TECHNICAL FIELD

The invention concerns in general the technical field of solar panels. Especially the invention concerns solar panels suitable to be adapted along three- dimensional surfaces and methods for manufacturing such solar panels.

BACKGROUND

Solar panels are typically made of silicon wafers, crystalline or polycrystalline, or by depositing material on a thin metal or organic film. Silicon wafer can be polished to be very thin and thus capable of being bent over cylindrical or cane shapes, in generally over any 2.5-dimensional (2.5D), or pseudo-3- dimensional (pseudo-3D), shape, but cannot be stretched over 3D surfaces or shapes, for example over a ball.

Thin film substrates have the same problem. Even though they are very thin, thus good for flexible solar panels that can be for example rolled for carrying, the substrate does not allow any stretching and, thus cannot be adapted along 3D surfaces.

There is still need for a solar panel which can be adapted on an actual 3D surface without breaking or causing damage to the solar panel. SUMMARY

An objective of the present invention is to provide solar panels suitable for adapting along a 3D surface and a method for manufacturing thereof.

The objectives of the present invention are reached by a solar panel and a method defined by the respective independent claims. According to a first aspect of the present invention, a solar panel for being adapted substantially along a three-dimensional surface is provided. The solar panel comprises a plurality of sub-panels, such as electrically series- or/and parallel-connected sub-panels. Each one of the plurality of sub-panels comprises at least one solar cell or, e.g., several solar cells connected electrically in series or/and in parallel. The solar panel further comprises at least one integrating portion arranged between two adjacent of the plurality of sub-panels. The at least one integrating portion attaches the two adjacent of the plurality of sub-panels to each other and is configured to enable a change of positions of the two adjacent of the plurality of sub-panels relative to each other for adapting the solar panel substantially along the three-dimensional surface.

Substantially along a three-dimensional surface refers herein, for example, to a situation where the solar panel has a form that corresponds to the form of the 3D surface along which it is to be adapted. The solar panel may or may not be or become in contact with the 3D surface once adapted.

The solar panel may further comprise the sub-panels being more rigid than the at least one integrating portion. The solar panel may additionally comprise a board, which is preferably rigid, on which the at least one solar cell comprised in one of the plurality of sub- panels is being arranged on. The board may be arranged on the opposite side of said solar cell with respect to a side of the solar panel adapted for receiving electromagnetic radiation, such as electromagnetic radiation from the sun or from an artificial light sources such lamps or light bulbs.

The at least one integrating portion may be configured to enable the changing of positions of the two adjacent of the plurality of sub-panels relative to each other pivotally with respect to a first axis of the at least one integrating portion. The first axis refers herein to an axis, real or imaginary, extending within the at least one integrating portion and substantially in parallel with a longitudinal axis of the at least one integrating portion.

The solar panel may comprise at least three sub-panels and at least two integrating portions, each one of the integrating portions arranged between two adjacent of the at least three sub-panels. The at least two integrating portions may, advantageously, be arranged only between different two adjacent of the at least three sub-panels with respect to others of the at least two integrating portions such that only one sub-panel may be common. At least one of the at least two integrating portions may, advantageously, comprise the first axis to be un-parallel with respect to at least one other of the at least two integrating portions.

According to a second aspect, a method for manufacturing a solar panel for being adapted substantially along a three-dimensional surface is provided. The method comprises

- obtaining a plurality of solar cells,

- arranging the obtained plurality of solar cells on a plane, the arranged obtained plurality of solar cells being arranged to form a plurality of sub-panels each one of which comprises at least one solar cell, and - covering continuously with a first surface layer the arranged obtained plurality of solar cells comprised in the plurality of sub-panels and at least a gap between two adjacent of the plurality of sub-panels to form at least one integrating portion extending the first surface layer continuously over the gap between the two adjacent of the plurality of sub-panels, thus attaching the two adjacent of the plurality of sub-panels to each other, the first surface layer arranged on the opposite side of the plurality of solar cells with respect to a side of the solar panel adapted for receiving electromagnetic radiation, that is with respect to the side of the plurality of solar cells adapted for receiving electromagnetic radiation, wherein the at least one integrating portion configured to enable a change of positions of the two adjacent of the plurality of sub-panels relative to each other.

The method may further comprise utilizing a board, such as a printed wiring board or a printed circuit board, providing the plane on which the plurality of solar cells may be arranged on. Furthermore, the plurality of sub-panels may then be separated from the rest of the plurality of sub-panels by removing the parts of the board between the plurality of sub-panels and by removing the respective parts of the first surface layer to said removed parts of the board other than the parts of the first surface layer forming the at least one integrating por- tion.

