Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
  • B63B35/34—Pontoons
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
  • B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
  • B63B2035/4433—Floating structures carrying electric power plants
  • B63B2035/4453—Floating structures carrying electric power plants for converting solar energy into electric energy
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B39/00—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude
  • B63B39/06—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water
  • B63B2039/067—Equipment to decrease pitch, roll, or like unwanted vessel movements; Apparatus for indicating vessel attitude to decrease vessel movements by using foils acting on ambient water effecting motion dampening by means of fixed or movable resistance bodies, e.g. by bilge keels
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B2241/00—Design characteristics
  • B63B2241/02—Design characterised by particular shapes
  • B63B2241/04—Design characterised by particular shapes by particular cross sections
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B2241/00—Design characteristics
  • B63B2241/02—Design characterised by particular shapes
  • B63B2241/10—Design characterised by particular shapes by particular three dimensional shapes

Definitions

• the invention relates to floating structures, in particular floating structures made up of frames supported by buoyant members. More specifically, the invention relates to floating structures which provide a platform for an installation, such as an array of PV panels, a desalination plant, or an energy storage unit, or for some other type of use.
• the floating structures may be used both inshore, e.g. on rivers or lakes, or offshore.
• conventional floating structures usually comprise a relatively large rigid frame, which is either supported by separate buoyant members or which is made up of hollow elements providing inherent buoyancy. With some exceptions, the frame of a conventional floating structure is usually rectangular. Conventional floating structures have a relatively high wave resistance or drag, leading to relatively high loads on their frames, which must therefore be strong and comparatively heavy.
• Prior art document WO 2017/118998 Al discloses a rectangular floating solar platform which includes a unified floating structure that is formed of a horizontal mesh of one or more horizontal support members connected to each other in a matrix pattern, and one or more vertical support members fixedly mounted on the horizontal mesh.
• the support members may be filled with a lightweight material.
• a horizontal planar modular deck is fixedly mounted on the unified floating structure and supports one or more arrays of solar panels.
• the horizontal mesh which extends under the entire surface of the platform and which is fully submerged, creates undesirably high drag forces.
• Prior art document WO 2017/023536 Al discloses a floating solar array made of a closed loop of flexible high density polyethylene pipes with elbows, T fittings and couplings forming a pontoon.
• An anti-lift membrane fills with water and mitigates the wind forces.
• the array can have a stabilizing skirt going downwardly from the border of the array, especially when it is used offshore in the sea. This arrangement also has a high drag relative to its buoyancy, which drag is further increased by the stabilizing skirt.
• Prior art document KR 101997077 Bl discloses a floating water solar power generation module which comprises: a closed circular or elliptical support frame provided at the outside of a structure; a support net having a rope provided in a lattice shape inside the support frame; an array of solar panels on the support net; and a plurality of rectangular floating bodies coupled to the bottom of the support frame by pairs of posts. Since these rectangular floating bodies are arranged tangential to the circular support structure, there will always be some floating bodies which are perpendicular to the waves, thus generating high drag forces.
• a floating structure which comprises a frame and a plurality of buoyant members connected to and supporting the frame, wherein at least some of the buoyant members may be at least partially formed as a body of revolution of a conic section.
• the buoyant members may be at least partially formed as a body of revolution of a conic section.
• the body of revolution may have a substantially vertical axis of revolution, so that the shape presented by the buoyant member is the same in each direction from which waves may arrive and the wave drag is independent of the orientation of the floating structure. In this way there is no need for any provisions to orient the floating structure in a particular direction, thus simplifying construction and maintenance.
• At least some of the buoyant members may be at least partially formed by an ellipsoid. Contrary to a paraboloid or a hyperboloid, an ellipsoid is closed in itself, which makes it very suitable for forming a buoyant member.
• An ellipsoid has an inherent stiffness and strength which is almost equal to that of a sphere, thus allowing a relatively thin-walled and lightweight structure. Also in terms of surface area per unit volume, an ellipsoid comes very close to a sphere. However, an a ellipsoid has a buoyancy-to-drag ratio that may be up to 50 percent higher than that of a sphere.
