Solar power collection system

Abstract

Solar power collection system (10) comprising: a support structure (11) formed of support poles (12) fixed to the ground; a network of tie rods (13) that maintain said support poles (12) in position; a plurality of solar power collection devices (16, 30); a solar movement system (25, 32) for moving said plurality of solar power collection devices (16, 30); said support structure (11) comprises linear structural elements (14) that connect said support poles (12); said plurality of solar power collection devices (16, 30) are movably fixed onto said linear structural elements (14); characterised in that said linear structural elements (14) intersect with each other to form intersections (15); said plurality of solar power collection devices (16, 30) are fixed onto said linear structural elements (14) at said intersections (15).

Description

[0001] “SOLAR POWER COLLECTION SYSTEM” DESCRIPTION

[0002] The present invention relates to a solar power collection system comprising a two-axis solar tracker capable of maintaining the solar power collection devices correctly oriented towards the sun, in particular it relates to a solar power collection system using photovoltaic panels.

[0003] The present invention also relates to a solar tracker.

[0004] Solar power collection devices means photovoltaic panels, thermal panels or solar concentrators.

[0005] Solar trackers normally have two degrees of freedom, thanks to which they align perfectly in real time a perpendicular line that goes from the photovoltaic panels to the solar rays.

[0006] Large-sized solar power collection systems normally need sturdy support structures, which are therefore cumbersome.

[0007] Furthermore, if these systems are positioned on an agricultural surface, said surface cannot be worked, unless the solar power collection devices are positioned raised, leaving the possibility of using such land for its original purposes, namely agricultural crops or grazing of livestock.

[0008] It should also be remembered that large-sized systems offer high resistance to winds, with the risks of breakage and interruption of power collection.

[0009] The object of the present invention is to provide a solar power collection system that is simple in its construction and in its operation. Another object is to provide a system which is lightweight.

[0010] A further object is to provide a system that allows full working of the underlying land.

[0011] Another object is to provide a system which is modular.

[0012] In accordance with the present invention, these objects and yet others are achieved by a solar power collection system comprising: a support structure formed of support poles fixed to the ground; a network of tie rods that maintain said support poles in position; a plurality of solar power collection devices; a solar movement system for moving said plurality of solar power collection devices; said support structure comprises linear structural elements that connect said support poles; said plurality of solar power collection devices are movably fixed onto said linear structural elements; characterised in that said linear structural elements intersect with each other to form intersections; said plurality of solar power collection devices are fixed onto said linear structural elements at said intersections.

[0013] These objects are also achieved by a solar tracker comprising: a solar power collection device; a solar movement system for moving said solar power collection device; said solar movement system comprises a circular guide having a U-shaped section turned towards the inside of said circular guide to form a guide for said rollers; said circular guide being positioned so that said rollers rotate inside said guide; said power collection device is fixed on a first side by means of two hinges to said circular guide; said power collection device is fixed on a second side to a movement system for inclining said power collection device.

[0014] Further characteristics of the invention are described in the dependent claims.

[0015] This solution has various advantages with respect to the solutions of the prior art.

[0016] The solar power collection system thus obtained has a simple and lightweight support structure.

[0017] Ropes or rods are used to support the panels and the relative tracker, and the support structure therefore offers a reduced resistance to the wind.

[0018] Movement of the panels in the two directions is very simple and efficient.

[0019] With the present invention, which uses support rods having a minimum height of 4-5 metres, it is possible to install large systems on agricultural surfaces while still keeping the land usable for its primary purpose of growing crops.

[0020] This is obtained by positioning the solar panels at a certain height from the ground, without however using critical or complex and / or cumbersome load-bearing structures.

[0021] The solution uses very thin poles, maintained in position by tie rods, leaving as much space as possible for crops.

[0022] The supports of the photovoltaic panels, like the trackers, also have reduced dimensions and are made from open structures that allow the sun to pass through to the underlying crops.

