Offshore wind power generation system with a submarine fixed support structure and a floating platform

Abstract

An offshore wind power generation system (1) comprising a submarine fixed connection station (2) configured as a fixed support structure (2) having a bottom portion (20) and a top portion (21), the top portion (21) being arranged at a height distance (h) from the bottom portion (20). The bottom portion (20) is configured to be connected to a seabed (S) arranged at a water depth (d), and the top portion (21) is arranged underwater at a predetermined depth distance (p) from a water surface (W). The system (1) further comprises a floating offshore platform (3) provided with at least one wind turbine (30), and a connecting interface (4) including a base connector (40) attached to the top portion (21) of the submarine fixed connection station (2), and a main connector (41) attached to the floating offshore platform (3). The main connector (41) is configured for selective coupling to the base connector (40) to establish a reversible mechanical connection.

Description

[0001] Offshore Wind Power Generation System with a Submarine Fixed Support Structure and a Floating Platform

[0002] TECHNICAL FIELD

[0003] The present invention relates to offshore wind power generation systems, particularly to a system comprising a submarine fixed connection station configured as a fixed support structure, a floating offshore platform equipped with at least one wind turbine, and a connecting interface for selectively coupling the floating offshore platform to the submarine fixed connection station. The invention is particularly suitable for intermediate water depths, where conventional fixed-bottom support structures are impractical, and mooring-based floating platforms present operational and structural challenges.

[0004] PRIOR ART

[0005] Fixed-bottom support structures, such as monopiles, jacket structures, and gravity-based foundations, are commonly used in shallow to moderate water depths, generally up to approximately 40 metres. Monopile foundations, in particular, have demonstrated high efficiency and costeffectiveness in shallow waters but become structurally impractical at greater depths due to excessive material requirements and installation constraints. Jacket structures, which are commonly used for depths beyond 20 metres, provide increased structural stability but require complex fabrication and seabed anchoring methods. These fixed-bottom support structures are configured to extend from a seabed to a point above a water level (i.e. they protrude from a water surface) to arrange a wind turbine on a dry connection point (i.e. arranged above the water surface).

[0006] For deeper waters, typically beyond 40 metres, floating offshore platforms are employed, relying on mooring-based station-keeping systems. These platforms remain buoyant and are secured to the seabed using catenary mooring lines, taut leg mooring systems, or tension-leg platforms. However, mooring-based solutions present several drawbacks. Mooring lines are subject to substantial loads due to wind, waves, and currents, leading to accelerated fatigue and degradation over time. Catenary-type mooring systems require long chains, often exceeding ten times the water depth, which significantly increases weight and cost. While tension-leg platforms offer improved stationkeeping performance, they experience high horizontal forces in shallow-to-moderate water depths, increasing the complexity and cost of tendon anchor design.

[0007] Mooring-based station-keeping systems also present limitations in severe sea states. High snatch loads occur when catenary lines become taut, an effect that is exacerbated due to shallow water effects. This leads to potential structural failures and the need for highly reinforced chain designs. The deployment of such systems is also complex, requiring precise offshore operations, anchorinstallation, and tensioning of mooring lines. The high catenary line loads expected result in the need of very powerful vessels for anchor proofloading and also for preloading the mooring lines during installation. This is particularly inconvenient if a tow-to-port operation is required to service the turbine, which usually means that these heavy vessels need to be mobilized both for the disconnection and re-connection of the platform once it has been serviced. Moreover, regular maintenance and inspection of mooring components are required due to wear, corrosion, and fatigue, leading to increased operational costs. Ensuring reliable electrical cable connections between a floating platform and the seabed-mounted power infrastructure is also particularly challenging due to the movement of the floating structure.

[0008] The large-scale adoption of mooring-based systems requires significant quantities of high-grade offshore-quality steel for mooring chains and anchoring components. Various solutions have been proposed to mitigate peak loads, including the use of dampers integrating rubber and steel elements. However, these solutions remain unproven in large-scale offshore wind applications and pose additional risks in terms of durability and long-term monitoring.

[0009] Given these limitations, there remains a technological gap for offshore wind power generation systems designed for water depths ranging from 40 to 80 metres, where fixed-bottom solutions are impractical and mooring-based floating platforms present excessive costs, maintenance challenges, and structural risks. There is therefore a need for an improved offshore wind power generation system that overcomes the limitations of mooring-based floating platforms while maintaining the adaptability required for deeper waters beyond conventional fixed-bottom structures.

[0010] SUMMARY OF THE INVENTION

[0011] The present invention addresses the problem of providing a reliable, efficient, and cost-effective offshore wind power generation system suitable for intermediate water depths, particularly in the range from approximately 40 metres to 80 metres. Within this water-depth range, conventional fixed-bottom support structures become technically impractical or economically inefficient, and typical mooring-based floating platforms exhibit significant technical disadvantages. These disadvantages include substantial structural loads, accelerated wear, maintenance complexity, and limitations in severe environmental conditions, as outlined in the prior art. The present invention therefore seeks to overcome these drawbacks by providing an alternative station-keeping solution that avoids reliance on mooring lines and their associated limitations.

[0012] A first aspect of the invention refers to an offshore wind power generation system comprising a submarine fixed connection station configured as a fixed support structure, a floating offshoreplatform equipped with at least one wind turbine, and a connecting interface configured for selective coupling between the floating offshore platform and the fixed submarine connection station.

[0013] The submarine fixed connection station comprises a bottom portion and a top portion arranged at a predetermined height distance from the bottom portion. The bottom portion of the fixed support structure is configured to be connected to a seabed arranged at a predetermined water depth, and the top portion is configured to be arranged underwater at a predetermined depth distance from a water surface. It is explicitly clarified herein that the term "fixed support structure" may be interpreted as referring to a substantially rigid structure that is directly anchored to the seabed, thereby explicitly excluding conventional flexible mooring structures based on cables, ropes, or chains.

[0014] The floating offshore platform comprises at least one wind turbine arranged for generating electrical power from wind energy. The floating platform is configured to remain buoyant at or near the water surface and is capable of limited movement in response to environmental loads such as wind, waves, and currents.

[0015] The connecting interface comprises a base connector attached to the top portion of the submarine fixed connection station and a main connector attached to the floating offshore platform (e.g. to a lower portion of the floating offshore platform). The main connector is configured to be selectively coupled and decoupled from the base connector, thereby providing a secure and reversible mechanical connection between the floating offshore platform and the submarine fixed connection station. This selective coupling allows for simplified installation, maintenance, and potential relocation of the floating offshore platform.