• the ellipsoid has a major axis and a minor axis which is perpendicular to the major axis, and wherein the minor axis has a length that is between 25 - 85 percent, preferably between 35 - 70 percent, more preferably between 45 - 60 percent, and most preferably approximately 50 percent of a corresponding length of the major axis.
• the minor axis substantially coincides with the vertical axis of revolution, an oblate ellipsoid is formed.
• Such an oblate ellipsoid has a relatively large diameter and is therefore inherently stable. It provides resistance against upward and downward movement by virtue of its relatively large area.
• the major axis may substantially coincide with the vertical axis of revolution, so that a prolate ellipsoid is formed.
• Such a prolate ellipsoid can have a relatively large underwater volume, thus providing high buoyancy.
• the at least some of the buoyant members may be formed by full ellipsoids. In this way the wave drag of each buoyant member as a whole is minimized.
• the at least some of the buoyant members may comprise an upper semi -ellipsoid, a lower semi-ellipsoid and an intermediate element between the upper and lower semi -ellipsoids.
• the intermediate element between the upper and lower halves of the buoyant member may perform various functions.
• the intermediate element may comprise a disk extending at least partially beyond a periphery of the upper and lower semi-ellipsoids. Such a disk may serve to damp motion of the buoyant member.
• the intermediate element may comprise a cylinder having substantially the same diameter as the upper and lower semi -ellipsoids.
• each buoyant member may comprise an enclosed and watertight internal volume.
• the buoyant members may be constructed from materials that are heavier than water, like e.g. metals, fiber reinforced plastics or even concrete, so that a sturdy structure is obtained which can endure the rigors of offshore operations.
• the buoyant members may be attached directly to the frame, but in an embodiment of the floating structure each buoyant member is connected to the frame by at least one post. In this way the frame and anything mounted on the frame may be kept free from the water in which the structure floats.
• the buoyant member may be connected to the frame by a single post. This leads to a structure that is easy to assemble.
• the single post may be concentric with the axis of revolution of the buoyant member.
• the buoyant member may be connected to the frame by a plurality of posts. In this way the loads can be transferred to various parts of the frame, thus reducing load concentrations.
• the posts may be mounted on a periphery of the buoyant member, so as to avoid a load concentration in a top surface of the buoyant member.
• the at least one post may comprise an enclosed and watertight internal volume. In this way the posts may contribute to the buoyancy of the structure.
• buoyant members are connected to each other only through the frame and/or through the at least one post. In this way there is no connecting structure between the buoyant members at or below the still waterline, which would lead to an increase in drag of the floating structure, generating higher loads and requiring a stronger and heavier structure. Moreover, connections close to the water splash zone or even underwater are sensitive to corrosion and difficult to inspect and repair.
• all buoyant members may be substantially identical. This simplifies construction and assembly of the floating structure. Moreover, it simplifies logistics and leads to a reduction in the amount of stock which in turn results in substantial savings.
• At least some of the buoyant members may include a ballast weight. In that way the buoyancy of each individual buoyant member may be adapted to the part of the weight of the structure that it has to support.
• the ballast In order to load the ballast into the buoyant member, it may comprise at least one opening. Such an opening may also serve to allow inspection of the interior of a buoyant member, regardless of whether it includes ballast weight.
• At least some of the buoyant members may include exterior handling and/or mounting features. This allows parts to be mounted on the buoyant members, and allows the buoyant structures to be handled more easily, e.g. during assembly or transport.
• At least some of the buoyant members may include access features and interior functional features.
• functional features which may be accessible through the access features, may be a battery, a tuned mass damper, a gas or liquid container and associated ducting or plumbing, etc.
• the buoyant member may serve an additional function, besides keeping the frame afloat.
• the number of buoyant members and their volume, as well as a length of the at least one post are selected as a function of the weight of the frame, such that the frame is supported at a distance above a still waterline of a body of water in which the floating structure is used. In this way the frame can be kept free of waves on the body of water on which the structure is floating.
