System for generating electrical energy

Abstract

The present invention provides a system for generating electrical energy, the system comprising: a hydraulic cylinder comprising a piston housing and a piston, wherein one of the piston and the piston housing is configured to move with a floating structure and the piston is configured to move relative to the piston housing when the floating structure moves; a hybrid cylinder comprising: a hydraulic portion comprising a hydraulic piston housing and a hydraulic piston, wherein the hydraulic portion of the hybrid cylinder is in fluidic communication with the hydraulic cylinder; and a pneumatic portion comprising a pneumatic piston housing and a pneumatic piston, wherein the hydraulic piston and pneumatic piston are configured to move together; and a generator in fluidic communication with the pneumatic portion of the hybrid cylinder, wherein movement of the pneumatic piston is configured to generate electrical energy in the generator.

Description

[0001] SYSTEM FOR GENERATING ELECTRICAL ENERGY FIELD OF THE INVENTION

[0002] The present invention relates to a system for generating electrical energy, a method of installing such a system, a floating construction comprising a floating structure and the system, and a method of generating electrical energy.

[0003] BACKGROUND

[0004] Various technologies are known which harvest tidal variation for generation of electrical energy. Such known technologies include tidal barrages which capture on a very large scale the water from the high tide behind a dam and release the water through a hydroelectric turbine to generate electricity. Such systems have been in use for many decades, for example the La Rance Tidal Barrage in France. However, there are down sides to such mechanisms which rely on using a dam, for example high initial construction costs, effects on animals and plants living near the dam, limiting suitability of sites and disruption of the migration of living creatures. Thus, there is vast room for improvement in providing a system which harvest tidal range energy which overcomes or avoids at least one of these issues.

[0005] SUMMARY OF THE INVENTION

[0006] According to an aspect of the invention, there is provided a system for generating electrical energy, the system comprising: a hydraulic cylinder comprising a piston housing and a piston, wherein one of the piston and the piston housing is configured to move with a floating structure and the piston is configured to move relative to the piston housing when the floating structure moves; a hybrid cylinder comprising: a hydraulic portion comprising a hydraulic piston housing and a hydraulic piston, wherein the hydraulic portion of the hybrid cylinder is in fluidic communication with the hydraulic cylinder; and a pneumatic portion comprising a pneumatic piston housing and a pneumatic piston, wherein the hydraulic piston and pneumatic piston are configured to move together; and a generator in fluidic communication with the pneumatic portion of the hybrid cylinder, wherein movement of the pneumatic piston is configured to generate electrical energy in the generator.According to an aspect of the invention, there is provided a method of installing a system for generating electrical energy comprising: providing the system as described herein; attaching the piston to the floating structure or at least one fixed structure; attaching the piston housing to the other of the floating structure or the at least one fixed structure; fluidly connecting the hydraulic cylinder to the hydraulic portion of the hybrid cylinder; and fluidly connecting the pneumatic portion of the hybrid cylinder to the generator.

[0007] According to an aspect of the invention, there is provided a floating construction comprising a floating structure and the system as described herein, preferably wherein the floating structure is floating platform, pontoon, marina, barge, port structure, floating craft, recreational vessel, barge or floating port terminal, other use cases include floating port infrastructure and loading platforms, floating piers and marinas, floating hotels or buildings, floating concrete structures, floating parks and green space, real estate on buoyant platforms, floating homes, buoyant or semi buoyant constructions, floating roads, tunnels, bridges and pontoons, floating greenhouses and urban farms, floating car parks, and / or hybrid floating renewable energy platforms.

[0008] According to an aspect of the invention, there is provided a method of generating electrical energy using the system as described herein or the floating construction as described herein.

[0009] BRIEF INTRODUCTION TO THE DRAWINGS

[0010] Embodiments of the invention will be more clearly understood from the following description, given by way of example only, with reference to the accompanying drawings, in which:

[0011] Figure 1 is a schematic illustration of a system for generating electrical energy according to an embodiment of the present invention;

[0012] Figure 2 is a schematic illustration of a floating structure which may be used as part of the system;

[0013] Figure 3 illustrates a variation of water level between a low tide and high tide during a 24-hour period;

[0014] Figure 4 is a schematic illustration of a hydraulic cylinder as shown in figure 1;

[0015] Figure 5 is a schematic illustration of a hybrid cylinder as shown in figure 1 ; andFigures 6-9 are schematic illustrations of the system of figure 1 which show details of the system during operation.

[0016] The same references are used for similar features throughout the drawings. The features shown in the figures are not necessarily to scale and the size or arrangements depicted are not limiting. It will be understood that not all of the features of the assembly are depicted in each figure and the figures may only show a few parts relevant for describing a particular feature.

[0017] The foregoing aspects, features and advantages of the invention will be apparent from the drawings and the detailed description related thereto.

[0018] DETAILED DESCRIPTION

[0019] The idea of the present invention is to use tidal forces in generating electrical energy from movement of a floating structure. The electrical energy which is generated may be used in any appropriate way, for example may be stored in at least one battery and / or may be used by the floating structure.

[0020] In an embodiment, a system is provided for generating electrical energy. In particular, the system may be configured to generate electrical energy from movement of a floating structure. Movement of the structure may be used to generate electrical power.

[0021] The system comprises a hydraulic cylinder, a hybrid cylinder (comprising a hydraulic portion and a pneumatic portion) and a generator.

[0022] Figure 1 illustrates an example of an embodiment of the system 1 according to the present invention. The system 1 is used to convert movement of floating structure 100 into electrical energy. The conversion uses the hydraulic cylinder 10 and the hybrid cylinder 20 as described in further detail below. In general, movement of the floating structure 100 causes fluid to be moved throughout the system 1 from the hydraulic cylinder 10 to the hybrid cylinder 20. The hydraulic cylinder 10 converts the floating structure’s movement into pressure in hydraulic fluid in the system 1. In turn, hydraulic fluid in a hydraulic portion of the hybrid cylinder 20 is used for compressing / moving gas from a pneumatic portion of the hybrid cylinder 20 such that gas is moved to the generator 60 which results in generation of electrical energy.

[0023] In general, it is understood that variation of the tide is slow over given period (e.g. a day) and the present system allows electrical energy to be generated despite this. In particularthis is possible due to the combination of the hydraulic cylinder 10 and the hybrid cylinder 20. For example only, each tidal cycle may provide several metres (e.g. 6 metres) of vertical movement over approximately six hours, creating a steady, predictable motion rate of movement per hour (e.g. 1 metre per hour). This consistent movement drives the system 1 to generate electricity.

[0024] The integration of hybrid and hydraulic systems creates a novel energy conversion chain that amplifies power generation potential. This hybrid approach combines the reliability of pneumatic compression with the force multiplication benefits of hydraulic systems. These parts of the system can work in concert - the hydraulic cylinder 10 can capture the initial tidal movement, while the downstream components including the hybrid cylinder 20 multiply its effect, leading to enhanced compressed gas generation. This dual-system configuration represents a new approach that offers greater efficiency than single-system designs.

[0025] A key advantage of the present invention is that it may be used to generate electrical power with minimal impact on the operation of the floating structure 100, as the system can be integrated within the infrastructure of the floating structure 100 and the movement of the floating structure 100 and ongoing operation of the floating structure 100 is not interrupted or impeded. The system 1 primarily operates above the water level and has very minimal environmental impact.

[0026] The floating structure 100 may be any appropriate floating structure. For example, the floating structure 100 may be a floating platform, pontoon, marina, barge, port structure, floating craft, recreational vessel, barge or floating port terminal, other use cases include floating port infrastructure and loading platforms, floating piers and marinas, floating hotels or buildings, floating concrete structures, floating parks and green space, real estate on buoyant platforms, floating homes, buoyant or semi buoyant constructions, floating roads, tunnels, bridges and pontoons, floating greenhouses and urban farms, floating car parks, and / or hybrid floating renewable energy platforms. Preferably, the floating structure 100 has significant mass (for example only, the floating structure could be approximately 2,000 to 20,000 tonnes, could be approximately 5,000 to 15,000 tones, e.g. could be approximately 10,000 tonnes, although it will be understood that the mass may significantly higher, or even lower). As explained below, movement of the floating structure 100 is used to drive the hydraulic cylinder 10.The arrows included in figure 1 indicate some relevant movements of different parts / components of the system. For example, a piston 12 of the hydraulic cylinder 10 may move up and down with the floating structure 100 (arrow A). Hydraulic fluid may move to or from the hydraulic cylinder 10 (arrows B and C). Hydraulic fluid is directed from the hydraulic cylinder 10 towards the hybrid cylinder 20 (arrow D). Hydraulic fluid may move to or from a hydraulic portion of the hybrid cylinder (arrows I and H). A hydraulic piston in the hydraulic portion of the hybrid cylinder 20 may move within the hydraulic portion of the hybrid cylinder 20 (arrow J). It is noted that this movement is shown and described herein as left or right, but could be any appropriate directi on / orientati on. Hydraulic fluid ejected from the hydraulic portion of the hybrid cylinder 20 is directed towards the hydraulic cylinder 10 (arrows F and E), optionally via a reservoir 80, and back towards the hydraulic cylinder 10. Gas is compressed in the hybrid cylinder 20 and is directed towards the generator 30 (arrows K and L), optionally via a gas vessel 65.

