Agrivoltaic system with insect and weather protection system

Abstract

The present invention relates to an agrivoltaic plant in which the photovoltaic (PV) modules are supported by a tensile structure, specifically a tensile structure consisting of a plurality of concrete piles, preferably prestressed reinforced concrete, held in a stable position by tensioned steel cables. The unique feature of the system according to the invention is the possibility of integrating the PV modules with a system for protecting crops from weather events and harmful insects, thanks to a particular configuration of the component parts, particularly a module-to-pile fastening element specifically designed for prestressed reinforced concrete piles. The agrivoltaic system according to the invention is preferably, but not exclusively, installed on land covered by a tree crop.

Description

[0001] TITLE: AGRIVOLTAIC SYSTEM WITH INSECT AND WEATHER PROTECTION SYSTEM

[0002] TECHNICAL FIELD

[0003] The present invention relates to agrivoltaic systems and plants of the type based on a tensile structure for supporting photovoltaic modules.

[0004] BACKGROUND ART

[0005] According to the Fraunhofer Institute ISE, the term “agrivoltaics”, or agri-PV, refers to the simultaneous use of a land for agriculture activity (including livestock farming) and photovoltaic (PV) energy generation. In other words, agri-PV systems are hybrid systems designed to allow power generation without sacrificing the continuity of agricultural and pastoral activities.

[0006] Therefore, due to their “hybrid” nature, agrivoltaic systems present technical differences compared to traditional PV systems.

[0007] A first distinguishing element is that agrivoltaic systems have a support structure for PV modules, which in a “traditional” system is not present as they are generally mounted at a fixed and predetermined angle on the roof e.g. of the home or industrial warehouse. The agri-PV system’s support structure is designed to hold the module at a fixed angle with respect to the sun’s rays or at a variable angle using a “solar tracker” (i.e. an electromechanical device designed to favorably orient a photovoltaic module to the sun's rays). Furthermore, the agri- PV system's structure must necessarily take into account the type of crop growing on the land where it is installed.

[0008] A second difference is the arrangement of the PV modules, which must be arranged to allow the passage of agricultural machinery, such as a combine harvester, considering that the modules may not have a fixed angle.

[0009] In the majority of known agrivoltaic systems, the support structure essentially consists of a metal frame comprising pillars or columns anchored to the ground and joined together by crosspieces or longitudinal members, generally wind braces. Various configurations of this type of support structure are known.

[0010] This support structure has recently been improved to allow the insertion of a protective cover against atmospheric events or harmful insects, in accordance with the teachings disclosed in the Italian patent application 102022000011186 “Photovoltaic system for an agrivoltaic system comprising a protective cover“ in the name of the Polytechnic University of Milan and the Polytechnic University of Turin.

[0011] Despite these improvements, the main drawback of agri-PV based on metal-frame structures for supporting the PV-modules is their strong visual impact, which affects public acceptance. In addition to being visually impactful, these conventional support structures are poorly scalable, making expansion of the agrivoltaic system (to increase power output) and / or system tailoring (e.g. to accommodate the needs of a new crop) challenging or, in any case, costly.

[0012] Finally, considering the extensive use of raw materials these support structures are costly and not exactly environmental friendly.

[0013] The visual impact and the related economic and environmental costs is even more significant for agrivoltaic systems installed together with tree crops, as they necessarily require the installation of solar modules above the rows of trees.

[0014] Different types of support structures have been proposed to solve, or at least mitigate, the issues of agri-PV systems based on conventional structures made of metal frames.

[0015] For example, agrivoltaic systems are known in the art in which PV modules are supported on by tensile structures consisting of a system of piles firmly anchored to the ground and held in place by a system of steel cables tensioned by stay rods.

[0016] In addition to a significantly reduced visual impact, a tensile structure supporting the PV modules offers additional advantages such as ease of installation, greater adaptability to the system’s changing needs, and therefore lower costs, especially for agrivoltaic systems installed over tree crops. Systems of this type have been proposed by REM TEC Sri. Specifically, this well-known solution is based on a tensile structure consisting of a system of metal piles supporting a tubular metal crosspiece to which a plurality of pairs of PV modules are fixed at right angles (each module is positioned on opposite sides of the crosspiece).

[0017] Including a weather-proof covering, especially for tree crop protection, is technically challenging and represents the main limitation of this well-known agrivoltaic system.

[0018] Furthermore, the way the PV modules are attached to the tubular crosspiece leads to the following problems: first, the structural fatigue resulting by the torque (due to weight) which is applied to the module fastenings, especially if a tracking device is present; second, a reduction of the power output due to the number of modules of the agri-PV system which is necessarily lower than in a conventional PV system having the same surface area.