• the invention further provides a buoyant member for use in a floating structure of the type defined above.
• Fig. 1 is a perspective top view of a first embodiment of a floating structure made up of four interconnected triangular frames and supported by a plurality of ellipsoid buoyant members in accordance with the invention
• Fig. 2 is a perspective top view of a second embodiment of the floating structure in accordance with the invention, comprising a rectangular frame having the buoyant members directly attached;
• Fig. 3 is a view corresponding with that of Fig. 1 , but showing each triangular frame of the floating structure supporting an array of PV panels;
• Fig. 4 is a perspective bottom view of the floating structure supporting PV panels as shown in Fig. 3;
• Fig. 5 is a rear view of the first embodiment of the floating structure according to arrow V in Fig. 1 ;
• Fig. 6 is a side view of the first embodiment of the floating structure supporting PV panels according to arrow VI in Fig. 3, showing an exemplary still waterline around the buoyant members;
• Fig. 7 is a perspective view of an ellipsoid showing the major and minor axes
• Fig. 8 is a perspective view of an oblate ellipsoid buoyant member as used in the first embodiment of the floating structure;
• Fig. 9 is a view corresponding with that of Fig. 8 of a second embodiment of the buoyant member
• Fig. 10 is a perspective view of third embodiment of the buoyant member having an intermediate cylindrical segment between upper and lower semi-ellipsoids;
• Fig. 11 is a side view of the buoyant member of Fig. 10;
• Fig. 12 is a longitudinal sectional view of a variant of the third embodiment of the buoyant member
• Fig. 13 is a longitudinal sectional view of the upper semi -ellipsoid part of the buoyant member of Fig. 12;
• Fig. 14 is a is a view corresponding with that of Figs. 8 and 9 of a prolate ellipsoid buoyant member as used in a fourth embodiment of the buoyant member; and
• Fig. 15 is a side view of the buoyant member of Fig. 14.
• An embodiment of a floating structure 1 as illustrated in Fig. 1 comprises a plurality of frames 2 which are mutually connected along their adjacent edges.
• Each frame 2 is supported by one or more - in this embodiment three - buoyant members 3.
• each buoyant member 3 is connected to the triangular frame 2 by a post 6.
• the three buoyant members 3 are shown to be connected to the respective frame 2 near a corner 7 of the frame 2, i.e. near one of the three angles of the triangle forming the frame 2.
• all three buoyant members 3 are identical, but if so required, e.g. because of uneven loading of the frame 2, the buoyant members could have different shapes and/or dimensions.
• Adjacent triangular frames 2 are connected such as to be movable with respect to one another, so that the floating structure 1 has some degree of flexibility.
• adjacent triangular frames 2 are pivotably connected.
• the frames 2 may be provided with pivotable connecting elements 19, in this case two connecting elements 19 near the corners 7.
• the pivotable connections between the frames 2 lead to the formation of an articulated floating structure 1 , in which the triangular frames 2 can follow movement of waves when the structure 1 is floating on a body of water.
• the structure of the triangular frames is described in detail in the applicant’s co-pending application entitled: “Articulated floating structure”.
• the buoyant members 3 have the shape of an oblate ellipsoid, i.e. a body of revolution about a vertical axis on the basis of an ellipse having a major axis a, b which is horizontal and a minor axis c which is vertical (Fig. 7).
• Such an ellipsoid-shaped buoyant member 3 has been found to have a relatively low wave drag in relation to its volume and buoyancy. As a result, loads on each frame 2 supported by ellipsoidal buoyant members 3 will be relatively low and the structure of the frame 2 may be lightweight.
• the buoyant members 3 are shown to be fully submerged in this embodiment (Fig. 6). However, it is also possible to give each buoyant member 3 a greater volume, so that it provides the required buoyancy even when it is only partially submerged. In that case the potential reserve buoyancy that may be generated when the buoyant member 3 is submerged to a greater extent than necessary for carrying the frame 2 may be used to increase dynamic stability of the floating structure 1. This reserve buoyancy will counter a downward movement of part of the triangular frame 2 when one side of the frame 2 is lifted by an approaching wave. Especially in cases where oversized buoyant members 3 are used to provide reserve buoyancy for increased dynamic stability, it is important to reduce the buoyancy-to-drag ratio as far as possible.
