PHOTOVOLTAIC FACILITY AND METHOD

Abstract

Photovoltaic installation comprising a vertical structure, a plurality of photovoltaic elements, every photovoltaic element comprising a cantilever beam carrying photovoltaic panels, the beam being affixed to the vertical structure, characterized in that the beams include blades of reused horizontal axis wind turbines or sections blades of reused horizontal axis wind turbines. The vertical structure is preferably a mast of a horizontal axis wind turbine in service.

Claims

1. A Photovoltaic installation comprising a vertical structure, a plurality of photovoltaic modules, each photovoltaic module comprising at least one cantilever beam held by the vertical structure as well as a plurality of photovoltaic panels held by the beam, characterized in that the beams include reused blades of horizontal-axis wind turbines or sections of reused blades of horizontal-axis wind turbines.

2. The photovoltaic installation of claim 1, comprising a plurality of collars on the vertical structure, the collars being pivotable around the axis of the vertical structure, the photovoltaic modules being assembled through the beams on the collars.

3. The photovoltaic installation of claim 1, wherein the vertical structure is a mast of a horizontal-axis wind turbine, or a stump of a mast of an not in service, or a vertical structure surrounding a mast of an horizontal-axis wind turbine, and wherein the vertical structure rests on a foundation basement of the horizontal-axis wind turbine.

4. The photovoltaic installation of claim 1, wherein the beams are pivotable around the vertical structures and are affixed at several heights around the vertical structure so as to allow an open configuration, in which the beams are distributed around the vertical structure and a folded configuration in which the beams are vertically aligned and superposed presenting a higher resistance to loads induced by snow and wind.

5. The photovoltaic installation of claim 4, including a secondary support post supporting the installation in the folded configuration.

6. The photovoltaic installation of claim 5, comprising an upper photovoltaic module not pivotable with a beam that has one extremity resting on the vertical structure and a second extremity resting on the secondary support post.

7. The photovoltaic installation of claim 6, wherein the photovoltaic modules rest on the secondary support post in the folded configuration.

8. The photovoltaic installation of claim 1, wherein the photovoltaic panels of each photovoltaic module are arranged in a plane.

9. The photovoltaic installation of claim 1, wherein the beams are inclinable with respect to the horizontal by pivoting around a horizontal axis.

10. The photovoltaic installation of claim 1, wherein the photovoltaic panels are bifacial.

11. The photovoltaic installation of claim 1, each photovoltaic module comprising a plurality of horizontal crosspieces affixed on the beam by their middle at right angle, each crosspiece carrying a double row of horizontal photovoltaic panels.

12. Photovoltaic installation according to claim 1, each crosspiece having in its middle a clamping structure configured to clamp the blade included in the beam.

13. A method of building a photovoltaic installation comprising the steps of: provide a plurality of blades of horizontal-axis wind turbines or sections of horizontal-axis wind turbines that constitute cantilever beams, assemble a plurality of photovoltaic modules each including a set of photovoltaic panels connected to a beam or to more than one beams, connect an extremity of the beams to a vertical structure to support the photovoltaic modules.

14. The method of claim 13, comprising the installation of a plurality of collars on the vertical structure 41, 42, 91), the collar being pivotable around a vertical axis, wherein the end of the cantilever beams are linked to the collars.

15. The method of claim 14, comprising the provision of a secondary vertical support post downwind of the vertical structure with respect to a prevailing wind direction, installation of a non-pivotable collar above the pivotable collars, installation of a fixed photovoltaic module whose beam is supported by the vertical structure and by the secondary vertical support post.

Description

SHORT DESCRIPTION OF THE DRAWINGS

[0024] This disclosure shows examples of realization of the invention illustrated by the drawings in which:

[0025] FIGS. 1a et 1b show a photovoltaic installation according to the invention installed on a mast of a wind turbine, in an open configuration.

[0026] FIG. 2 shows the photovoltaic installation of the invention in a compact configuration.

[0027] FIG. 3 shows a photovoltaic module mounted on a wind turbine’s blade.

[0028] FIG. 4 shows some advantages of the photovoltaic installation of the invention in function on a mast of a wind turbine.

[0029] FIG. 5 shows the photovoltaic installation of the invention after the end of life of the associated wind turbine.

[0030] FIG. 6 shows a variant of the invention.

[0031] FIG. 7 shows a variant of the invention with an auxiliary support post FIG. 8 shows an alternative arrangement of the photovoltaic module of the invention on a reused blade of a wind turbine.

[0032] FIG. 9 shows a possible way of connecting a blade of a horizontal axis wind turbine and the photovoltaic module of the invention.

[0033] FIG. 10 shows an example of the invention with a shell surrounding the mast of a wind turbine to support the photovoltaic modules.

[0034] In the figures, remarkable elements are identified by reference signs that are repeated in the text. The same reference sign is used to identify distinct elements that are identical or functionally equivalent. When many instances of an element are present, they are only in part identified by a sign to avoid overcrowding the figures.

