PHOTOVOLTAIC CELLS

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The present invention relates to a photovoltaic panel comprising at least one solar-tracking photovoltaic module provided with photovoltaic cells that can be oriented individually or in groups.

Currently, solar-tracking photovoltaic panels or modules are known in which the photovoltaic cells constituting the module itself are fixed with respect to the entire photovoltaic module and are not provided with movement means of their own that enable their optimal orientation.

The present invention is altogether innovative in so far as the inventive idea of enabling an independent orientability of the individual photovoltaic cells (or groups of cells ) constituting the entire photovoltaicmodule affords complete solution to the problem presented by the known art regarding the complex modalities of constraint of said photovoltaic modules on roof slabs, on roofs, or on other structures purposely designed and pre-arranged, in order to provide a valid and possible movement thereof necessary for enabling tracking of the Sun's path. In this regard, attention should be paid to the problems regarding the movement of panel-supporting structures of a known type, with the corresponding problems due to the weight and inertia of the masses to be displaced, as well as resistance thereof to the wind.

The main purpose of the present invention is hence to rendermovable the photovoltaic cells constituting the above modules on roof slabs, on roofs of dwellings, on roofs of greenhouses , · or on other purposely provided structures, simplifying significantly both the times and the costs for design of the corresponding supports currently necessary for movement of the entire photovoltaic modules.

A further purpose of the present invention, which is no less important than the previous one is to reduce the costs regarding the times for installation of the individual photovoltaic panels, the orientation and installation of fixed panels being easier and more practical, likewise enabling an optimal capture of the solar energy by said cells thanks to the fact that they are provided with orientation means inside the panel.

Another fundamental purpose of the present invention is, in fact, to provide a photovoltaic module that will optimize solar tracking both throughout the day and throughout the year with the change of seasons, said optimization being obtainable by rendering the cells constituting the entire photovoltaic panel orientable using movement means that are protected from atmospheric agents by the structure of the panel itself.

A further purpose of the present invention, which is no less important than the previous one, is to provide a photovoltaic module that will be completely integrable with roofs of dwellings, roof slabs, or greenhouse roofs, etc. where it will be installed both in order to obtain the maximum contribution by GSE (Gestore dei Servizi Energetic!) , and to obtain a zero or drastically reduced architectural impact, especially if installation is required in areas, such as historic centres, in which it is necessary to respect given aesthetic standards and municipal constraints.

The present invention has moreover been devised and studied for being used both for residential applications and for industrial applications, in particular for roofs of greenhouses for agricultural crops. In effect, another purpose of the present invention is to provide a photovoltaic module that will fulfil, for example if applied to a greenhouse, the dual function of shading and, at the same time, energyproduction, without it being strictly necessary to determine beforehand the amount of photovoltaic cells and hence of silicon to be installed according to the type of crop grown in the greenhouse.

The above purposes are achieved by providing a solar-tracking photovoltaic panel, which comprises one or more modules, each of which comprises a planar frame, which can be installed preferably parallel to the lie of a roof having a pitch with curved tiles or a roof slab or a plane roof or a greenhouse roof, in which the planar frame, in addition to being hinged along a main axis of rotation, which can be moved from East to West, by means of a main motor reducer, is provided with a plurality of photovoltaic cells, each of which can be oriented in an azimuthal plane, along a secondary axis of rotation of its own, via a secondary motor reducer, which drives a series of motion-transmission means, such as in particular a wormscrew and a plurality of gears, with said secondary axes of rotation of the photovoltaic cells perpendicular to themain axis of rotation of hinging of the frame itself.

The above purposes and the consequent advantages, as well as the characteristics of the invention according to the present disclosure will emerge more clearly from the ensuing detailed description of some preferred embodiments , presented by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 is a schematic top plan view of a solar-tracking photovoltaic module 1 according to the invention, which can be oriented by means of a motor reducer 2, designed for rotation of the entire frame 3 about a main axis of rotation 9 of its own; the frame 3 in turn supports a plurality of photovoltaic cells 4, which can be moved individually by means of a secondary motor reducer 5, which drives a wormscrew 6, turning on which are gears 7, which render the cells 4 further orientable about secondary axes of rotation 8 of their own perpendicular to the main axis of rotation 9; a plurality of electrical sliding contacts 10 - 11, present respectively on the hinges corresponding to the axes of rotation 8 - 9 of the frame 3 and of the cells 4, guarantees the flow of the electric current generated by the photovoltaic cells 4 to the electrical conductors

14 provided in the frame 3 of the photovoltaic module 1;