[0019] Finally, despite being based on a tensile structure, systems like the one proposed by REM TEC Sri require significant use of ferrous raw materials, resulting in higher installation and maintenance costs.

[0020] The use of coverings against adverse weather conditions and harmful insects is well known.

[0021] This is an extremely important and increasing issue due to climate change, which in recent years has made rainfall more severe and unpredictable, particularly hailstorms, causing sometimes irreparable damage to crops.

[0022] Typically, these coverings take the form of a net (or sheet) that rests on a ridge cable so that it can be lowered from both sides of the row, either manually or via an electric motor (or other), over the crop to be protected.

[0023] The ridge cable, in turn, is stretched between the tops of support piles fixed to the ground. Specifically, tensile structures for supporting the protective net are known: the applicant itself is a company that has been active for decades in the field of crop protection systems (against insects and weather), particularly tree protection, in which the support piles of the tensile structure are made of pre-stressed reinforced concrete and not metal.

[0024] Systems of this type are described, for example, in European patent EP2371207B1 in the name of the applicant.

[0025] Despite the extensive knowledge available in the field, briefly summarized herein, no agrivoltaic systems based on a tensile structure that integrates a system for protecting crops against weather and insects have been developed.

[0026] The reason is primarily how to match PV modules with the tensile structure, especially in the case of tree crops. Indeed, with agrivoltaics, the PV panels must be positioned on the top of the piles, which makes troublesome the placement of the ridge cable, whose positioning affects the structural stability of the entire tensile structure.

[0027] Furthermore, it is not easy to match the mechanism to extend / retract the protection net with the PV modules, especially when they are operated by a solar tracker. Indeed, the risk of the net getting entangled to the modules or to the mechanical parts of the tracker is very high, especially in the case of agrivoltaic systems for tree crops.

[0028] Despite many attempts, a convincing solution to this problem has not yet been found, and presently there are no agrivoltaic systems based on tensile structures that integrate a covering to protect the crops from extreme weather events and harmful insects.

[0029] Therefore, there is an urgent need to improve existing agrivoltaic systems, especially those based on a tensile structure to support the photovoltaic modules.

[0030] GENERAL DESCRIPTION OF THE INVENTION

[0031] Object / scope of the invention

[0032] In view of the above, the present invention intends to overcome the existing disadvantages and drawbacks of the prior art by providing an improved agrivoltaic system which, thanks to a particular arrangement, configuration, and combination of its component parts, provides remarkable efficiency and ease of use in the agricultural and livestock sector. In particular, the main purpose of the present invention is to provide an agrivoltaic system of the type comprising a tensile structure to support the photovoltaic modules, which, in addition to PV power generation, is capable of ensuring protection of crops from adverse weather conditions and harmful insects.

[0033] In addition to the main purpose, a further object of the invention is to provide an agrivoltaic system in which crop protection is ensured by a net or a sheet that, in case of need, is stretched (or unrolled) and subsequently collected (or rolled up), easily without interfering with the PV modules, even when they are not installed in a fixed position but are moved by a solar tracker. A third object of the present invention is to provide an agrivoltaic system, of the type comprising a tensile structure and a protection system, configured to be particularly useful and convenient when applied to tree cultivation.

[0034] A further object of the present invention is to provide an agrivoltaic system of the type specified above that is constructionally simple both in terms of installation and maintenance and expansion.

[0035] Finally, a final object of the present invention is to provide an agrivoltaic system using known technologies and at a low cost so as to facilitate its large-scale adoption.

[0036] Technical solution

[0037] These and still other purposes, which will appear more clearly in the detailed description which follows, are achieved by an improved agrivoltaic system equipped with a removable covering for protection against insects and atmospheric events. The idea underlying the invention as defined in the enclosed claim 1 is to have the same tensile structure as a support means of both the agrivoltaic system and the protection covering. Three preferred, but not exclusive, embodiments of said system are defined in the corresponding dependent claims.

[0038] The aforesaid claims, to which reference should be made for the sake of brevity, are hereinafter specifically defined and are intended as an integral part of the present specification.

