Photovoltaic solar panel system installed in field for agricultural or animal husbandry use and energy production method using same

Abstract

The system of photovoltaic solar panels comprises a plurality of photovoltaic solar panels (3) arranged in parallel and spaced rows (2) in an open field (F), thereby enabling agricultural or animal husbandry use of the area of the field (F) between said rows (2). Each photovoltaic solar panel (3) is carried by a support structure, in which there is inserted a tracking device configured to rotate the photovoltaic solar panel (3) during a diurnal motion of the sun. Each photovoltaic solar panel (3) comprises an array of double-sided photovoltaic solar cells (C) having opposite sides (A, B) exposed on a first side and a second side of the photovoltaic solar panel (3), respectively, to collect both direct solar radiation and diffused solar radiation. The tracking device is configured in such a way that the angle of inclination formed between the plane of each photovoltaic solar panel (3) and a vertical plane parallel to the longitudinal direction of the row (2) never exceeds a value of 45 DEG throughout the entire duration of the solar diurnal movement, unless at a temporary stage of the zenith of the sun, in which stage the solar panel (3) is positioned in the vertical direction of the row (2). The photovoltaic solar panel (3) is turned over within a period of time of no more than one hour. In this manner, the panel is controlled to move between a vertical position and a relatively close vertical position throughout the duration of the apparent motion of the sun, such that the projection of the photovoltaic system onto the ground is always minimized.

Description

Technical Field

[0001] The present invention relates to a system of photovoltaic solar panels, which are configured to be installed in an open field for agricultural and / or pastoral purposes. This type of system includes a plurality of photovoltaic solar panels, each photovoltaic solar panel including a plurality of photovoltaic solar cells.

[0002] wherein the photovoltaic solar panels are arranged in parallel and spaced rows, thereby enabling agricultural or pastoral use of the areas of the field between the rows,

[0003] wherein each photovoltaic solar panel has a planar configuration having a first side intended to be primarily oriented toward the sun and a second side opposite the first side, and

[0004] Therein, each photovoltaic solar panel is carried by a support structure into which is inserted a tracking device including an actuator and an electronic controller configured to rotate the photovoltaic solar panel during the diurnal apparent motion of the sun. Background Art

[0005] Photovoltaic solar panel systems of the type described above are already known and used for some time. In a widely used conventional solution, each row of photovoltaic solar panels is associated with one or more tracking devices configured to rotate the entire row of panels during the diurnal apparent motion of the sun, always keeping the first face of the photovoltaic solar panel facing the sun. In applications where it is desired to make the photovoltaic solar panel system coexist with possible agricultural or pastoral management, the solution means that, when assessing the space for agricultural or pastoral use, it is necessary to take into account the area corresponding to the planar projection of each row of panels, which area is not available when the panels are in a horizontal position. On the other hand, the space between the rows of panels must be sufficient to allow the passage of machines and equipment for agricultural purposes and for the maintenance of the photovoltaic system. It can be seen from this that for a given area to be reclaimed, there is a limit to the number of rows of panels that can be installed, or conversely, for a given number of rows of panels to be installed, there is a limit to the area that can be reclaimed.

[0006] The invention proceeds from the desire to find a better compromise between the need to have a production of electrical energy as high as possible by a system of photovoltaic solar panels and at the same time the need to have as large a field area as possible available for agricultural or pastoral use.

[0007] From US 2022 / 069767 A1 a system of photovoltaic solar panels comprising bifacial solar cells to be mounted on an inclined tower integrated with a plurality of reflectors is known.

[0008] Purpose of the Invention

[0009] The object of the present invention is to solve the above mentioned problems in a simple and effective manner.

[0010] In particular, the object of the invention is to provide a photovoltaic solar panel system which, for a predetermined extension of the field where it is installed, is able to achieve the best compromise between the high production of energy required and keeping most of the available land available for agricultural or pastoral purposes (if necessary).

[0011] A further object of the invention is to achieve the stated objectives using extremely simple and efficient means.

[0012] A further object of the invention is to provide a system of the type indicated above which can be easily adapted to each specific application.

[0013] Yet another object of the present invention is to reduce maintenance operations and in particular to reduce the need for regular cleaning of photovoltaic solar panels.

[0014] It is yet another object of the present invention to reduce the potential effects of soil stormwater erosion as a result of atmospheric precipitation. Summary of the invention

[0015] In view of achieving one or more of said objects, the present invention relates to a system of photovoltaic solar panels having the features of claim 1 .