[0027] The hydraulic cylinder 10 may be referred to as a hydraulic cylinder assembly. The hydraulic cylinder 10 may be a robust marine-grade cylinder with appropriate sealing to prevent contamination from seawater. The hydraulic cylinder 10 may house a piston 12 connected to a rod 16 that extends to attach to the floating structure (as described in further detail below).

[0028] The hydraulic cylinder 10 comprises a piston housing 11 and the piston 12. The piston 12 is configured to move relative to the piston housing 11. The piston 12 is configured to move relative to the piston housing 11 when the floating structure 100 moves. The piston 12 and piston housing 11 have a robust sliding connection.

[0029] One of the piston 12 and the piston housing 11 is configured to move with the floating structure 100. In other words, one of the piston 12 and the piston housing 11 (i.e. one or other, but not both) is attached, directly or indirectly, to the floating structure 100. For example, the piston 12 may be attached to the floating structure 100. For example, the piston 12 (e.g. a rod 16 of the piston 12 as shown in further detail in figure 4) may be rigidly attached to the floating structure 100. For example, the piston 12 may be attached to a section of a deck of the floating structure 100. In this case, the deck may comprise a reinforced section to resist bending pressure during operation of the system 1. As the piston 12 is attached to the floating structure 100, movement of the floating structure 100 transfers forcesto the piston 12 of hydraulic cylinder 10, and this action induces pressure build-up within the hydraulic cylinder 10.

[0030] The system 1 may comprise at least fixed structure. The fixed structure may be at least one pile 105. The pile 105 may be referred to as a guide pile. The or each pile 105 may be fixedly attached (e.g. moored) to the ground, e.g. in the ground and / or seabed. For example, each pile 105 may be fixedly moored to the seabed, or any ground beneath water / liquid on which the floating structure floats 100. At least one pile 105 may be configured to support the hydraulic cylinder. For example, the piston housing 11 may be attached to at least one pile 105, e.g. via attachment 106.

[0031] The system 1 may comprise multiple piles 105. The system 1 may comprise multiple piles 105 for each component. In other words, one component of the system, e.g. the piston 12 and / or piston housing 11 of the hydraulic cylinder 10 may be attached to one pile or multiple piles. A schematic illustration of the system 1 including the floating structure 100 and multiple piles 105 are shown in figure 2. For example, as shown in figure 2, the piston housing 11 may be attached to three piles, although any appropriate number may be used. The system may include additional piles which may be used to stabilise the floating structure 100, for example as shown in figure 2. Thus, the system 1 may comprise at least one pile 105 configured to restrain / restrict the floating platform’s position. For example, the floating structure 100 may be movably attached to at least one pile 105 so that movement of the floating structure 100 relative to the pile 105 is substantially restricted to vertical movement so that the floating structure 100 can move up and down with the tide, but the general position of the floating structure 100 at a given location is retained. The piles 105 may more generally be referred to as a guide / support system.

[0032] Providing multiple piles 105, particularly which are spaced around the floating structure 100, may be particularly useful. Providing multiple piles 105 may be beneficial in keeping the position of the floating structure 100 relative to the piles stable so that the movement between the piston 12 and the piston housing 11 in the hydraulic cylinder 10 is kept relatively stable (e.g. to avoid twisting or bending of the hydraulic cylinder 10 in unforeseen ways, e.g. during large waves / unusual tidal variations which may impact the floating structure 100).The floating structure 100 floats on a surface of the water. Figure 3 illustrates a variation of water level between a low tide and a high tide during a 24 hour period. In figure 3, the water level is indicated with a reference number 90. In figure 3, the distance between a low tide and a high tide is marked as Ah. As water level drops / rises due to tidal movements, gravity / buoyancy forces act upon the floating structure 100.

[0033] The system 1 may be referred to as an electromechanical system, and is configured to convert the potential energy of the floating structure 100 to electrical energy as the floating structure 100 moves in a defined tidal range. The means of transfer of this energy from the floating structure 100 to the electric generator 60 will be the work done by the forces exerted upon the floating structure 100. The work is a measure of energy transfer that occurs when an object is moved over a distance by an external force at least part of which is applied in the direction of the displacement. Given the nature of the tidal movement, the forces acting upon the floating structure 100 include the force of gravity and a buoyancy force. The system 1 is configured to transfer these forces acting upon the floating structure 100. The forces may be of varied magnitude depending on the mass of the floating structure 100, however the magnitude of the displacement (i.e. vertical distance moved) is limited and defined by the water level tidal movements.

[0034] In the figures and the following description, the piston 12 is attached to the floating structure 100 and the piston housing 11 is attached to at least one pile 105. As the at least one pile 105 is fixed, i.e. stationary, and the floating structure 100 moves up and down with the tide, the piston 12 and piston housing 11 can move relative to each other as the floating structure 100 moves up and down. This provides a robust sliding connection between the hydraulic cylinder 10 and the floating platform 100.

[0035] The hydraulic cylinder 10 is filled with hydraulic liquid. Any reference to hydraulic fluid in the hydraulic cylinder, hydraulic portion of the hybrid cylinder and the fluidic connections therebetween will be understood to mean hydraulic liquid. For example, the hydraulic fluid may be hydraulic oil, for example, biodegradable hydraulic oil (which is beneficial in creating no emissions during operation, and minimising impact on marine traffic or wildlife).

[0036] The hydraulic fluid can be moved through the system via pipes 40. The pipes 40 may otherwise be referred to as conduits. The pipes 40 may be part of a piping system. Pipes40 are generally referred to in the present description and are intended to include any rigid or flexible conduits and / or auxiliary used to convey the hydraulic fluid (and / or the gas form the hybrid cylinder) through the system 1. The pipes 40 can provide fluidic connections between components. In particular, to convey the hydraulic liquid from a pressurised side of hydraulic cylinder 10, towards the hydraulic portion of the hybrid cylinder 20 as well as to return the hydraulic fluid to an unpressurised side of the primary hydraulic cylinder 10. The pipes 40 will be understood to include any appropriate standard component, such as appurtenant valves, fittings and accessories.

[0037] The hydraulic cylinder 10 may otherwise be referred to as a double-acting hydraulic cylinder. In other words, the hydraulic cylinder 10 preferably has an outlet / inlet on either end / side of the hydraulic cylinder 10. In other words, the hydraulic cylinder 10 is preferably configured to have hydraulic liquid on either side of the piston 12 so that force is applied to a portion of the hydraulic liquid irrespective of the direction of the piston 12. Thus, the piston 12 can be used to pressurise hydraulic liquid above the piston 12 as the piston 12 moves upwards and to pressurise hydraulic liquid below the piston 12 as the piston 12 moves downwards.

[0038] The hydraulic cylinder 10 may be a long-stroke cylinder. The stroke length may be defined as the distance the piston 12 moves inside the piston housing 11. The stroke length can be aligned with the tidal range at the site. For example, the stroke length may be selected based on Ah. For example, the stroke length may be selected by checking the maximum tide at a location and determining how much a floating structure 100 would move up and down at that location. The piston size / stroke length can then be selected based on that. For example, the stroke length may be substantially the same as Ah for a given site. However, this is not necessary, for example, the stroke length may be larger than Ah or smaller than Ah.

[0039] A smaller stroke length than the Ah would limit the range of the device and could lead to operational inefficiencies. In this instance, the hydraulic cylinder 10 may also include a means of disconnecting the piston 12 from the floating structure 100 to avoid overload and damage. A stroke length of Ah or longer would therefore be preferred. A longer stroke length than Ah would be beneficial in providing range and flexibility to the device to accommodate more extreme variations in the tide level. This approach ensures that the hydraulic cylinder can handle the maximum expected tidal range without risk of damageand / or without additional adjustment of the connection of the piston 12 (which would add an additional level of complexity). Additionally, a longer stroke length can improve the overall efficiency and reliability of the system.