The expression "a plurality of" refers herein to any positive integer starting from two, e.g. to two, three, or four.

The terms "first" and "second" do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The exemplary embodiments of the invention presented in this patent application are not to be interpreted to pose limitations to the applicability of the appended claims. The verb "to comprise" is used in this patent application as an open limitation that does not exclude the existence of also un-recited features. The features recited in depending claims are mutually freely combinable un- less otherwise explicitly stated.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objectives and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF FIGURES

The embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. Figures 1 A and 1 B illustrate schematically a solar panel according to an embodiment of the present invention in two different positions.

Figures 2A and 2B illustrate schematically a solar panel according to an embodiment of the present invention in two different positions. Figures 3A and 3B illustrate schematically a solar panel according to an embodiment of the present invention in two different positions.

Figure 4 illustrates schematically a solar panel according to an embodiment of the present invention. Figure 5 illustrates schematically a solar panel according to an embodiment of the present invention adapted along an imaginary 3D surface (the actual surface not shown).

Figures 6A-6C illustrate schematically sectional views of a solar panel according to an embodiment of the present invention. Figure 7 illustrates a flow diagram of a method according to an embodiment of the present invention.

Figure 8 illustrates a flow diagram of a method according to an embodiment of the present invention.

DESCRIPTION OF SOME EMBODIMENTS Figures 1 A and 1 B illustrate schematically a solar panel 100 according to an embodiment of the present invention. In Fig. 1 A, the solar panel 100 is illustrated in a flat position 1000A. In Fig. 1 B, the solar panel 100 is illustrated in a position adapted, or adaptable, along a 3D surface 1000B, not just along a 2.5D or a pseudo-3D surface. An example of a 3D surface is a surface of a ball.

The solar panel according to an embodiment in Figs. 1 A and 1 B comprises a plurality of sub-panels 1 10. Each one of the sub-panels 1 10 comprises at least one solar cell. The solar panel 100 further comprises at least one integrating portion 120 arranged between two adjacent sub-panels 1 10. The at least one integrating portion 120 attaches the two adjacent of the plurality of sub-panels 1 10 to each other. The at least one integrating portion 120 is further configured to enable a change of positions of the two adjacent of the plurality of sub- panels 1 10 relative to each other. According to an embodiment of the present invention, the solar cells may be typical crystalline silicon solar cells or any other suitable type of solar cell.

According to an embodiment of the present invention, the diameter of a sub- panel 1 10 may advantageously be from about 0.1 centimeter to about 50 cen- timeter. More advantageously, the diameter of a sub-panel 1 10 may be from about 1 centimeter to about 35 centimeters. Most advantageously the diameter may be from 5 centimeters to about 10 centimeters. Smaller sub-panels 1 10 enable the solar panel 100 to be adapted better along 3D surfaces, especially the surfaces having complex 3D form. According to an embodiment of the present invention, the solar panel 100 may comprise at least three sub-panels 1 10 and at least two integrating portions 120. Each one of the integrating portions 120 may be arranged between two adjacent of the at least three sub-panels 1 10.

According to an embodiment of the present invention, the at least two integrating portions 120 may, advantageously, be arranged only between different two adjacent of the at least three sub-panels 1 10 with respect to others of the at least two integrating portions 120 such that only one sub-panel 1 10 may be common. In Fig. 1 A, there are six sub-panels 1 10 and five integrating portions 120, wherein each one of the five integrating portions 120 is arranged between different two adjacent sub-panels 1 10 with at most one of the sub-panels 1 10 being common to any two of the integrating portions 120.

According to an embodiment of the present invention, at least one of the at least two integrating portions 120 may, advantageously, comprise the first axis 130 to be un-parallel with respect to at least one other of the at least two inte- grating portions 120. In Fig. 1 A, all of the first axes 130 are un-parallel.

According to an embodiment of the present invention, the area 150 of the face surface of the at least one solar cell forms at least partly the area of the face surface of the one of the plurality of sub-panels 1 10 comprising said at least one solar cell. According to another embodiment of the present invention, said face surfaces may, preferably, be substantially parallel with respect to each other.

According to an embodiment of the present invention, the change of positions of the two adjacent of the plurality of sub-panels 1 10 may be pivotal around a first axis 130 of the at least one integrating portion 120.

The first axis 130 refers herein to an axis, real or imaginary, which extends within the at least one integrating portion 120 and is substantially in parallel with a longitudinal axis 130, 650 of the at least one integrating portion 120.