[0039] The present invention will be more fully understood by reference to the following tables of drawings, in which:

[0040] Figure 1 is a perspective view of the agrivoltaic system according to the present invention;

[0041] - Figure 2 is a plan view of the agrivoltaic system according to the invention, highlighting the layout of the different types of support piles and the so-called “double perimeter row” configuration;

[0042] Figure 3 illustrates the tensile structure of the agrivoltaic system in Figure 1 with the protective covering in the extended position. Particularly, (a) is a view orthogonal to the direction of the row, and (b) a view along the direction of the row;

[0043] Figure 4 is a perspective view of the system shown in Figure 1 , illustrating how the photovoltaic system and tracker are fixed to the support piles of the tensile structure;

[0044] Figure 5 shows the covering of the agrivoltaic system according to the second embodiment of the invention, where (a) is the covering in the retracted configuration, and (b) the covering in the extended configuration;

[0045] Figure 6 shows a detail of the tensile structure of the agrivoltaic system according to the third embodiment of the invention, highlighting the means for attaching the module to the support cable.

[0046] DETAILED DESCRIPTION OF THE INVENTION

[0047] It is an object of the present invention an agrivoltaic system which is indicated with the reference number (1) in Figure 1. Said system (1) includes the following units: a tensile structure (10) fixed to a field (T) wherein an agricultural activity is performed, preferably a cultivation (P) growing or livestock farming; a photovoltaic system (20), fixed to the tensile structure (10), and comprising a plurality of photovoltaic modules (21); a covering (30) fixed to the tensile structure (10) and able to assume a first configuration in which the covering (30) is retracted, and a second configuration in which the covering (30) is, at least partially, extended so that in association with said photovoltaic modules (21) said covering (30) provides protection to an agricultural activity from atmospheric events, excessive solar radiation and insects.

[0048] For the sake of fully disclose the invention, a detailed description of three preferred, but not exclusive, embodiments of the agrivoltaic system are provided hereinafter.

[0049] Preferred embodiment

[0050] The preferred embodiment refers to an agrivoltaic system (1) installed on land (T) covered by a tree crop (P) such as an apple orchard.

[0051] In the preferred embodiment, described herein by way of illustration and not limitation of the present invention, the tensile structure (10) is made up of a plurality of support piles (11) fixed to the ground (T) and a plurality of thread-like elements (12) kept under tension by a plurality of anchorage means (13) in order to stabilize the tensile structure.

[0052] In this embodiment, the support piles (11) are made of pre-stressed reinforced concrete, although other types of concrete piles, as well as other materials, could be used.

[0053] Support piles (11) can be divided according to the position in the tensile structure and function. With reference to the unit Figure 2, the following are called: head piles (111) those piles placed at the beginning and at the end of a row directed along the direction (X); lateral piles (112) those of the rows placed at the lateral ends of the system (1); corner piles (113) those placed at the four corners of the system (1); intermediate piles (114) the remaining ones, i.e. the piles placed within the system (1) perimeter.

[0054] In the preferred embodiment, the head, lateral, corner and intermediate piles (111 ,112,113,114) can be divided according to their height into high piles (111a, 112a, 113a, 114a) and low piles (111 b, 112b, 113b, 114b). As will be explained below, high piles support the photovoltaic system (20) and the covering (30), while low piles perform a stabilizing function of the tensile structure (10) or other functions as explained below.

[0055] In summary, the plurality of support piles (11) of the tensile structure (10) can be divided into a plurality of head piles (111), lateral piles (112), corner piles (113) and intermediate piles (114).

[0056] Furthermore, the tensile structure (10) of the agrivoltaic system (1) according to the invention includes a plurality of anchorage means (13). These anchorage means (13) can be divided according to the type of pile to which they are fixed or the anchoring position on the pile itself. As will be explained below, the anchorage means (13) stabilize the tensile structure (10) in association with a plurality of thread-like elements (12) kept in tension between said anchors (13).

[0057] In particular, with reference to the attached Figure 2, internal anchors (131) are defined as the anchors used to stabilize the intermediate piles (114), and external anchors (132) are those used to stabilize the head, lateral and corner piles (111 ,112,113). Both of these anchors (131 ,132) are fixed to the ground (T). The plurality of anchorage means (13) also includes upper anchors (133) and lower anchors (134) fixed, respectively, to the top or base of a pile (11).

[0058] In any case, the support piles (11) are constrained in the position according to the design of the system by keeping the thread-like elements (12) under tension between an internal or external anchor (131 ,132) and an upper anchor (133) or between an upper anchor (133) and a lower anchor (134).

[0059] In the preferred embodiment, the thread-like elements (12) are steel cables of suitable tensile strength, preferably cables with a diameter between 4 and 9 mm. However, for the purposes of implementing the present invention, other thread-like elements could also be used, for example steel wires, provided they are of equivalent resistance.

[0060] In this embodiment, each of the intermediate piles (114) is held in position by two cables (12), each being tensioned between an internal anchor (131) and an upper anchor (133). However, depending on the configuration of the agrivoltaic system, it is also possible that the stabilization of the tensile structure (10) requires a crosspiece consisting of two additional cables (12), each being tensioned between an upper anchor (133) and a lower anchor (134). Similar considerations apply to the other types of piles (111 ,112,113).