[0040] For example only, the long-stroke cylinder may be a 6-metre stroke hydraulic cylinder, e.g. akin to the ones being used for dam equipment in hydropower projects (e.g. manufactured by Montanahydraulik), optionally with a cross-sectional area of lm2 / total usable volume of approximately 6 m3.

[0041] It is noted that the cycle can change, for example, Ah for a given site may be approximately 6-7 m for example in spring tide, but only approximately 4 m in neap tide. The stroke length may be selected with both ranges in mind. In further detail, the stroke length could be chosen with the envelope of tide range in mind so that the piston 12 would work for the larger spring tides, smaller neap tides, and have an allowance for more extreme ranges for the location and operational thresholds. For example, the stroke length may be selected based on the greater magnitude of Ah. Choosing the higher value (e.g. 6-7 m for spring tide) ensures that the hydraulic cylinder can accommodate the maximum expected tidal range without risk (or at least reducing risk) of damage and / or operational inefficiencies. When the tide is lower, such as during neap tide (approximately 4 m), the hydraulic system can be adjusted to operate within this reduced range (e.g. the system may be self-adjusting to a degree as the range will be limited naturally by the tide, however, a controller / control system may provide the ability for adjustment to protect the system from damage from ranges outside the specified operating range). This flexibility allows the system to function effectively across varying tidal conditions, which is beneficial in providing a reliable system and reducing / minimising the need for frequent adjustments.

[0042] Only a single hydraulic cylinder 10 may be used. Alternatively, multiple hydraulic cylinders 10 may be used, for example, two hydraulic cylinders 10 as shown in figure 2, or three or four or more cylinders. Any appropriate number of hydraulic cylinders 10 may be provided.

[0043] A more detailed version of the hydraulic cylinder 10 is shown in figure 4. The piston housing 11 may otherwise be referred to as a piston barrel. The hydraulic cylinder 10 is configured so that the piston 12 can move within the piston housing 11. The piston housing 11 may otherwise be referred to as a chamber in which the piston 12 moves. The pistonhousing 11 of the hydraulic cylinder 10 may comprise a first section 13 and a second section 14 on either side of the piston 12 (i.e. on either side of a piston head 15). Thus, the movement of the piston 12 within the piston housing 11 may apply force to hydraulic fluid in either the first section 13 or the second section 14 depending on the direction of movement of the piston 12. For example, as the piston 12 moves upwards in figure 1, fluid in the first section 13 (as shown in figure 4) will be pressurised. When the piston 12 moves in the opposite direction, i.e. downwards relative to the piston housing 11, fluid in the second section 14 will be pressurised.

[0044] The hydraulic cylinder 10 is fluidly connected (e.g. by hydraulic piping 40) with the hybrid cylinder 20, and particularly with the hydraulic portion 21 of the hybrid cylinder 20 (shown in further detail in figure 5). This allows the pressure of flowing hydraulic liquid to transmit force. The complete hydraulic system / loop can be formed in this way, and can act as a single closed container / loop enabling transmission of the pressure to all portions of the fluid without loss (Pascal’s principle).

[0045] In particular, the system 1 may be configured to direct fluid from the first section 13 and / or the second section 14 of the hydraulic cylinder 10 towards the hybrid cylinder 20 depending on the relative direction and / or position of the piston 12 in the hydraulic cylinder 10. Thus, the system 1 may be configured to direct hydraulic fluid from one section or the other depending on where the piston 12 is within piston housing 11. For example, the system 1 may switch the source of hydraulic fluid when the piston 12 reaches the end of the range. For example, hydraulic fluid may be directed from the first section 13 (the upper section) towards the hybrid cylinder 20 when the piston 12 is moving upwards. When the piston 12 reaches the end of its range, the system 1 may switch so that hydraulic fluid may be directed from the second section 14 (the lower section) towards the hybrid cylinder 20 as the piston 12 is moving downwards. Sensors may be used to check the position and / or direction of the piston 12 so that the switching of the hydraulic fluid can be controlled.

[0046] When a force is applied by the piston 12 of the hydraulic cylinder 10 to the fluid, the hydraulic fluid is moved towards the hydraulic portion 21 of the hybrid cylinder 20. In turn, the pressurised hydraulic liquid moves the hydraulic piston 23 and the pneumatic pistons 30, 35 in the hybrid cylinder 20. The pressure of the hydraulic fluid in the piping 40 on the pressurised side of the system may be approximately 7-8 bar (although the system 1 may beconfigured to run at other pressures, and may be controlled using release valves and other known mechanisms).

[0047] A more detailed version of the hybrid cylinder 20 is shown in figure 5. The hybrid cylinder 20 may otherwise be referred to as a hydraulically driven compressor / air compressor / device / assembly. The hybrid cylinder 20 is configured to discharge compressed gas towards the generator 60, preferably via a gas vessel (described below). The hybrid cylinder 20 is configured to transfer energy from hydraulic fluid at high pressure, to mechanical moving parts (pistons), which consequently compresses gas (e.g. air) to increase the pressure (e.g. from atmospheric up to operational pressure). High pressure liquid is released into the hydraulic portion 21 of the hybrid cylinder 20 which moves at greater frequency of cycles than movement of the piston 12 of the hydraulic cylinder 10, generating compressed air more efficiently and continually which passes to the generator 60 to generate electricity.

[0048] The system 1 may comprise non-retum valves that prevent undesired direction of flow of the compressed gas exiting the hybrid cylinder 20. For example, non-return valves may be integrated in the hybrid cylinder 20, e.g. as part of, or upstream of, outlets 20b and 20c, and or may be separate, e.g. in piping 40i downstream of the hybrid cylinder 20 used to convey the compressed gas from the hybrid cylinder 20 towards the generator 60.

[0049] The hybrid cylinder 20 comprises a hydraulic portion 21 and at least one pneumatic portion 28, 34. The hydraulic portion 21 of the hybrid cylinder comprises a hydraulic piston housing 22 and a hydraulic piston 23, the hydraulic piston having hydraulic piston head 27.

[0050] The hydraulic portion 21 may otherwise be referred to as a double-acting hydraulic cylinder portion. In other words, the hydraulic portion 21 preferably has an outlet / inlet on either end / side of the hydraulic portion 21. In other words, the hydraulic portion 21 is preferably configured to have hydraulic liquid on either side of the hydraulic piston 23. Thus, the hydraulic piston 23 can be moved by pressurised hydraulic liquid on either side of the hydraulic piston. For example, in figure 1, the hydraulic piston 23 can be moved by pressurised hydraulic liquid on the left of the hydraulic piston 23 to move the hydraulic piston 23 to the right, and by pressurised hydraulic liquid to the right of the hydraulic piston 23 to move the hydraulic piston 23 to the left. It is noted that the directions referred to here relateto the figures, e.g. figure 1, and the hybrid cylinder 20 could alternatively be provided in any orientation.

[0051] The hydraulic piston housing 22 of the hybrid cylinder 20 may comprise a first hydraulic section 25 and a second hydraulic section 26 on either side of the hydraulic piston 23 (i.e. on either side of hydraulic piston head 27).

[0052] The system 1 may be configured to direct hydraulic liquid from the hydraulic cylinder 10 towards the first hydraulic section 25 of the hybrid cylinder 20 or the second hydraulic section 26 of the hybrid cylinder 20 depending on the relative direction and / or position of the hydraulic piston 23 (optionally, the hydraulic piston head 27 specifically) in the hydraulic portion 21 of the hybrid cylinder 20. Thus, the system 1 may be configured to direct hydraulic liquid towards one section or the other of the hydraulic portion 21 depending on where the hydraulic piston 27 is within hydraulic piston housing 22 and / or the hydraulic piston speed and / or direction. For example, the system 1 may switch the direction of the fluid when the hydraulic piston 23 reaches the end of the range. For example, hydraulic liquid may be directed towards the first section 25 (e.g. the right-hand section) to move the hydraulic piston 23 to the left. When the hydraulic piston reaches the end of its range, the system 1 may switch so that hydraulic liquid may be directed towards the second section 26 (e.g. the lefthand section) to move the hydraulic piston 23 to the right. Sensors may be used to check the position and / or speed / direction of the hydraulic piston 23 so that the fluid switching can be controlled.