[0016] By employing a fixed support structure and a selectively couplable connecting interface, the invention provides effective station-keeping capability at intermediate water depths without the disadvantages associated with mooring-based systems, such as high loads, complex maintenance, and limited structural reliability under severe environmental conditions.

[0017] The depth distance at which the top portion of the submarine fixed connection station is arranged underwater may be in the range from 5 to 30 metres, preferably from 10 to 25 metres, and more preferably from 15 to 20 metres, within a predetermined tolerance of 1.5 metres. Such depth ranges may be advantageous for enhancing the stability and operational reliability of the system by ensuring sufficient submersion to avoid excessive wave-induced loads, while also facilitating installation, maintenance, and connection operations.

[0018] The bottom portion of the submarine fixed connection station may be arranged at a water depth in the range from 20 to 100 metres, preferably from 30 to 90 metres, and more preferably from 40 to 80 metres. Such water depth ranges may be particularly advantageous as they correspond to depthswhere conventional fixed-bottom structures become impractical and where the proposed fixed support structure combined with a floating offshore platform provides optimal cost-effectiveness, ease of installation, and structural reliability.

[0019] The height distance between the bottom portion (seabed level) and the top portion of the submarine fixed connection station may correspond to a percentage of the water depth in the range from 40 to 90%, preferably from 65 to 87.50%, and more preferably from 70 to 75.00%. Such relative dimensional arrangements may provide structural advantages by optimising the stability and load distribution of the fixed support structure while minimising material usage and costs, facilitating easier installation and ensuring optimal coupling conditions with the floating offshore platform. An important consideration here is that a depth distance being greater than 10 or 15 metres (e.g. in the range 10 to 30 m, preferably in the range 15 to 30 m, more preferably in the range 15 to 20-25 metres) may be specially advantageous for allowing a remotely operated vehicle (ROV) to aid in the connection process of the floating offshore platform to the submarine fixed connection station by means of the connecting interface. Further, selecting water depths above 30 metres may lead to a higher operational draft of the floating offshore platform, which may restrict port operations (e.g. for maintenance purposes) or require a significant amount of water ballast in the floating offshore platform to reach this relatively high operational draft, which inevitably means that the platform is heavier than it could be. Further lowering the connection point (i.e. the position of the base connector) does have the advantage of reducing overall moment of wind and wave forces that has to be handled by the anchor points of the fixed support structure, which is why specific design conditions may favour a deeper connecting interface position, especially when overall water depth is in the range of 60 to 80 m.

[0020] In some embodiments, the floating offshore platform may comprise a pivot column and a turret connector arranged within said pivot column. The main connector may be rigidly connected to a lower portion (e.g. to a bottom portion) of the turret connector (or the main connector may be part of the lower portion of the turret connector), and the turret connector may comprise a bearing system configured to allow rotation of the floating offshore platform relative to the submarine fixed connection station about a central geometrical vertical axis of the turret connector. Preferably, the bearing system may be further configured to prevent a vertical relative displacement between the turret connector and the floating offshore platform. This may help reduce unwanted motion of a submarine cable (e.g. configured to transmit electrical energy generated by the wind turbine) and thereby reduce the risk of cable wear or failure. Such a configuration may enable the floating offshore platform to weathervane in response to wind and current conditions, thereby reducing structural loads and improving the operational efficiency of the wind turbine.In the context of the present invention, the term "pivot column" refers to a structural element of the floating offshore platform comprising a receiving portion configured to receive (e.g. lodge) the turret connector. The name "pivot" indicates that the floating offshore platform is configured to weathervane relative to the submarine fixed connection station about a vertical geometrical axis (which is a spatial reference) arranged in the pivot column. The name "column" refers to the specific configuration of this receiving portion, which is generally elongated to accommodate the turret connector, which itself is typically an elongated element, such as a vertically oriented component. However, it should be understood that the term "column" is not intended to be restrictive in terms of a particular shape, and the receiving portion may adopt different geometric configurations while still performing the function of receiving (e.g. lodging) the turret connector.

[0021] The bearing system may preferably comprise at least one lower bearing and / or at least one upper bearing, wherein the lower bearing may be configured to interact with a lower portion of the turret connector and the upper bearing may be configured to interact with an upper portion of the turret connector. While a single bearing configuration is feasible, this will in most cases mean a complex bearing (e.g. such as a nautilus-type double row conical bearing) operating fully submerged, which presents some challenges to the durability of the system. The inclusion of a bearing system with at least two bearings may enhance rotational stability, and most importantly improve the longevity of the rotating components, in particular in those preferred embodiments in which the at least one upper bearing may be positioned above a water level, which substantially facilitates maintenance.

[0022] In some embodiments, the pivot column, the turret connector and the connecting interface may be configured such that, when the floating offshore platform is coupled to the submarine fixed connection station, the turret connector is maintained in a predetermined operating position relative to the submarine fixed connection station (e.g. the lower portion of the turret connector may be maintained at a constant distance from the bottom portion of the submarine fixed connection station), such that relative displacement along the vertical direction between the floating offshore platform and the submarine fixed connection station at the turret connector is constrained, while the floating offshore platform is allowed to rotate about a central geometrical vertical axis of the turret connector. Such a configuration may facilitate reliable coupling and operational stability while preserving weathervaning capability. Additionally or alternatively, the connection between the turret connector and the floating offshore platform may be configured such that, when the turret connector is coupled to the submarine fixed connection station and maintained in said predetermined operating position relative to the submarine fixed connection station, relative displacement along the vertical direction between the floating offshore platform and the turret connector is constrained, while relative rotation about the central geometrical vertical axis is allowed by the bearing system.In some embodiments, the pivot column may be arranged offset with respect to a geometrical center of the floating offshore platform, preferably in a peripheral region of the floating offshore platform, and optionally at or adjacent to a corner region of a polygonal floating offshore platform, such as a triangular floating offshore platform. Such an arrangement may facilitate maintaining the turret connector in said predetermined operating position relative to the submarine fixed connection station, such that relative displacement along the vertical direction between the floating offshore platform and the submarine fixed connection station at the turret connector is constrained, when the floating offshore platform is coupled to the submarine fixed connection station.