According to an embodiment of the present invention, the change of positions of the two adjacent of the plurality of sub-panels 120 may be in twisting manner around a second axis 140. The second axis 140 herein refers to an axis which is substantially perpendicular to the first axis 130 of the at least one integrating portion 120. The second axis 140 may be substantially parallel with face surfaces of the sub-panels 140 when the solar panel 100 is in the flat po- sition 1000A.

According to an embodiment of the present invention, the first surface layer 500 may be made of a material, preferably a transparent material, enabling the change of positions of the two adjacent of the sub-panels relative to each other. The first surface layer may, in addition to its property of transmitting elec- tromagnetic radiation through it, protect the solar cells from forces external to the solar panel. The material may be, for example, polyethylene terephthalate (PET) or polyethylene terephthalate, ethylene tetrafluoroethylene (ETFE) or polyethene-co-tetrafluoroethene. According to an embodiment, the thickness of the first surface layer may be from 0.2 to 0.7 millimeters, preferably from 0.3 to 0.6 millimeters, and most preferably about 0.5 millimeters.

Figures 2A and 2B illustrate schematically a solar panel 100 according to an embodiment of the present invention. In Fig. 2A, the solar panel 100 is in the flat position 1000A, and in Fig. 2B, the solar panel 100 is illustrated in a position adapted, or adaptable, along a 3D surface 1000B. According to the em- bodiment of the present invention in Figs. 2A and 2B, the at least one integrat- ing portion 120 may be wider than depicted in Figs. 1 A and 1 B. This provides a continuous face surface of the solar panel 100.

According to an embodiment of the present invention, the solar panel 100 as a whole may be adapted along a 3D surface by choosing the positions of the at least one integrating portion 120 appropriately. This may be achieved by ensuring that in case of plurality of integrating portions 120, such as at least two, the first axes 130 of the integrating portions 120 are not parallel with respect to each other but include at least one of the axes having a different direction relative to the axes of the rest of the integrating portions 120. Figures 3A and 3B illustrate schematically a solar panel 100 according to an embodiment of the present invention in two different positions. In Fig. 3A, the solar panel 100 is in the flat position 1000A, and in Fig. 3B, the solar panel 100 is illustrated in a position adapted, or adaptable, along a 3D surface 1000B. Figs. 3A and 3B show an embodiment of the integrating portion 120 according to another embodiment of the present invention. By having the integrating portion comprising multiple portions with substantially the same first axes 130, the attachment between the two adjacent sub-panels 1 10 may be made stronger while making the face surface of the solar panel 100 more uniform compared to the embodiment of the present invention shown in Figs. 1 A and 1 B. The so- lar panel 100 may also comprise means for alignment which may be configured to align with the space or spaces between the multiple portions of the at least one integrating portion 120.

Figure 4 illustrates schematically a solar panel 100 according to an embodiment of the present invention. The embodiment of the solar panel 100 in Fig. 4 further illustrates the way of positioning the at least one integrating portion 120, in this case eleven, for adapting the solar panel 100 along a 3D surface. In this case, the different first axes 130 of the integrating portions 120 are substantially parallel or perpendicular relative to each other.

Figure 5 illustrates schematically from a perspective view a solar panel 100 according to an embodiment of the present invention adapted, or adaptable, along a 3D surface (the actual surface not shown). As can be seen in Fig. 5, the solar panel 100 according to an embodiment of the present invention may be adapted along an actual 3D surface, not just along a 2.5D or a pseudo-3D surface. Figure 6A illustrates schematically by a sectional view a solar panel 100 according to an embodiment of the present invention. In Fig. 6A, the solar panel 100 comprises solar cells 510, or sub-panels 1 10, on a flat surface or a plane. The solar cells 510 as well as a gap between at least one of the two adjacent of the solar cells 510 may be covered with a first surface layer 500. The first surface layer 500 may, advantageously, be arranged on the side of the solar cells 510 adapted for receiving electromagnetic radiation, such as electromagnetic radiation from the sun or from artificial light sources such as lamps or light bulbs, for the solar cells 510 to convert into electrical energy, including the operating conditions from an open-circuit to a short-circuit condition. According to an embodiment shown in Fig. 6A, the solar cells 510 may further be covered with a second attaching layer 605 which may be arranged between the solar cells 510 and the first surface layer 500. The second attaching layer 605 may be made of a material, preferably a transparent material, such as pol- yurethane encapsulate, ethylene-vinyl acetate (EVA) or polyethylene-vinyl ace- tate, or hot melting filler. The second attaching layer 605 may be used to attach the first surface layer 500 to the solar cells and/or to the sub-panels 1 10. According to an embodiment, the thickness of the first surface layer may be from 0.1 to 1 .0 millimeters, preferably from 0.4 to 0.7 millimeters.