[0023] The support structure, formed of uprights and tie rods, does not need foundation works in reinforced concrete, which impact significantly on the underlying land and are difficult to remove at the end of the system's operating life. The underlying crops are not excessively disturbed by the support structure.

[0024] Further characteristics and advantages of the present invention will become more apparent from the following detailed description of a practical embodiment thereof, illustrated by way of a non-limiting example in the appended drawings, in which:

[0025] Figure 1 schematically shows a solar power collection system, in accordance with the present invention;

[0026] Figure 2 schematically shows a tracker of a solar power collection system, in accordance with a first embodiment of the present invention;

[0027] Figure 3 schematically shows a tracker of a solar power collection system, in accordance with a second embodiment of the present invention;

[0028] Figure 4 schematically shows a device for adjusting the inclination of a solar power collection device, in accordance with a first embodiment of the present invention;

[0029] Figure 5 schematically shows a device for adjusting the inclination of a solar power collection device, in accordance with a second embodiment of the present invention;

[0030] Figure 6 schematically shows a detail of the pulleys of a tracker of a solar power collection system, in accordance with a second embodiment of the present invention; Figure 7 schematically shows a detail of the lower fixing hinges of a solar power collection device, in accordance with the present invention;

[0031] Figure 8 schematically shows a detail of the upper fixing hinges of a solar power collection device, in accordance with the present invention;

[0032] Figure 9 schematically shows a detail for adjusting the inclination of a solar power collection device, in accordance with a first embodiment of the present invention;

[0033] Figure 10 schematically shows a device for adjusting the inclination of a solar power collection device, in accordance with a third embodiment of the present invention.

[0034] With reference to the appended figures, a solar power collection system 10, in accordance with the present invention, comprises a support structure 11 formed of vertical support poles 12 aligned with each other and preferably maintained in position by a network of tie rods or stiff rods 13, alternatively, the support poles 12 can also be rigidly fixed to the ground without tie rods.

[0035] The support poles 12 are of a height such as to allow people and means to pass underneath them, and to allow the growing of crops.

[0036] The support poles 12 and tie rods 13 are fixed into the ground preferably by means of poles buried by being beaten or screwed into the ground, to avoid heavy foundation works.

[0037] The support poles 12 are fixed to the buried poles preferably by means of a hinge or a pin located at their base. This solution allows, in the installation phase, the poles to be lifted from the ground by rotating them extremely easily on the pins at the base of the poles, by means of a simple system of levers.

[0038] The support poles 12 are connected to each other by means of a network of linear structural elements 14. The linear structural elements 14, depending on the dimensions of the system 10 and the needs, could be formed of ropes or cables or preferably steel rods or hollow tubes. It is also possible to use a combination of them, such as a combination of taut ropes and stiff rods.

[0039] The diameter of the linear structural elements 14 is normally comprised between 4 and 6 cm.

[0040] The linear structural elements 14, together with the support poles 12 and the tie rods 13, form a tensile structure, and in particular the elements 14 intersect with each other at 90° and form intersections 15.

[0041] The solar power collection devices 16 comprising the relative solar tracking systems will be fixed to the elements 14, and in particular at the intersections 15, as specified in more detail below. The devices 16 will therefore be arranged along the elements 14 to form rows and columns aligned with each other.

[0042] The support poles 12 have a height greater than 3 m, more preferably greater than 4 m. Consequently, the solar power collection devices 16 that are applied above the elements 14 are positioned above the 3-5 m given by the height of the support poles 12.

[0043] The devices 16 are fixed to the support structure 11 where the elements 14 intersect with each other. In proximity to the intersection 15 of the elements 14, sleeves 20, preferably T-shaped, are fixed. The short section of the T is fixed to the element 14 by means of screws, for example. Each of the sleeves 20, of which there are four, are fixed at a predetermined and equal distance to each other, from the centre of the intersection 15 of each of the two elements 14 that intersect with each other.

[0044] A roller 21 rotatable around the vertical axis is fixed on the long section of the T of the sleeve 20, which is turned upwards.

