Reference data

[0001] This application is a continuation of provisional US Patent Application US61906050 filed on 19 November 2013, the content thereof is hereby incorporated by reference. Field of the invention

[0002] The present invention concerns a modular structure specifically designed for photovoltaic panels and a photovoltaic system with such modular structure.

Description of related art [0002] The system power of a photovoltaic system depends on the number of used photovoltaic panels, thereby a photovoltaic system occupies a broad area which may be exploited for other scope.

[0003] Sport facilities such as tennis courts or soccer fields, private gardens with little or no use during the day are all surfaces that can be converted into solar power, within a few hours a day and could return to their original function if the system with photovoltaic panels could easily occupy a small area when light exposure is not exploited.

[0004] Having efficient photovoltaic systems is beneficial only if they can be incorporated in a manner that is cost effective and not burdensome. This is no easy task since it typically takes many years for a roof-mounted solar installation to pay for itself. Also, roof mounted systems are hard to access, and there have been many reports of safety concerns during fires across some part of the world.

[0005] Another drawback of the photovoltaics panels' installation is its expensiveness, not due to the cost of panels, which have significantly decreased in recent years, but rather due to associated hardware and soft costs such as labor associated with system designs and installations.

[0006] An aim of this invention is to propose a modular system for photovoltaic panels without the drawbacks of the prior art photovoltaic systems.

[0007] Another object of the invention is to provide such a modular supporting structure allowing the photovoltaic panels and the overall photovoltaic system to be quickly and easily installed for light exposure.

[0008] A further object of the present invention is to provide such a supporting structure allowing the photovoltaic panels to be easily put in service.

[0009] A further object of the present invention is to provide such a supporting structure which, owing to its specifically designed constructional features, is very reliable and safe in operation. Brief summary of the invention

[0010] According to the invention, these aims are achieved by means of a modular structure for photovoltaic panels comprising a frame and at least one segment attached to the frame, where the segment comprises at least two photovoltaic panels and at least two pantographs mounted to the panel sides, wherein the pantographs are configured to move reversibly from a retracted position to an expanded position.

[0011] According to the invention, these aims are also further achieved by means of a photovoltaic system for generating electric power comprising such a modular structure. [0012] According to the modular structure and system of the invention, there is a possibility to retract the system. Thanks to this retracted position, the use of the system under conditions and on surfaces where it is impossible to provide a fixed photovoltaic system is now allowed, introducing therefore a commercially viable concept that is the dual function of a surface ideally exposed to solar energy but also assigned to another use. Brief Description of the Drawings

[0013] The invention will be better understood with the aid of the description of an embodiment given by way of example and illustrated by the figures, in which:

Fig. 1 a shows a view of a photovoltaic structure with a plurality of segments in the fully expanded position;

Fig. 1 b shows an example of photovoltaic system in a semi expanded position with a plurality of segments;

Fig. 2a shows an example of photovoltaic structure in the fully retracted position, the box being not closed; Fig. 2b shows an example of photovoltaic system in a retracted position, the box being not closed;

Fig. 2c shows an example of photovoltaic system in a retracted position, the box being closed with the cover;

Fig. 3a shows a frame in an expanded position; Fig. 3b shows a frame in a retracted position;

Fig. 4 shows a large view of a segment in a semi expanded position;

Fig. 5 shows a large view of a wheel; Fig. 6 shows the cover;

Fig. 7 shows an embodiment with photovoltaic systems located in a container, from above

Fig. 8a, 8b and 8c show a front view of further embodiments of a panel used in the modular structure according to the present invention.

Detailed Description of possible embodiments of the Invention

[0014] The photovoltaic system 200 according to the invention is a solar energy generator fully assembled and completely contained in a small space, with a specific modular structure 100 that allows two modes: compact (or retracted) as shown in figure 2c and open (or deployed) as shown in figure 1 b. An intermediate or semi expanded position of the photovoltaic system 200 is shown in figure 2b.

[0015] The coexistence of these two modes is based on the fact that a pair of photovoltaic panels 48a, 48b (see figure 4) are disposed on two pantographs 42, 42', each of which comprises two bars 46a, 46b and two levers 44a, 44b moveably attached together at four articulation points (p1 , p2, p3, p4) forming a pivoting joint and defining together a parallelogram. These pantographs 42, 42' are preferably actuated by an electromechanical system which is itself controlled by a switch in the manual mode, or an electronic device control.

[0016] These bars 46a, 46b and levers 44a, 44b are connected together by pivoting joints/articulations points, form together two pantographs 42, 42' allowing a movement similar to the movement of an "accordion " . [0017] In the retracted position, the modular structure 100 as shown in figure 2a presents itself in the form of a group of vertical photovoltaic panels 48 horizontally stacked very tightly and, borne by a basement (12) which allows the lifting and the transportation of the assembly as a monolithic object.