According to an embodiment of the present invention, as shown also in Fig. 6A, there may be a board 615 arranged on the opposite side of the solar cells 510 with respect to the first surface layer 500. The board 615 may advantageously be rigid or at least more rigid than the first surface layer 500. The board 615 may preferably provide a plane for arranging the solar cells 510 having their face surfaces to be in parallel relative to each other. According to an embodiment of the present invention, the solar panel 100 may comprise a board 615 on which the at least one solar cell 510 comprised in one of the plurality of sub-panels 1 10 is being arranged on. The board 615 may be arranged on the opposite side of said solar cell 510 with respect to a side of the solar panel 100 adapted for receiving electromagnetic radiation, such as electromagnetic radiation from the sun or from artificial light sources such as lamps or light bulbs.

According to an embodiment of the present invention, the board 615 may preferably be a printed wiring board (PWB) or a printed circuit board (PCB). The board 615 may also be made of any other suitable, preferably substantially rigid, material.

Figures 6B and 6C illustrates schematically by sectional views of a solar panel 100 according to an embodiment of the present invention in which the solar panel 100 is illustrated in a flat position 1000A in Fig. 6B, and in a position adapted, or adaptable, along a 3D surface 1000B in Fig. 6C. Fig. 6B illustrates similar elements as shown in Fig. 6A with the difference that a part of the board 615 has been removed from the gap between the solar cells 615 or the sub-panels 1 10. The part may preferably be such that it extends through the board 615 and at least part of the second attaching layer 605, if any. According to an embodiment of the present invention, the at least one integrating portion 120 may comprise, in addition to a portion of the first surface layer 500 between two adjacent of the plurality of sub-panels 1 10, at least part of the second attaching layer 605, as shown in Figs. 6B and 6C.

According to an embodiment of the present invention, the part of the board removed may be such that it does not extend completely through the board 615 but leaves a small part intact which still enables the change of positions of the two adjacent of the plurality of sub-panels 1 10 or solar cells 510 relative to each other. According to an embodiment, the small part intact of the board 615 may also be comprised in the at least one integrating portion 120. According to an embodiment of the present invention, a part of the second attaching layer 605 may be removed from the gap between the solar cells 615 or the sub-panels 1 10. The part of the second attaching layer 605 may preferably be such that it extends through the second attaching layer 605. According to an embodiment of the present invention, the part is such that it does not extend completely through the second attaching layer 605 but leaves a small part intact which still enables the change of positions of the two adjacent of the plurality of sub-panels 1 10 or solar cells 510 relative to each other.

Figures 6B and 6C further illustrate a longitudinal axis 650 in accordance with an embodiment of the present invention. The point 650 representing the longitudinal axis 650 is within the at least one integrating portion 120 and extends between the two adjacent sub-panels 1 10 or solar cells 510. The first axis or axes 130 of the at least one integrating portion 120 according to an embodiment of the present invention may substantially be parallel with the longitudinal axis 650. According to an embodiment of the present invention, the first axis or axes 130 may be aligned with the longitudinal axis or axes 650 of the at least one integrating portion 120.

According to an embodiment of the present invention, there may be electrical connection means 660, such as a conductor, arranged within the material of the at least one integrating portion 120 to electrically interconnect two sub- panels 1 10. According to an embodiment, the two sub-panels 1 10 are not adjacent sub-panels 1 10 but the electrical interconnection may be formed between two sub-panels 1 10 that do not have a common integrating portion 120.

According to an embodiment of the present invention, the sub-panels 1 10 of the solar panel 100 are substantially rigid. According to an embodiment of the present invention, the sub-panels 1 10 are more rigid than the at least one integrating portion 120 which is configured to enable the change of positions of the two adjacent of the plurality of sub-panels 1 100 relative to each other.

According to an embodiment of the present invention, the solar panel 100 comprises electrical connection points 400 disposed on the opposite side of the plurality of sub-panels 1 10 with respect to a side of the solar panel 100 adapted for receiving electromagnetic radiation.

Figure 7 illustrates, at 700, a flow diagram of a method for manufacturing a solar panel 100 according an embodiment of the present invention. At 710 refers to a start-up phase of the method. Suitable materials, systems and machinery are obtained for manufacturing a solar panel 100 according to an embodiment the present invention.