[0061] In the preferred embodiment, described herein by way of illustration and not limitation of the present invention, the photovoltaic system (20) comprises a plurality of PV modules (21) of a known type. In this embodiment, the modules (21) are fixed to the tensile structure (10) by means of a metal support structure (22) which comprises a plurality of crosspieces (221), preferably with a triangular section, fixed to the photovoltaic modules (21).

[0062] As illustrated in the enclosed Figure 3, in the preferred embodiment the crosspieces (221) represent a support surface for the perimeter edges of two adjacent modules (21) and they block these edges to the crosspieces (221) by means of appropriate clips. On the opposite side to the support surface, the crosspieces (221) are constrained to a shaft (224) directed along the direction (X) of the rows and parallel to the ground (T).

[0063] Preferably, the crosspieces (221) are arranged orthogonally to the shaft (224) which has a square cross-section.

[0064] In the preferred embodiment, the support structure (22) also comprises a plurality of flanges (222), each being fixed to the upper end of an intermediate pile (113).

[0065] In this embodiment, each flange (222) includes, near the upper end, a dry-type bearing (223), which has a square hole of suitable size matching the shaft (224). In this way, the shaft (224) engages the bearing and the PV modules (21) are rotatably constrained to the support structure (22). Clearly, the system (1) includes a plurality of shafts (224) aligned along the direction (X) of the row so that each of these operates a plurality of PV modules (21), for example 8.

[0066] This mechanism allows the surface of the modules (21) to be oriented with respect to the direction of solar radiation i.e. to “track the sun”, maximizing the power production of the agrivoltaic system (1). For this purpose, in the preferred embodiment, the support structure (22) is rotatably moved around the shaft (224) by an electric motor (226) with a reducer via a chain motion transmission system.

[0067] To dynamically balance the rotary motion of the solar tracker and increase its positioning accuracy, the support structure (22) includes a counterweight which, in the preferred embodiment, takes the form of a plurality of cast iron counterweights (222), each being fixed to a crosspiece (221). However, other types of motors and transmissions as well as balancing systems can be used equivalently.

[0068] It shall be apparent to those skilled in the art that the single-degree-of-freedom solar tracking mechanism (single-axis solar tracker) is the optimal choice in terms of cost / benefit ratio. However, by appropriately modifying the flange (222) to provide it with an additional degree of freedom, it is possible to integrate a dual-axis solar tracker into the support structure (22) of the PV modules (21).

[0069] The movement of the solar tracker is governed by a control unit whose functions will be described below.

[0070] The agrivoltaic system (1) according to the invention includes a covering (30) fixed to the tensile structure (10), which, as previously mentioned, can assume two configurations: a configuration in which the covering (30) is retracted (defined as the "first configuration"), and a configuration (defined as the "second configuration") in which said covering is, at least partially, extended so as to protect the tree crop (P) from atmospheric events, excessive solar radiation and harmful insects (the PV modules also clearly contribute to the protective effect). In the preferred embodiment, described herein by way of illustration and not limitation of the present invention, the covering (30) is made up of a plurality of high-density polyethylene (HDPE) nets (31).

[0071] There are known a number of ways to fix the nets (31) to the tensile structure (10) and to move them from the second to the first configuration.

[0072] In the preferred embodiment, each net (31) protects a row of crops (P) for a predetermined length.

[0073] As illustrated in the enclosed Figures 3a and 3b, each net (31) is supported along the longitudinal median axis by a support cable (121), commonly called a “ridge cable”; the lateral edges, commonly called “selvedges”, of adjacent nets (31) are held by plastic hooks. By replicating the scheme briefly described herein for all the rows, it is possible to protect the space beneath the plurality of nets (31) and therefore the entire cultivated surface (T).

[0074] The ridge cable (121) is supported by head piles (111), lateral piles (112), corner piles (113) or intermediate piles (114) depending on their position in the agrivoltaic system (1). By extending the net (31) on both sides of the ridge cable (121) and hooking the edges of adjacent nets (31) using a plurality of hooks (322), the agrivoltaic system (1) passes to the second configuration. Conversely, by releasing the hooks (322) from the edges and packing the nets (31) along the ridge cable (121), the agrivoltaic system (1) passes back to the first configuration.