[0053] The pneumatic portions may otherwise be referred to as air compression drums, and in particular, a hydraulically driven air compression drums. The pneumatic portions are configured to generate compressed air (which can be used to turn part of the generator, e.g. a rotary motor). The hybrid cylinder 20 preferably comprises two pneumatic portions. It is noted that providing two pneumatic portions is beneficial in improving efficiency of the system. In general, energy is lost at each stage throughout the system and providing two pneumatic portions is one way of improving efficiency. Additionally, providing two pneumatic portions beneficially provides greater stability of air pressure, less heat generated, and a longer lifespan. Each of the pneumatic portions may effectively provide a single-acting pneumatic compression cylinder. In other words, each pneumatic portion may only have a single outlet. Preferably, the pneumatic portions are provided on either side of the hydraulicportion 21 of the hybrid cylinder 20. In other words, the hydraulic portion 21 of the hybrid cylinder 20 is positioned between a pneumatic portion on either end of the hybrid cylinder 20. Preferably, the outlet of each pneumatic portion is provided on either end of the hybrid cylinder 20. As shown in the figures, the hybrid cylinder comprises a first pneumatic portion 28 and a second pneumatic portion 34. The first pneumatic portion 28 comprises a first pneumatic piston housing 29 and a first pneumatic piston 30. The second pneumatic portion 34 comprises a second pneumatic piston housing 37 and a second pneumatic piston 35.

[0054] Alternatively, only a single pneumatic portion may be provided. In this case, the pneumatic portion would preferably be a double-acting cylinder, e.g. may comprise an outlet on either side of a pneumatic piston, which is beneficial for improved balance and efficiency.

[0055] The hydraulic piston 23 and the pneumatic pistons 30, 35 are configured to move together. More specifically, the hydraulic piston 23 and the pneumatic pistons 30, 35 are attached so as to move together. For example, a piston rod of the hydraulic piston 23 may extend either side to form piston rods 24a, 24b of the pneumatic pistons 30, 35. The piston rod 24 in the hybrid cylinder 20 may essential form one rod (although could be formed by several separate rods which are attached together or one integral rod).

[0056] Thus, the hybrid cylinder 20 is used to convert pressure (due to the hydraulic fluid in the hydraulic portion 21 of the hybrid cylinder 20) into translational movement and force on the hydraulic piston 23 in the hybrid cylinder 20 to the pneumatic pistons 30, 35 in the hybrid cylinder 20. The pneumatic portions 28, 34 of the hybrid cylinder 20 can intake gas at a lower pressure (e.g. at atmospheric pressure), and by action of the pneumatic pistons, compress the gas to a higher pressure (which may be referred to as an operational pressure) and discharge it towards the generator 60, preferably via the gas vessel 65.

[0057] Overall, the system 1 is beneficial in that movement of the floating structure 100 moves the piston 12 relative to the piston housing 11. Thus, movement of the floating structure 100 results in a force being applied by the piston 12 to fluid in the hydraulic cylinder 10. Fluid is moved through the system 1 from the hydraulic cylinder 10 towards the hybrid cylinder 20. As fluid is moved into the hybrid cylinder 20, and specifically into the hydraulic portion 21 of the hybrid cylinder 20, force is applied to the hydraulic piston from the fluid such that the hydraulic piston 23 in the hybrid cylinder 20 is moved. As the hydraulic piston 23 and the pneumatic pistons 30, 35 of the hybrid cylinder 20 are configured to movetogether, the pneumatic pistons 30, 35 move and compress gas in the pneumatic portions 28, 34 of the hybrid cylinder 20. The gas is directed towards the generator 60 which results in generation of electrical energy. The system 1 is beneficial in that it uses the movement of the floating structure 100 for generating electrical energy.

[0058] Preferably, the hydraulic portion 21 of the hybrid cylinder 20 is smaller than the hydraulic cylinder 10. In other words, the volume of fluid which can fit within the hydraulic portion 21 of the hybrid cylinder 20 is smaller than the volume of fluid in the hydraulic cylinder 10.

[0059] Preferably, the hydraulic portion 21 of the hybrid cylinder 20 is smaller in diameter (i.e. having a smaller bore size) than the hydraulic cylinder 10, preferably much smaller. Preferably, the hydraulic portion 21 of the hybrid cylinder 20 is smaller in length than the hydraulic cylinder 10. The hydraulic liquid (which may be referred to at this stage as drive fluid) will arrive to the hybrid cylinder 20 at the same high pressure as generated by the driving force on the hydraulic cylinder 10 due to the connection to the floating structure 100 (ideally, although there may be some reduction in pressure due to mechanical losses in reality). The force exerted upon the larger area of fluid by the piston 12 would be transferred by incompressible hydraulic liquid to the smaller area by the hydraulic piston 23 of the hybrid cylinder 20. Smaller force will be utilised at the receiving end (in the hydraulic portion 21 of the hybrid cylinder 20) to compress the gas to a far lesser pressure than one on the liquid side, which will however be sufficient to drive a rotary mechanism.

[0060] Preferably, the hydraulic portion 21 of the hybrid cylinder 20 is as small as possible, in order to limit the consumption of drive fluid, however, still be of sufficient size (cross-sectional area) to develop enough force to overcome the air pressure within the pneumatic portions 28, 34 of the hybrid cylinder 20.

[0061] Although the components may be of any appropriate size and determined to work at a preferred operating pressure, the following ranges / dimensions are provided for explanation. Considering a 6-metre stroke hydraulic cylinder 10 with a cross-sectional area of Im2, the size of the hydraulic portion 21 of the hybrid cylinder may be determined (based on the assumption that the driving force in downward motion is incurred by the mass of the structure, due to the resistance in the system 1). The air pressure for operation of the generator may be 7-8 bar. Therefore, the pneumatic portions of the hybrid cylinder 20 may beset to operate in this range (although may of course operate at other ranges). The pneumatic portions 28, 34 of the hybrid cylinder 20 may have a diameter (internally) of approximately 200 to 500 mm, or preferably approximately 300 to 400 mm, or preferably approximately 300 mm. The stroke length may be approximately 200 to 500 mm, or preferably approximately 300 to 400 mm, or preferably approximately 300 mm. Although the stroke length of the hydraulic portion 21 is the same as the pneumatic portions, the diameter / cross-sectional area may be different. In particular, the cross-sectional area of the hydraulic portion 21 may be smaller than the cross-sectional area of the pneumatic portions 28, 34. For example, if the cross sectional area of the pneumatic portions 28, 34 is approximately 0.07 m2 (i.e. if diameter is approximately 300 mm), the diameter of the hydraulic portion may be approximately 35 mm. If the stroke length is approximately 300 mm, this would result in a volume of the hydraulic portion of the hybrid cylinder of approximately 2.9 x 10'4m3(compared to 6 m3in the hydraulic cylinder). Thus, approximately 20,700 strokes of the hydraulic portion of the hybrid cylinder may occur during one stroke of the hydraulic cylinder.

[0062] For example only, a ratio of the diameter of the pneumatic portions 28, 34 of the hybrid cylinder 20 to the diameter of the hydraulic portion of the hybrid cylinder may be between approximately 20:1 to 2:1, or more preferably between approximately 15:1 to 3:1, or more preferably between approximately 10:1 to 5:1. For example only, a ratio of the volume of hydraulic cylinder to the volume of the hydraulic portion 21 of the hybrid cylinder 20 may be between approximately 5000:1 to 1000:1, preferably between approximately 4000:1 to 2000: 1, more preferably approximately 3500: 1. It is noted that these are exemplary ranges and the ratio may be selected outside of these ranges if preferred for optimizing a given system.

[0063] The hybrid system provides advantages over a purely pneumatic system in terms of the footprint and spatial requirements, as well as the fact that more standard equipment, that is already commercially available may be used.

[0064] The system 1 represents a significant technical advantage. By introducing an incompressible fluid system between the primary movement of the floating structure 100 and compressed air generation from the hybrid cylinder 20, the system 1 can achieve mechanical multiplication of the input force. This multiplication enables multiple compression cycles (ofthe gas in the hybrid cylinder 20) from a single tidal movement, effectively increasing the energy density captured from each tidal cycle. This overcomes the traditional limitation of tidal frequency, extracting more energy from each rise and fall without requiring greater tidal range.

[0065] The hybrid cylinder comprises an inlet 20a for gas, preferably air, e.g. filtered atmospheric air or any appropriate gas. The inlet 20a may be used as a gas inlet point to the pneumatic portions 28, 24 of the hybrid cylinder 20. The gas inlet 20a (or piping 40h between the gas inlet 20a and the pneumatic portions 28,34 of the hybrid cylinder 20) may include at least one filtration element.

[0066] The generator 60 is in fluidic communication with the pneumatic portions 28, 34 of the hybrid cylinder 20, e.g. via piping 40i, 40j. Movement of the pneumatic pistons 30, 35 are configured to generate electrical energy in the generator 60. In other words, gas is passed from the pneumatic portions 28, 34 of the hybrid cylinder 20 towards the generator 60, and into the generator 60 so as to use the gas to generate electrical energy. Known types of generator can be used.