EXAMPLES OF EMBODIMENTS OF THE INVENTION

[0035] FIG. 1a shows an example of a hybrid site producing energy and comprising a wind turbine and a photovoltaic installation according to the invention. The wind turbine is of the horizontal axis variety with a mast 41 atop of which sits a nacelle 43 that hosts the electric machines needed to convert the kinetic energy of the rotor 45 into electricity. The wind turbine of FIG. 1a is a non-limiting example. The invention could be applied to masts of wind turbines with a different structure, for example double-rotor turbines.

[0036] The photovoltaic installation foresees a plurality of modules 16, preferably identical, one whereof is shown by FIG. 3 as example. Each module is carried by a structure ideally constituted by a reused blade of a wind turbine 25, or by a section of a blade of a wind turbine, that is connected cantilever-fashion to the vertical structure 41. Advantageously, blades of wind turbines can withstand very high static and dynamic loads, even after many years of service, and can carry very well a considerable surface of solar panels 18.

[0037] In a variant of the invention the solar panels 18 of the modules 16 are flat structures, also called “leaves”, as shown by FIG. 3. Solar panels 18 are preferably bifacial to collect, in addition to the direct solar rays, also the light diffused by the ground, the vegetation, and the snow.

[0038] FIG. 3 shows modules 16 comprising a single beam 25 each. The invention includes however also variants, not illustrated, with several beams in each module 16. The beams can be placed parallel, in a “V” shape, or any suitable arrangement and can have one or more blades of wind turbine or sections of blades of wind turbines. The blades of wind turbines can contribute also to the constructions of the ribs 26 or of the frame 28.

[0039] Even discounting the shadow cast by the mast 41 and the rotor 45, the solar irradiation conditions of the wind turbines are often excellent. The sites of installation of the wind turbines are connected to the power network and usually have an access route, which favours the installation of photovoltaic systems considerably. Moreover, the energy generated by the photovoltaic panels can be used by the wind turbine when there is a calm in the wind, to power service equipment or start the rotor if withdrawing the needed energy from the electric network is not possible or desirable.

[0040] The photovoltaic installation can be conceivably also coupled to an energy stockage system, for example an electrolyser to generate hydrogen, pumps to lift water in a suitable reservoir, batteries or any other stockage system. The energy can also be used on site, for example to desalinate sea water.

[0041] The structure of the photovoltaic “leaf” 16 allows advantageously to fold the modules and/or recuce the photovoltaic surface, as shown in FIGS. 1a, 1b et 2. To this effect, modules 16 are mounted at different levels on supporting collars 23, capable of overlapping each other. The active surface of the installation can then be changed by pivoting the collars about the vertical axis 71 (see FIG. 1b) of mast 41 or of the vertical support structure. FIGS. 1a and 1b show a fully open configuration that maximises the active surface, while FIG. 2 show a possible folded configuration, minimising the windage or the snow cover, for example. Possibly, this folded structure can rest in part on a support post, not shown in the figure, to stand higher loads in this configuration.

[0042] Figures show two solar modules on each collar 23. Such an organization is balanced and reduces the height of the structure, but other variants are possible, which leads to a more compact folding, in which each collar carries only one photovoltaic “leaf” 16. One could also imagine variant with two, three, four or more “leaves” 16 per collar.

[0043] The motion of collars 23 and modules 16 is provided by electric motors, preferably under remote control, not shown.

[0044] The photovoltaic installation of the invention offers many advantages. FIG. 4 shows a hybrid installation according to the invention: panels 18 cover an ample area 50 at the foot the mast 41 that is protected from sunlight, and from frost. It can be used as shaded area for cattle, for horticulture, to protect ski slopes or hiking trails from falls of ice. Solar modules 15 Also provide a considerable attenuation, in a limited zone, of the noise generated by the rotor 45.

[0045] In addition, the photovoltaic structure of the invention can be useful also to study the collisions between birds or bats and the turbine’s rotor. Such studies are normally difficult and expensive due to the vegetable cover and require regular cuts of the grass at the foot of the mast. Thanks to the invention, the victims of chocs fall on the solar panels (arrow 60) where they can easily be counted and classified visually.

[0046] At the end of the technical life of the wind turbine, the mast and the electric machines are recycled. Foundations, however, are often left in place, or else only the upper layer of the foundations are dismantled. A stump 42 of mast could advantageously be preserved to carry the photovoltaic installation and continue the production of electricity, as seen in FIG. 5.

[0047] The movement of the photovoltaic modules is not limited to a pivoting about the vertical axis. In conceivable variants, the photovoltaic modules can be inclined with respect the horizontal as shown in FIG. 6. To simplify the drawing, FIG. 6 shows only four blades 25 without the covering of photovoltaic panels 18. In this example the photovoltaic modules turn about an axis 73 (see FIG. 3) orthogonal to the longitudinal axis of the blades 25, but in possible variants the photovoltaic modules could also pivot on the longitudinal axis 72 of the blades 25.

[0048] A possible variant of the invention foresees the installation of the photovoltaic modules on a mast of a wind turbine as disclosed above, on beams on any nature, if blades of a wind turbine having the desired properties are not available. Preferably the beams are made of metal, wood, or a material that is recyclable or reusable.

