarios are modeled: a standalone floating wind farm (12 OFWTs), a standalone wave energy park (450 WECs), and a co-located wind-wave park (10 OFWTs + 75 WECs), with shared substation and export cabling infrastructure. Engineering-based models are developed to calculate Annual Energy Production (AEP), capacity factors, and component-level material inventories, while openLCA is used to quantify greenhouse gas emissions and broader environmental impacts. Energy Payback Time (EPBT) and Greenhouse Gas Payback Time (GPBT) are further computed to evaluate energy and climate performance over the systems’ lifetime.

Results show that shared infrastructure substantially reduces material demand, vessel use, and installation requirements in the co-located scenario, leading to lower embodied impacts per kilowatt-hour compared to the sum of standalone systems. However, differences in capacity factor estimation and technology convergence influence the distribution of environmental burdens between wind and wave subsystems. Across all scenarios, the manufacturing stage—particularly steel and copper—dominates total impacts. The analysis also highlights how future energy grid decarbonization could extend GPBT values, as improvements in background electricity mix reduce upstream emissions.

Overall, this thesis demonstrates that co-locating offshore wind and wave energy can deliver measurable environmental benefits through shared infrastructure and optimized spatial planning. The findings provide new quantitative evidence for policymakers, developers, and marine planners seeking integrated offshore renewable strategies and highlight methodological pathways for future LCA studies that assess hybrid ORE systems. ... Read more

Accurate prediction of nonlinear wave structure interaction remains a challenge for the design of large wave energy converter (WEC) arrays. This thesis develops and validates a weakly nonlinear frequency domain (NLFD) framework for modelling multi device point absorber arrays in realistic irregular seas. The formulation embeds nonlinear restoring, viscous drag, and power take off (PTO) dynamics directly within the frequency domain (FD) balance while retaining linear hydrodynamic coupling from HAMS-MREL. This enables fully coupled array simulations at a fraction of the computational cost of time domain (TD) approaches.

The solver was benchmarked against a nonlinear MATLAB TD reference and verified against the linear HAMS-MREL solution. Nonlinear heave dynamics were reproduced with amplitude errors of 11 to 17% and near identical phase, and the model collapses to the linear limit when nonlinear terms are disabled. These validations establish a robust foundation for irregular sea analyses.

A systematic study across four sea states, three spacings of 5D, 10D and 15D, and four incident headings quantified the mechanisms governing array performance. Nonlinear effects broaden spectral peaks without shifting the dominant frequency. Spacing redistributes absorbed power between devices while leaving the array averaged interaction factor close to unity. Hydrodynamic coupling is weak beyond roughly ten diameters, but nonlinear and directional effects still introduce measurable differences between rows at 15D. Directional incidence imposes the strongest control: long side headings between 60 degrees and 90 degrees maintain radiative synchronisation and produce mild constructive interaction, whereas oblique headings reduce phase coherence and suppress amplification.

A device level case study shows that array behaviour is governed by radiative phase alignment rather than geometric proximity. Devices experiencing radiative softening exhibit larger response and absorbed power, while those subject to radiative stiffening show reduced motion despite nearly identical incoming excitation. This establishes the link between local impedance modification and array scale performance.

Overall, the results show that weakly NLFD methods capture the essential physics of large WEC arrays with clarity, computational efficiency, and controlled accuracy. The framework supports phase based layout, directional alignment, and PTO tuning strategies for early stage design of future wave energy farms.
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Harnessing wave energy from the world’s oceans provides an enormous chance to fulfil substantial parts of the energy transition’s demand for electricity from renewable sources. The technology that makes this possible is wave energy converters (WECs) - offshore structures that can convert the energy in waves into electricity. Although the energy conversion of this precommercial technology is not directly linked to greenhouse gas emissions like in other conventional power plants, environmental sustainability over the whole life cycle of the device needs to be ensured for a sustainable large-scale application. To assess this, in recent decades some Life Cycle Assessment (LCA) studies have been carried out on different WECs. However, there is still a gap in terms of number, quality, coverage of more sustainable design alternatives as well as impact assessment beyond greenhouse gas (GHG) emissions. Therefore, in this study a specific type of WEC – the point absorber – is assessed for its environmental sustainability by means of LCA. A parameterized cradle-to-grave LCA model of a single representative point absorber is implemented to assess the environmental impacts of a WEC, the influence of different hull materials, hotspots in impacts of WEC components as well as variations induced by different deployment locations. A GHG-intensity of 300-325gCO2eq./kWh with periphery and 52-77gCO2eq./kWh without periphery is found for a WEC deployed in the Dutch North Sea depending on the hull material. Using an alternative fibre reinforced concrete material for the hull can reduce impacts across all impact categories between 10% and 78%. Next to the structural materials in the WEC the electrical cable and vessel operations, especially for maintenance, were found to contribute significantly. This study showed that impacts of electricity from WECs have to decrease to reach the level of other renewable electricity generation technologies but revealed possible levers to achieve such a reduction. ... Read more