[0067] The generator 60 may comprises a rotary mechanism 61 comprising a rotor configured to rotate about an axis. The rotor may be in in fluidic communication with the pneumatic portions 28, 34 of the hybrid cylinder 20. In other words, gas expelled from the pneumatic portions 28, 34 of the hybrid cylinder 20 may be used (directly or indirectly) to turn the rotor. The rotary mechanism 61 may be an air vane motor or turbine used to convert the energy of pressurised gas flow to mechanical rotation. Rotation of the rotary mechanism about the axis can turn a shaft 62 connected to the rotary mechanism (i.e. such that the shaft rotates - arrow M - about the same axis).

[0068] The generator 60 may be configured generate electrical energy due to rotation of the rotary mechanism 61. In particular, the rotary mechanism converts the energy of compressed gas flow, to create rotary movement, e.g. of its shaft 62 which is rigidly connected with the shaft of the electric generator 63. For example, the generator may be a permanent magnet generator 63 (which may optionally be air-cooled) used to convert the mechanical rotation (e.g. via the shaft 62) to electric current. Thus, the electric generator 63 generates electric current which is transferred by electrical connections towards a consumer and / or at least one storage system 68. The generator may comprise any appropriate (possibly well-known)system / device for converting energy from the compressed gas flow into electrical energy. The at least one storage system 68, e.g. a battery storage system, for storing the electrical energy generated by the system 1. The storage system 68 may comprise, for example, lithium-ion batteries and associated electrical components (e.g. a rectifier, inverter, cables, breakers, earthing, and a control system).

[0069] The system may comprise the gas vessel 65. The gas vessel 65 may otherwise be referred to as a compressed gas receiver vessel or a compressed air receiver vessel. The gas vessel 65 may be positioned between the hybrid cylinder 20 and the generator 60. The gas vessel 65 may be configured to control the flow of gas from the hybrid cylinder 20 to the generator 60. The gas expelled from the pneumatic portions 28, 34 of the hybrid cylinder 20 may be used to turn the rotor, passing through the gas vessel 65 between the hybrid cylinder and the generator (i.e. the gas is used indirectly). The gas vessel 65 may be a pressure vessel used to receive fluctuating flow of compressed gas (e.g. air) from the hybrid cylinder 20, provide storage capacity and facilitate controlled discharge of compressed gas towards the generator 60. In other words, the gas vessel 65 may be used to store compressed gas that is incoming at varying flow from the hybrid cylinder 20 and then release it in a controlled fashion towards the generator 60. The gas vessel 65 (or surrounding piping, e.g. 40j) may include any appropriate valves for controlling discharge of gas towards the generator, e.g. a pressure reducing valve. The gas vessel 65 (or surrounding piping, e.g. 40j) may include any appropriate additional valves for overall operation and / or maintenance of the system, e.g. a safety relief valve, drain valve, and / or other valves.

[0070] An automatic, self-regulating pressure reduction valve may be utilised to enable controlled discharge of air from the hybrid cylinder towards the generator 60t. Valves can be used even with highly widely fluctuating inlet pressures and flows and can ensure regulated downstream supply of gas (e.g. air). The valve can be selected to deliver the preferred flow of gas, e.g. at a set pressure point. There are various commercially available options of the valve construction, such as pilot operated valves, or those with external power supply - e.g. the solenoid operated valves.

[0071] The gas vessel 65 may have a vent and / or pressure valve in the vessel (or downstream) which may be opened if pressure within the vessel is greater than a predetermined threshold.The hydraulic cylinder 10 and the hydraulic portion 21 of the hybrid cylinder 20 may form part of a hydraulic circuit for the hydraulic liquid. In other words, the hydraulic liquid may move between the hydraulic cylinder 10 and the hydraulic portion 21 of the hybrid cylinder 20, albeit via other components, such as the hydraulic reservoir 80, one or more control blocks 50, 55, a control valve 75 (e.g. a pressure control valve), and one or more release valves 41a, 41b, and piping 40a-40g provided between relevant components (described further below).

[0072] The system 1 may comprise primary hydraulic control block 50 configured to direct fluid from the first section 13 and / or the second section 14 of the hydraulic cylinder 10 towards the hybrid cylinder 20. The primary hydraulic control block 50 may be used to divert flow of hydraulic fluid depending on operational cycle. An example of the primary hydraulic control block is shown in the figures having a physical structure which allows for fluid to be directed between different inputs and outputs. The primary hydraulic control block 50 may be solenoid 53 operated (although other means of operation may be used instead).

[0073] For example, the primary hydraulic control block 50 may comprise at least two fluid directing compartments, namely a first compartment 51 and a second compartment 52. In the first compartment 51, a first fluid input is directed to a first fluid output and a second fluid input is directed to a second fluid output. In the second compartment 52, a first fluid input is directed to a second fluid output and a second fluid input is directed to a first fluid output. In other words, switching between the first compartment 51 and second compartment 52 redirects fluid to a different outlet, i.e. from the first outlet to the second outlet and vice versa.

[0074] In operation, the primary hydraulic control block 50 may direct fluid via the first compartment 51 when the piston 12 is moving downwards, as shown in figures 6 and 7.

[0075] Thus, pressurised fluid is directed along piping 40a to piping 40c towards the hybrid cylinder. Unpressurised fluid ejected by the hybrid cylinder 20 is directed along piping 40d and 40b towards the hydraulic cylinder 10.

[0076] In operation, the primary hydraulic control block 50 may direct fluid via the second compartment 52 when the piston 12 is moving upwards, as shown in figures 8 and 9. Thus, pressurised fluid is directed along piping 40b to piping 40c towards the hybrid cylinder.

[0077] Unpressurised fluid ejected by the hybrid cylinder 20 is directed along piping 40d and 40a towards the hydraulic cylinder 10.The system may comprise a comprise a secondary hydraulic control block 55 configured to direct fluid from the hydraulic cylinder 10 towards the first hydraulic section 25 of the hybrid cylinder 20 or the second hydraulic section 26 of the hybrid cylinder. The secondary hydraulic control block 55 may be used to divert flow of hydraulic fluid depending on operational cycle. An example of the secondary hydraulic control block 55 is shown in the figures having a physical structure which allows for fluid to be directed between different inputs and outputs. The secondary hydraulic control block 55 may be solenoid 58 operated (although other means of operation may be used instead).

[0078] For example, the secondary hydraulic control block 55 may comprise at least two fluid directing compartments, namely a first compartment 56 and a second compartment 57. In the first compartment 56, a first fluid input is directed to a first fluid output and a second fluid input is directed to a second fluid output. In the second compartment 57, a first fluid input is directed to a second fluid output and a second fluid input is directed to a first fluid output. In other words, switching between the first compartment 56 and second compartment 57 redirects fluid to a different outlet, i.e. from the first outlet to the second outlet and vice versa.

[0079] In operation, the secondary hydraulic control block 55 may direct fluid via the first compartment 56 to move the hydraulic piston 23 left, as shown in figures 6 and 8. Thus, pressurised fluid is directed along piping 40f towards the hybrid cylinder 20, and particularly towards the first hydraulic section 25 of the hybrid cylinder 20. Unpressurised fluid ejected by the hybrid cylinder 20 is directed along piping 40g and 40e towards the hydraulic cylinder 10.

[0080] In operation, the secondary hydraulic control block 55 may direct fluid via the second compartment 57 to move the hydraulic piston 23 right, as shown in figures 7 and 9. Thus, pressurised fluid is directed along piping 40g towards the hybrid cylinder 20, and particularly towards the second hydraulic section 26 of the hybrid cylinder 20. Unpressurised fluid ejected by the hybrid cylinder 20 is directed along piping 40f and 40e towards the hydraulic cylinder 10.

[0081] As described further below, the system may employ a hydraulic mechanism designed to maintain the floating structure in a static position against tidal forces until a predetermined threshold is reached. The predetermined threshold is a threshold set for a measuredcharacteristic of the system, e.g. pressure or loading, wherein the predetermined threshold is indicative of a threshold level of loading of the system and / or usable mass of the floating structure. Upon reaching this threshold, the system may allow controlled movement while maintaining consistent force or pressure. This bidirectional system operates during both falling and rising tides, utilising both the usable mass and the natural buoyancy forces as the primary input by holding the structure in a static position until a predetermined loading or buoyancy is reached (based on a measured characteristic, e.g. pressure). The core of this mechanism is the hydraulic cylinder 10 that connects the floating structure to a fixed structure (such as a dock, pier, or piles). The hydraulic cylinder 10 contains piston 12 that separates two chambers 13,14 filled with hydraulic fluid. Movement of the piston 12 allows the extension or retraction of the rod 16 connected to the floating structure, precisely controlling its vertical position relative to the fixed structure.