[0016] In one embodiment, each photovoltaic solar panel has a solar cell having a first side that is relatively more efficient in generating electrical energy and a second side that is relatively less efficient in generating electrical energy. Each photovoltaic solar panel may have solar cells, all of which have their first sides exposed on the first side of the photovoltaic solar panel. In an alternative example, each photovoltaic solar panel has an alternating distribution of first solar cells, the first side of which is exposed on the first side of the photovoltaic solar panel, and second solar cells, the first side of which is exposed on the second side of the photovoltaic solar panel.

[0017] If each photovoltaic solar panel has a relatively more efficient first side with solar cells exposed on the first side of the photovoltaic solar panel, the system is further characterized in that the tracking device is configured and programmed as follows: after the photovoltaic solar panel is flipped over, the side of the photovoltaic solar panel exposed to the sun is always the side exposed to the sun during the first part of the solar motion, so that flipping of the panel involves passing through a position in which the photovoltaic solar panel is horizontal.

[0018] If each photovoltaic solar panel has a distribution of solar cells with a more efficient first side of the solar cells alternately exposed on the first side of the photovoltaic solar panel and on the second side of the photovoltaic solar panel, the system is characterized in that the device tracking is configured and programmed in the following manner: after the photovoltaic solar panel is flipped over, the side exposed to the sun is the side that was not exposed to the sun during the first part of the solar motion, so that flipping of the panel does not necessarily involve passing through a position in which the photovoltaic solar panel is horizontal.

[0019] Thanks to the characteristics described above, the system according to the invention allows satisfying in an optimal way at the same time the need for high energy productivity and the need for high productivity of areas designated for agricultural or pastoral use.

[0020] It can be seen that the solution of the invention arises from the observation that by always orthogonalizing the first face of the photovoltaic solar panel to the direction of incidence of direct solar radiation, the conventional idea of ​​following the apparent motion of the sun can be abandoned, thanks to which diffuse solar radiation can be better utilized.

[0021] According to the present invention, the inclination angle of the photovoltaic solar panel relative to the vertical never exceeds 45°, and preferably never exceeds 35° and even more preferably never exceeds 20°, that is, it is always in a position significantly closer to the vertical plane than the horizontal plane. Since the photovoltaic cells are arranged on the back of the panel, they make use of diffuse light, and this technique allows a significant increase in energy production. In this way, for the same amount of available solar energy, it is possible to obtain a yield of electrical energy that is only slightly lower than that produced by a conventional system, which always orthogonalizes the front of the photovoltaic solar panel to the incident direction of solar radiation. At the same time, the system according to the present invention allows a substantial improvement in the area that can be used for agricultural reclamation relative to conventional systems. This is determined by the fact that the space occupied by the solar panel in a sub-vertical position in the factory is much smaller than that occupied by the conventional photovoltaic solar panel, and the conventional photovoltaic solar panel remains in a horizontal position for a longer time in the middle of the sun's line of sight.

[0022] Due to this feature, the overall results obtainable by the system according to the invention are significantly better than those of conventional systems, both from the point of view of the production of electrical energy and of the development of agricultural land.

[0023] PV solar panels are maintained in a near vertical position during most of their use time, which also significantly reduces panel surface deterioration due to atmospheric precipitation, thereby reducing scheduled maintenance operations.

[0024] The invention also relates to a method of generating energy using the above system.

[0025] According to a further aspect, the invention also relates to a system of photovoltaic solar panels, comprising a plurality of photovoltaic solar panels, each photovoltaic solar panel comprising a plurality of photovoltaic solar cells and intended to be arranged in parallel and spaced rows in an open field, thereby enabling agricultural or pastoral use of the areas of the field between the rows,

[0026] wherein each photovoltaic solar panel has a planar configuration and is carried by a support structure with or without the insertion of a tracking device configured to rotate the photovoltaic solar panel during the diurnal apparent motion of the sun,

[0027] The system is characterized in that, for each row of photovoltaic solar panels, two photovoltaic solar panels are arranged in a V-shape, forming an angle between them which is never greater than 60° and having a bisector which is inclined with respect to a vertical plane parallel to the row direction at an angle which is never greater than 60°, preferably never greater than 40°, and

[0028] The system is characterized in that the two photovoltaic solar panels arranged in a V-shape have faces facing each other and carrying corresponding arrays of bifacial photovoltaic solar cells, wherein the first face is directed toward the inner side of the V-shape, so that the solar panels utilize both direct solar radiation mainly on the first face and diffuse solar radiation mainly on the second face, as well as solar radiation reflected between the faces of the two panels.

[0029] In the prior art, rows of photovoltaic solar panels are spaced up to four times the orthogonal projection of the multi-panel surface on the ground. The V-configuration described here enables the minimum distance (pitch) required between rows to be reduced by about 50%.