Figure 2 is a schematic top plan view, with the corresponding vertical cross section represented at the top in said figure, of a first embodiment of application of a photovoltaic panel P comprising a plurality of photovoltaic modules 1 according to the invention on a roof 15 with curved tiles; as highlighted in the same graphic representation, the fifth module 1, which is present to the extreme right in the top plan view, is totally integrated with the roof

15 in the resting position, namely when the string 17 of the cells 4 is rotated through 180° within the cylindrical polycarbonate support 18; in this case, the entire module 1 shows the back of the support 19 that carries the cells 4 and has a colouring that reproduces the tile colour of the roof 15, which is useful for its complete integration with the roof itself, for the purposes of obtaining both the maximum contribution by GSE (Gestore dei Servizi Energetici) and a minimum architectural impact, which is especially required in areas such as historic centres of towns;

Figure 3 is a top plan view of a second preferred embodiment of a photovoltaic module 1 according to the invention; this second embodiment is substantially similar to the one made up of planar silicon cells 4 illustrated Figure 1; the peculiarity of this secondpreferred embodiment lies in the use of high-efficiency cells on which the solar radiation is focused via purposely designed parabolic surfaces 16, as well as in the reduced space required for orientation by means of universal joint of the parabolic surfaces 16 with a different diameter of the "transparent" tubes containing the strings 17;

Figure 4, in the same way as Figure 2, shows in top plan view and in cross-sectional view the module with parabolic surfaces 16 of Figure 3; in particular, in the cross-sectional view represented above the one in plan view, the structure with parabolic surfaces 16, functioning as support for the silicon cell, is more evident; the bottom part 19 of the parabolic surface 16 once again reproduces the tile colour of the roof 15;

- Figure 5, in the same way as Figure 2, shows in top plan view and in cross-sectional view, the planar-cell modules 1 of Figure 1, installed on a shed or greenhouse and with the cells 4 spaced apart from one another in a plane 22, in order to enable filtering of at least 50% of the sunlight;

Figure 6, in the same way as Figure 4, shows in top plan view and in cross-sectional view the modules with parabolic surfaces 16 of Figure 3, installed and with the cells 4 spaced apart from one another in a plane 22 in order to enable filtering of at least 50% of the sunlight.

From the attached figures it emerges that the embodiments appearing therein by way of non-limiting example are modules 1 with orientable cells 4 with said modules 1 studied in particular for being easily applied on roofs of sheds and greenhouses or on dwellings for residential use.

The modules 1 with orientable cells 4 for use on residential dwellings are designed to replace the existing customary tiles, reproducing the same structure of the traditional tiled roof 15 in order to minimize, at least when they are inoperative, namely in the hours of poor or inexistent sunlight, the visual impact that they could cause and at the same time guarantee an optimal protection from water and an improved thermal insulation.

As may be noted in Figure 1, the solar-tracking photovoltaic module 1 according to the invention, at least in the first preferred embodiment here represented, can be oriented by means of a motor reducer 2 , designed for rotation of the entire frame 3 of the module 1 about a main axis of rotation 9 of its own . The frame 3 in turn functions as support to a plurality of photovoltaic cells 4; in particular, four cells are shown in Figure 1. The cells 4 can in turn be moved by means of a secondary motor reducer 5. The latter drives a wormscrew 6, turning on which are gears 7, which render the cells 4 further orientable about their own axes of rotation 8 that are perpendicular to the main axis 9.

A plurality of electrical sliding contacts 10 - 11, present respectively on the hinges corresponding to the axes of rotation 8 - 9 of the frame 3 and of the cells 4, guarantees the flow of the electric current generated by the photovoltaic cells 4 themselves to the electrical conductors 14 provided in the frame 3 of the photovoltaic module 1 and therefrom to the inverter, which converts it to 220 Vac or 380 Vac for subsequent injection into the grid of the Gestore dei Servizi Energetici.

In order to reproduce in an optimal way the structure of a traditional tiled roof 15 and at the same time not to penalize too much the yield thereof in electrical energy produced per square metre of photovoltaic surface, the modules 1 have been designed for tracking the Sun along an arc of approximately 100° in a horizontal direction with an elevation of approximately 30° in a vertical direction.

As may be noted, in particular in Figures 1 and 3, the system of rotation and solar tracking of the panels about two mutually perpendicular axes can be equated to a tracking system of a gyroscopic type. Said tracking system has been developed for all the applications of the modules 1 with orientable cells 4 and is able to provide the maximum achievable efficiency for approximately two thirds of the daytime hours.

