Open Access
Review
23 April 2025Research Progress on Offshore Wind Turbine Foundation Structures and Installation Technologies
Offshore wind power, as an important component of renewable energy, has gradually become one of the key technologies in global energy transition. The development of offshore wind power faces complex technical challenges, including strong wind, waves, currents, foundation bearing capacity, and installation technologies for wind turbines, among other issues. In recent years, with technological advancements, significant breakthroughs have been made in the design of offshore wind power foundation structures, installation technologies, and equipment. This paper provides a comprehensive review of the recent progress in offshore wind power technologies, deeply exploring innovative technologies in areas such as the overall development trends, foundation structures, installation technologies, and equipment of offshore wind power. Special attention is given to the design and safety analysis of wind turbine foundation structures under different foundation conditions, as well as installation technologies for wind power in complex sea conditions and deep-water areas. The paper argues that the applicable depth of fixed foundations is expected to extend beyond 50 m. The jacket foundation remains the mainstream choice for future large-scale wind turbines, with the potential to increase its applicable water depth to 100 m. Furthermore, floating foundations have significant potential for cost reduction and efficiency improvements. Developing entirely new foundation structures and installation technologies suitable for deep-water environments is also a key direction for future development.
Open Access
Article
19 May 2025Research on Thermal Fault Detection and Location of Photovoltaic Connectors Based on Multiple Model Estimator
Offshore photovoltaic (PV) systems encounter challenges due to high humidity and salt spray environments. The PV connectors on the DC input side of inverters are particularly susceptible to increased contact resistance and local overheating caused by environmental corrosion. This paper introduces a novel thermal fault location method utilizing a multiple model estimator (MME). The approach develops a lumped thermal model and an abnormal overheating disturbance model for the PV connectors. By combining a Kalman filter with a probability fusion algorithm, the method effectively detects thermal faults. Simulation and experimental results demonstrate that this approach can accurately locate faults while requiring only a minimal number of thermal sensors, thereby enhancing the reliability of offshore PV systems.
Open Access
Article
29 May 2025Hydrodynamic Performance and Energy Capture Characteristics of a Floating Inner Rotor Wave Energy Device
The development of efficient wave energy converters (WECs) is essential for harnessing marine renewable energy, particularly in regions with low wave energy flux. This study investigates a floating WEC with an internal eccentric rotor designed to enhance energy capture efficiency. The device consists of a floating body for wave energy absorption, an internal rotor for mechanical-to-hydraulic energy conversion, and a mooring system for stability. A numerical model was developed and validated against wave tank experiments, showing good agreement in peak values and amplitudes. Frequency-domain analysis examined the effects of structural parameters, draft, and center of gravity offset on hydrodynamic characteristics, while time-domain analysis evaluated the impact of rotor mass and power take-off (PTO) damping on energy capture. Multi-parameter optimization led to an improved structural design, increasing instantaneous power output by 150% and total power output by 108%. These findings provide a basis for further optimization of WECs in low-energy wave environments.
Open Access
Article
10 June 2025Influence of Surface Waves—Von Karman Street Interaction on Bottom Sediments Transport in the Vicinity of a Wind Turbine Mast: Experimental and Theoretical Study
Cylindrical structures used in offshore energy production systems are subjected to various stresses and loads (waves and currents). Understanding the interactions between these cylindrical structures and bedforms is critical, as rapid changes in the bathymetry can expose and damage pile foundations and cables. The impact of a vertical cylinder on a sandy sedimentary bottom subjected to hydrodynamic currents and surface waves is experimentally and theoretically studied. Tests were carried out at the wave flume where patterns are produced. It is observed that patterns emerge due to a subcritical instability at the water-sand interface at the bottom. The characteristics of these patterns can be explained using the Swift-Hohenberg equation. Finally, the experimental results will be applied to the numerical model using the Swift-Hohenberg equation.
Open Access
Article
26 June 2025Assessment and Spatialization of the Potential of Marine Renewable Energies in the Gulf of Guinea: Case of the Cameroonian Coast
This study explores, through mathematical simulation and Geographic Information Systems, the electricity production potential of Marine Renewable Energies (MRE) on the Cameroonian coast. The study uses data from the National Institute of Cartography and, in the absence of in situ oceanographic observation, data from the National Oceanic and Atmospheric Administration and those of Copernicus Marine Services, to determine and identify, after calculations on Excel and spatial representation on ArcGIS 10.2.2, areas with high MRE potential. The analyses carried out show that the Cameroonian coastline is full of significant potential for the development of MRE. Indeed, with a potential of approximately 6 kW at sea and approximately 1 kW on the coast, current energy constitutes a capitalizable opportunity. Concerning wave energy, the average production potential of the Cameroonian marine area is approximately 3.37 kW/m. However, it is much higher on the Kribi coast (between 4 and 7 kW/m). Furthermore, significant potential for tidal energy can be identified in the Wouri estuary, as well as in other sectors such as marine thermal energy and osmotic energy, although this requires further analysis to be better understood. These results would help promote research on these energies in Cameroon.
Open Access
Article
30 June 2025Hydrodynamic Analysis of Offshore Floating Photovoltaic Structure with Elastic Connection
Offshore Floating Photovoltaic structure (OFPV) represents a promising solar energy technology characterized by high conversion efficiency and suitability for large-scale deployment. However, the safety and economic synergy problems of floating structures restrict the industrialization and large-scale development of OFPV. We propose a novel OFPV with elastic connection and modularizable HDPE float blocks. The numerical wave tank is established by the turbulence model in FLOE-3D, based on the Navier-Stokes equations. Hydrodynamic analysis of the OFPV is conducted by using the Generalized Mode-Order (GMO) approach. Furthermore, the dynamic responses and mooring loads of the OFPV with elastic and rigid connections are compared. The results show that the average pressure of the photovoltaic support structure with the elastic connection is positively correlated with the wave height. The tension value of the elastic cable is higher at the outermost peak tension. The OFPV with the elastic connection structure has more obvious advantages in extreme wave state conditions than the rigid connection. This study provides theoretical support for the design and engineering application of OFPV.