[0023] In one embodiment, the bearing system may be configured as an interface arranged between the pivot column and the turret connector. This bearing system may be configured to allow a sliding and / or rolling (e.g. at least one bearing may be configured to slide and / or at least one bearing may be configured to roll) contact interaction between the pivot column and the turret connector, such that the floating offshore platform is allowed to rotate about the central geometrical vertical axis of the turret connector relative to the submarine fixed connection station. By enabling controlled rotational movement, the bearing system may facilitate weathervaning of the floating offshore platform in response to wind and current conditions, thereby optimising aerodynamic efficiency and reducing structural loads.

[0024] In an alternative configuration, the turret connector may comprise an outer trunk element and an inner shaft, wherein the outer trunk element may be configured to be attached to the pivot column, and the inner shaft may be configured to be attached to the submarine fixed connection station by means of the connecting interface (e.g. a bottom portion of the inner shaft may correspond to the bottom portion of the turret connector to which the main connector is configured to be attached). The bearing system may be arranged as a contact interface between the outer trunk element and the inner shaft, allowing a relative rotation between these components. This configuration may enable the floating offshore platform to rotate relative to the submarine fixed connection station about a central geometrical vertical axis of the turret connector. Such an arrangement may enhance the robustness of the rotational interface while ensuring reliable mechanical coupling and minimising undesired resistance to rotational movement.

[0025] In a manner broadly compatible with any of the preceding embodiments, the connecting interface may further comprise a mechanical decoupling interface configured to at least partially isolate and reduce the transmission of motion (e.g. moments and / or forces) from the floating offshore platform to the submarine fixed connection station (i.e. when the floating offshore platform is connected to the submarine fixed connection station by connecting the main connector to the base connector). The mechanical decoupling interface may be arranged between (e.g. connecting) the base connector and the submarine fixed connection station, or between (e.g. connecting) the main connector andthe floating offshore platform, this last option being preferred for maintenance purposes, since the floating offshore platform may be towed to a port. The decoupling element may be particularly beneficial in mitigating the effects of wave-induced motions, preventing excessive structural loads from being transferred to the fixed support structure, thereby improving the durability and stability of the entire system. This marks a substantial deviation of this invention from traditional monopile or jacket foundations used in fixed offshore wind, where the very high moments caused by wind forces on the turbine rotor are transmitted throughout the support structure, with increasing strength required as the tower extends towards the seabed. In the present invention, thanks to this decoupling element, virtually zero moment is transmitted at this point. Buoyancy effects on the floating offshore platform will instead be responsible to counter the moment caused by wind forces on the turbine rotor. This makes it so the submarine fixed connection station is significantly lighter and less complex than a typical jacket structure designed to operate in this similar water depth range.

[0026] In some embodiments comprising the mechanical decoupling interface, the turret connector may be maintained substantially in said predetermined operating position relative to the submarine fixed connection station, such that relative displacement along the vertical direction between the floating offshore platform and the submarine fixed connection station at the turret connector is constrained, while one or more other portions of the floating offshore platform are allowed to undergo limited angular movement, including pitch and / or roll, under wave loading. Such a configuration may reduce transmission of wave-induced loads and moments to the submarine fixed connection station while preserving reliable coupling and weathervaning capability.

[0027] The mechanical decoupling interface may be configured as a spherical joint, or as a cardan-type connector, or as an elastic interface comprising one or more elastic elements. These configurations of the mechanical decoupling interface may allow multidirectional angular movement, thereby accommodating pitch and roll motions of the floating offshore platform relative to the submarine fixed connection station. In some embodiments, the mechanical decoupling interface may be arranged above the main connector (e.g. as an interface between the main connector and the turret connector).

[0028] In preferred embodiments, the mechanical decoupling interface is configured as an elastic interface comprising one or more elastic elements. This configuration may help dissipating / absorbing energy resulting from relative motion between the floating offshore platform and the submarine fixed connection station. The one or more elastic elements may be arranged distributed between the base connector and the submarine fixed connection station, or between the main connector and the offshore floating platform, such that the one or more elastic elements provide an elastic spherical joint between the base connector and the submarine fixed connection station, or between the main connector and the offshore floating platform. Thus, the one or more elastic elements may bedistributed perimetrally, e.g. distributed around the vertical geometrical axis as an interface between the base connector and the submarine fixed connection station, or as an interface between the main connector and the offshore floating platform.

[0029] The incorporation of the elastic elements may be advantageous in reducing dynamic loads and vibrations, thereby enhancing the operational lifespan and structural reliability of the system. Furthermore, these elastic elements may be particularly important during the hook-up operation (i.e. the operation of connecting the floating offshore platform to the submarine fixed connection station by connecting the main connector to the base connector), since it significantly reduces impact loads that can occur when the hook-up is done under any significant level of wave loading, which is almost always going to be the case. While a more traditional, rigid spherical joint does provide the decoupling effect, it lacks this additional benefit of providing some damping. A cardan-type mechanism would have this drawback as well, and would also make it more difficult to provide space for a coaxial cable connection running through the connecting interface, which is also typically a requirement for such a system, making it the least attractive option.

[0030] In preferred embodiments, the elastic interface may be arranged between the main connector and the offshore floating platform, preferably between the lower / bottom portion of the turret connector and the main connector. In some embodiments the bottom portion of the turret connector may be configured to have a substantially spherical shape, such that the one or more elastic elements of the elastic interface may be arranged surrounding the bottom portion of the turret connector, for example, distributed in two groups, a first group surrounding a lower part of the bottom portion of the turret connector and a second group surrounding an upper part of the bottom portion of the turret connector.

[0031] The fixed support structure may be configured as a jacket structure, wherein the bottom portion of the fixed support structure may be configured as a foundation interface for anchoring the submarine fixed connection station to the seabed. A jacket structure may provide enhanced structural stability and load distribution, making it particularly suitable for intermediate water depths where conventional monopile foundations become impractical, and floating mooring-based systems present operational challenges.

[0032] The jacket structure may preferably comprise a plurality of interconnected leg members extending from the foundation interface to the top portion of the submarine fixed connection station, and will typically feature built-in anchor elements using the “suction bucket” principle. Additionally, the jacket structure may preferably comprise a plurality of brace members interconnecting the leg members to provide structural reinforcement, ensuring resistance to operational and environmental loads such as wave action, current forces, and wind-induced loads from the floating offshore platform. The useof a jacket structure may offer advantages in terms of modular fabrication, transportation, and installation efficiency. Note that the jacket structure needed for the present invention, due to the advantages describe in this document, can be significantly lighter and simpler than traditional jackets for fixed offshore turbines operating at a similar water depth.