[0018] In one preferred embodiment, in the retracted position each panel 48 has its whole surface completely covered by the adjacent panel ensuring thereby the absence of exposition to light of the considered panel 48. A cover 60 is then used to avoid the exposition to light for the last panel 48.

[0019] In the deployed or expanded position shown in figure 1 a the modular structure 100 with several segments 40 _Ί , 40 ₂ , 40 ₃ , ...40 _n of two panels 48, has all panels 48 parallel on the ground arranged to provide maximum surface exposure to the sun.

[0020] In another preferred embodiment shown in figure 1 b, in the extended or expanded position of the modular structure 100, the panels 48 can be inclined with respect to the ground with a slight angle β (for instance between 5 and 45°). In figure 1 b, the photovoltaic system 200 is shown with the modular structure 100 and the open box 70.

[0021] This ability to retract the photovoltaic system 200 allows the use of the system 200 under conditions and on surfaces where it is hard to provide a fixed photovoltaic system. [0022] Sports facilities such as tennis courts or soccer fields, private gardens with little or no use in day backyards are all surfaces that can be converted as solar power plants, within a few hours a day and return to their original function in within less than a minute.

[0023] The possibility to retract the system 200 allows a photovoltaic system, when installed on a flat roof with large dimensions, to be controlled by the fire alarm system and thus retract before the fire brigade arrives, providing the entire surface and security necessary for their operation since the photovoltaic panels are inactive when the system is in compact mode. [0024] Figure 1 a shows a modular structure 100 for photovoltaic panels 48 which comprises a frame 10, a plurality of segments 40 _Ί , 40 ₂ ...40 _n . Each segment 40 _Ί , 40 ₂ ...40 _n comprises at least two photovoltaic panels 48a, 48b and at least two pantographs 42, 42' mounted to the two lateral sides of the photovoltaic panels 48a, 48b. As mentioned above the pantographs 42, 42' are configured to move reversibly from a retracted position to an expanded position.

[0025] Figures 3a and 3b show enlarged views of the frame 10. The frame 10 comprises a basement 12 and two arms 14, 14' which lower end 14a, 14'a are attached to the basement 12 with a pivoting articulation. Also each arm 14, 14' cooperates with a pantograph 42, 42' of the first segment

[0026] As can also be seen in the figures 3a, 3b, the frame 10 further comprises two secondary arms 16, 16'. Each secondary arm 16, 16' has respectively a lower portion B0, B'O respectively attached to the pantograph with an articulation joint (at the lower end portion B1 , B1 ' of the first levers 44b, 44b' visible in figure 4) and an upper portion B3, B'3 respectively attached to an intermediate point C2, C'2 of the respective arms 14, 14' with an articulation joint. Also, preferably, the lower portions B0, B'O of the secondary arms 16, 16' comprises a roller 56.

[0027] In the embodiment illustrated in figures 3a and 3b, in the frame 10, are mounted two parallel material axis 24a, 24b formed by a first material axis 24a which is fixed to the basement 12, and a second material axis 24b which ends are respectively attached to the upper portion AO, AO' of said arms 14, 14'. In order to guide the movement from the retracted position to the extended position and vice versa, an X-shape spider 26 with four ends is used. Each end of the X-shape spider 26 is equipped with one sliding element 28a, 28b, 30a, 30b. These sliding element 28a, 28b, 30a, 30b are mounted on the two material axis 24a, 24b as follows. A first pair of sliding elements 28a, 28b is slidably mounted on the first material axis 24a and a second pair of sliding elements 30a, 30b is slidably mounted on the second material axis 24b. [0028] In the present document the term "X shape spider" 26 constitutes two crossed rods attached together so as to pivot with respect to the other from :

-a first closed position wherein the two rods are almost parallel to each other, with the smallest angle a defined between the two rods being a very small angle of a few degrees

to

- a second open position wherein the two rods define between them an X shape with the previous angle a being now larger than 20°, and preferably larger than 45°, and vice versa.

[0029] Furthermore, in this test, the term "Slidably" means that one sliding element is mechanically cooperating with a material axis in such that the sliding element can slide along the material axis"

[0030] As Referred to figure 4 an example of one segment 40 comprising two photovoltaic panels 48a and 48b, and two pantographs 42 and 42' has been considered for simplicity but the segment 40 in the context of this invention can also comprises more than two in line panels 48 (for instance three, four or more panels 48). With more than two panels 48 the segment 40 would require more than two in line pantographs 42, that can be considered also as two side enlarged pantographs, each of which comprises as many rods and as many bars as photovoltaic panels 48.