At 720, a plurality of solar cells 510 is obtained. These may be self- manufactured or obtained from a solar cell provider. At 730, the plurality of solar cells 510 is arranged, preferably on a plane, to form a plurality of sub-panels 1 10 each one of which comprises at least one solar cell 510. In this step, the sub-panels 1 10 or the solar cells 510 may be interconnected by electrical connection means, such as conductors, to each other. In this step, if one sub-panel 1 10 comprises more than one solar cell 510, the solar cells 510 may be appropriately connected electrically in series or/and in parallel to form a sub-panel 1 10 with at least part of the solar cells 510 electrically interconnected. The solar cells 510 may be arranged such that they are grouped physically close to each other such that distinctive groups or sets of solar cells 510 are being formed representing the sub-panels 1 10. The grouping may also be performed with respect to the 3D surface along which the solar panel 100 may, or is designed to, be adapted. In this step, the sub- panels 1 10 may also be electrically interconnected by electrical connection means 660 in series or/and in parallel in an appropriate manner with respect to the 3D surface or, for example, with regard to an interfacing device or an elec- tronic load to be connected to the solar panel 100.

At 740, the solar cells 510 or sub-panels 1 10 and at least one gap between two adjacent of the solar cells 510 or sub-panels 1 10 are covered with a first surface layer to from at least one integrating portion 120 for providing a continuous face surface of the solar panel 100. According to an embodiment of the present invention, electrical connection means 660, such as a connector or connectors 660, may be arranged to be comprised in the at least one integrating portion 120, for example, within the material of the at least one integrating portion 120. The electrical connection means 660 may thus be arranged, for example, within, on or along the part of the first surface layer 1 10, the part of the second attaching layer 605, or the intact part of the board 615 comprised in the integrating portion 120.

Method execution is ended at 750 at which the solar panel 100 for adapting along a 3D surface has been manufactured.

Figure 8 illustrates, at 800, a flow diagram of a method for manufacturing a so- lar panel 100 according an embodiment of the present invention.

The start-up phase 810 may be similar to the start-up phase 710 in Fig. 7.

At 820, a plurality of solar cells 510 and a board or multiple boards 615 are obtained. The solar cells may be self-manufactured or obtained from a solar cell provider. The board or boards 615 may preferably be PWBs or PCBs. Step 830 is similar to the step 730 in Fig. 7 except the plurality of solar cells 510 is arranged on the board 615 to form a plurality of sub-panels 1 10 each one of which comprises at least one solar cell 510.

At 840, the solar cells or sub-panels 1 10 and at least one part of the board 615 between two adjacent of the solar cells 510 or sub-panels 1 10 are covered with a first surface layer 500 to from at least one integrating portion 120 for providing a continuous face surface of the solar panel 100. According to an embodiment of the present invention, electrical connection means 660, such as a connector or connectors 660, may be arranged to be comprised in the at least one integrating portion 120. At 850, at least one of the plurality of sub-panels 1 10 are separated from the rest of the plurality of sub-panels 1 10 by removing the parts of the board 615 between the plurality of sub-panels 1 10 and by removing the respective parts of the first surface layer 500 to said removed parts of the board 615 other than the parts of the first surface layer 500 forming the at least one integrating portion 120.

Method execution is ended at 860 at which the solar panel 100 for adapting along a 3D surface has been manufactured. According to an embodiment of the present invention, the separation may be performed by engraving the part of the board by, e.g., sawing or laser cutting or etching.

According to an embodiment of the present invention, the steps 840 and 850 may be performed in any order. The sub-panels 1 10 may be first separated from each other by removing the parts of the board 615 between the sub- panels 1 10 after which the sub-panels 1 10 as well as the at least one gap between two adjacent of the sub-panels 1 10 may be covered to form at least one integrating portion 120 attaching the two adjacent sub-panels 1 10 to each other. According to an embodiment of the present invention, the second attaching layer 605 may melt when the first surface layer 500 is being laminated on the second attaching layer 605 thus filling gaps between the first surface layer 500 and the solar cells and the board 615, if any, as well as flows away from thicker parts such as electrical connection means. The second attaching layer 605, when melting, may also form a planar surface for the first surface layer 500.

The solar panel according to an embodiment of the present invention may be used along actual 3D surfaces such as over the surface of a ball or may be arranged along the surface of a device which primary purpose is, for example, transportation or protection and not electrical energy production. A device such as mentioned above may be, for example, a backpack or a safety helmet.

The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.