[0045] A circular guide 25 having a U-shaped section, with the open part of the U turned inwards, is positioned horizontally so that the rollers 21 are inserted into the open part of the U of the circular guide 25. The circular guide 25 can therefore rotate by means of the rollers 21 , while still remaining locked to them thanks to the U-shaped profile.

[0046] The open part of the U of the circular guide 25 therefore forms a track for the rollers 21. The rollers 21 are fixed onto the elements 14 and the circular guide 25 is fixed, even though it can rotate, to the rollers 21 , thanks to the U-shaped profile.

[0047] As fixing means for fixing the devices 16 to the support structure 11 , as an alternative to the sleeves 20, it is possible to use vertical screws or pins fixed by perforating the elements 14 and locking them in the holes with nuts or welding them. The rollers 21 are placed at the head of said screws or pins.

[0048] For movement of the circular guide 25, a cable 26 is passed on the outer edge of the guide 25 and makes at least one complete round. Preferably, the outer edge of the guide 25 comprises a guide seat for passage of the cable 26.

[0049] The cable 26 is moved by two motors (not shown) located at the ends of the elements 14. One motor moves the cable 26 in one direction and the other motor moves the cable 26 in the opposite direction, so as to allow the guide 25 to make a clockwise movement and an anti-clockwise movement.

[0050] As an alternative, it is possible to use a motor on one side and a counterweight on the other side of the cable 26.

[0051] The cable 26 can therefore make all the guides 25 located on one row or one column of the system rotate synchronously.

[0052] As an alternative to the cable 26, it is possible to motorise at least one roller 21 of each guide 25, operating each guide 25 singly.

[0053] One side of a photovoltaic panel 30 is fixed onto the circular guide 25 by means of two hinges 31 .

[0054] The other side of the photovoltaic panel 30 is fixed to a device 32 for adjusting the inclination thereof.

[0055] The device 32 comprises a double pantograph formed of a first horizontal rod 40 fixed to the circular guide 25, in an opposite position to the two hinges 31 , by means of two couplings 41 .

[0056] From the ends of the first rod 40, a second rod 42 and a third rod 43 depart, fixed to the first rod 40 by means of couplings 41 , which intersect with each other.

[0057] The couplings 41 are, in particular, devices that allow a particular movement of the rods.

[0058] The rod 40 can rotate around its own axis. The rod 43, and in the same way the rod 42, can rotate around two couplings 41 .

[0059] The couplings 41 are, for example, obtained with a parallelepiped-shaped block with two pins located on the same plane but perpendicular to each other, i.e. exiting from four faces of the parallelepiped, as shown in Figure 7.

[0060] A fourth rod 47 and a fifth rod 48 that intersect with each other are fixed at the ends of the two rods 42 and 43, by means of pins 46.

[0061] The ends of the fourth rod 47 and the fifth rod 48 are fixed to one side of the panel 30, opposite to the one where the two hinges 31 are fixed. Fixing to the panel 30 is obtained by means of two couplings 50.

[0062] The couplings 50 are, in particular, devices that allow a particular movement of the rods.

[0063] The rod 48, and in the same way the rod 47, can rotate around an axis parallel to the upper side of the panel 30, and at the same time can rotate around an axis perpendicular to the previous one.

[0064] The couplings 50 are, for example, obtained with a parallelepiped-shaped block with two pins located on the same plane but perpendicular to each other, i.e. exiting from four faces of the parallelepiped, as shown in Figure 8.

[0065] The rods are positioned inclined and intersect with each other to form a pantograph structure, but the rods at the intersections are not hinged to each other.

[0066] The movement of the device 32 can take place with different methods.

[0067] A pulley 51 is fixed at the centre of the intersection 15. The pulley 51 receives a first cable 52 that performs at least one full rotation around it.