[0030] A 50% reduction in the orthogonal projection of the panel surface on the ground increases the light below the axis of rotation.

[0031] In a first example, a tracking device is configured to simultaneously and identically rotate two photovoltaic solar panels arranged in a V-shape during the sun's diurnal apparent motion.

[0032] In an alternative example, the tracking device is configured to rotate two photovoltaic solar panels arranged in a V-shape independently of each other during the diurnal apparent motion of the sun.

[0033] In a preferred embodiment, a flat or raised reflecting / diffusing surface is provided at the bottom of the space defined between two photovoltaic solar panels, which can also be used as a drainage channel for transporting rainwater to avoid the risk of soil scouring or erosion by rainwater, thereby ensuring the hydraulic stability of the installation site. DETAILED DESCRIPTION

[0034] Further features and advantages of the invention will emerge from the following description made with reference to the accompanying drawings, provided by way of non-limiting examples only, in which:

[0035] - Figure 1 , Figure 1A and Figure 1B are a perspective view and two side elevation views of a plurality of rows of photovoltaic solar panels installed in a field for agricultural and / or pastoral purposes, constituting a first example of a system according to the invention,

[0036] - Figure 2 yes Figure 1 , Figure 1A and Figure 1B The front view of one row of photovoltaic solar panels is shown in the figure.

[0037] - Figure 3 a1), a2), a3) and a4) show by way of example the positions of conventional photovoltaic solar panels at dawn, just before the solar zenith, just after the solar zenith and at sunset, respectively.

[0038] -- Figure 3 b1), a2), a3) and a4) show the corresponding positions in the case of an embodiment of the system according to the invention,

[0039] - Figure 4 a), b), c), d), e), f) show the different positions gradually taken up by the photovoltaic solar panel of a preferred embodiment of the invention during a turning phase, which is carried out at time intervals of, for example, about half an hour, substantially at the solar zenith,

[0040] - Figure 5 is a schematic diagram showing the variation of the tilt angle relative to the horizontal plane of a photovoltaic solar panel forming part of a system according to the invention (line I) and a photovoltaic solar panel according to conventional technology (line PA),

[0041] - Figure 6 and Figure 7 are schematic side views of a photovoltaic solar panel forming part of a system according to the invention according to two different exemplary embodiments,

[0042] - Figure 8 is based on Figure 6 A front view of a row of photovoltaic solar panels of an embodiment,

[0043] - Fig. 9 is a table showing the different ratios of the direct component to the diffuse component of solar radiation collected by a photovoltaic solar panel for different atmospheric conditions, and

[0044] - Fig.10 , Fig.11 is a side elevation view showing a further example of a photovoltaic solar panel system installed in a field designated for agricultural and / or pastoral use according to a further aspect of the present invention,

[0045] - Fig.11A yes Fig.10 , Fig.11 A system perspective,

[0046] - Fig. 11B , Fig. 11C yes Fig.10 , Fig.11 , Fig.11A A further side view of the system,

[0047] - Fig.12 Is formed based on Figures 10 to 11C Side elevation view of a single row of a part of the system of a variant of the solution,

[0048] - Fig. 12A is based on Fig.12 A perspective view of a variant system,

[0049] - Fig. 12B , Fig. 12C yes Fig.12 , 12A Further side view of the system.

[0050] Figure 1 , Figure 1A , Figure 1B , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 A first embodiment of a system according to the invention is shown. The system, indicated as a whole by 1, comprises a plurality of mutually parallel and spaced rows 2, installed in a field designated for agricultural and / or pastoral use.

[0051] Due to its characteristics, the system according to the invention reconciles at the same time the need for a high rate of production of electrical energy and the need for a high rate of production of areas designated for agricultural and / or pastoral use, for reasons that will become apparent hereinafter.

[0052] Each row 2 comprises an arrangement of photovoltaic solar panels 3 arranged substantially in the same plane and each carrying a plurality of bifacial photovoltaic solar cells C having opposite sides A and B exposed on opposite faces of the panel 3 (see Figure 6 , Figure 7 ).

[0053] The A side of each bifacial solar cell is designed to convert direct solar radiation into electricity, while the B side is designed to convert diffuse solar radiation.

[0054] Reference Figure 6 , Figure 7 , two alternative solutions can be provided. In the first solution, if Figure 6 As shown, all sides A of the battery are on each photovoltaic solar panel 3 ( Figure 6 ) are on the same face intended to collect mainly direct solar radiation, while all their sides B are on the opposite face intended to collect mainly diffuse solar radiation. Figure 7 and also shown in Figure 8 As shown in the front view in , each photovoltaic solar panel 3 has cells that are alternately distributed, with side A of the cells on the first side of the panel and side B of the cells on the first side of the panel.