[0075] In the preferred embodiment, the ridge cable (121) is supported by low head piles (111 b), lateral piles (112b) and corner piles (113b) positioned near the corresponding high head piles (111a), lateral piles (112a) and corner piles (113a) as schematically shown in Figure 2. Said piles (111 b, 112b, 113b) are inclined at a suitable angle to improve the stability of the tensile structure (10). Advantageously, this solution allows the PV system (20) and the covering (30) to be matched. In fact, in the case of an agrivoltaic system (1) intended for tree crop (P), the PV modules (21) must necessarily be positioned on top of the support piles (11) above the plants (these can have a height of approximately 3 - 4 m). This prevents the positioning of the ridge cable (121) as in traditional crop protection systems without a photovoltaic system. Moreover, modifying the positioning of the ridge cable affects the structural stability of the entire tensile structure, making this issue non-trivial to solve due to the need to balance conflicting technical requirements.

[0076] In a tensile structure-based crop protection system, the load of the protective covering is concentrated at the top of the piles. Adding PV modules, which in the case of tree crops must be placed at the top of the piles, necessarily means modifying the system configuration to properly distribute the loads of the covering.

[0077] In addition to this issue, it is important to consider that to maximize power production, the rows should be positioned as close together as possible compatibly with the space needed for agricultural machinery. However, this affects the structural stability of the entire tensile structure. Furthermore, ensuring the flatness of the support structure beyond 5 meters in length is not easy.

[0078] The solution to these conflicting technical issues was identified by the present inventor through a procedure that essentially involves: a) defining a typical agrivoltaic system layout and safety parameters; b) simulating of the structure’s behavior under load; c) verifying structural stability and identifying deviations from the predefined safety parameters; d) adjusting the initial layout and optimizing the structural calculation, repeating steps b) and c) where necessary until the ideal layout is obtained; e) field testing of the ideal layout and model validation. Using this procedure, the applicant has identified a configuration of the agrivoltaic system (1), named “double perimeter row” which maximizes PV power production while simultaneously ensuring structural stability. In this configuration, schematically shown in the enclosed Figure 2, the perimeter piles (111 ,112,113) are fixed to the ground (T) non-orthogonally and are placed next to an intermediate pile (114) fixed orthogonally on which a PV module (21) is fixed. It shall be apparent to those skilled un the art that such a PV module (21) could not be installed in traditional systems.

[0079] In the preferred embodiment, the transition from the first to the second configuration and vice versa is carried out manually by packing the net (31) onto the ridge cable (121).

[0080] Alternatively, a manual or motorized movement system (32) of the net (31) can be used, as disclosed in an alternative embodiment.

[0081] Finally, in the preferred embodiment, described herein by way of illustration and not limitation of the present invention, the agrivoltaic system (1) according to the invention includes a control unit (40) which manages the movement of the solar tracker.

[0082] In particular, the control unit (40) processes the signal received from a pyroheliometer (41) of a known type in order to measure the intensity of direct solar radiation reaching the ground under a well-defined angle. Based on the detected value, the control unit (40) acts on the motor (226), preferably a Brushless DC (BLDC) motor, which, via the reducer and the chain transmission, rotates the shaft (224) to orient the surface of the PV modules (21) integral therewith in the direction that maximizes either the production of photovoltaic energy or the intensity of solar radiation towards the crop (P) at particular times of the year.

[0083] Furthermore, the control unit (40) can orient the PV modules in specific directions to allow maintenance works on the system (1) and on the plants (P). For example, during phytosanitary treatments it can orient the modules (21) in such a way as to shield their surfaces from nebulized particles which, if deposited, would reduce the performance of the modules. Second embodiment

[0084] The second embodiment refers to an agrivoltaic system identical to that of the preferred embodiment, except for the covering movement system, which is not manual but motorized. Said movement system is schematically shown in Figure 5 and it is indicated with the reference number (32). For the sake of convenience, where necessary, the same references used for the previous embodiment will be used.

[0085] The motorized movement system (32) of the covering (30) depends on how the covering is supported by the tensile structure (10).

[0086] In the second embodiment, described herein by way of illustration and not limitation of the present invention, the covering (30) takes the form of a plurality of nets (31) as in the previous embodiment. In this case, the selvedges of the adjacent nets (31) are not fixed to each other by hooks. Actually, in this embodiment, each net (31) is slidably constrained along the longitudinal median axis to a ridge cable (121) by means of a plurality of hooks or rings. Similarly, the selvedges of the nets (31) are slidably constrained to two lateral guide ropes (321) by means of a plurality of rings or eyelets.