For the remaining third of daytime hours, namely the hours comprising dawn and dusk, the module 1 of this sort functions in any case in an optimal way as compared to technically known solar-tracking modules in so far as now the individual cells 4 are well oriented vertically.

Represented schematically in top plan view in Figure 2 is a first embodiment of application of a plurality of photovoltaic modules 1 according to the invention on a roof 15 with curved tiles. As highlighted in said graphic representation of Figure 2, the fifth module 1, present to the extreme right in the top plan view, is totally integrated with the roof 15 in. the resting position.

The resting position, as already said, can be assumed in the hours of poor sunlight when the string 17 of the cells 4 is rotated through 180° within the cylindrical polycarbonate support 18 and when, consequently, the entire module 1 shows the back of its support 19 that carries the cells 4, which presents a colouring that reproduces the tile colour of the roof 15 with curved tiles.

Said resting position is useful both for complete integration of the photovoltaicmodule 1 with the roof itself 15 for the purposes of obtaining both the maximum contribution on the part of GSE (Gestore dei Servizi Energetici) and a minimum architectural impact, especially in areas, such as historic centres where it is preferable to achieve it.

Represented in Figure 3 is a top plan view of a second preferred embodiment of a photovoltaic module 1 according to the invention, substantially similar to the one made up of planar silicon cells 4 illustrated in Figure 1, but provided with a further peculiarity as compared to the latter . In effect, said peculiarity lies in the reduced space of encumbrance necessary for orientation by means of universal joint of the parabolic surfaces 16 that collect the sunlight, as well as in the different diameter of the "transparent" tubes containing the strings 17.

As represented in Figure 4, in particular in the cross-sectional view represented above the top plan view of the photovoltaic module 1, the structure with parabolic surfaces 16, which functions as support for the silicon cell 4, emerges more clearly, whilst the bottom part 19 of the parabolic surface 16, as already described previously, once again reproduces the tile colour of the roof 15.

The modules 1 for roofs of sheds and greenhouses for agricultural crops must be built so as to allow filtering of the sunlight . For this purpose, asmaybe noted from Figures 5 and 6, the silicon covering is only partial and is provided only as a function of the maximum solar-tracking arc that it is intended to obtain.

In this latter case, the orientable module 1 performs the dual function of shading of the greenhouse and production of energy, without any constraint regarding the problem of determining beforehand the amount of silicon to be installed according to the type of crop to be grown. It is thus possible to seek in an appropriate way the point of maximum use of the silicon for production of electrical energy without having to set the cells at a distance from one another as a function of the minimum amount of light necessary for the particular type of crop.

Figures 2 and 4 represent at a reduced scale the vertical cross section (above) and the top plan view (below) of a module 1. Represented at the right-hand ends of the representations, is the module 1 in a resting position as should appear, when, that is, the string of the cells is rotated through 180° and the module reproduces the tile colour of the roof.

The basic characteristics of the module 1 according to the present invention lie not only in the actual embodiment, but also in the reduction by approximately 35% of the photovoltaic surface or of equivalent silicon necessary, given the same surface occupied and equivalent efficiency produced by a module 1 according to the known art having similar dimensions.

The drawing of Figure 1 represents clearly operation of each individual frame 3 and/or string 17 making up the photovoltaic module 1.

The electrical connections between the various cells 4 , set in series , are provided in the same frame 3 that carries the cells 4, where the electrical conductors 14 have previously been placed.

The electrical connection of the cells 4 is ensured by the presence of some sliding springs arranged in the housing of the frame 3 designed to enable vertical rotation of the cells 4 themselves.

The frame 3 that carries the cells 4 is in turn electrically connected to the other strings 17 making up the module 1 by means of sliding contacts 10-11, provided, respectively, on the axis of rotation 9 of the frame 3, at the hinges 12, on the axis of rotation 9 of the entire module 1, and on the axis of rotation of the cells 4, at the hinges 13 corresponding to the axes of rotation 8 of the cells 4, which are fixed with respect to the module.

The vertical orientation of the cells 4 is obtained by rotation of a wormscrew 6 governed by a secondary motor reducer 5, constrained to the frame 3, and by a plurality of gears 7, fixed with respect to the cells.

The horizontal orientation is instead governed by a motor reducer 2, constrained to the frame 3 of the module 1, appropriately geared down by a purposely provided r.p.m. reduction gear.

All the electrical connections that connect the strings 17 making up the module 1 are provided in the module 1 itself so that installation of the modules 1 on a roof 15 or a roof slab 22 can come about in a simple, fast and reliable way.