To stay on track for the 1.5°C pathway of the Paris Agreement, an accelerated energy transition is essential. Efficient offshore energy infrastructure planning, incorporating novel methods, is crucial and requires transparent, industry-wide discussion. However, two main challenges emerge: (i) the often-overlooked integration of energy islands in literature and (ii) the lack of a standardized techno-economic comparison method. A comprehensive review of offshore wind supply chain feasibility studies highlighted the need for explicit implementation of standardization, syntax and semantics in model development. Detailed assessment of international and industry standards revealed that no single standard fully covers the study's scope. Nevertheless, one ISO standard showed significant similarities in component definitions, with which this study's component definition is maximally aligned. The developed open-source model enables automated supply chain configuration generation, eventually calculating economic metrics such as the Levelized Cost of Hydrogen (LCOH). Applying the developed techno-economic model to the 19.5GW case study hub North in the North Sea Energy programme demonstrated its applicability and the techno-economic advantages of integrating an offshore energy island. The key finding is that island-based configurations are economically more efficient for hydrogen production compared to platform or onshore setups. Comparison with other studies on hydrogen import indicates that the calculated LCOH range of 8.54 - 10.40 €/kg has the potential to compete with hydrogen imports, which often have overly optimistic estimates ranging from 4 to 9 €/kg. Ultimately, in this way, a standardized, transparent method for industry-wide collaboration is presented. ... Read more

The offshore wind market has become a substantially growing industry to meet the worldwide increasing energy demands. This results in heavier crane operations on offshore jack-up vessels due to the increasing size of wind turbine components. To ensure the seabed can support the loads on the jack-up legs, a temporary foundation for the leg's footings is established before crane operations through a process known as preloading. Where the two diagonal opposing leg pairs are loaded alternatively by the weight of the vessel until a stable condition is reached. Traditionally, the capacity of those foundations is determined based on storm loads adopted from offshore oil and gas jack-up guidelines.

The main objective of this thesis is to develop a robust method for analysing the applied preload in past jack-up crane operations conducted by Jan de Nul's Vole au vent. This analysis aims to provide a better understanding of the effectiveness of traditional offshore jack-up guidelines within the rapidly growing offshore wind industry, where heavy crane operations are now performed on a daily basis. Such understanding is crucial, as these guidelines were not originally intended for the advanced state of the current offshore wind sector and are not specifically calibrated for its unique demands.

To accomplish this objective, a method is designed to assess the preload safety factors of past jacking operations and determine their optimal value for heavy lifting operations. This safety factor provides the ratio between operational leg reactions and applied preload. The developed models are then applied to a case study using measuring data from jacking operations of the Vole au vent to validate their effectiveness.

This method is based on reliability analyses which evaluate the probability of failure by assessing if a certain limit state is exceeded. Failure for jacking operations can occur when the leg reactions during crane operations become larger than the applied preload. From the acquired measuring data, certain probability distributions of the leg reactions can be obtained, which are used by a Monte Carlo Simulation to assess the probability of preload exceedance through the defined limit states. This probability of preload exceedance quantifies the reliability of the applied preload in different soil types at three offshore wind farm sites.

This research then defines optimal targets for the annual probability of preload exceedance based on the consequences of failure of operations in both low-risk and high-risk soil profiles. These targets provide a balance between operational efficiency and safety. From those targets, an optimal preload safety factor is obtained and compared to what was originally applied during the jack-up operations.