[0087] In turn, the two lateral guide ropes (321) are kept under tension by low head piles (111 b), by lateral piles (112b) or by corner piles (113b) depending on their position in the tensile structure (10). Said piles (111 b, 112b, 113b) have a lower height than the corresponding high head piles (111a), high side piles (112a) and high corner piles (113a) which keep the ridge rope (121) under tension so that the two lateral guide ropes (321) are at a lower, or equal, height than the ridge cable (121).

[0088] In the second embodiment, the movement system (32) is of the type described in the Chilean patent application CL2014000252A1. This system essentially includes a towing rope (323), placed above the ridge cable (121), connected via a series of return lines to a motorized winch (326). By acting on the control unit (40), manually or following an event detected by appropriate sensors, it is possible to activate the motorized winch (326) and extend the plurality of nets (31) over the crops (P) i.e. passing from the first configuration to the second configuration and vice versa packing the nets.

[0089] By replicating the scheme briefly described for all the rows, it is possible to protect the space underneath the nets (31) and therefore the entire surface of the crop (P).

[0090] From the description provided, it shall be apparent to those skilled in the art that a number of equivalent movement system (32) are possible.

[0091] For example, based on the type of crop (P), it is possible for the low piles (111 b, 112b, 113b) supporting the lateral guide ropes (321) to have the same height as the high piles (111a, 112a, 113a). By using the high piles (111 a, 112a, 113a) to tension the lateral guide ropes (321) and the low piles (111 b, 112b, 113b) to tension the ridge cables (121) it is also possible to place the ridge cables (121) at a lower height than that of the lateral guide ropes (321).

[0092] Configurations of this type are particularly useful when crop treatment (P) requires the use of straddle agricultural machinery that therefore requires adequate height clearance.

[0093] Indeed, completely different handling systems are possible, which involve opening and closing the safety net perpendicular to the direction (X) of the row and not parallel to it as in the case described above.

[0094] A system of this type can be made, e.g. by fixing the protection net (30) along the longitudinal median axis of the ridge cable (121), and arranging the lateral guide ropes (321) perpendicular, and not parallel, to the direction (X) of the row. The lateral guide ropes (321), kept in tension by low support piles (111 b,112b, 113b), slide the edges of the net (31) through a plurality of rings or eyelets (322) arranged, this time, along the transverse edges. Movement from the first configuration to the second, and vice versa, is made possible by one or more towing ropes

[0095] (323) connected via a series of pulleys and return lines to a motorized winch (326). In the second embodiment, described herein by way of illustration and not limitation of the present invention, in addition to the solar tracker sensors (41), the control unit (40) manages the weather sensors (42) and the cable sensors (43) through a suitable software.

[0096] The first sensors, of a known type, detect the conditions that determine the opening of the protective covering (30) above the cultivation (P) by acting on the motorized winches (326). These conditions include parameters such as temperature, atmospheric pressure, relative humidity, dew point, wind direction and intensity, but also weather warning signals issued by the Civil Protection or government agencies.

[0097] When a potentially harmful weather condition for the crops is detected (P), the control unit (40) activates the movement system (32) and extends the protective net (31). Conversely, when the weather sensors (42) detect stable weather conditions, the protective net (31) can be retracted unless it is preferable to keep in the first configuration as a protection against harmful insects.

[0098] The second type of sensors managed by the control unit (40), i.e. the cable sensors (43), detect the tension state of the cables (12) of the tensile structure (10) and hence its structural stability. Known sensors useful for this purpose are strain gauges suitably placed in critical positions of the tensile structure (10). In this way it is advantageously possible to activate predictive maintenance of the tensile structure by adjusting the tension of a specific cable and replacing worn components.

[0099] Second embodiment

[0100] In the third embodiment, described herein by way of illustration and not limitation of the present invention, the tensile structure does not include the support structure (22) to secure the PV system (30) as schematically depicted in Figure 6.

[0101] In this embodiment, the photovoltaic modules are supported directly by steel support cables (122) kept under tension by anchorage means (13) fixed to the support piles (11). Preferably, two lateral cables (122) and a central cable (123) are used to support, respectively, at the sides and along the median axis, a string of photovoltaic modules (21) consisting, e.g. of 8 modules. However, the PV modules (21) could be adequately supported with only two lateral cables (122).

[0102] In any case, the ropes (122,123) are fixed to at least two plates (116), which are in turn fixed by means of a flange to the support piles (11). Depending on the length of the string of modules (21) to be supported, additional plates (116) can be fixed to the support piles (11). Advantageously, the plates (116) can be rotatably fixed to the support piles so as to allow the installation of a single-axis tracker similar to that described in the case of the first embodiment. Preferably, the plates (116) have a symmetrical shape and a length approximately equal to that of the PV modules (21). Furthermore, if the support of the modules (21) is ensured by three cables (122,123), the plates have a cable hole for the passage of the central support cable (123).