[0033] Alternatively, the fixed support structure may be configured as a gravity-based foundation, wherein the bottom portion of the fixed support structure may be configured as a base structure designed to rest on the seabed. A gravity-based foundation may provide a stable anchoring solution by relying on its own weight to maintain positioning without requiring additional seabed penetration, making it particularly suitable for seabed with low penetrability or where piling operations are not feasible.

[0034] The base structure may have a bottom surface with a contact area configured to distribute the weight of the structure evenly on the seabed, preventing excessive seabed penetration and settlement. Preferably, the base structure may further comprise at least one ballast chamber, which may be configured to contain a material that provides an optimised mass distribution within the foundation. The ballast chamber may enhance stability by counteracting overturning moments and resisting sliding forces induced by environmental loads. Additionally, the base structure may include sidewalls extending upward from the foundation to enhance hydrodynamic resistance and structural rigidity, further improving performance under high wave and current conditions.

[0035] In yet another alternative, the bottom portion of the fixed support structure may be configured as a foundation interface for anchoring the submarine fixed connection station to the seabed. The fixed support structure may be configured as a columnar body, wherein the foundation interface of the columnar body may comprise one or more leg structures configured to anchor the submarine fixed connection station to the seabed. The leg structures may be designed to provide a secure and stable connection to the seabed, ensuring resistance against environmental loads such as wave action and current forces. The foundation interface may include a single leg structure or a plurality of leg structures, preferably three (e.g. a tripod), to optimise load distribution and ensure enhanced structural stability.

[0036] The submarine fixed connection station may further comprise a lifting mechanism configured to selectively move the top portion relative to the bottom portion along a vertical direction to selectively adjust the height distance. The ability to adjust the height distance may offer advantages in installation, maintenance, and operational adaptation, particularly in response to environmental variations such as seabed settlement or long-term changes in sea level (e.g. due to climate change along the operational lifetime of the submarine fixed connection station). The lifting mechanism may allow precise control over the positioning of the top portion, facilitating the coupling and decoupling operations between the floating offshore platform and the submarine fixed connection station.The lifting mechanism may be configured as a telescopic mechanism integrated into the submarine fixed connection station. The telescopic mechanism may preferably comprise an actuator system configured to extend and retract one or more telescopic guides connected to the top portion, thereby enabling adjustment of the height distance. The use of a telescopic mechanism may facilitate controlled height adjustments, allowing for improved adaptability of the system during installation, maintenance, or operational modifications. The actuator system may be configured to provide precise and reliable movement of the telescopic guides, ensuring secure positioning of the top portion at a desired height while maintaining structural integrity.

[0037] The lifting mechanism may further comprise an automated control system configured to dynamically adjust the height distance based on stable changes / variations in the depth distance. Such variations may result from settlement of the submarine fixed connection station when anchored to the seabed or from long-term environmental changes such as rising sea levels due to climate change. The automated control system may be configured to continuously monitor relevant parameters (e.g. sea level and / or wind force) and adjust the lifting mechanism accordingly, ensuring optimal height positioning between the submarine fixed connection station and the floating offshore platform throughout the system’s operational lifetime.

[0038] BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figs. 1A, 1B and 1C respectively depict a front view, a lateral view and a general isometric view of an offshore wind power generation system 1 according to embodiments of the invention. The offshore wind power generation system 1 of Figs. 1A-1C comprises a floating offshore platform 3 connected to a submarine fixed connection station 2 by means of a connecting interface 4 (not visible).

[0040] Figs. 2A and 2B respectively depict a front view and a lateral view of the same offshore wind power generation system 1 shown in Figs 1A-1C, wherein the floating offshore platform 3 is depicted disconnected from the submarine fixed connection station 2 to show the position of the connecting interface 4. Fig. 2C illustrates a detailed view of the area surrounded by a dotted line in Fig. 2B.

[0041] Fig. 3A shows a detailed view of a particular turret connector 33 compatible with some embodiments of the offshore wind power generation system 1 of the first aspect of the invention. Fig. 3B depicts a detailed view of the pivot column 32 of a floating offshore platform 3 configured to receive a turret connector 33. Fig. 30 shows a turret connector 33 arranged within the receiving portion 320 of Fig.

[0042] 2B.

[0043] DETAILED DESCRIPTION OF THE DRAWINGSFigs. 1A, 1B and 1C respectively depict a front view, a lateral view and a general isometric view of an offshore wind power generation system 1 according to exemplary embodiments of the present invention. As illustrated in these figures, the offshore wind power generation system 1 comprises a floating offshore platform 3 connected to a submarine fixed connection station 2 by means of a connecting interface 4 (not visible in these general views).

[0044] Referring particularly to Fig. 1A, the submarine fixed connection station 2 is configured as a fixed support structure. The fixed support structure (which is exemplary represented as a jacket structure) has a bottom portion 20 and a top portion 21 arranged at a predetermined height distance “h” from the bottom portion 20. The bottom portion 20 is optionally configured as a foundation interface 201 anchored securely to the seabed S and arranged at a predetermined water depth “d”. The top portion 21 of the submarine fixed connection station 2 is arranged underwater at a predetermined depth distance “p” measured from the water surface W. These dimensional relationships (p, h, d) are explicitly represented to illustrate clearly the relative positioning of the main elements of the invention.

[0045] The floating offshore platform 3 comprises at least one wind turbine 30 arranged for generating electrical power from wind energy. The floating offshore platform 3 is configured to remain buoyant. A vessel V is depicted floating next to the floating offshore platform 3 as a reference, although this vessel V does not form part of the invention itself.

[0046] The top portion 21 of the submarine fixed connection station 2 may be arranged underwater at a depth distance "p" within a range from 5 to 30 metres, preferably from 10 to 25 metres, and more preferably from 15 to 20 metres, within a predetermined tolerance of 1.5 metres. Such depth ranges may be advantageous for enabling ROV-assisted operations related to the connecting interface, optimize platform draft, and reduce loads going into the fixed support structure.

[0047] Additionally, the bottom portion 20 of the submarine fixed connection station 2 may be arranged at a water depth "d" within a range from 20 to 100 metres, preferably from 30 to 90 metres, and more preferably from 40 to 80 metres. These water depth ranges correspond to depths where conventional fixed-bottom structures become impractical, and where the proposed fixed support structure, combined with the floating offshore platform 3, provides an optimal balance between costeffectiveness, ease of installation, and structural reliability.