[0082] The system may be configured to restrict movement of the piston relative to the piston housing until a predetermined threshold is reached. The “threshold” refers to the load in the cylinder, for example, measured by a pressure sensor, which is a proxy for the usable mass - i.e. the pressure builds towards the threshold (which may be referred to as a trigger value), at which point we know that the system is loaded with the desired usable mass. In other words, the threshold may be indicative of a level of loading and / or usable mass of the floating structure. In this way, as one of the piston and piston housing is attached to the floating structure, the system may be configured to resist movement of the floating structure until a predetermined threshold is reached. The system may be configured to restrict movement of the floating vessel until a predetermined threshold is reached. In other words, the system may be configured to maintain a position of the floating vessel (i.e. in a static position) against tidal forces, i.e. buoyancy / gravity forces. The system may be configured to subsequently allow movement of the piston relative to the piston housing. In other words, the system may subsequently allow movement of the floating structure, i.e. after the predetermined threshold is reached. Movement of the piston relative to the piston housing may be prevented by restricting flow of hydraulic fluid from the hydraulic cylinder to the hydraulic portion of the hybrid cylinder (to restrict movement of the piston / piston housing and thus restricting movement of the floating structure). This may be done in a variety of ways. For example, using some form of control valve 75 (as described further below).The predetermined threshold may be a predetermined pressure, i.e. based on a pressure of a fluid in the hydraulic system. The system may comprise at least one pressure sensor configured to determine pressure of a fluid in the system, preferably wherein the at least one pressure sensor is configured to measure pressure of hydraulic fluid in the hydraulic cylinder. Preferably, the system comprises at least two pressure sensors, preferably located in both chambers of the hydraulic cylinder 10 to continuously monitor system pressure. In other words, the system may comprise at least two pressure sensors, wherein a first pressure sensor 17 is positioned in first section 13 of the hydraulic cylinder 10 and a second pressure sensor 18 is positioned in the second section 14 of the hydraulic cylinder 10. It is noted that pressure of they hydraulic fluid could be measured elsewhere in the system, e.g. in the piping (e.g. 40 a and / or 40b) and / or at least one of the primary hydraulic control block 50 and / or the secondary hydraulic control block 55.

[0083] Preferably, the system comprises at least one load cell. The at least one load cell may be positioned at at least one connection point between the floating structure 100 and the fixed structure (e.g. the piles 105) to directly measure the tension or compression forces. For example, a first load cell 107 may be positioned at attachment 106. For example, a second load cell 108 may be positioned at the connection between the piston 12 and the floating structure 100.

[0084] Preferably, the system comprises at least one position sensor 19. The position sensor 19 is configured to monitor the position the piston 12, e.g. relative to the piston housing 11. The position sensor 19 could be positioned elsewhere, e.g. within the piston housing 11. The position sensor 19 may be used to track the position / extension of the hydraulic cylinder to monitor floating structure position relative to water level. Thus, the position sensor 19 and may be used to monitor the position of the floating structure 100. The position sensor 19 could instead be used to monitor the position of the floating structure 100 directly (e.g. may be positioned on the fixed structure).

[0085] The system may comprise a control valve 75 (which may be referred to as a pressure control valve and / or a throttle). The control valve 75 may be configured to regulate fluid flow between chambers (i.e. between the hydraulic cylinder 10 and the hybrid cylinder 20), for example, based on pressure readings, maintaining the set threshold pressure and / or force. It is noted that the pressure readings are indicative of the load or force on the hydraulic cylinder,which is a proxy for the usable mass. The control valve 75 may be configured to restrict flow of hydraulic fluid from the hydraulic cylinder to the hydraulic portion of the hybrid cylinder. Thus, the control valve 75 can be used to control movement of hydraulic fluid in the system 1. The control valve 75 may be set / tuned to the system. The control valve 75 may effectively be a valve which can be opened or closed and provide a range of opening inbetween. The control valve 75 can be used as part of the way pressure in the system 1 is controlled. For example, when the valve of the control valve 75 is fully open, hydraulic fluid may move freely. When the control valve 75 is partially closed, this restricts movement of the hydraulic fluid in the system 1. This may be particularly useful for providing resistance in the system, which may be used to counteract forces moving the floating structure (i.e. gravity or buoyancy). In this way, movement of the floating structure may be restricted by resistance in the hydraulic circuit, i.e. by only allowing a certain rate of fluid flow through the control valve 75, the liquid in the hydraulic system, and particularly the hydraulic cylinder can resist movement of the piston. Due to the rigid connection between the hydraulic cylinder (e.g. the piston) and the floating structure 100, movement of the floating structure 100 can be resisted by the system, and particularly, by the hydraulic system. This can be controlled by varying the extent of opening of the control valve 75.

[0086] The control valve 75 may be calibrated for the specific location at which the control valve 75 is provided in the system 1. The primary hydraulic control block 50 (if provided) may comprise the control valve 75 and / or the secondary hydraulic control block 55 (if provided) may comprise the control valve 75. However, this is not a necessity, and the control valve 75 may be positioned in any appropriate part of the system where flow between the hydraulic cylinder and the hydraulic portion of the hybrid cylinder can be restricted.

[0087] Multiple control valves may be provided.

[0088] In further detail, in an example, as the tide falls / during falling tide, the natural buoyancy of the floating structure 100 creates an upward force. The hydraulic cylinder 100 resists this force, maintaining the floating structure’s position relative to the fixed structure 106. A controller 70 may continuously monitor the force applied to the system 1 via at least one load cells and pressure sensors. When the force / pressure reaches the predetermined threshold (calibrated to a specific mass equivalent), the control valve 75 modulates to allow controlled fluid flow between chambers, i.e. between the hydraulic cylinder 10 and the hybridcylinder 20. This permits the hydraulic cylinder 10 to extend while maintaining constant pressure, effectively allowing the floating structure 100 to descend with the tide at a controlled rate.

[0089] In further detail, in an example, during a rising tide, the process works in reverse. As the water level increases, the floating structure 100 experiences increased buoyancy. The hydraulic cylinder 10 retracts as the pressure control valve 75 allows regulated fluid flow, maintaining the set threshold force as the vessel rises.

[0090] The controller 70 specific control logic. For example, the controller 70 (which may otherwise be referred to as Electronic Control Unit (ECU) may use a control algorithm to ensure precise pressure maintenance. The system may operate as follows:

[0091] • Measurement Phase: Continuous monitoring of pressure sensors and load cells. • Comparison Phase: Measured values are compared to setpoint thresholds.

[0092] • Control Phase: When the threshold is reached, the pressure control valve 75 is modulated to maintain constant pressure while allowing movement.

[0093] • Safety Monitoring: Continuous checking for anomalous readings that might indicate system failure or unsafe conditions.

[0094] The controller 70 may include a calibration subsystem. The calibration subsystem may be part of the controller 70 and may be configured to carry out a specific function. The controller 70 / calibration subsystem may be configured to allow operators to set and adjust the threshold mass / force values. The threshold mass can be precisely calibrated, e.g. through a controller (e.g. ECU) interface. This allows adaptation to different floating structure 100 types, loading conditions, or operational requirements, such as differing tide ranges.

[0095] Calibration may be carried out in any appropriate way, for example, calibration may involves: 1. Setting a desired holding force based on floating structure 100 mass and buoyancy characteristics.

[0096] 2. Establishing maximum safe operational parameters.

[0097] 3. Defining the response curve of the pressure control valve 75 (i.e. how open or closed the control valve is based on the measured pressure and / or load).