[0103] In this embodiment, the PV modules (21) are fixed to the support cables (122) by means of first fastening means (135) which take the shape of a body, preferably cylindrical, having a flange protruding therefrom: the cylindrical body wraps around and clings to the cables (122,123) while the flange offers a support surface to which the edges or the lower surface of the PV modules (21) are secured by means of second fastening means of a known type.

[0104] The flange can be secured to the PV modules (21) by inserting a resilient material to absorb vibrations when the system is moved or in the event of strong winds.

[0105] With reference to Figure 6, in the third embodiment, each PV module (21) is supported by three pairs of first fastening means (135) distributed across the three cables (122,123).

[0106] Other technical details for implementing this embodiment can be derived from the previous ones or deduced in a trivial way by the skilled in the art through experimental activities. CONCLUSIONS

[0107] It has been found that the invention described hereinabove fully achieves the intended aim and objects.

[0108] In fact, an agrivoltaic system equipped with a protection covering based on a common tensile structure has been disclosed. Thanks to a particular arrangement, configuration and combination of the component parts, said agrivoltaic system is suitable for providing particular efficiency and ease of use in the field.

[0109] Although the description and examples provided contain many details, they should not be interpreted as limiting the invention, but simply as illustrative illustrations of some embodiments of the present invention. Indeed, numerous variations are possible.

[0110] Therefore, any modifications of the present invention that fall within the scope of the following claims are considered to be part of the present invention.

[0111] Where the characteristics and techniques mentioned in any claim are followed by reference signs, these reference marks have been applied solely for the purpose of increasing the intelligibility of the claims and consequently these reference marks have no limiting effect on the interpretation of each element identified by way of example from these reference signs.