• An ellipsoid as shown here is an example of a body of revolution of a conic section. Other examples of such bodies of revolution are a paraboloid or a hyperboloid.
• the axis of revolution A is the minor axis c of the ellipsoid.
• the ellipsoid will be rotation symmetric about the minor axis c and will have a circular planform. In this way the buoyant member will have uniform flow characteristics in all directions so that the drag of the floating structure is independent of its orientation with respect to the waves.
• the major axes a and b are not equal, the buoyant member will be elliptical not only in side view, but also in top view.
• the ellipsoid buoyant member 3 When all three axes a, b and c are equal, the ellipsoid buoyant member 3 will in fact be spherical. However, although a spherical buoyant member has the lowest surface area per unit volume, and is therefore inherently stiff and strong, so that it can be thin-walled and lightweight, such a spherical buoyant member has been found to have a considerably higher drag than an ellipsoid buoyant member of which the three axes a, b and c are not equal.
• the ellipsoid is a body of revolution about the minor axis of the ellipse, which results in a shape that is generally horizontally oriented and relatively flat, an oblate ellipsoid.
• This shape ensures good stability for the buoyant member 3, since an oblate ellipsoid will follow the surface of the water in which it floats.
• Its relatively flat shape leads to a substantial resistance to vertical movement into or out of the water, which means that the risk of the water reaching a frame supported by the oblate ellipsoid is limited. Consequently, the frame 2 can be arranged closer to the buoyant member 3, thus reducing the total height of the floating structure 1.
• the ratio between the length of the major axis and the length of the minor axis may be varied, depending on the requirements.
• the minor axis is substantially shorter than the major axis, and its length is in the order of half of the length of the major axis, but other ratios are conceivable as well.
• the ratio between the major axis and the minor axis becomes very large, a very slender, almost tubular shape will result. Such a shape is not efficient in terms of buoyancy-to-drag ratio, since it has a relatively large surface area per unit volume, and moreover requires additional stiffening and strengthening.
• the ellipsoid buoyant member 3 may comprise an enclosed and watertight internal volume 21 to provide buoyancy. This allows the structure of the buoyant member 3 to be made from a material that is heavier than water, such as a metal, a plastic, a fibre reinforced composite or even concrete.
• the internal volume 21 might be filled with a lightweight material, like e.g. a plastic foam, in order to maintain buoyancy if the structural integrity of the buoyant member 3 is compromised.
• the buoyant member 3 comprise an upper semi-ellipsoid 22 and a lower semi-ellipsoid 23, which are connected at an equatorial joint line 27 (Fig. 8). The connection may be by welding, by an adhesive, or by mechanical means, e.g.
• the ellipsoid buoyant member 3 carries a post 6 for connection to the frame 2.
• a post 6 for connection to the frame 2.
• the central post 6 can have a flange 34 at its lower end (Figs. 14, 15) and can be attached to the buoyant member 3 by welding, by an adhesive connection or by mechanical connecting members, e.g. bolts between the flange 34 of the post 6 and a flange 35 on top of the upper semi-ellipsoid 22.
• the post 6 may further comprise an enclosed and watertight internal volume, so as to add buoyancy.
• an intermediate element 24 can be arranged between the upper and lower semi -ellipsoids 22, 23 (Fig. 9).
• the intermediate element 24 comprises a disk which extends beyond a periphery of the upper and lower semi-ellipsoids 22, 23.
• the disk may be circular or annular, and may be concentric with the upper and lower semi-ellipsoids 22, 23, so that the combination of ellipsoid buoyant member 23 and disk 24 is symmetric about axis A and will have uniform flow characteristics in all directions.
• the disk 24 may serve as a damping element which will resist oscillating movement of the buoyant member 3 in the water by increasing resistance to flow around the equatorial joint line 27 in vertical direction. In this way additional dynamic stability can be generated.