[0055] Reference again Figure 1 , Figure 1A , Figure 1B and Figure 2 , the attached drawings do not illustrate the construction details of the photovoltaic solar panels 3 and in particular do not illustrate the configuration of the frame carrying said panels, which may be of any known type.

[0056] Also not illustrated are the construction details relating to the supporting structure of each row 2. According to conventional technology, each row comprises a supporting structure 4, indicated by F, consisting of a plurality of uprights 5 driven into the ground of the field where it is installed.

[0057] Still according to conventional technology per se, between the frame of each array carrying photovoltaic solar panels 3 and the supporting structure 4, a tracking device of any known type is inserted, which is capable of imparting a progressive rotational movement to the photovoltaic solar panels 3 of each row 2 during the diurnal apparent motion of the sun. The construction details of the tracking devices are also not described here, both because they can be made in any known way and because eliminating these details from the attached drawings makes the latter easier to understand. According to the prior art, each tracking device comprises an actuator, for example controlled by an electronic controller E( Figure 2 and Figure 8 ) according to a predetermined program controlled servo-controlled electric actuator 50 (in Figure 2 and Figure 8 ). Still according to the prior art, the system is provided with an electronic controller configured to rotate the photovoltaic solar panels according to any predetermined program during the diurnal apparent motion of the sun.

[0058] Figures 3 to 5The main difference between the system according to the invention in the embodiment described here and conventional systems which always keep one face of the photovoltaic solar panel orthogonal to the direction of incidence of the solar radiation is shown.

[0059] In particular, Figure 5 The variation of the angle formed between the plane of the photovoltaic solar panel and the horizontal plane as a function of time is shown in the case of the embodiment described here (line I) and in the case of a conventional system (line PA). Figure 5 In the diagram, on the abscissa, the time "0" corresponds essentially to the solar zenith and the numbers indicate the hours before and after the time "0". However, it must be taken into account that the hour of the day corresponding to certain locations of photovoltaic solar panels varies greatly for each specific application, depending on the geographical location and on the day of the year. Figure 5 In the schematic diagram of FIG. 1 , the numbers on the abscissa axis are only exemplary.

[0060] Reference Figure 5 For example, in a conventional system ( Figure 5 At dawn (e.g. around 6 a.m.), the plane of the photovoltaic solar panels of the conventional system forms an angle of 60° with respect to the horizontal plane, i.e. an angle of 30° with respect to the vertical (see also Figure 3 a1). Still in the case of conventional systems, during the morning, the plane of the photovoltaic solar panel follows the solar path and therefore the angle formed with respect to the horizontal plane is greatly reduced. For example, in the middle of the morning, the angle with the horizontal plane is 30°, which means an angle with the vertical of 60°. At the end of the morning, the photovoltaic solar panel is getting closer and closer to the horizontal position, where it remains essentially for a long time, for example from one hour before the solar zenith to one hour after the solar zenith (see also Figure 3 a2 and Figure 3 a3).

[0061] Refer again Figure 5 In the case of conventional systems, the rotation of the photovoltaic solar panel gradually continues in the afternoon, reproducing inversely what happens in the morning, so that the angle formed relative to the horizontal plane increases again from the value of zero to a value of 60° (see also Figure 3 a4).

[0062] like Figure 5 As shown, during the entire diurnal apparent motion of the Sun, the system according to the invention maintains the photovoltaic solar panels at an angle relative to the horizontal plane, which, in the example shown, varies gradually between 90° and 70°, corresponding to a variation of the angle formed relative to the vertical between 0° and 20°, except for a time interval around the solar zenith (for example lasting about half an hour), during which each photovoltaic solar panel is subjected to a flipping movement, as will be described in more detail below.

[0063] exist Figure 3 and Figure 5 In the example of the invention shown in FIG. 1 , in the early morning, the photovoltaic solar panel is vertical or nearly vertical. During the morning, the angle formed relative to the horizontal plane gradually decreases, and in this example, linearly decreases between the value of 90° and the value of 70°, which means that near the solar zenith, the photovoltaic solar panel ( Figure 5 The maximum inclination angle reached by line I) relative to the vertical is approximately 20°.