[0068] The cable 52 is moved by two motors (not shown) located at the ends of the elements 14. One motor moves the cable 52 in one direction and the other motor moves it in the opposite direction, so as to allow the pulley 51 to make a clockwise movement and an anticlockwise movement. As an alternative, it is possible to use a motor on one side and a counterweight on the other side of the cable 52.

[0069] The pulley 51 comprises another pulley 53 fixed coaxially and stably to the pulley 51 .

[0070] In a first embodiment, a pair of pulleys 54 is located at the centre of the first rod 40 and, at the ends of the two rods 42 and 43, where the fourth rod 47 and the fifth rod 48 are fixed, and in particular where the pins 46 are located, a worm gear 55, which can be screwed into seats arranged in the pins 46, is horizontally positioned.

[0071] The pins 46 are, for example, obtained by means of a parallelepiped-shaped block with two side pins that join the rods 42 and 47 and the corresponding rods 43 and 48, as shown in Figure 9.

[0072] Perpendicularly to the two side pins, the parallelepiped has a threaded through hole where the worm gear 55 can be screwed.

[0073] A roller 56 is stably fixed at the centre of the worm gear 55.

[0074] The pulleys 51 and 53 rotate around a vertical axis, the pulleys 54 rotate around a horizontal axis perpendicular to the axis of the pulleys 51 and 53.

[0075] The roller 56 rotates around an axis parallel to the axis of the pulleys 54.

[0076] A double wire 57 is wound and can rotate around the pulley 53, passes into the pair of pulleys 54 and wraps around the roller 56, with one wire on one side and one on the other of the roller 56.

[0077] Moving the cable 52, in one direction or in the other, causes the pulley 51 , and consequently the pulley 53, to rotate. Movement of the wire 57 returns the movement of the pulley 53 to the pair of pulleys 54, which cause the roller 56 to rotate in one direction or in the opposite direction. The roller 56 causes the worm gear 55 to rotate and consequently moves the pins 46 towards or away from each other, altering the geometry of the pantograph. In this manner, it is possible to raise or lower the side of the panel 30, while the other side of the panel 30 can follow the movement thanks to the hinges 31 .

[0078] In this movement, the couplings 41 and 50 in turn follow the movement of the panel 30 and consequently of the rods 42, 43, 47 and 48.

[0079] The cable 52 can therefore make all the pulleys 51 located on one row or one column of the system rotate synchronously.

[0080] As an alternative to the cable 52, it is possible to motorise the pulley 51 and operate each panel 30 singly.

[0081] In a second embodiment, the pulley 51 is present, which is fixed at the intersection 15, over which the pulley 53 is superimposed and fixed to it. At the centre of the first rod 40, there is a pulley 60 with axis parallel to the rod 40 and a pulley 61 with axis perpendicular to the rod 40. At least one pulley 62 is fixed to both pins 46, which join the rods 42 and 43 to the rods 47 and 48.

[0082] A wire 63 is wound around the pulley 53, passes into the pulley

[0083] 60 and therefore into the pulley 61 , which returns it laterally with respect to the pulley 60 until it reaches the pulleys 62.

[0084] The wire 63 is wound one or more times in the pulleys 62. The end of the wire 63 is fixed to one of the intersection points 46. The pulleys 62 can be considered to be winches that form a hoist.

[0085] The cable 52 passes into the pulley 51 and its movement causes the pulley 53 to rotate. The wire 63 is returned by the pulleys 60 and

[0086] 61 to the pulleys 62.

[0087] The movement of the wire 63 causes the pulleys 62 to approach or move away, depending on the direction in which the pulley 51 is made to rotate. Consequently, it raises or lowers the side of the panel 30, while the other side of the panel 30 follow the movement thanks to the hinges 31.

[0088] In this movement, the couplings 41 and 50 in turn follow the movement of the panel 30 and consequently of the rods 42, 43, 47 and 48.

[0089] The cable 52 can therefore make all the pulleys 51 located on one row or one column of the system rotate synchronously.

[0090] As an alternative to the cable 52, it is possible to motorise the pulley 51 and operate each panel 30 singly.