• the ellipsoid was a body of revolution about the minor axis of the ellipse.
• the ellipsoid is a body of revolution about the major axis of the ellipse.
• the axis A of revolution is vertical, and the buoyant member 3 has the shape of a prolate ellipsoid, which has a generally vertical orientation and is relatively high.
• a prolate ellipsoid has less resistance to vertical movement in the water than an oblate ellipsoid, and will therefore maintain its vertical orientation, rather than following the movement of the surface of the water.
• the buoyant member 3 again comprises an upper semi-ellipsoid 22 and a lower semi-ellipsoid 23, which are connected at an equatorial joint line 27 by any of the connecting techniques discussed above.
• the central post 6 has a flange 34 at its lower end for attachment to a flange 35 on top of the upper semi -ellipsoid 22. If so required, the post 6 may again comprise an enclosed and watertight internal volume, so as to add buoyancy.
• This embodiment on the basis of a prolate ellipsoid may be used in situations where a relatively high amount of buoyancy is required under a relatively small frame. It has a similarly high buoyancy-to- drag ratio as the previous embodiments on the basis of an oblate ellipsoid.
• the intermediate element 24 comprises a cylinder 25 having the same diameter as the upper and lower semi-ellipsoids 22, 23 (Fig. 10).
• the volume and buoyancy of the buoyant member 3 may be increased, without substantially affecting the favorable hydrodynamic characteristics of the ellipsoid shape.
• This embodiment of the buoyant member 3 has a slightly lower buoyancy-to-drag ratio than a prolate ellipsoid having a similar volume and orientation, but is easier to manufacture.
• the intermediate element 24 could also comprise e.g. two oppositely oriented conical segments. This would allow the buoyant member 3 to be divided along its equatorial plane and then stored or transported efficiently by stacking or nesting the two halves. The same effect could be achieved by any shape having its greatest dimension along the equatorial plane.
• the upper semi -ellipsoid 22 is attached to the cylinder 24 along an upper joint line 27U, while the lower semi-ellipsoid 23 is attached to the cylinder 25 along a lower joint line 27L.
• the buoyant member is made of metal and the connections between the various parts are made by welding, but other materials and other connecting techniques are conceivable as well..
• a stiffening ring 28U may be arranged on the upper joint line 27U, and the upper semi -ellipsoid 22 and the cylinder 25 may be welded to an upper and lower surface, respectively, of the stiffening ring 28U (Fig. 12).
• a stiffening ring 28L may be arranged on the lower joint line 27U between the lower semi-ellipsoid 23 and the cylinder 25, and may be welded on opposite sides to these parts.
• the upper stiffening ring 28U may include three protruding lugs 26 which may serve as attachment points for three posts 6A-C.
• these posts 6A-C which may be attached to the lugs 26 by welding, by an adhesive or by mechanical fasteners, are arranged on the periphery of the buoyant member 3.
• the posts 6A-C which connect the buoyant member 3 to the frame 2, will thus transfer the substantially vertical loads from the frame 2 directly into the vertical cylinder 25, thereby avoiding any loads substantially perpendicular to the upper semi -ellipsoid 22.
• the number of lugs 26 and posts 6 may be varied, depending on structural requirements.
• the posts 6 might be reinforced by e.g. bracing to adjacent posts 6.
• the buoyant member 3 is substantially “square” in side view, having a total height H, i.e. a distance between centers of the upper and lower semi-ellipsoids 22, 23, which is substantially equal to the diameter D of the upper and lower semi-ellipsoids 22, 23 and cylinder 25.
• the diameter D and height H may e.g. be 2 m, resulting in an internal volume of approximately 5 m 3 and a buoyancy of approximately 50 kN in water.
• the buoyancy provided by an ellipsoid member 3 without the cylindrical section 25, i.e. having only the upper and lower semi-ellipsoids 22, 23 would be less than half of this value.
• the dimensions may be varied, depending on the dimensions and weight of the frame 2. In particular by varying the height of the cylinder 25, the buoyancy may be varied in a simple manner.