[0064] With reference to the preferred embodiment shown here, during a relatively short period of time, in the example of about 30 minutes, each photovoltaic solar panel is flipped in such a way that at the beginning and at the end of said time interval, the photovoltaic solar panel is tilted on opposite sides of the vertical plane. An example of such a flipping motion is shown in FIG. Figure 4 , where it can be seen that during the time interval of the flipping movement, the photovoltaic solar panel is tilted from a 20° inclination ( Figure 4 a) A 20° inclination ( Figure 4 f). Figure 4 b. Figure 4 c. Figure 4 d and Figure 4 e shows various intermediate positions between the flip start position and the flip end position.

[0065] In this example, during the entire course of the morning and the entire course of the afternoon, the photovoltaic solar panel remains in said subvertical position, i.e. it never exceeds an inclination angle of 20° relative to the vertical, but is closer to a fully vertical position at the beginning and end of the solar diurnal movement. The above-mentioned maximum inclination angle is exceeded only during the above-mentioned time intervals (during which the flipping movement occurs).

[0066] Figure 4 The example refers to Figure 6 In the case of an embodiment of the invention, the cells of the photovoltaic solar panel all have their first side A exposed on the first face of the panel. Therefore, the turning movement must be such that the face carrying the cell side A that faces the sun during the morning also always faces the sun during the afternoon, which means that during the turning movement the photovoltaic solar panel must pass through a horizontal position (see Figure 4 c and Figure 4 d) However, it is also provided Figure 7 , Figure 8Embodiment in which both the side A of some cells and the side B of other cells are exposed on each face of the photovoltaic solar panel 3. In the case of this embodiment, it can therefore be assumed that the turning movement occurs in such a way that the face that does not face the sun in the afternoon is the face that faces the sun in the morning. In this case, the turning movement can occur without passing through the horizontal position, but only by a rotation from -20° to +20° relative to the vertical plane. This feature may be of certain importance because it excludes the limited space between the rows for the passage of agricultural machinery and / or machinery for maintenance of the photovoltaic system, even for short time intervals.

[0067] As already discussed above, in fact an essential element of the invention is to obtain a system that allows the space occupied by the system of photovoltaic solar panels in a plan to be greatly reduced, thus increasing the space available for agricultural development.

[0068] Reference Figure 1B , since the inclination angle of each photovoltaic solar panel 3 relative to the vertical plane never exceeds Figure 1B The angle of inclination shown, apart from the time interval necessary for the panel turning movement, shows that there is a space of width D between each row and the other, which is greater than the space required to connect the columns 5 of row 2 with the columns 5 of row 2. Figure 1 The space available in a conventional system arranged at the same distances as shown.

[0069] Of course, abandoning the keeping of the main face of the photovoltaic solar panel constantly orthogonal to the direction of incidence of the solar radiation reduces the amount of energy obtained from direct solar radiation, but the overall result does not involve a significant reduction in energy production, thanks to the fact that the subvertical orientation of the photovoltaic solar panel allows a more efficient use of diffuse solar radiation through the sides of the photovoltaic cells on the face not exposed to the sun.

[0070] Fig. 9 is a table showing that the ratio of direct solar radiation utilized by the face of a photovoltaic solar panel facing the sun to the diffuse solar radiation utilized by the face of a photovoltaic solar panel not facing the sun varies greatly with changing weather conditions. Fig. 9 The table also shows the variation in power in Watts per square meter as atmospheric conditions change. If in full sun the available energy is 1000W / m2, this energy gradually decreases to 50W / m2 in progressively worsening atmospheric conditions, when the sky is cloudy. At the same time, the ratio between direct solar radiation and diffuse solar radiation ranges from 90%-10% to 0%-100%.

[0071] The above further explains how the incidence of diffuse solar radiation can become important, in particular in geographical areas with variable atmospheric conditions, which once again demonstrates the advantage of the underlying idea of ​​the present invention, namely to always keep the photovoltaic solar panel in a sub-vertical position, in which the inclination angle of the photovoltaic solar panel relative to a vertical plane parallel to the row direction does not exceed a predetermined value.

[0072] In the example described above, this predetermined maximum value of the inclination angle relative to the vertical is 20°. However, it falls within the present invention to assume that the angle does not exceed a value of 45°, and preferably it does not exceed an angle of 35° and even more preferably it does not exceed an angle of 20°.

[0073] exist Figure 1 In practical application of the solution, simulation activities are carried out via software to determine, for a given geographical area and for each day of the year, the results obtained in terms of the electric energy produced for different values ​​of the angle of inclination of the panels 3, within the range of variation of this angle that forms the object of the invention. On the basis of such simulations, an active tracking algorithm can be defined, i.e. the panels position themselves within the chosen range of angles to the optimal angle of incidence for energy production, at any time of the day useful for production.