[0048] Furthermore, in some embodiments, the height distance "h" between the bottom portion 20 and the top portion 21 of the submarine fixed connection station 2 may correspond to a percentage of the water depth "d" in the range from 40 to 90%, preferably from 65 to 87.50%, and more preferably from 70 to 75.00%. Such relative dimensional arrangements may provide structural advantages byoptimising the stability and load distribution of the fixed support structure while minimising material usage and costs.

[0049] For improved clarity and to provide explicitly disclosed support for advantageous illustrative embodiments, the following table (Table 1) provides non-limiting examples of preferred numerical ranges and combinations of relevant parameters (depth distance “p”, water depth “d” and height distance “h”).

[0050] Table 1 - Illustrative Embodiments of Numerical Ranges

[0051] Height distance as % Embodiment Depth distance (p) [m] Water depth (d) [m]

[0052] of water depth (h) [%] 1 5-30 20-100 40-90

[0053] 2 10-25 40-90 65-85

[0054] 3 15-20 50-70 70-75

[0055] 4 20-30 60-90 75-87.5

[0056] 5 15-25 40-80 70-80

[0057] 6 10-20 30-60 65-75

[0058] 7 5-15 20-40 40-65

[0059]

[0060] As shown in Fig. 1B, the floating offshore platform 3 includes an optional pivot column 32. As described in further detail below (particularly regarding Figs. 2C and 3A-3C), this pivot column 32 comprises a receiving portion configured to receive a corresponding turret connector (not explicitly visible in Figs. 1A-1C). The pivot column 32 and the associated turret connector arrangement allow the floating offshore platform 3 to weathervane relative to the submarine fixed connection station 2 about a vertical geometrical axis “O” (identified in Fig. 1 B), thereby optimising aerodynamic efficiency of the wind turbine 30 while reducing structural loads.

[0061] Referring now to Fig. 1 C, a general isometric view clearly depicts the structural elements of the submarine fixed connection station 2 configured as a jacket structure. As shown, the exemplary jacket structure comprises a plurality of interconnected leg members 202 extending from the foundation interface 201 of the bottom portion 20 to the top portion 21 of the submarine fixed connection station 2. The jacket structure further comprises a plurality of brace members 203 arranged to interconnect the leg members 202, thus providing structural stability, reinforcement, and optimised load distribution to withstand environmental loads such as wave action, current forces, and loads transferred from the floating offshore platform 3.Additionally illustrated in Fig. 1C is a submarine cable C, configured to transmit electrical energy generated by the wind turbine 30. While the submarine cable C itself is not part of the invention, its presence clearly indicates compatibility with the offshore wind power generation system 1 according to the invention, facilitating practical integration of the system into an offshore power transmission network.

[0062] The configuration of the submarine fixed connection station 2 depicted in Figs. 1A-1C as a jacket structure is exemplary. In other embodiments compatible with the invention, the submarine fixed connection station 2 may alternatively be configured as a gravity-based foundation. A gravity-based foundation relies on its own mass to provide stability and anchoring, and comprises a base structure with a bottom surface configured to distribute weight evenly on the seabed S, optionally including ballast chambers and sidewalls to enhance stability and hydrodynamic resistance.

[0063] In yet another alternative compatible embodiment, the fixed support structure of the submarine fixed connection station 2 may be configured as a columnar body, wherein the bottom portion 20 comprises a foundation interface that may include one or more leg structures (preferably three) anchored securely to the seabed S. Such a columnar body configuration provides structural stability through optimised load distribution and robust anchoring capability.

[0064] By employing the submarine fixed connection station 2 in combination with the floating offshore platform 3 selectively coupled through the connecting interface 4, the offshore wind power generation system 1 according to the present invention achieves effective station-keeping capability at intermediate water depths, typically ranging from approximately 40 to 80 metres, without the significant disadvantages of conventional mooring-based systems, such as high structural loads, operational complexity, and limited reliability under severe environmental conditions.

[0065] Figs. 2A and 2B respectively depict a front view and a lateral view of the same offshore wind power generation system 1 illustrated previously in Figs. 1A-1C. In Figs. 2A-2B, the floating offshore platform 3 is depicted disconnected from the submarine fixed connection station 2, clearly revealing the connecting interface 4. Fig. 2C provides a detailed cross-sectional view of the area enclosed by the dotted line in Fig. 2B, explicitly illustrating the detailed configuration of the connecting interface 4 and the arrangement of the pivot column 32, turret connector 33, and bearing system 330.

[0066] Referring to Figs. 2A and 2B, the submarine fixed connection station 2 includes a bottom portion 20 and a top portion 21. The connecting interface 4 comprises a base connector 40 attached to the top portion 21 of the submarine fixed connection station 2 and a main connector 41 attached to the floating offshore platform 3. The main connector 41 is configured to be selectively coupled to and decoupled from the base connector 40, thus enabling a secure yet reversible mechanical connection.This selective coupling facilitates simplified installation, maintenance, and potential relocation of the floating offshore platform 3.

[0067] In Fig. 2B, the pivot column 32 is clearly visible as part of the floating offshore platform 3. The pivot column 32 defines a receiving portion 320 configured to lodge the turret connector 33 (depicted explicitly in Fig. 2C and 3B). Fig. 2B also illustrates the submarine cable C, configured to transmit electrical energy generated by the wind turbine 30 to external infrastructure, although this submarine cable C is not part of the invention itself.

[0068] Fig. 2C presents a detailed cross-sectional view, explicitly showing the internal arrangement of the pivot column 32, the turret connector 33, and the bearing system 330. In particular, the main connector 41 is rigidly connected to a lower portion 31 (e.g. to a bottom portion) of the turret connector 33. The turret connector 33 comprises the bearing system 330, which is configured to enable rotation of the floating offshore platform 3 relative to the submarine fixed connection station 2 about a central geometrical vertical axis O of the turret connector 33. Such a configuration enables the floating offshore platform 3 to weathervane in response to wind and current conditions, thereby reducing structural loads and improving operational efficiency of the wind turbine 30. In some embodiments, the connection between the turret connector 33 and the floating offshore platform 3 is configured such that, when the main connector 41 is coupled to the base connector 40 and the turret connector 33 is maintained in said predetermined operating position relative to the submarine fixed connection station 2, relative displacement along the vertical direction between the turret connector 33 and the floating offshore platform 3 is constrained. In this coupled state, the bearing system 330 continues to allow rotation of the floating offshore platform 3 about the central geometrical vertical axis O of the turret connector 33.