The findings of this thesis indicate the need to evaluate and improve the standards to better align with the industry's evolving requirements.

It is shown that the currently used preload safety factor from traditional offshore jack-up guidelines is not yet correctly calibrated for heavy crane operations on jack-up vessels. To achieve an optimal balance between operational efficiency and safety, the applied preload, with respect to the experienced loads from heavy crane operations, should be slightly lowered compared to what is currently applied.

In addition, this research observed that the measured conditions during jack-up operations are not correctly estimated, leading to operational and preload uncertainties. ... Read more

The rapid growth of Floating Offshore Wind (FOW) has spurred intensive research across various aspects of the floating system. A standard practice in mooring system design within the industry is that anchors remain fixed on the seabed. In contrast, plate-type anchors exhibit mobility under loading, a crucial factor considering the thousands of loading cycles experienced by FOW turbines during operation. Understanding the strain accumulation mechanism during cyclic loading has substantial implications for design. This thesis delves into the behavior of Drag Embedded Anchors (DEAs) subjected to static monotonic and cyclic loading, utilizing 3-dimensional Finite Element simulations. The installation trajectory of DEAs is initially defined through established analytical methodologies. Subsequently, the movement of the anchor and soil response under monotonic and cyclic loads is elucidated. Analytical expressions for monotonic force-displacement curves are examined, identifying optimal models and offering relevant parameter values for different anchor trajectory points. Under cyclic loading, the influence of average load and cyclic load amplitude is studied, along with exploring the feasibility of applying an existing 1-dimensional model for predicting anchor response.
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During single-blade offshore wind turbine (OWT) installation, wind disturbance results in blade root motion. The sensitivity to this wind disturbance is more significant for larger blades, reducing the allowable installation weather limit. A potential solution is a Hook Mounted Compensator (HMC) between the crane and the load that can provide high-precision compensation across multiple degree of freedom (DOF), and compensate for the influence of wind on the OWT blade. Several Actuation Method (AM)s have been identified that can be used in a HMC. However, these AMs have not been modelled dynamically and their effectiveness for the desired application is unknown. The aim of this study is to analyse and assess the compensation effectiveness of these AMs in a HMC. For this purpose, the AMs are simulated and analysed in various levels of complexity and DOFs. Initially, the system is considered in a 1DOF. A linear representation is formulated, based on which a Proportional-Integral-Derivative (PID) controller for each AM is formulated. This enables simulation of the Single-Blade Installation System (SBIS) in the time domain. Assessment criteria are used to quantify the compensation effectiveness and actuation input of the AMs. To simulate the SBIS for each AM, 3DOF numerical models are developed that describe the operation of the AMs in their respective operational planes. Six actuation methods are included in the assessment. Based on the assessment results, three AMs are combined in a HMC concept. A XY table is used to control blade root position in the x- and y-directions, gyroscopes for the z-direction, and COG shifting with counterweight to prevent gyroscope saturation. The PID controllers based on the linear 1DOF representation are used, operating in parallel, to control the blade root position in all DOF. The blade root motion is reduced by 96% along the blade axis and 86% radially. The blade root motion is sensitive to the mean wind speed, turbulence intensity, and angle of the incoming wind. The HMC shows robustness to variations in tugger line angle and pretension. The static blade pitch angle affects the magnitude and distribution of the wind-induced moment on the blade. For a pitch angle of -180, the moment around the z-axis is minimal, providing optimal HMC performance. The HMC concept can not directly actuate the blade around the z-axis. Instead, the XY table translates the blade at the COG, resulting in increased cylinder stroke and high power consumption for other pitch angles. Two AMs were assessed to actuate the blade around the z-axis, both showing poor performance. Further exploration of AMS that can directly control the blade rotation around the z-axis could lead to improvement of the HMC concept. Additional improvement can be made in optimization of counterweight and gyroscopes sizes, potentially reducing weight and improving system performance. Further suggestions for future work include; exploring the compensating for the now neglected hub motion using the HMC, examining the stability of the HMC once the blade is mated to the hub, and the impact of sensor noise and delay on the HMC’s performance.