[0074] Fig.10 , Fig.11 , Fig.11A , Fig. 11B and Fig. 11C According to yet another aspect of the invention, a system of photovoltaic solar panels to be installed in a field designated for agricultural and / or pastoral use is shown.

[0075] In these figures, Figures 1 to 9 Those parts which are common to the present invention are denoted by the same reference numerals.

[0076] exist Fig.10 , Fig.11 , Fig.11A , Fig. 11B and Fig. 11C In the case of a system, for each row 2 of photovoltaic solar panels, two series of photovoltaic solar panels 3A, 3B are provided respectively, which are composed of a plurality of bifacial photovoltaic solar cells and are arranged in two planes forming a V-shape, the two planes having faces facing each other, so that the photovoltaic solar cells utilize both direct solar radiation mainly on the inner face of the V-shape (which is the main face of the cell) and diffuse solar radiation mainly on the outer face, as well as solar radiation that is reflected by one or more reflections between the faces of the two panels 3A, 3B.

[0077] The two panels 3A, 3B can be rotated about a horizontal axis 6 by means of any known type of tracking device (not shown) controlled by an electronic controller.

[0078] In this solution, a single tracking device is configured to cause a simultaneous rotation of the two panels 3A, 3B about the axis 6, the two panels thus always remaining in the same relative position.

[0079] According to the invention, the panels 3A, 3B form between them an angle α that is never greater than 60°. Moreover, the bisector 7 of the angle defined between the two photovoltaic solar panels 3A, 3B forms an angle β that never exceeds a value of 60° and preferably never exceeds a value of 45° relative to the vertical plane.

[0080] The tracking device is configured to rotate the set of two panels 3A, 3B during the diurnal apparent motion of the sun so that the bisector 7 is oriented vertically midway along the apparent motion of the sun ( Fig.10 b) and at the same time at the beginning and end of the sun's diurnal motion ( Fig.10 a and 10c) are inclined on opposite sides (with respect to the vertical angle not exceeding 60 °). During the morning and afternoon, according to the predetermined program of the configuration electronic controller, the tracking device gradually rotates the group of two panels from one position to another.

[0081] Fig.10 An example is shown, in which the angle α is equal to approximately 60°, while the angle β is equal to approximately 20° at the beginning and at the end of the sun's path.

[0082] Fig.11 Basically Fig.10 The same is shown, but by means of a dashed line, in which the two panels form an angle α′ between them which is smaller than α.

[0083] Fig.11A and Fig. 11B Shows Fig.10 , Fig.11 These figures show that also in this embodiment the system of the invention is configured for installation in a field F designated for agricultural and / or pastoral use and the aim is to make two productions as efficient as possible: the production of electrical energy and the agricultural and / or pastoral production.

[0084] Fig. 11C It is shown that the spacing D between the rows is sufficiently selected to ensure that at the beginning and end of the sun's path, when the direction of incident solar radiation is as shown by R in the figure, the panels 3B of each row do not shade the panels 3A of an adjacent row.

[0085] Fig.12 , Fig. 12A , Fig. 12B and Fig. 12C refers to Fig.10 , Fig.11A variation of the solution of , in which the two series of panels 3A, 3B are controlled by respective tracking devices to rotate about respective axes 6A, 6B which may coincide with each other or, as the case may be, be parallel to each other and slightly spaced apart. Thus, in this solution, the two series of panels 3A, 3B may rotate either synchronously or in the same rotational manner (e.g. Fig.10 , Fig.11 solution) and are independent of each other, so that the angle α formed between the two series of panels 3A, 3B can vary over time, such as Fig. 12B a), b) and c).

[0086] Fig. 12C It is shown that by taking advantage of this possibility, when the direction of the incident solar ray is the direction indicated by R, the angle α formed between the two series of panels 3A, 3B can be reduced at the beginning and end of the solar path, so that the length of the spacing D of the panels 3B of each row is prevented from shading the panels 3A of the adjacent row is less than Fig. 11C The situation is proportionally small.

[0087] Preferably, the reflective / diffusing surface 9 ( Fig.12 ) is disposed on the bottom of the space between two photovoltaic solar panels arranged in a V shape, which can be a flat surface or a convex surface (such as Fig.12 example shown) and it can also be configured to act as a drainage channel to convey rainwater to a dedicated drain and reduce the risk of soil runoff due to atmospheric precipitation.

[0088] Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what has been described and illustrated purely by way of example, without thereby departing from the scope of the invention as defined by the appended claims.