• the upper and lower semi-ellipsoids 22, 23 do not have a purely elliptical contour, but are formed by two spherical segments 32, 33 having very different radii.
• the radius KR of the so-called “knuckle” segment 33 is less than a fifth of the radius CR of the “crown” segment 32.
• the radius CR of the crown 32 is 80 percent of the diameter D of the buoyant member 3, while the knuckle radius KR is some 15 percent of the diameter D.
• This semi-ellipsoid shape is one of a family of similar shapes defined in German industrial norms, in this case DIN 28013.
• This composite spherical shape is easier to manufacture than a purely elliptical shape, while still having substantially the same contour, and consequently also substantially the same hydrodynamic characteristics.
• the term “semiellipsoid” or semi-elliptical is used in this application, that term also covers such contours constituted by spherical segments having different radii.
• these shapes may also be made from different materials, like e.g. fiber reinforced composites or plastics.
• the buoyant member 3 includes an opening 29 in the upper semi -ellipsoid 22, which is bordered by an inverse L-shaped flange 30 and closed off by a cover 31.
• the cover 31 is attached to the flange by a plurality of fasteners, e.g. bolts, and a watertight seal or gasket (not shown) is clamped between the flange 30 and cover 31.
• the opening 29 allows access to the interior of the buoyant member 3, e.g. for inspection or maintenance purposes.
• ballast could be introduced into the internal volume 21 through this opening. Ballast may be used to trim the frame 2, e.g. when the buoyant members 3 are identical while the frame 2 is unevenly loaded, and/or to adjust stability and dynamic properties of the floating structure.
• purely ellipsoid buoyant members 3 of Figs. 8, 9, 14 and 15 could also be provided with an opening, and could also include ballast.
• one or more buoyant members 3 could also be provided with a tuned mass damper arranged in the interior.
• a tuned mass damper could include a mass suspended from a top of the buoyant member 3 by a spring, and possibly also guided with respect to the sides of the buoyant member 3. The mass damper would provide a similar damping effect as the intermediate disk 24 discussed above, but would add less mass to the buoyant member 3, and would not affect the natural frequency of the buoyant member 3.
• the buoyant member 3 could be provided with further handling and/or mounting features arranged on the upper semi-ellipsoid 22 or on the cylindrical segment 25.
• the buoyant member 3 could also be provided with e.g. a mounting ring on the lower semi-ellipsoid for attaching anchoring means, as will be discussed below.
• Similar handling and/or mounting features could be provided on the purely ellipsoid buoyant members 3 of Figs. 8, 9, 14 and 15.
• each triangular frame 2 supported by the buoyant members 3 has an open load-bearing structure comprising three beams 14, which are connected at their ends.
• an internal grid 15 may be arranged between the load-bearing beams 14.
• the internal grid 15 includes four longitudinal girders 16 and a transverse girder 17.
• the internal grid 14 not only serves to support an installation, but also forms a connection between the buoyant members 3 and the load-bearing frame 2, since the posts 6 are shown to be connected to the outer longitudinal girders 16 and to the transverse girder 17 (Fig. 4).
• one of the posts 6A-C of the buoyant member 3 of Figs 10-13 could also be connected to one of the girders 16, 17, while the other two posts could then be connected to the beams 14.
• the floating structure 1 supports a solar power generating installation.
• the installation comprises a plurality of arrays of PV panels (Fig. 3).
• each triangular frame 2 carries a substantially triangular array 4 of PV panels.
• the PV panels are shown to be arranged in rows 5, the length of which decreases from the base 11 towards the apex 13 of the triangle.
• adjacent rows 5 are arranged in the shape of a rooftop, and walkways 18 are shown to be arranged between each pair of rows 5.
• each triangular frame 2 is covered by the array 4 of PV panels, it is also conceivable to reserve a part of the surface area for other parts of the installation, like e.g. control electronics, a transformer or batteries for storage.
• the floating structure 1 could be made up of triangular frames 2 carrying PV panels and one or more triangular frames 2 carrying other parts of the installation.