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To facilitate the energy transition, effective collaboration among all stakeholders is necessary. However, there is currently a lack of understanding regarding the impact of different components in the value chain on the energy system's overall structure and the final energy price. This knowledge gap poses a significant obstacle to cooperation and progress in the energy transition. It creates the risk that effort goes into developing certain partial solutions when they may not be feasible from a larger system perspective. By focusing on their own component, stakeholders do not fully take into account the needs and interests of others involved. As the development of green hydrogen projects is in its early stages, it is important to think in terms of systems. Stakeholders should establish an ecosystem where players operating in different parts of the value chain are collaborating together. This helps to de-risk projects, share lessons and promote the development of innovative, first-mover initiatives.

This study aims to develop a standardised method to evaluate offshore wind to hydrogen concepts through a techno-economic analysis. This analysis method combines technical analysis with economic evaluation of projects and concepts to determine the potential economic outcomes and impacts of implementing a particular technology or project.

Through stakeholder interviews, the study found that stakeholders in the offshore wind and hydrogen market have distinct objectives and concerns. Key factors influencing their willingness to contribute include confidentiality, competition, and reputation.

To increase the transparency of the model, it was developed in Python. A standard notation system was developed, which was presented alongside the model's results. This should aid in the understanding of the underlying assumptions. ... Read more

This research aims to improve the current knowledge and insight into the construction process, logistics, and construction costs associated with the offshore pumped storage hydropower plant. The main objective is to enhance the construction costs by optimizing the work method based on these sheltering effects.

The diffraction and sheltering effects due to the caisson dam will be determined using the Goda diffraction tables. Additionally, the Levelised Cost of Storage (LCOS) will be used to assess the cost-effectiveness of this bulk energy storage technology and enables the comparison with alternatives, such as lithium-ion and hydrogen storage.

In summary, this research addresses the promising potentials of work method optimization for offshore caisson projects regarding the local wave climate. For a case study in the North Sea, it has not only highlighted the relevance and importance of including wave sheltering. Moreover, with a LCOS of € 140-260/MWh it also shows the competitiveness of the offshore pumped storage hydropower concept once again. Alternative energy storage methods such as lithium-ion or hydrogen are in the range of € 200-400/MWh for lithium-ion and € 200-1900/MWh for hydrogen storage. Therefore, offshore pumped storage hydropower (PSH) can be a favorable solution enhancing the energy transition. ... Read more

The purpose of this report is to design a wave energy converter, in particular a U-oscillating water column (U-OWC), to maximize energy conversion in the low wave energy environment of Gwadar, Pakistan. At present Pakistan’s 1000km coastline is largely undeveloped and the county is devoid of any wave energy harnessing devices or studies. However, recent years have seen an influx of Chinese investment being made under the China-Pakistan economic corridor agreement, which is stimulus for the near future construction of a large rubble mound breakwater to shelter an assistance vessel basin in the city of Gwadar.

Typically, a WEC is not feasible in low incident wave energy environments because the economic return from minimal energy generation cannot offset the capital cost of the structure. However, the opportunity in Gwadar is unique in the sense that a substantial investment is already envisaged for the creation of a breakwater. Therefore, it is worth investigating if re-designing this structure with vertical caissons embedded with U-OWC chambers is feasible. In this way, the structure can fulfill the dual role of sheltering the assistance vessel basin against wave attack, and produce renewable energy over its design life.

To assist with this task, existing data and methods available in literature along with numerical codes have been utilized. A 10 year SWAN hindcast has been performed, the result of which have been condensed into 60 representative design sea-states on the basis of which the U-OWC chamber geometry
and turbine configuration have been optimized. This was achieved by employing a random sampling technique to determine which combinations produce the most power and by identifying the ideal turbine
operating revolutions for each sea-state.

Next, the approximate cost of the caisson breakwater integrated with U-OWC chambers is calculated and compared against the currently proposed rubble mound design. It is expected that despite an attempt to maximize the energy generation by the device, its levelized cost of energy will be high, given
the low wave energy in the region. Nevertheless, if the design proves cheaper than its rubble mound counterpart, it goes to show that wave energy converter can be deployed in low energy environments provided an opportunity exists where they can be integrated into proposed marine structures. This will
be an important finding, considering that the majority of the global coastline is subjected to moderate to low incident wave energy, and neglected from WEC deployment considerations. ... Read more