[0049] FIG. 7 shows a variant of the invention with an off-centre post that provide a secondary support to the folded configuration. The installation has eight superposed photovoltaic modules 16, each with a reused blade of a wind turbine 25 that makes a horizontal beam. It shall be understood that these numbers are not essential features, and that the installation could have more modules, or less. The upper collar 24 is fixed and the topmost photovoltaic module rests by all the time on the collar 24 which is attached to the mast 41 on one end and on the secondary post 48 at the other end opposed. The secondary post 48 is preferably placed downwind of the mast 41 considering the direction of the prevalent wind, in a position that does not interfere with the operation and with the maintenance of the wind turbine.

[0050] When the collars support only one photovoltaic module, as shown, a counterweight 21 can be provided in a diametrically opposed position to the root of the blade 25 to balance each level. That is not essential, however: the collars could carry each two or more modules and in some cases the counterweight could be dispensed with.

[0051] Collars 23 below collar 24 can turn about the vertical axis of the mast 41 and have each a photovoltaic module 16. The beams 25 are reused blades of horizontal axis wind turbines, and each blade 25 is fixed on a collar 24, for example by the root fixture already existing, foreseen initially to mount the blade on the hub of the wind turbine.

[0052] The photovoltaic modules carried by the collars 23 can take the folded configuration as shown in the figure, with all the modules overlapping and covered by the uppermost immovable module, as well as an open configuration in which the photovoltaic modules are regularly spaced to maximise the light collection. Preferably, in the folded configuration shown, the photovoltaic module rest on the secondary support 48, as well as being held by the mast 41. This can be obtained by rests regularly spaced on the secondary post, or by any other suitable means.

[0053] The motion of the turning collars 23 can be obtained in many ways. A favourable solution consists in driving the lowermost collar with a motor-reducer group 83 sweeping an angle of 315°, wherein the lowermost collar drives in succession the upper collars by progressively diminishing arcs of 270°, 225°, 180°, 135°, 90°, 45°, which provides a regular distribution with eight modules at equal angles. Stops (not visible) are foreseen to transmit the rotation of a collar to the collar immediately above along the desired sectors of angle. Nevertheless, there are other possible solutions. It may be possible and advantageous to reuse the electric motors used for the yaw of the nacelles of the wind turbine to drive the solar installation of the invention, since the performances needed in both applications are not dissimilar.

[0054] The space between the lowermost collar and the ground level can be protected by a shelter 80 that defines a technical and maintenance room for the electric and mechanic machines needed to the good operation of the solar installation. This shelter may protect the inverters required to transfer the photovoltaic power on an AC network, as well as the motor 83.

[0055] FIG. 8 shows an arrangement of the photovoltaic panel in a photovoltaic module that is alternative to that of the FIG. 3. In this variant, the blade 25 has many horizontal crosspieces 26 that cross the blate at right angle and are regularly spaced on its length. Each crosspiece 26 is fixed on the blade 25, for example by structures 27 that claim the blade 25 resting on its upper face and on its lower face, as represented in FIG. 9. The crosspieces extend symmetrically on both sides of the blade 25. The clamping geometry is designed having regard to the internal structure of the blade of the wind turbine 25, especially in consideration of the position of the internal reinforcements (shown summarily in section).

[0056] Each crosspiece is equipped by a double row of photovoltaic panels 18. Advantageously, the crosspieces are independent one form the other and can follow the unavoidable flexions of the blade 25 without transmitting dangerous stresses to the panels 18.

[0057] FIG. 10 shows schematically a variant of the invention in which a mast 41 of a horizontal axis wind turbine is girdled by a shell 91. The shell 91 is placed around the mast 41 before the mounting of the collars 23 and of the photovoltaic modules 16, such that the collars 23 are supported by the shell 91 rather than immediately by the mast 41. Advantageously, the shell does not follow the movements of flexion and oscillation of the mast 41. To insulate mechanically the shell 61 from the mast 41, the former is preferably connected to the mast only at the bottom end or affixed directly on the foundation basement 49 without direct contact with the mast 41.

[0058] Advantageously, when the wind turbine reaches the end of its useful life, the mast 41 can be dismounted completely and recycled, while the photovoltaic installation remains in place, on the shell 91.

[0059] All the variants of the invention disclosed herein can be equipped of a shell as hereby illustrated, with the advantage, among others, of a more precise rotation of the photovoltaic modules in situation of violent wind. The shell 91 or, in its absence, the mast 41, can have notches 95 defining the position of the photovoltaic modules in the open configuration.

TABLE-US-00001 Reference numbers used in the drawings 15 photovoltaic installation 16 photovoltaic module 18 photovoltaic panels 21 counterweight 23 pivotable collar 24 fixed collar 25 reused blade of wind turbine, beam 26 rib 27 clamping means 28 frame 41 mast 42 vertical structure, stump of a mast 43 nacelle 45 blade of wind turbine in service, rotor 48 support post 49 foundation basement 50 protected zone 60 fall 71 vertical axis 72 longitudinal beam’s axis 73 transversal beam’s axis 80 shelter 83 motor 91 shell 95 notches