[0091] In a third alternative embodiment, it is possible to raise and lower the panel 30 by means of a linear actuator fixed on one side of the guide 25, in a position opposite to the hinges 31 , which operates a vertical pin (or a worm gear) secured to the upper side of the panel 30.

[0092] By operating the cable 26, the panels 30 are moved, turning them from east to west in order to follow the sun in its cardinal position.

[0093] By operating the cable 52, the panels 30 are inclined, in order to follow the sun as it rises.

[0094] In a fourth alternative embodiment, a circular rack 70 is positioned inside the circular guide 25, and in particular inside the opening of the U.

[0095] A motor 71 with a gear 71 that engages in the rack 70 is located on the linear structural element 14. Preferably, opposite to the gear 72, and outside the circular guide 25, a further pin 73 with a roller is fixed to the guide 25, in order to counter the thrust of the gear 72.

[0096] The motor 71 allows the panel 30 to rotate on command.

[0097] The device 32 for adjusting the inclination of the panel 30 comprises, in this case, a single pantograph formed of the rods 74 and 75 that intersect each other.

[0098] The rods 74 and 75 on one side (upper) are fixed to a worm gear 81 by means of two hinges 83. The worm gear 81 is controlled by a motor 82, located at one end thereof.

[0099] The hinges 83 can rotate around an axis perpendicular to the axis of the worm gear 81.

[0100] The worm gear 81 is fixed to the upper part of the panel 30 by means of two hinges 84.

[0101] The hinges 84 can rotate around an axis parallel to the axis of the worm gear 81 .

[0102] The hinges 83 slide inside a guide that encloses the worm gear 81 which moves them in an opposing motion, so as to raise and lower the rods 74 and 75 to lift the panel 30.

[0103] If the hinges 83 move towards each other, the panel 30 is raised, whereas if they move away from each other, the panel 30 is lowered.

[0104] The rods 74 and 75 on the other side (lower) are fixed to the circular guide 25 by means of two hinges 76.

[0105] The two hinges 76 are preferably joined to each other by means of a rod 77 to reduce the stresses to which the circular guide 25 could be subjected by the movement of the rods 74 and 75.

[0106] The hinges 76 and the hinges 83 allow the respective rods to which they are connected to rotate and therefore to follow the different inclination of the panel 30.

[0107] In an alternative embodiment, the worm gear 81 , rather than being connected to the panel 30, can be connected in the place of the lower rod 77, and the rod 77 is located between the hinges 83, to reduce the stresses to which the panel 30 could be subjected by the movement of the rods 74 and 75.

[0108] Functioning is the same.

[0109] Furthermore, in order to avoid deformations (ovalisation) of the guide 25 during movement of the panel 30, at least a first connection cable 85 is provided, fixed to the edge of the guide 25, arranged along a diameter of the guide 25, perpendicular to the side of the panel 30 that rotates on the hinges 31 , and preferably a second connection cable 86 perpendicular to the first connection cable 85. The centre of the cables 85 and 86 can also be an excellent point for fixing the electric cables (not shown) for the motors 71 and 82 and for the panel 30, reducing the possible torsions and using reduced bends for the electric cables.

[0110] In one example of an embodiment, the solar power collection system 10 measures 120 m x 120 m with 40 lines and 40 columns, for a total of 1 ,600 photovoltaic panels 30.

[0111] Support poles 12 that are 5 m high with a diameter of 12 cm have been used, and steel bars 13 with a diameter of 4 cm.

[0112] The circular guides 25 have a diameter of 2 m.

[0113] The photovoltaic panels 30 are 700 W and have dimensions of 2.4 m x 1.3 m.

[0114] In another example of an embodiment, the circular guides 25, rather than being located on the support structure 11 , have been located on a structure of another type, existing or created ad hoc, such as being placed on a roof for example, or on ballasted supports or on foundations. In particular, the rollers 21 are positioned on structures of another type.