[0069] As shown in Fig. 1 C, in some embodiments, the pivot column 32 may be arranged offset with respect to a geometrical centre of the floating offshore platform 3, preferably in a peripheral region of the floating offshore platform 3, and optionally at or adjacent to a corner region of a polygonal floating offshore platform 3, such as a triangular floating offshore platform 3. Such an arrangement may be compatible with embodiments in which, when the main connector 41 is coupled to the base connector 40 and the turret connector 33 is arranged in said predetermined operating position relative to the submarine fixed connection station 2, relative displacement along the vertical direction between the floating offshore platform 3 and the submarine fixed connection station 2 at the turret connector 33 is constrained, while one or more other portions of the floating offshore platform 3 are allowed to undergo limited angular movement under wave loading.

[0070] The bearing system 330 depicted in Fig. 2C preferably comprises at least one lower bearing 330a and / or at least one upper bearing 330b. Specifically, the lower bearing 330a is configured to interactwith the lower portion 31 of the turret connector 33, while the upper bearing 330b interacts with an upper portion 34 of the turret connector 33. Thus, the lower 330a and upper 330b bearings are configured as respective contact interfaces between the turret connector 33 and the pivot column 32 of the floating offshore platform 3. This configuration involving at least two bearings enhances rotational stability, minimises friction, and improves the longevity of the rotating components.

[0071] In the particular embodiment shown in Fig. 2C, the bearing system 330 is configured as an interface arranged directly between the pivot column 32 and the turret connector 33, enabling sliding contact interaction. This sliding contact allows controlled rotation of the floating offshore platform 3 about the central geometrical vertical axis “O” relative to the submarine fixed connection station 2, optimising aerodynamic efficiency and reducing environmental-induced loads. It should be noted, however, that in alternative compatible embodiments, the turret connector 33 and the bearing system 330 may alternatively adopt configurations according to those depicted in Figs. 3A-3C, as described further below.

[0072] Fig. 2C also illustrates an optional configuration in which the connecting interface 4 further comprises a mechanical decoupling interface 42 configured to at least partially isolate and / or reduce the transmission of movements and / or forces from the floating offshore platform 3 to the submarine fixed connection station 2. Such a decoupling element 42 is particularly advantageous in mitigating wave-induced motions, preventing excessive structural loads from being transferred to the fixed support structure, and consequently improving the durability and stability of the entire system.

[0073] The mechanical decoupling interface 42 shown in Fig. 2C is exemplary represented configured as an elastic interface 42 comprising one or more elastic elements arranged between the turret connector 33 and main connector 41 and configured to behave as (e.g. configured as, or to simulate the presence of) an elastic spherical joint between the turret connector 33 and the main connector 41. However, in other compatible embodiments, the mechanical decoupling interface 42 may be configured as a cardan-type connector or as a physical spherical joint. The system of elastic elements shown in Fig. 2C is arranged around (e.g. perimetrally) the lower / bottom portion 31 of the turret connector 33 (which is represented with the optional configuration in which it has a substantially spherical shape) and comprises elastic elements distributed around (e.g. around the vertical geometrical axis) two parallel circles (i.e. two groups arranged one above the other; it should be noted that Fig. 2C merely illustrates a cutt-off view, so that only parts of these elastic elements are visible), thereby being configured to accommodate multidirectional angular movement, including pitch and roll motions of the floating offshore platform 3 relative to the submarine fixed connection station 2. In other compatible embodiments, the mechanical decoupling interface (e.g. including also a system of elastic elements) may be arranged either at or near the base connector 40 and / or themain connector 41, thus providing controlled flexibility in multiple rotational axes while ensuring structural integrity and effective motion compensation.

[0074] Thus, Figs. 2A-2C illustrate various detailed structural and functional features of the offshore wind power generation system 1 according to exemplary embodiments, highlighting critical elements such as the selectively couplable connecting interface 4, pivot column 32, turret connector 33, bearing system 330, and optional mechanical decoupling interface 42. These configurations collectively enable a robust, reliable, and adaptable offshore wind power generation system, optimised for intermediate water depths and capable of overcoming limitations associated with conventional solutions.

[0075] Although not explicitly shown in Figs. 1A-1C and Figs. 2A-2C, in some embodiments compatible with those illustrated figures, the submarine fixed connection station 2 may further comprise an optional lifting mechanism configured to selectively move the top portion 21 relative to the bottom portion 20 along a vertical direction in order to selectively adjust the height distance "h". The lifting mechanism may, for example, be arranged within the top portion 21 and may be integrated into the structure of the submarine fixed connection station 2 without altering its external appearance as shown in the figures. In other embodiments, the lifting mechanism may be integrated in one or more parts of the submarine fixed connection station 2. In some embodiments, the lifting mechanism is configured as a telescopic mechanism comprising one or more telescopic guides connected to the top portion 21, and an actuator system configured to extend and retract the telescopic guides. This configuration allows for controlled and precise adjustment of the height distance "h", improving the adaptability of the system during installation, maintenance, or in response to operational modifications.

[0076] Further, the lifting mechanism may optionally comprise an automated control system configured to dynamically adjust the height distance "h" based on measurements of changes in the depth distance "p". Such changes may result, for example, from settlement of the submarine fixed connection station 2 after connection to the seabed S, or due to long-term environmental changes, such as rising sea levels caused by climate change. The automated control system may be configured to monitor relevant parameters (e.g. by means of one or more sensors) and operate the lifting mechanism accordingly, ensuring that the top portion 21 remains positioned at an optimal height distance “h” (e.g. within a predetermined range provided for the height distance “h”) to enable reliable and consistent coupling with a floating offshore platform 3 throughout the operational life of the system 1.

[0077] In some embodiments, when the main connector 41 is coupled to the base connector 40, the pivot column 32, the turret connector 33 and the connecting interface 4 cooperate to maintain the turret connector 33 in a predetermined operating position relative to the submarine fixed connection station2, such that relative displacement along the vertical direction between the floating offshore platform 3 and the submarine fixed connection station 2 at the turret connector 33 is constrained. In this coupled state, the bearing system 330 continues to allow weathervaning of the floating offshore platform 3 about the central geometrical vertical axis O.

[0078] Fig. 3A depicts a detailed lateral view of a turret connector 33 which may be in the system 1 of Figs.

[0079] 1A-1C and 2A-2C as an alternative to the turret connector 33 shown in Fig. 2C. The turret connector 33 of Fig. 3A comprises an outer trunk element 35 and an inner shaft 36. The outer trunk element 35 is configured to be attached to the pivot column 32, and the inner shaft 36 is configured to be attached to the submarine fixed connection station 2 by means of the connecting interface 4. The bearing system 330 is arranged as contact interface between the outer trunk element 35 and the inner shaft 36 to allow a relative rotation between the outer trunk element 35 and the inner shaft 36, thereby enabling a rotation of the floating offshore platform 3 relative to the submarine fixed connection station 2 and about the central geometrical vertical axis “O” of the turret connector 33.