Claims

1. A system of photovoltaic solar panels, configured to be installed in an outdoor field (F) for agricultural and / or pastoral purposes, comprising a plurality of photovoltaic solar panels (3), each photovoltaic solar panel (3) comprising a plurality of photovoltaic solar cells (C), in, The photovoltaic solar panels (3) are arranged in parallel and spaced rows (2), thereby enabling agricultural or pastoral use of the areas of the field (F) between the rows (2), Each photovoltaic solar panel (3) has a planar configuration having a first surface and a second surface opposite to the first surface, wherein each photovoltaic solar panel is carried by a support structure into which is inserted a tracking device comprising an actuator and an electronic controller configured to rotate the photovoltaic solar panel (3) during the diurnal apparent motion of the sun, The system is characterized by: - each photovoltaic solar panel (3) comprises an array of planar bifacial photovoltaic solar cells (C) coplanar with each other and arranged in the plane of the respective photovoltaic solar panel (3), The bifacial photovoltaic solar cell (C) has opposite side surfaces (A, B) respectively exposed on the first surface and the second surface of the photovoltaic solar panel (3), so that the first surface of the photovoltaic solar panel (3) can mainly collect direct solar radiation, and the second surface of the photovoltaic solar panel (3) can mainly collect diffuse solar radiation. - the electronic controller of the tracking device is configured in such a way that, throughout the duration of the diurnal apparent movement of the sun, the angle of inclination formed between the plane of each photovoltaic solar panel (3) and a vertical plane parallel to the longitudinal direction of the row (2) never exceeds a value of 45°, and preferably never exceeds a value of 35°, and even more preferably never exceeds a value of 20°, except during temporary phases of solar zenith, during which the solar panel (3) performs a tilting movement for a period not exceeding one hour, Wherein, the electronic controller of the tracking device is configured and programmed in the following manner: - said inclination angle of said photovoltaic solar panel (3) varies gradually between an angle close to 0° at the beginning and end of the diurnal apparent motion of the sun and an angle substantially between 5° and 40° at the solar zenith, preferably between 15° and 35°, even more preferably equal to about 20°, and - substantially near the solar zenith, the photovoltaic solar panel is flipped over a time interval not exceeding one hour so that at the beginning and end of the time interval the photovoltaic solar panel (3) is tilted on opposite sides relative to a vertical reference plane parallel to the longitudinal direction of the row (2).

2. The system according to claim 1, wherein: Each photovoltaic solar panel (3) includes a solar cell (C) having a first side (A) that is relatively more efficient in generating electrical energy and a second side (B) that is relatively less efficient in generating electrical energy.

3. The system according to claim 2, wherein: Each photovoltaic solar panel (3) comprises solar cells (C) respectively exposing a first side surface (A) on the first surface of the photovoltaic solar panel (3).

4. The system according to claim 2, wherein: Each photovoltaic solar panel (3) has an alternating distribution of first solar cells (C) and second solar cells (C), wherein the first side surface (A) of the first solar cell (C) is exposed on the first side of the photovoltaic solar panel (3), and the first side surface (A) of the second solar cell (C) is exposed on the second side of the photovoltaic solar panel (3).

5. The system according to claim 1, wherein: Each photovoltaic solar panel (3) comprises a solar cell (C) having a first side (A) which is relatively more efficient in generating electrical energy and a second side (B) which is relatively less efficient in generating electrical energy, And wherein the solar cells (C) of each photovoltaic solar panel have their first side (A) exposed on the first surface of the photovoltaic solar panel (3), The system is further characterized in that the tracking device is configured and programmed in the following manner: after the photovoltaic solar panel (3) is flipped over, the side of the photovoltaic solar panel exposed to the sun is always the side exposed to the sun in the first part of the sun's apparent movement, so that the flipping of the photovoltaic solar panel involves passing through a horizontal position of the photovoltaic solar panel.

6. The system according to claim 1, wherein: Each photovoltaic solar panel (3) comprises a solar cell (C) having a first side (A) which is relatively more efficient in generating electrical energy and a second side (B) which is relatively less efficient in generating electrical energy, Each photovoltaic solar panel (3) has an alternating arrangement of first solar cells (C) and second solar cells (C), wherein the first side surface (A) of the first solar cell (C) is exposed on the first side of the photovoltaic solar panel (3), and the first side surface (A) of the second solar cell (C) is exposed on the second side of the photovoltaic solar panel (3), The system is characterized in that the tracking device is configured and programmed in the following manner: after the photovoltaic solar panel is flipped over, the side of the photovoltaic solar panel exposed to the sun is the side that is not exposed to the sun during the first part of the solar motion, so that the flipping of the photovoltaic solar panel does not involve passing through a horizontal position of the photovoltaic solar panel.