Claims

CLAIMSWhat is claimed:1) Agrivoltaic plant (1) including: a tensile structure (10) fixed to a field (T) wherein an agricultural activity is performed, preferably a cultivation (P) growing or livestock farming; a photovoltaic system (20), fixed to the tensile structure (10), and comprising a plurality of photovoltaic modules (21); a covering (30) fixed to the tensile structure (10) and able to assume a first configuration in which the covering (30) is retracted, and a second configuration in which the covering (30) is, at least partially, extended so that in association with said photovoltaic modules (21) said covering (30) provides protection to an agricultural activity from atmospheric events, excessive solar radiation and insects.2) Agrivoltaic plant (1) according to claim 1 wherein said land (T) is intended for the cultivation of arboreal species (P).3) Agrivoltaic plant (1) according to claim 1 wherein said tensile structure (10) includes: a plurality of support piles (11) fixed to the ground (T) by means of anchoring means (115), wherein said plurality (11) is made up of a plurality of head piles (111), lateral piles (112), of corner piles (113) and intermediate piles (114); optionally, a plurality of high head piles (111a), high lateral piles (112a), high corner piles (113a), low head piles (111b), low lateral piles (112b), low corner piles (113b); a plurality of anchorage means (13) consisting of a plurality of internal anchors (131), a plurality of external anchors (132) and a plurality of upper anchors (133), a plurality of lower anchors (134), wherein said internal or external anchors (131 ,132) are fixed to the ground (T) and said upper anchors (133) are fixed to the top of the support piles (11),wherein said support piles (11) are held in position by a plurality of thread-like members (12) kept in tension between an internal or external anchor (131 ,132) and an upper anchor (133) or between an upper anchor (133) and a lower anchor (134).4) Agrivoltaic plant (1) according to claim 3 wherein said support piles (11) are prestressed reinforced concrete piles.5) Agrivoltaic plant (1) according to claim 3 or 4 wherein said thread-like elements (12) are metal ropes or wires, preferably steel ropes.6) Agrivoltaic plant (1) according to one or more of the previous claims wherein said photovoltaic modules (21) are fixed to the tensile structure (10) by means of a support structure (22).7) Agrivoltaic plant (1) according to claim 6 wherein said support structure (22) includes: a plurality of cross members (221) attached to the photovoltaic modules (21) and constrained to a shaft (224) parallel to the ground (T) and directed along the direction (X) of the cultivation (P). two or more flanges (222), each being attached to the upper end of a pile (11), wherein said flanges (222) include a bearing (223) rotatably constrained to said shaft (224); optionally, a counterweight attached to said support structure (22), preferably a plurality of counterweights (222) each being attached to a cross member (221).8) Agrivoltaic plant (1) according to any preceding claim 7 wherein said support structure (22) includes a plurality of flanges (222) each being attached to the upper end of an intermediate pile (113), said flanges (222) each including a bearing (223) rotatably constrained to said shaft (224), said support structure (22) wherein said shaft (224) is square in cross-section and said bearings (223) are of the dry type and have a square bore of a size chosen to mate with said shaft (224).9) Agrivoltaic plant (1) according to the preceding claim 7 or 8 wherein said support structure (22) comprises a plurality of cross members (221), arranged orthogonally to the shaft (224), which constrain the photovoltaic module (21) along two perimeter edges.10) Agrivoltaic plant (1) according to claim 9 above wherein said support structure (22) is rotatably moved around the shaft (224) by a motor (226), preferably an electric motor with a gearbox and a chain drive transmission.11) Agrivoltaic plant (1) according to one or more of the preceding claims wherein the covering (30) comprises a plurality of nets (31), or sheets, conformed so that in said second configuration they provide protection to the agricultural activity from insects or from atmospheric precipitation such as hail, snow and rain.12) Agrivoltaic plant (1) according to one or more of the preceding claims which further includes a handling system (32) of the covering (30) from said first configuration to said second configuration, and vice versa, wherein said handling system (32) is of a manual or motorized type.13) Agrivoltaic plant (1) according to one or more of the preceding claims that further includes a control unit (40) configured to: manage the motion of the photovoltaic modules (21) around the shaft (224) by means of a motor (226) and solar sensors (41); or manage the motion of the covering (30) by means of a motor (326) and weather sensors (42); or monitor the tension state of the tensile structure (10) by means of a plurality of cable tension sensors (43).14) Agrivoltaic plant (1) according to one or more of the preceding claims characterized in that the tensile structure (10) has a "double perimeter row" configuration to maximizeenergy production, said configuration wherein the perimeter piles (111 ,112,113) are fixed to the ground (T), not orthogonally, and are put beside an intermediate pile (114) fixed orthogonally on which a photovoltaic module (21) is fixed.15) Agrivoltaic plant (1) according to one or more of claims 12 to 14 wherein the tensile structure (10) includes: a plurality of lateral guide ropes (321) kept in tension by low head piles (111 b), low lateral piles (112b), low corner piles (113b) or by high head piles (111a), high lateral piles (112a), high corner piles (113a); and a plurality of ridge ropes (121), kept in tension by high head piles (111a), high lateral piles (112a), high corner piles (113a), or by low head piles (111 b), low lateral piles (112b), low corner piles (113b), said high piles (111a,112a, 113a) having a height greater than or equal to the corresponding low piles (111 b, 112b, 113b), said agrivoltaic plant (1) wherein: the covering (30) includes a plurality of nets (31) each being slidably fastened along the longitudinal median axis, directed parallel to the direction (X), to one of said ridge cables (121) via a plurality of hooks or rings, each of said nets (31) also having the selvedge s, i.e. the longitudinal edges, slidingly constrained to two of said lateral guide ropes (321), directed parallel to the direction (X), via a plurality of rings or hooks; the movement system (32) includes at least one tow rope (323) for each of said nets (31), where said tow rope (323) is connected via a series of transmissions to a motorized winch (326), wherein said winch (326) can be activated by the control unit (40), manually or following an event detected by weather sensors (42) in order to extend, and vice versa, retract the net (31) along the direction (X).6) Agrivoltaic plant (1) according to one or more of claims 12 to 14 wherein the tensile structure (10) includes: a plurality of lateral guide ropes (321) kept in tension by low head piles (111 b), low lateral piles (112b), low corner piles (113b) or by high head piles (111a), high lateral piles (112a), high corner piles (113a); and a plurality of ridge ropes (121), kept in tension by high head piles (111a), high lateral piles (112a), high corner piles (113a), or by low head piles (111b), from low lateral piles (112b), from low corner piles (113b), said high piles (111a,112a, 113a) having a height greater than or equal to the corresponding low piles (111 b, 112b, 113b), said agrivoltaic plant (1) wherein: the covering (30) includes a plurality of nets (31) each of which is fixed along the longitudinal median axis, directed parallel to the direction (X), to one of said ridge cables (121) via a plurality of hooks or rings, each of said nets (31) also having the selvedges, i.e. the transverse edges, slidingly constrained to two of said lateral guide ropes (321), directed perpendicularly to the direction (X), via a plurality of rings or hooks; the movement system (32) includes at least one tow rope (323) for each of said nets (31), where said tow rope (323) is connected via a series of transmissions to a motorized winch (326), wherein said winch (326) can be activated by the control unit (40), manually or following an event detected by weather sensors (42) in order to extend, and vice versa, retract the net (31) perpendicular to the direction (X).

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