[0031] As can be seen in this figure 4 each pantograph 42, 42' of the segment 40 comprises two parallel mobile levers 44a, 44b and two parallel bars 46a, 46b pivoting and connected to each other by four articulations points p1 , p2, p3, p4 defining together a parallelogram. The two pantographs 42, 42' sustain two photovoltaic panels 48a, 48b. Each of the two pantographs 42, 42' forms a shape constituted by two Xs which are in line and in which the panel 48a (48b) is carried by one of the two Xs of each pantograph 42, 42', namely by one mobile lever 44a (44b) and one bar 46a (46b). Each pantograph is attached by said articulation points p1 , p2, p3 and p4 to a respective side of the two panels 48a, 48b. For each pantograph, two adjacent articulation points p1 and p2 are mounted to one panel 48a of the two panels and two other adjacent articulation points p3 and p4 are mounted to the other panel 48b of the two panels.

[0032] In a preferred embodiment, as shown in figures 4, the levers 44a and 44b are placed and fixedly attached along one of the two lateral side of the two panels 48a, 48b of the segment 40 and the bars 46a and 46b are placed and fixedly attached along one of the two lateral sides of the two panels 48a, 48b of the segment 40. This is valid for the other side of the segment 40 with the same references signs amended with the punctuation sign prime as follows " ' " [0033] In one embodiment each articulation point p1 , p2, p3, p4 comprises a shaft 52 (shown in figure 5) fitted in the bars 46a, 46b.

[0034] In the embodiment shown in figure 5 the shaft 52 is fitted into a swivel bearing 50. Another embodiment without the swivel bearing 50 is also possible. [0035] As mentioned above the figure 4 shows for simplicity an example of one segment 40 comprising two photovoltaic panels 48a and 48b in one piece, and two pantographs 42 and 42' but according to furthers aspects of the present invention, If W and L are respectively considered as the width and the length of the panel 48a, the panel 48a can have dimensions nxL and nxW and different configurations.

[0036] A particular example of this variant is shown in figure 8a where the panel 48a' has twice the width of the panel 48a. In this case the distance between the two pantographs 42, 42' sustaining the panel 48a' is twice the distance between the two pantographs 42, 42' sustaining the panel 48a. In this case, the length of the two mobile levers 44a, 44b and of the two mobile bars 46a, 46b is the same than for the two pantographs 42, 42' sustaining the panel 48a.

[0037] Another particular variant of this embodiment is shown in figure 8b. The panel 48a" has twice the length of the panel 48a (2L) but same width W. In this case, the lengths of the levers 46a, 46b and the bars 44a, 44b must be adapted and made longer so that light exposure is possible on all the panels 48a" of the corresponding segment(s) supporting this type of panels 48a". Preferably, in this case, the length of the levers 46a, 46b and of the bars 44a, 44b is twice the length of the levers 46a, 46b and the bars 44a, 44b used for panels 48a. In this case, the distance between the two pantographs 42, 42' sustaining the panel 48a" is the same than for sustaining the panel 48a.

[0038] Another particular variant of this embodiment is depicted in figure 8c. The panel 48a'" has twice the length (2L) and twice the width (2W) of the panel 48a. In this case, the lengths of the levers 46a, 46b and the bars 44a, 44b must be adapted so that light exposure is possible on the panels, and the distance between the two pantographs 42, 42' must also be adapted so that the two pantographs 42, 42' can sustain them. Other values of the dimensions (length and width) of the photovoltaic panels not shown in the drawings can also be possible.

[0039] All considerations made here are applied to a plurality of segments and respective side of the segments.

[0040] For attaching the frame 10 to the segment 40, considering the segment 40 in figure 4 being the first segment, a lower portion B1 of the levers 44b of the pantographs 42 are attached by a pivoting joint to the lower portion B0 of the secondary arm 16 and wherein an upper portion A1 of the bar 46b of the pantograph 42 are attached by a pivoting joint to an upper portion AO of the arm 14 of the frame 10. The same is done for the other side of the segment meaning that a lower portion ΒΊ of the levers 44'b of the pantographs 42' are attached by a pivoting joint to the lower portion B'O of the secondary arm 16' and wherein an upper portion ΑΊ of the bars 46'b of the pantograph 42' are attached by a pivoting joint to an upper portion AO' of the arm 14' of the frame 10. [0041] A pair of railroads 20, 20' are necessary since each rail road is placed along a side of the basement 12 for the rolling of a corresponding roller 56 (during the opening or the closing of the X-shape spider 26) when the segment 40 move reversibly from the retracted position to the expanded position and from the expanded position to the retracted position. Such railroads 20, 20' can be formed by U-bend channels attached to the basement lateral sides, or formed by the basement lateral portions when the basement 12 is made from a folded metal sheet.