In order to reduce the amount of silicon by more than 90%, using the same mechanics illustrated above, it is possible to obtain modules 1 that, instead of using normal silicon cells (of the amorphous or polycrystalline type) as described above, use a system provided with parabolic surfaces 16, designed to concentrate the solar rays on a cell 4 of far smaller size as compared to the previous ones, as represented in Figures 3, 4 and 6, which is positioned on the focus of said parabolic surface 16.

In this latter case, it is the parabolic surface 16 itself that is orientable for solar tracking, by means of said two orthogonal axes 8-9, the tiny silicon cell 4 being now fixed in the focus of said parabolic surface.

Clearly visible in Figures 3, 4 and 6 is the substantial analogy with the string 17 made up of silicon cells 4: the particularity in this case lies in the reduced space necessary for orientation by means of universal joint of the parabolic surfaces 16, which require a different diameter of the "transparent" tubes containing the strings 17 (not represented in Figures 3, 4 and 6) .

Figure 4 shows said module 1 constituted by parabolic surfaces 16 represented both in cross-sectional view and in top plan view. The representation in cross-sectional view provides an approximate idea of the structure obtained with the parabolic surface 16 which constitutes the support for the silicon mini-cell 4.

As already described previously, present underneath the parabolic surface 16 is the part of frame of a tile colour, which, with -the cells in the resting position, enables reproduction of a roof.

As regards the industrial applications of the orientable modules 1 according to the present invention, given that the constraints of an architectural type have been eliminated, it is expected to obtain easily horizontal rotation of the modules 1 up to more than 120°, with the further advantage of solar tracking with a saving of approximately 50% of silicon installed.

Another peculiarity of these modules 1 according to the invention lies in the fact that they can be mounted almost horizontally (a small inclination is necessary only for draining off the water) , thus obtaining a considerable saving of ground or surface occupied given the same amount of power .

For all the embodiments represented in the attached figures, there may be envisaged also versions with a single motor reducer which drives of the module 1 according to both of its axes, with a single system of gears for orientation of the cells.

The invention presents the further advantage of being characterized, in the preferred embodiments represented, by a high degree of simplicity of construction with consequent evident saving in production costs. The main advantages, in fact, due precisely to the simplicity of the constructional features, lead to the further advantage of minimizing the production costs and hence the costs of the product for the end user.

The invention moreover presents the undoubted advantage of enabling optimization of the use of the photovoltaic surfaces for energy production, without the need, which is particularly felt in installations on sheds and greenhouses for agricultural crops, to set the cells at a distance from one another as a function of the minimum amount of light necessary for the particular type of crop to be grown.

Another indisputable advantage of the modules 1 according to the present invention lies in the fact that it is now possible to orient all the cells or mini-cells 4, or just a part thereof, so as to enable filtering of an optimal amount of sunlight within the greenhouse according to the particular type of crop that is to be grown.

Finally, management of the movement can be obtained with known orientation systems set on the basis ^' of "maximum efficiency" with automatic tracking or on a "time of year / time of day" basis. For greenhouses, the management system will take into account also the measurements of the amount of light and temperature reached within the greenhouses themselves using purposely provided sensors.

It is also evident that numerous modifications, adaptations, integrations, variations, and substitutions of elements with other functionally equivalent ones may be made to the embodiment described herein by way of illustrative and non-limiting example, without thereby departing from the sphere of protection of the ensuing claims .

LEGEND

1. solar-tracking photovoltaic module

2. motor reducer for rotation of the frame 3 of the photovoltaic module 1

3. frame of the photovoltaic module

4. photovoltaic cells

5. secondary motor reducer 6. wormscrew

7. gears

8. secondary axis of rotation of the individual cell 4

9. main axis of rotation of the photovoltaic module 1 10. electrical sliding contacts at the hinge 12 corresponding to the axis of rotation 9 of the entire module 1

11. electrical sliding contacts at the hinges 13 corresponding to the axes of rotation of the individual cells 4

12. hinge corresponding to the axis of rotation 9 of the entire module 1

13. hinges corresponding to the axes of rotation of the individual cells 4

14. electrical conductors provided in the frame

15. roof having a pitch with curved tiles

16. parabolic surfaces

17. string of photovoltaic cells

18. cylindrical polycarbonate support

19. back of the support of the cell 4 reproducing the tile colour of the roof

20. gutter for offlet of water

21. heat-insulated support of the photovoltaic module 1

22. roof slab or flat roof