[0080] The outer trunk element 35 comprises a top portion 35a and a base portion 35b, wherein the top portion 35a is configured to be attached / coupled to the floating offshore platform 3 (e.g. to the receiving portion) to avoid a relative movement (e.g. relative rotation) between the outer trunk element 35 and the floating offshore platform 3. Fig. 3A shows the outer trunk element 35 configured as columnar body configured as a tubular element, however this element is also compatible with other configurations. The outer trunk element 35 is configured to receive the inner shaft 36 in a respective inner receiving space configured to lodge / receive the inner shaft 36.

[0081] The inner shaft 36 comprises a top portion 36a and a base portion 36b, and is configured to be arranged within the outer trunk element 35 (as shown in Fig. 3A). The base portion 36b of the inner shaft 36 is configured to be coupled to the submarine fixed connection station 2. In the preferred embodiment shown in Fig. 3A, the inner shaft 36 is configured as a tubular element, which represents a preferred configuration for the inner shaft 36.

[0082] The bearing system 330 of the turret connector 33 of Fig. 3A comprises two bearings: a lower bearing 330a (which is preferably configured as a radial bearing 330a) and a top bearing 330b that connects the outer trunk element 35 to the inner shaft 36. The connection of the bearings 330a, 330b is configured to allow the outer trunk element 35 to weathervane (e.g. to rotate) together with the floating offshore platform 3 relative to the inner shaft 36 and the submarine fixed connection station 2 (i.e. when the turret connector 33 is effectively connecting the floating offshore platform 3 to a submarine fixed connection station 2, as shown in Fig. 3C).The embodiment of Fig. 3A shows the turret connector 33 comprising one lower bearing 330a (also referred to as neck bearing or radial bearing) as part of the bearing system 330, but in other embodiments the bearing system 330 may comprise a plurality of lower bearings 330a (e.g. two or three). The lower bearing 330a comprises an outer interface and an inner interface. The outer interface is configured to be in contact with the outer trunk element 35 (e.g. with an inner surface of the inner receiving space facing the inner shaft 36), and the inner interface is configured to be in contact with the inner shaft 36 (e.g. with an outer surface of the inner shaft 36). This arrangement of the lower bearing 330a causes this element to be capable to support radial loads (i.e. loads received by the lower bearing 330a in a radial direction with respect to the turret connector 33, which is configured to extend longitudinally along an axial direction - which is a vertical direction in Fig. 3A -and radially along any direction being perpendicular to the axial direction). Fig. 3A represents the preferred option in which the lower bearing 330a may be arranged at the base portion 35b (in other compatible embodiments, the lower bearing 330a may be arranged proximal to said base portion 35b) of the outer trunk element 35 and / or the base portion 36b of the inner shaft 36. The lower bearing 330a may be configured as a ball or a roller bearing. However, in preferred embodiments, the lower bearing 330a may be configured as a friction bearing (also known as plain bearing) configured to provide sliding contact / motion between the respective surfaces of the outer trunk element 35 and the inner shaft 36. For example, the outer interface may be configured to be attached to the outer trunk element 35 and the inner interface may be configured to be in sliding contact with the inner shaft 36.

[0083] The bearing system 330 of the turret connector 33 shown in Fig. 3A also comprises an optional upper bearing 330b, which comprises a respective outer interface and a respective inner interface (not identified in Fig. 3A). The outer interface of the upper bearing is configured to be attached on top (i.e. above) of the top portion 35a of the outer trunk element 35, which allows the upper bearing 330b to support mainly axial loads. The inner interface is configured to be attached to the inner shaft 36.

[0084] The upper bearing 330b may be configured as a slew bearing (e.g. as a bearing comprising a plurality of rolling-elements arranged between two respective ring elements, thereby enabling a rotational movement between the two ring elements, such that the inner and the outer interfaces of the upper bearing 330b are each arranged at one of the ring elements). In other compatible embodiments, the upper bearing 330b may be configured as a friction bearing.

[0085] The base portion 36b of the inner shaft 36 of Fig. 3A is connected to the main connector 41, which is configured to be selectively coupled to (i.e. coupled to and decoupled from) the submarine fixed connection station 2 (i.e. by connecting the main connector 41 to the base connector 40 arranged in the submarine fixed connection station 2).The mechanical decoupling interface 42 described for Fig. 2C is also compatible with the turret connector 33 of Fig. 3A.

[0086] The top portion 35a of the outer trunk element 35 shown in Fig. 3A comprises a contact element 351 , which is optionally configured as an integral part of the top portion 35a of the outer trunk element 35. The contact element 351 is configured such that, when the turret connector 33 is arranged within the receiving portion 320 of the pivot column 32, the contact element 351 contacts on top of a contact interface 320b of the floating offshore platform 3. This configuration allows the turret connector 33 to be supported / kept in an operating position by the contact interface 320b. Fig. 3A shows a contact element 351 configured as a perimetral flange portion (e.g. as a ring) configured to locally increase a radius of the turret connector 33. However, in other compatible embodiments, the contact element 351 may be configured as one or more perimetral flange portions (e.g. one or more independent flange portions arranged along the perimeter of the top portion 35a of the outer trunk element 35).

[0087] Although not visible in Fig. 3A, the contact element 351 may further comprise one or more attaching means (e.g. mechanical connectors, such as a plurality of screws) configured to attach the contact element 351 to the contact interface 320b of the floating offshore platform 3, such that the contact element 351 is rigidly attached / connected to the contact interface 320b.

Claims

CLAIMS1. An offshore wind power generation system (1) comprising:a submarine fixed connection station (2) configured as a fixed support structure (2) comprising a bottom portion (20) and a top portion (21) arranged at a predetermined height distance (h) from the bottom portion (20), wherein the bottom portion (20) is configured to be connected to a seabed (S) arranged at a water depth (d), wherein the top portion (21) is configured to be arranged underwater at a depth distance (p) from a water surface (W);a floating offshore platform (3) comprising a wind turbine (30); anda connecting interface (4) comprising a base connector (40) and a main connector (41), wherein the base connector (40) is attached to the top portion (21) of the submarine fixed connection station (2), wherein the main connector (41) is attached to the floating offshore platform (3), and wherein the main connector (41) is configured to be selectively coupled to the base connector (40) for coupling the floating offshore platform (3) to the submarine fixed connection station (2).