[0098] The system 1 may comprise hydraulic reservoir 80 (which may be any appropriate hydraulic reservoir). The hydraulic reservoir 80 may otherwise be referred to as a break tank. The hydraulic reservoir 80 may form part of the hydraulic circuit. The hydraulic reservoir 80may be beneficial in maintaining, or assisting in maintaining pressure in the hydraulic circuit. The hydraulic reservoir 80 may provide an unpressurized tank containing hydraulic fluid. A size of the hydraulic reservoir may be selected to ensure that there is enough hydraulic fluid in the system. The hydraulic reservoir 80 may be positioned downstream of the outlet of the hydraulic portion of the hybrid cylinder 20. Thus, the hydraulic reservoir 80 is configured to receive unpressurised fluid from the hydraulic portion 21 of the hybrid cylinder 20. This reduces resistance to movement of the hydraulic piston, which would otherwise reduce efficiency of energy generation. In particular, by managing fluid flow and reducing / preventing excess pressure build-up, the system maintains efficient and reliable operation. The ability to draw fluid into the hydraulic cylinder 10 from the hydraulic reservoir 80 during both extension and retraction of the piston 12 allows the hydraulic system to adapt to varying external forces and operational conditions. In particular, the hydraulic reservoir 80 may be configured to provide pressurised fluid to the system and stores excess fluid during operations. The hydraulic reservoir 80 may be positioned downstream of the secondary hydraulic control block 55. The hydraulic reservoir 80 may be configured to receive fluid ejected from the hydraulic portion 21 of the hybrid cylinder 20. The hydraulic reservoir 80 may be configured to eject fluid towards the hydraulic cylinder 10. The hydraulic reservoir 80 may be used to collect hydraulic fluid expelled from the unpressurised chamber of hydraulic portion of the hybrid cylinder 20 and facilitate priming of the unpressurised chamber of the hydraulic cylinder 10 with hydraulic fluid.

[0099] In further detail, an external force (e.g. gravity) moves the piston 12 within the hydraulic cylinder 10. This force can be applied in either direction, causing the piston 12 to extend or retract. As the piston 12 moves, hydraulic fluid is drawn into the hydraulic cylinder 10 from the hydraulic reservoir 80. During extension, hydraulic fluid is pulled into the hydraulic cylinder 10 on one side of the piston 12. During retraction, hydraulic fluid is pulled into the hydraulic cylinder 10 on the opposite side. The hydraulic system manages fluid flow and pressure. Fluid released back to the hydraulic reservoir 80 is beneficial in reducing / preventing pressure build-up, ensuring smooth operation and preventing system seizing. This fluid is then available to replenish the other side of the system as needed.

[0100] The system 1 may comprise a plurality of long-stroke hydraulic cylinders 10 each comprising a piston housing 11 and a piston 12, wherein one of the piston 12 and the pistonhousing 11 is configured to move with the floating structure 100 and the piston 12 is configured to move relative to the piston housing 11 when the floating structure 100 moves.

[0101] Although it is described above that the hydraulic cylinder 10 is a double-acting long-stroke cylinder, multiple, short-stroke cylinders may be provided instead and arranged in a cascading series. In this case, the plurality of hydraulic cylinders are provided in a cascading structure comprising primary hydraulic cylinders each comprising a piston housing 11 and a piston 12 wherein one of the piston 12 and the piston housing 11 is configured to move with the floating structure, and comprising at least one stage of downstream hydraulic cylinders. This variation provides at least two hydraulic cylinders in series. The stroke length may be determined based on the tidal range (Ah) as well as the arrangement of cylinders in the series / parallel. In this case, the stroke length of the cylinders arranged in series may be smaller than the long-stroke cylinder described above.

[0102] In an alternative embodiment, the hydraulic cylinder 10 may instead be a double- ended cylinder.

[0103] The cascading embodiment offers better maintainability due to component availability, however, the system comprising at least one single hydraulic cylinder (i.e. providing one or more cylinder in parallel and connected to the rest of the system, rather than in series) provides more straightforward operation with fewer moving parts. Providing a cascading structure of cylinders may be beneficial in allowing the system to be more easily tuned for different variations in tide over the year, and may be beneficial in allowing higher variations to be account for during unusual variations in tide, e.g. during a storm.

[0104] The system 1 may comprise a controller 70 to control any / all components of the system 1. The controller 70 may be referred to as a central processing unit (CPU). The controller may be referred to as an Electronic Control Unit (ECU). The controller 70 may be a microprocessor-based controller that processes sensor inputs and controls the hydraulic system accordingly. The controller 70 may include any number of controller sub-systems which may be in communication (e.g. via wired or wireless connections). The controller 75 may be used to control relevant parts of the system 1, for example, the first hydraulic control block 50 and / or the second hydraulic control block 55 and / or any pressure relief mechanisms and / or the gas vessel 65. The controller 75 may receive feedback from any sensors included in the system 1, e.g. relating to pressure of the hydraulic fluid, to pressure of the gas in / fromthe hybrid cylinder, to a position / speed / direction of any / all pistons in the hydraulic cylinder and / or hybrid cylinder. The controller 75 may include at least one display for providing information, e.g. data relating to at least one sensor, to an operator. The operator may provide an input via the display or a corresponding input unit (e.g. a keyboard).

[0105] The system 1 may include various safety mechanisms, including emergency shutdowns / release mechanisms, pressure relief valves, and comprehensive monitoring systems. For example, the system 1 may include an emergency release mechanism which is a Safety system configured to quickly disengage the hydraulic hold if dangerous conditions are detected, e.g. if pressure and / or load sensors indicate a measurement above a safety limit. In other words, the system would may be configured to implement an emergency release system for safety. The system may include manual override controls (not shown) which may comprise physical controls allowing operators to bypass the automated system. Conservative pressure ratings and redundant systems may be implemented to ensure safe operation in the marine environment. In further detail, the system 1 may include any combination of the following safety features:

[0106] • Pressure Relief Valves: Prevent system overpressure in case of extreme loading conditions.

[0107] • Redundant Sensors: Multiple sensing points ensure reliable operation even if individual sensors fail.

[0108] • Mechanical Stops: Physical limitations to cylinder travel prevent extreme extension or retraction.

[0109] • Emergency Power Supply: Backup power (UPS) ensures safe operation during main power loss.

[0110] • Manual Bypass System: Allows operators to take direct control in case of electronic system failure.

[0111] • Fault Detection Logic: The ECU continuously monitors for sensor readings that might indicate system failure.

[0112] The use of the hydraulic and hybrid cylinders is particular useful compared to known mechanical geared generator systems, as such systems can become jammed which can beproblematic to resolve. In the present invention, the pressure can be released in the system if it is too high.

[0113] In the above embodiments, at least one pressure relief mechanism may be provided (which may otherwise be referred to as a pressure relief facility). The pressure relief mechanism is configured to open and release hydraulic fluid (to a safe location) in case of overpressure in hydraulic piping system (or any component in the overall system). The pressure relief mechanism may be opened automatically (e.g. if a pressure sensor indicates that a given pressure measured at a corresponding location is reached) and / or may be opened manually by an operator. For example, in the figures, first pressure relief valve 41a and a second pressure relief valve 41b are provided between the hydraulic cylinder 10 and the primary control block 50. Any appropriate pressure relief mechanisms / valves may be used. Additional / al ternative pressure relief mechanisms may be provided in additional / al ternative locations in the system.

[0114] Although the hydraulic control blocks 50,55 are described above as each having a physical structure with two alternative fluid directing compartments, the hydraulic control blocks 50,55 are shown only indicatively in the scheme - and may be configured to function based on the figures (rather than having the physical structure shown in the figures). In other words, the system may implement the function of the hydraulic control blocks 50,55 in ways other than those described above.

[0115] Although the hydraulic control blocks 50,55 are described above as primary and secondary, it will be understood that the “primary” and “secondary” terms are labels only. For example, only one of the control blocks may be provided, e.g. the primary or the second hydraulic control block.

[0116] It is noted that various components described above are beneficial in improving efficiency / optimising energy generation, but are not essential, e.g. the gas vessel 65 and / or the hydraulic reservoir 80.

[0117] The system may comprise at least one pressure sensor, and preferably multiple pressure sensors. For example, the system may be configured to determine pressure between the hydraulic cylinder 10 and the primary control block 50 (from either the first section 13 and / or the second section 14). For example, the system 1 may be configured to determine pressure of the liquid between the primary control block 50 and the hybrid cylinder 20 and / orbetween the primary control block 50 and the secondary control block 55 and / or between the secondary control block 55 and the hybrid cylinder 20. For example, the system 1 may be configured to determine pressure between the hybrid cylinder 30 and the secondary control block 55. The pressure may be determined by any appropriate pressure sensor. Data relating to the sensed pressure may be used by the primary control block 50 and / or secondary control block 50 and / or any valves in the system (e.g. the release vale) to maintain pressure in a given part of the system 1 with in a preferred range.

[0118] The piping 40 may include any appropriate valves for overall operation and / or maintenance of the system, e.g. pressure control valves, a safety relief valve, drain valve, and / or other valves.