[0042] For an automatic moving of the two photovoltaic panels 48a, 48b out of (within) the box 70 into the extended (retracted position), a mechanism allows closing or opening of the X shaped spider 26, where closed position of the X shaped spider 26 corresponds to the retracted position of the segment and open position of the X shaped spider 26 corresponds to the deployed position of the segment.

[0043] In one embodiment shown in figures 3a and 3b, the mechanism is driven by an actuator 32 imposing the sliding of one of the sliding elements 28a, 28b, 30a, 30b on the respective material axis 24a, 24b.

[0044] Also at least two wheels 54, 54' are necessary for each segment 40 with at least one wheel for each pantograph 42, 42 '. These two wheels 54, 54' are placed in a lower most position of the corresponding pantograph 42 or 42', for the rolling of a corresponding wheel 54, 54' when the segment 40/ pantograph 42, 42' move reversibly from the retracted position to the expanded position and vice versa.

[0045] For the proper functioning of the structure, the segment 40 further comprises four gas cylinders 22a, 22b or gas springs used as counterweight for the panels during the passage from the retracted position to the expanded position. Two ends of each gas cylinder 22a, 22b are respectively attached to a bars 46a, 46b and to a levers 44a, 44b of a pantograph 42, 42'. This is valid for the other side of the segments.

[0046] In other embodiment the shaft 52 is a hollow shaft. As shown in figure 1 a, for collecting energy using an electrical module 59 placed in each panel 48, an electrical wire 58 is located within the panels 48 and connected to the modules 59. The end of electrical wire 58 passes through the hollow shaft.

[0047] Figures 1 b, 2b and 2c illustrate a photovoltaic system 200 for generating electric power which comprises a modular structure 100. The structure has a plurality of segments 40 _Ί , 40 ₂ , 40 _n placed in line and attached together by the ends of the pantographs. Each segment is attached to the next segment by attaching the upper portion A2 and the lower portion B2 of the segment respectively to the upper portion A1 , the upper portion B1 of the next segment. This is valid for the other side of the segment.

[0048] An open box 70 is used to accommodate the modular structure. When the whole system is in the retracted position, the modular structure 100 is completely located within said box 70 as shown in figure 2c. In this case a cover 60 is used allowing closing the box and preventing panels to capture light. The cover 60 is attached to the last segment 40 _n (considering that the segment in figure 4 is the last segment) by attaching upper portion A2 and lower B2 of the segment respectively to upper portion Ac and lower portion Be of the cover 60.

[0049] In another non-shown embodiment, the cover 60 and the box 70 are articulated by a hinge so as to open the box 70 when the modular structure 100 is to be expanded.

[0050] In another embodiment M x 2 photovoltaic systems 200 can be placed in a container 300 as shown in figure 7. M and 2 are the number of systems placed in the container 300 respectively in the length and the width directions. For example a container 300 can contain 10 x 2 systems 200. As shown in Figure 7 in dotted line, the photovoltaic systems 200 are oriented within the container 300 so as to expand outwardly from the long sides of the container 300. Reference numbers used on the drawings

10 Frame

12 Basement

14 and 14' Arms of the frame 10

14a and 14'a Lower portions of the arms 14 and 14' of the frame 10

16 and 16' Secondary arms 16 and 16' of the frame

20 and 20' Railroad

22a and 22b Gas cylinders on pantograph 42

24a and 24b First and second material axis

26 X shape spider

a Angle between the two rods of the X shape spider

28a and 28b Sliding element on first material axis

30a and 30b Sliding element on second material axis

AO, AO' Upper portions of the arms 14 and 14' of the frame 10

B0, B'O Lower portions of the secondary arms 16 and 16' of the frame 10

B3 and B3' Upper portions of the secondary arms

C2 and C'2 intermediate points of the respectively arms 14, 14'

40 Segment

40i, 40 ₂ ..., 40 _n Succession of segments

42 and 42' Pantograph on one side and other side of the segment

44a and 44b Levers of the pantograph of one side

46a and 46b Bars of the pantograph of one side

48 Panels

48a and 48b Panels on one segment

W Width of the panel

L Length of the panel

β Inclination of the panel with respect to the ground

50 Swivel bearing

52 Shaft

54 Wheel

56 Roller

59 Electrical module

58 Electrical wire 60 Cover

70 Box

P1 , p2, p3, p4 Articulations points

A1 , B1 Upper and lower portion of respectively for the bar and the lever

A2, B2 Upper and lower portion of respectively for the lever and the bar

60 Cover

Ac, Be Upper and lower portions of the cover

70 Box

100 Modular structure

200 Photovoltaic system

300 Container