[0115] The system further comprises a control system that operates the cables 26 and 52 or the motors 71 and 82 to keep the panels constantly directed towards the sun, so that the sun is perpendicular to the absorbing surface of the panels, with known methods deriving from the weather forecasts, using an algorithm based on date and time and on the installation geographical coordinates. When the position of the sun is such as to cause shadowing of the panels positioned in the back rows, the control system adjusts the position of the panels so as to eliminate the shadows that could cause significant drops in energy production.

[0116] The control system is also capable of: rapidly repositioning the panels in a particular position if needed (hail, high wind, etc.), keeping the system in movement to avoid the formation of ice, detecting any anomalies in the movement members, detecting detachment of the panels, performing environmental measurements of various kind.

Claims

CLAIMS1 . Solar power collection system (10) comprising: a support structure (11 ) formed of support poles (12) fixed to the ground; a network of tie rods (13) that maintain said support poles (12) in position; a plurality of solar power collection devices (16, 30); a solar movement system (25, 32) for moving said plurality of solar power collection devices (16, 30); said support structure (11 ) comprises linear structural elements (14) that connect said support poles (12); said plurality of solar power collection devices (16, 30) are movably fixed onto said linear structural elements (14); characterised in that said linear structural elements (14) intersect with each other to form intersections (15); said plurality of solar power collection devices (16, 30) are fixed onto said linear structural elements (14) at said intersections (15).

2. The system according to claim 1 , characterised in that said solar movement system (25, 32) comprises: fixing means for fixing said devices (16) to the support structure (11 ); a roller (21 ) fixable onto each of said fixing means; a circular guide (25) having a U-shaped section turned towards the inside of said circular guide (25) to form a guide for said rollers (21 ); said circular guide (25) being positioned so that said rollers (21 ) rotate inside said guide (25).

3. The system according to one or more of the preceding claims, characterised in that a circular rack (70) is located inside the opening of the U of said circular guide (25).

4. The system according to one or more of the preceding claims,characterised in that it comprises a first control cable (26) for controlling rotation of said circular guide (25), wound externally around said circular guide (25).

5. The system according to one or more of the preceding claims, characterised in that said power collection device (30) is fixed on a first side by means of two hinges (31 ) to said circular guide (25).

6. The system according to one or more of the preceding claims, characterised in that said power collection device (30) is fixed on a second side to a movement system (32) for inclining said power collection device (30).

7. The system according to one or more of the preceding claims, characterised in that said movement system (32) for inclining said power collection device (30) comprises a second cable (52) that is wound around a first pulley (51 ); a second pulley (53) fixed coaxially and stably to said first pulley (51 ); a worm gear (55) fixed to a roller (56); a movement structure (32) for moving said power collection device (30); a third cable (57) that connects said second pulley (53) to said roller (56).

8. The system according to one or more of the preceding claims, characterised in that said movement system (32) for inclining said power collection device (30) comprises a second cable (52) that is wound around a first pulley (51 ); a second pulley (53) fixed coaxially and stably to said first pulley (51 ); a hoist (62); a movement structure (32) for moving said power collection device (30); a fourth cable (63) that connects said second pulley (53) to said hoist (62).

9. The system according to claim 6, characterised in that said movement system (32) comprises a worm gear (81 ), controlled by a motor (82).1 0. The system according to one or more of the preceding claims, characterised in that said movement system (32) comprises crossed rods.1 1 . Solar tracker comprising: a solar power collection device (16, 30); a solar movement system (25, 32) for moving said solar power collection device (16, 30); said solar movement system (25, 32) comprises a circular guide (25) having a U-shaped section turned towards the inside of said circular guide (25) to form a guide for said rollers (21 ); said circular guide (25) being positioned so that said rollers (21 ) rotate inside said guide (25); said power collection device (30) is fixed on a first side by means of two hinges (31 ) to said circular guide (25); said power collection device (30) is fixed on a second side to a movement system (32) for inclining said power collection device (30).

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