[0119] Although it is described above that the piston 12 is attached to the floating structure 100 and the piston housing 11 is attached to at least one pile 105, it could be the other way round, i.e. the piston housing 11 could be attached to the floating structure 100 and the piston 12 could be attached to at least one pile 105. In other words, one of the piston 12 and the piston housing 11 of the hydraulic cylinder 10 may be attached to the floating structure 100 and the other of the piston 12 and the piston housing 11 of the hydraulic cylinder 10 may be attached to the at least one pile 105.

[0120] Although the system may be provided with at least one pile to be fixedly moored to the seabed, other options are available, for example a part of the system 1, e.g. the piston 12 or piston housing 11 of the hydraulic cylinder 10 may be attached to a different structure, e.g. a pre-existing structure or land mass. For example, the fixed structure may be a dock or pier. The fixed structure may include multiple fixed structure, e.g. a combination of a dock and / or pier and / or at least one pile.

[0121] The system may be part of a floating construction, i.e. comprising the floating structure 100 and the system 1 described above in any of the embodiments or variations. Although the system 1 may be provided together with floating structure 100, the system may be provided separately and attached to a floating structure 100, e.g. a pre-existing structure.

[0122] The system may be considered to provide a modular system which allows for scaling to match local requirements and power demand.

[0123] The floating structure provides inherent flexibility in system scaling. The power generation potential can be adjusted by varying the mass and dimensions of the floating craft.Larger floating structures can accommodate bigger cylinder systems and generate more power, while smaller installations might suit locations with different requirements. This scalability feature means the same core technology can be deployed across various locations and power requirements without fundamental design changes. The floating structure also offers advantages in installation, maintenance, and potential relocation compared to fixed tidal installations.

[0124] The present invention may include at least one method associated with the system and / or floating construction described above. For example, in an embodiment, a method of generating electrical energy is provided using the system and / or floating construction as described in any of the above embodiments and / or variations. For example, in an embodiment, a method of installing a system for generating electrical energy comprising: providing the system as described in any of the above embodiments and / or variations; attaching the piston to the floating structure or at least one pile; attaching the piston housing to the other of the floating structure or the at least one pile; fluidly connecting the hydraulic cylinder to the hydraulic portion of the hybrid cylinder; and fluidly connecting the pneumatic portion of the hybrid cylinder to the generator. When installed, the system can be used with the floating structure (i.e. the floating construction) to generate electricity.

[0125] The present disclosure is described in various levels of detail and no limitation as to the scope of the claimed subject matter is intended by either the inclusion or non-inclusion of features, components, or the like in the summary. The claimed subject matter is not necessarily limited to the particular embodiments or arrangements illustrated herein.

[0126] The accompanying drawings are provided for illustration purposes only. The dimensions, positions, order, and relative sizes reflected in the drawings attached hereto may vary. It will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the present subject matter. Thus, it is intended that the present subject matter covers such modifications and variations as come within the scope of the appended claims and their equivalents.

[0127] In the foregoing description, it will be appreciated that the phrases “at least one”, “one or more”, and “and / or”, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. The term “a” or “an” entity, as used herein, refers toone or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein.

Claims

CLAIMS1. A system for generating electrical energy, the system comprising:a hydraulic cylinder comprising a piston housing and a piston, wherein one of the piston and the piston housing is configured to move with a floating structure and the piston is configured to move relative to the piston housing when the floating structure moves;a hybrid cylinder comprising:a hydraulic portion comprising a hydraulic piston housing and a hydraulic piston, wherein the hydraulic portion of the hybrid cylinder is in fluidic communication with the hydraulic cylinder; anda pneumatic portion comprising a pneumatic piston housing and a pneumatic piston, wherein the hydraulic piston and pneumatic piston are configured to move together; anda generator in fluidic communication with the pneumatic portion of the hybrid cylinder, wherein movement of the pneumatic piston is configured to generate electrical energy in the generator.

2. The system of claim 1, wherein the system is configured to restrict movement of the piston relative to the piston housing until a predetermined threshold is reached, and is configured to subsequently allow movement of the piston relative to the piston housing.

3. The system of claim 2, further comprising at least one pressure sensor configured to determine pressure of a fluid in the system, wherein the predetermined threshold is a predetermined pressure threshold, preferably wherein the at least one pressure sensor is configured to measure pressure of hydraulic fluid in the hydraulic cylinder.

4. The system of any one of the preceding claims, further comprising a control valve configured to restrict flow of hydraulic fluid from the hydraulic cylinder to the hydraulic portion of the hybrid cylinder.

5. The system of any one of the preceding claims, wherein the system is configured to move fluid in the hydraulic cylinder, when a force is applied by the piston of the hydraulic cylinder to said fluid, towards the hydraulic portion of the hybrid cylinder to move the hydraulic piston and the pneumatic piston in the hybrid cylinder.

6. The system of any one of the preceding claims, wherein the hydraulic portion of the hybrid cylinder is smaller than the hydraulic cylinder.

7. The system of any one of the preceding claims, wherein the hybrid cylinder comprises two pneumatic portions, preferably wherein pneumatic portions are provided on either side of the hydraulic portion of the hybrid cylinder.

8. The system of any one of the preceding claims, further comprising at least one fixed structure to be fixedly attached to the seabed, preferably wherein one of the piston and the piston housing of the hydraulic cylinder is attached to the floating structure and the other of the piston and the piston housing of the hydraulic cylinder is attached to the at least fixed structure.

9. The system of any one of the preceding claims, wherein the piston housing of the hydraulic cylinder comprises a first section and a second section on either side of the piston,the system being configured to direct fluid from the first section and / or the second section of the hydraulic cylinder towards the hybrid cylinder depending on the relative direction and / or position of the piston in the hydraulic cylinder.

10. The system of claim 9, further comprising a primary hydraulic control block configured to direct fluid from the first section and / or the second section of the hydraulic cylinder towards the hybrid cylinder, preferably wherein the primary hydraulic control block comprises a control valve configured to restrict flow of hydraulic fluid from the hydraulic cylinder to the hydraulic portion of the hybrid cylinder.

11. The system of any one of the preceding claims, wherein the hydraulic piston housing of the hybrid cylinder comprises a first hydraulic section and a second hydraulic section on either side of the hydraulic piston,the system being configured to direct fluid from the hydraulic cylinder towards the first hydraulic section of the hybrid cylinder or the second hydraulic section of the hybrid cylinder depending on the relative direction and / or position of the hydraulic piston in the hydraulic portion.

12. The system of claim 11, further comprising a secondary hydraulic control block configured to direct fluid from the hydraulic cylinder towards the first hydraulic section of the hybrid cylinder or the second hydraulic section of the hybrid cylinder.

13. The system of any one of the preceding claims, wherein the generator comprises a rotary mechanism comprising a rotor configured to rotate about an axis, the rotor being in fluidic communication with the pneumatic piston, wherein the generator is configured generate electrical energy due to rotation of the rotary mechanism.

14. The system of any one of the preceding claims, further comprising a gas vessel configured to control the flow of gas from the hybrid cylinder to the generator.

15. The system of any one of the preceding claims, further comprising a hydraulic reservoir.

16. The system of any one of the preceding claims, wherein the system comprises:(a) a plurality of hydraulic cylinders each comprising a piston housing and a piston, wherein one of the piston and the piston housing is configured to move with the floating structure and the piston is configured to move relative to the piston housing when the floating structure moves; or(b) a plurality of hydraulic cylinders each comprising a piston housing and a piston, wherein the plurality of hydraulic cylinders are provided in a cascading structure comprising primary hydraulic cylinders each comprising a piston housing and a piston wherein one of the piston and the piston housing is configured to move with thefloating structure, and comprising at least one stage of downstream hydraulic cylinders.

17. A method of installing a system for generating electrical energy comprising:providing the system of any one of the preceding claims;attaching the piston to the floating structure or at least one fixed structure; attaching the piston housing to the other of the floating structure or the at least one fixed structure;fluidly connecting the hydraulic cylinder to the hydraulic portion of the hybrid cylinder; andfluidly connecting the pneumatic portion of the hybrid cylinder to the generator.

18. A floating construction comprising a floating structure and the system of any one of the preceding claims, preferably wherein the floating structure is floating platform, pontoon, marina, barge, port structure, floating craft, recreational vessel, barge or floating port terminal, other use cases include floating port infrastructure and loading platforms, floating piers and marinas, floating hotels or buildings, floating concrete structures, floating parks and green space, real estate on buoyant platforms, floating homes, buoyant or semi buoyant constructions, floating roads, tunnels, bridges and pontoons, floating greenhouses and urban farms, floating car parks, and / or hybrid floating renewable energy platforms.

19. A method of generating electrical energy using the system of any one of claims 1 to 16 or the floating construction of claim 18.

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