2. The system (1) of any of the preceding claims, wherein the depth distance (p) is in the range 5 to 30 m, preferably 10 to 25 m, and more preferably 15 to 20 m, within a predetermined tolerance of 1.5 m.

3. The system (1) of any of the preceding claims, wherein the bottom portion (20) of the submarine fixed connection station (2) is configured to be arranged at water depth (d) in the range 20 to 100 m, preferably 30 to 90 m, more preferably 40 to 80 m.

4. The system (1) of any of the preceding claims, wherein the height distance (h) corresponds to a percentage of the water depth (d) in the range 40 to 90%, preferably in the range 65 to 87.50% and more preferably in the range 70 to 75.00%.

5. The system (1) of any of the preceding claims, wherein the floating offshore platform (3) comprises a pivot column (32) and a turret connector (33) arranged within said pivot column (32), wherein the main connector (41) is rigidly connected to a lower portion (31) of the turret connector (33), and wherein the turret connector (33) comprises a bearing system (330) configured to allow a rotation of the floating offshore platform (3) relative to the submarine fixed connection station (2) and about a central geometrical vertical axis (O) of the turret connector (33);wherein preferably the bearing system (330) comprises at least one lower bearing (330a) and / or at least one upper bearing (330b), the lower bearing (330a) being configured to interact with a lower portion (31) of the turret connector (33) and the upper bearing (330b) being configured to interact with an upper portion (34) of the turret connector (33).

6. The system (1) of claim 5, wherein the pivot column (32), the turret connector (33) and the connecting interface (4) are configured such that, when the main connector (41) is coupled to the base connector (40), the turret connector (33) is arranged in a predetermined operating position relative to the submarine fixed connection station (2), such that relative displacement along the vertical direction between the floating offshore platform (3) and the submarine fixed connection station (2) at the turret connector (33) is constrained, while the bearing system (330) allows rotation of the floating offshore platform (3) about the central geometrical vertical axis (O).

7. The system (1) of claim 5 or 6, wherein the bearing system (330) is configured as an interface arranged between the pivot column (32) and the turret connector (33), the bearing system (330) being configured to allow a sliding and / or rolling contact between the pivot column (32) and the turret connector (33), such that the floating offshore platform (3) is allowed to rotate about the central geometrical vertical axis (O) of the turret connector (33) relative to the submarine fixed connection station (2).

8. The system (1) of claim 5 or 6, wherein the turret connector (33) comprises an outer trunk element (35) and an inner shaft (36), wherein the outer trunk element (35) is configured to be attached to the pivot column (32), wherein the inner shaft (36) is configured to be attached to the submarine fixed connection station (2) by means of the connecting interface (4), wherein the bearing system (330) is arranged as contact interface between the outer trunk element (35) and the inner shaft (36) to allow a relative rotation between the outer trunk element (35) and the inner shaft (36), thereby enabling a rotation of the floating offshore platform (3) relative to the submarine fixed connection station (2) and about the central geometrical vertical axis (O) of the turret connector (33).

9. The system (1) of any of the preceding claims, wherein the connecting interface (4) further comprises a mechanical decoupling interface (42) arranged between the base connector (40) and the submarine fixed connection station (2), or between the main connector (41) and the offshore floating platform (3), wherein the mechanical decoupling interface (42) is configured to reduce or eliminate a transmission of motion from the floating offshore platform (3) to the submarine fixed connection station (2) when the main connector (41) is coupled to the base connector (40), wherein preferably the mechanical decoupling interface (42) is configured as spherical joint or as a cardantype connector or as an elastic interface (42) comprising one or more elastic elements.

10. The system (1) of claim 9, wherein the mechanical decoupling interface (42) is configured as the elastic interface (42) and wherein the one or more elastic elements are distributed between the base connector (40) and the submarine fixed connection station (2), or between the main connector(41) and the offshore floating platform (3), such that the one or more elastic elements provide an elastic spherical joint between the base connector (40) and the submarine fixed connection station (2), or between the main connector (41) and the offshore floating platform (3).

11. The system (1) of any of the preceding claims, wherein the fixed support structure (2) is configured as a jacket structure, wherein the bottom portion (20) of the fixed support structure (2) is configured as a foundation interface (201) configured to anchor the submarine fixed connection station (2) to the seabed (S), wherein preferably the jacket structure further comprises:- a plurality of interconnected leg members (202) extending from the foundation interface (201) to the top portion (21) of the submarine fixed connection station (2); and- a plurality of brace members (203) interconnecting said leg members (202) to provide structural stability and load distribution under operational and environmental loads.

12. The system (1) of any of claims 1 to 10, wherein the fixed support structure (2) is configured as a gravity-based foundation, wherein the bottom portion (20) of the fixed support structure (2) is configured as a base structure configured to rest on the seabed (S), the base structure having a bottom surface with a contact area for distributing a weight of the base structure on the seabed (S), wherein preferably the base structure further comprises:at least one ballast chamber within the base structure, configured to contain a material configured to provide a mass distribution within the at least one ballast chamber providing stability against overturning and sliding forces caused by operational and environmental loads; and sidewalls extending upward from the base structure for enhancing hydrodynamic resistance and structural rigidity.

13. The system (1) of any of claims 1 to 10, wherein the bottom portion (20) of the fixed support structure (2) is configured as a foundation interface (201) configured to anchor the submarine fixed connection station (2) to the seabed (S), wherein preferably the fixed support structure (2) is configured as a columnar body and wherein the foundation interface (201) of the columnar body comprises one leg structure (202) configured to be anchored to the seabed (S) or a plurality of leg structures (202), preferably three, configured to be anchored to the seabed (S).

14. The system (1) of any of the preceding claims, wherein the submarine fixed connection station (2) further comprises a lifting mechanism configured to selectively move the top portion (21) relative to the bottom portion (20) along a vertical direction for selectively adjusting the height distance (h).

15. The system (1) of claim 14, wherein the lifting mechanism is configured as a telescopic mechanism integrated into the submarine fixed connection station (2), preferably comprising an actuator system configured to extend and retract one or more telescopic guides connected to the top portion (21) to adjust the height distance (h).

16. The system (1) of claim 14 or 15, wherein the lifting mechanism further comprises an automated control system configured to dynamically adjust the height distance (h) based on measurement of changes in the depth distance (p).

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