7. A system of photovoltaic solar panels comprising a plurality of photovoltaic solar panels, each photovoltaic solar panel comprising a plurality of photovoltaic solar cells and intended to be arranged in parallel and spaced rows (2) in an open field so as to enable agricultural or pastoral use of the areas of the field between the rows (2), in, Each photovoltaic solar panel has a planar configuration and is carried by a support structure (4) with or without the insertion of a tracking device configured to rotate the photovoltaic solar panel during the diurnal apparent motion of the sun, The system is characterized in that, for each row (2) of photovoltaic solar panels, two series of photovoltaic solar panels (3A, 3B) are provided, arranged in two planes to form a V-shape, the photovoltaic solar panels forming an angle (α) between the two planes, the angle (α) never being greater than 60° and having a bisector of an inclination angle (β) relative to a vertical plane parallel to the direction of the row, the angle (β) never being greater than 60° and preferably never being greater than 40°, and The system is characterized in that two photovoltaic solar panels arranged in a V-shape have faces facing each other and carrying corresponding arrays of bifacial photovoltaic solar cells, so that the photovoltaic solar cells utilize both direct solar radiation and diffuse solar radiation, as well as solar radiation reflected between the faces of the two panels.

8. The system according to claim 7, characterized in that The system includes a tracking device configured to simultaneously and identically rotate two photovoltaic solar panels arranged in a V-shape during the sun's diurnal apparent motion.

9. The system according to claim 7, characterized in that The system includes a tracking device configured to rotate two photovoltaic solar panels arranged in a V-shape independently of each other about two axes (6A, 6B) that are coincident or parallel and spaced apart from each other during the diurnal apparent motion of the sun.

10. The system according to claim 7, characterized in that A flat or convex reflective / diffusing surface (9) is provided on the bottom of the space defined between two photovoltaic solar panels (3) arranged in a V-shape, which is preferably configured to act as a drainage channel.

11. The system according to claim 7, characterized in that The rows are arranged at a spacing (D) sufficient to avoid shading of the solar panels (3A, 3B) of each row by adjacent rows at the beginning and end of the apparent motion of the sun.

12. A method for collecting solar energy, comprising: A photovoltaic solar panel system is provided, the system comprising a plurality of photovoltaic solar panels (3), each photovoltaic solar panel comprising a plurality of photovoltaic solar cells (C), wherein the photovoltaic solar panels (3) are arranged in parallel and spaced rows (2) in an open field (F), thereby enabling agricultural or pastoral use of the areas of the field (F) between the rows (2), Each photovoltaic solar panel (3) has a planar configuration having a first surface and a second surface opposite to the first surface, wherein each photovoltaic solar panel is carried by a support structure into which is inserted a tracking device comprising an actuator and an electronic controller configured to rotate the photovoltaic solar panel (3) during the diurnal apparent motion of the sun, The method is characterized in that: - each photovoltaic solar panel (3) comprises an array of planar bifacial photovoltaic solar cells (C) coplanar with each other and arranged in the plane of the respective photovoltaic solar panel (3), The bifacial photovoltaic solar cell (C) has opposite side surfaces (A, B) respectively exposed on the first surface and the second surface of the photovoltaic solar panel (3), so that the first surface of the photovoltaic solar panel (3) can mainly collect direct solar radiation, and the second surface of the photovoltaic solar panel (3) can mainly collect diffuse solar radiation. - the tracking device is controlled in such a way that, throughout the duration of the diurnal apparent movement of the sun, the angle of inclination formed between the plane of each photovoltaic solar panel (3) and a vertical plane parallel to the longitudinal direction of the row (2) never exceeds a value of 45°, and preferably never exceeds a value of 35°, and even more preferably never exceeds a value of 20°, except during temporary phases of solar zenith, during which the solar panel (3) performs a tilting movement for a period not exceeding one hour, The tracking device is controlled in particular in the following manner: - said inclination angle of said photovoltaic solar panel (3) varies gradually between an angle close to 0° at the beginning and end of the diurnal apparent motion of the sun and an angle substantially between 5° and 40° at the solar zenith, preferably between 15° and 35°, even more preferably equal to about 20°, and - substantially near the solar zenith, the photovoltaic solar panel is flipped over a time interval not exceeding one hour so that at the beginning and end of the time interval the photovoltaic solar panel (3) is tilted on opposite sides relative to a vertical reference plane parallel to the longitudinal direction of the row (2).

13. The method according to claim 12, characterized in that During the apparent motion of the sun, the inclination angle of the photovoltaic solar panel varies within an indicated range of variation according to a law determined based on a simulation by software, which calculates the electrical energy generated for a given geographical area at each hour of each day of the year and for different values ​​of this inclination angle within the indicated range of variation.

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