• the floating structure 1 could carry a different type of installation, e.g. a desalination plant, or an energy storage unit, e.g. an array of batteries.
• Other possible uses for the floating structure are the generation of wind energy through one or more turbines, or the generation of wave energy.
• a further floating structure could support energy intensive activities, like e.g. a hydrogen production unit, a hydrogen-to-fuel conversion plant, or a data center.
• the floating structure could also be used for urbanization, i.e. housing and/or recreation, for agriculture or for aquaculture.
• the floating structure could be used as an offshore mooring or satellite port, where ships could load or offload cargo or supplies, in particular fluidic cargo that can be brought ashore through pipelines.
• the interior of one or more of the buoyant members 3 could be put to practical use, e.g. as a storage compartment for gas or even liquid - which would then at the same time serve as ballast.
• batteries could be accommodated in the interior of one or more buoyant members 3, serving at once as energy storage and as ballast.
• the favorable flow characteristics of the buoyant members 3 of the invention lead to a reduction of hydrodynamic loads on the frame 2. Loads on the frame 2 are further reduced by keeping the frame 2 free of the water during normal use. Moreover, in this way the installation carried by the floating structure, in this case the array 4 of PV panels, is also protected from adverse effects due to the impact of waves. As shown in Fig. 6, the buoyant members 3 are almost fully submerged below the still waterline WL, while the frame 2 is supported at a height h above the still waterline. This is achieved by careful selection of the number of buoyant members 3 and their volume, as well as the length of the posts 6 as a function of the weight of each respective triangular frame 2 and the array 4 of PV panels which it supports.
• the number and volume of the buoyant members 3 could be selected such that they are only partially submerged, e.g. such that the still waterline WL substantially coincides with the equatorial line 27 of each buoyant member 3.
• the height h above the waterline WL is selected in accordance with the intended use. For inland waters, like lakes or even rivers, where wave heights will be limited, a free height of 1-2 m may be sufficient, whereas for offshore applications much higher structures, possibly with the frames 2 up to 25 m above the still waterline WL may be needed.
• the hydrodynamic loads on the frames 2 are further reduced by the fact that the only parts of the floating structure which are submerged are the buoyant members 3, and possibly parts of the posts 6. There is no structure connecting the buoyant members 3 below the still waterline WL, since the buoyant members 3 are connected to each other only indirectly, i.e. through the frame 2 and through the posts 6.
• the buoyant members 3 may be directly connected to the frame 2, as shown in the embodiment of Fig. 2.
• the floating structure 1 consists of a single frame 2, which is rectangular and which is formed by a plurality of parallel beams 14 running perpendicular to the rows of PV panels 5.
• the floating structure 1 may further be provided with anchoring means for maintaining the floating structure 1 substantially at a fixed location in a body of water.
• the anchoring means may e.g. include so-called spud poles, which are driven into the bottom of the body of water and along which the structure 1 can float up and down without changing its orientation.
• the anchoring means could include one or more anchors fixed in the bottom, to which the floating structure 1 could be connected by chains or other flexible elements, so that the structure could change its orientation, e.g. to keep the PV panels in an optimum position relative to the sun.
• the floating structure When used on relatively smaller inland waters, the floating structure could also be anchored to the shore.
• the number of buoyant members supporting a frame could be more or less than three.
• each buoyant member must be inherently stable, e.g. in the way of a float used for fishing.
• other shapes than ellipsoids could be used for the buoyant members 3, e.g. paraboloids or hyperboloids.
• the buoyant members 3 could be connected to the frame 2 by other structures, like e.g. inclined posts or truss beams.
• Any suitable material can be used in the construction of the frames 2, the buoyant members 3 and the posts 6. Such materials include aluminum, steel, concrete or plastics, which may or may not be fiber reinforced.

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• 2020
  • 2020-12-23 EP EP20838563.3A patent/EP4267454A1/de active Pending
  • 2020-12-23 WO PCT/EP2020/087840 patent/WO2022135729A1/en unknown

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