PHOTOVOLTAIKMODUL

Abstract

A photovoltaic module (1;1A) comprising a front transparent cover (2), which preferably defines a planar or flat reference plane (5) tangential to a main surface of the cover (2) on the outside, a rear cover (3), and an arrangement of photovoltaic cells (4) which are interconnected via an electrical connection structure in a circuit diagram and which are arranged between the front cover (2) and the rear cover (3). At least some, preferably all, of the photovoltaic cells (4) of the arrangement are arranged in an inclined position with respect to their respective photoelectrically active surfaces (4a, 4b), preferably in an inclined position relative to the reference plane (5) defined by the outer surface (2a) of the front cover (2).This provides a PV module that achieves higher power per unit area because a larger total photoelectrically effective surface area can be accommodated within the same external size of the PV module.

Description

[0001] The invention relates to a photovoltaic module, in particular a photovoltaic module for subsequent installation on buildings of all kinds, for roof or facade-integrated installation in buildings or roofs thereof or for installation on open spaces.

[0002] The term photovoltaics is abbreviated as “PV” in the following and may be used synonymously with “solar”.

[0003] For such PV modules, silicon-based semiconductor materials in single-crystal, polycrystalline, or amorphous form are commonly used today, based on so-called "wafers" (disk-shaped substrates), and combinations thereof in the structure of flat or planar rectangular cells connected to each other via an electrical connection structure in a circuit diagram in parallel and / or series. Other semiconductor materials are also used.

[0004] These PV cells have a top or front, flat, photoelectrically active surface onto which the light rays of the desired effective wavelength are directed, providing an electrical voltage at the cell terminals. In so-called "bifacial" PV cells, the opposite, i.e., rear, flat surface is also photoelectrically active, so their use in a PV module can utilize radiation coupling into the PV module from both sides, thus enabling higher performance. For the purposes of the invention, PV cells of various internal compositions, interconnections, and materials can be used.

[0005] In a PV module, also referred to as a "collector," several PV cells are interconnected by the electrical interconnection structure in the circuit diagram and encapsulated in an integral structure. A PV module may also contain other electrical functional components such as circuits and protection devices.

[0006] The structure of the PV module as a functional unit typically comprises a flat, transparent front cover made of glass or plastic, a rear cover, the electrically coupled arrangement of PV cells arranged between the front cover and the rear cover, and often a circumferential frame that surrounds an outer periphery of the PV module including an outer periphery of the front cover and the rear covers and is tightly connected to the covers in order to form the structurally and mechanically sufficiently rigid and usually self-supporting PV module as a finished functional unit for mounting on a suitable external support structure.

[0007] When using bifacial PV cells in a PV module, the rear cover is usually also transparent. Otherwise, this is not required.

[0008] It is also known to arrange a transparent encapsulation material inside the PV module between the PV cells and the front cover and / or the rear cover. This material protects the PV cells from mechanical or corrosive environmental influences and increases rigidity. Polyurethane (PU), ethylene-vinyl acetate (EVA), polyethylene-octene elastomer (POE), or co-extrusion materials integrated with EVA and POE are frequently used for this purpose. These materials are not further specified here, however, because for the purposes of the invention, all encapsulation materials known for use in PV modules can be used.

[0009] Major research efforts are being undertaken to increase the efficiency of PV cells through improved materials, allowing higher amounts of electricity to be generated from a single PV module on the same surface area and under the same solar irradiation. However, the rate of efficiency improvement is limited, and improvements are very costly.

[0010] The object of the invention is to provide a PV module that achieves higher performance per area.

[0011] To solve this problem, the invention proposes a PV module with the features of patent claim 1. Preferred embodiments are specified in the dependent claims.

[0012] The invention therefore relates in particular to a PV module with a front-side transparent cover, which preferably defines a plane or flat reference plane tangential to a main surface of the cover on the outside, a rear cover, an array of photovoltaic cells which are connected to one another in a circuit diagram via an electrical connection structure and which are arranged between the front cover and the rear cover, wherein at least some, preferably all, of the photovoltaic cells of the array are arranged in an inclined position of their respective photoelectrically active surfaces, preferably in a position inclined relative to the reference plane (5) defined by the outer surface (2a) of the front cover (2).

[0013] According to a preferred embodiment, the photovoltaic cells with their photoelectrically active surfaces are arranged next to one another in a transverse direction of the photovoltaic module and / or in a longitudinal direction and / or a diagonal direction of the photovoltaic module, offset and inclined to one another.

[0014] According to a preferred embodiment, the photovoltaic cells with their photoelectrically active surfaces are arranged next to one another in a transverse direction of the photovoltaic module and / or in a longitudinal direction and / or in a diagonal direction of the photovoltaic module, offset parallel to one another.

[0015] According to a preferred embodiment, an angle between the photoelectrically active surfaces of adjacent photovoltaic cells is between 30 and 105 degrees.

[0016] According to a preferred embodiment, the angle of inclination between the photoelectrically active surfaces of the photovoltaic cells and the reference plane is between 15 and 75 degrees, preferably between 30 and 60 degrees.

[0017] According to a preferred embodiment, the photovoltaic cells are bifacial cells and the back cover is transparent.

[0018] According to a preferred embodiment, the photovoltaic cells are fixed in the inclined position by holding elements arranged within the photovoltaic module.

[0019] According to a preferred embodiment, a transparent embedding material is arranged between the photovoltaic cells and the front cover and / or the rear cover.

[0020] According to a preferred embodiment, channels are formed in the embedding material through which a fluid can pass, and the channels are open on the outside of the PV module or communicate with a peripheral collecting channel.

[0021] According to a preferred embodiment, the photovoltaic cells are elongated strips of a flat semiconductor substrate whose long sides are oriented parallel to the reference plane.

[0022] According to a preferred embodiment, the strips of photovoltaic cells are formed by physically dividing larger photovoltaic cells.

[0023] According to a preferred embodiment, the length of the short side of the elongated strips is between 10mm and 30mm.

[0024] According to a preferred embodiment, the photovoltaic cells have an anti-reflection layer and / or a macroscopically structured surface.

[0025] According to a preferred embodiment, the photovoltaic module has a lens arrangement between the front cover and / or the rear cover and the photovoltaic cells in order to direct / diffract light rays coupled into the photovoltaic module in the direction of the photoelectrically active surfaces of the inclined photovoltaic cells.

[0026] According to a preferred embodiment, the photovoltaic module has a frame (7) which surrounds an outer circumference of the photovoltaic module, preferably including an outer circumference of the front cover and the rear covers.

[0027] The invention is described below using preferred embodiments with reference to the accompanying drawings. They show: Fig. 1 shows a schematic cross-section of a PV module according to the invention according to a first embodiment; Fig. 2 shows a schematic cross section of a PV module according to the invention according to a second embodiment; Fig. 3 shows a schematic cross-section of a PV module according to the invention according to a third embodiment; and Fig. 4 a schematic cross section of a PV module according to the invention in a modification of the Fig. 1 according to a fourth embodiment; Fig. 5 a schematic cross section of a PV module according to the invention in a further modification of the Fig. 1 according to a fifth embodiment.

[0028] The PV module according to the invention is a mechanically sufficiently rigid and preferably self-supporting structure which, as a finished functional unit, is suitable for mounting on a suitable external support structure.

[0029] Please note that the PV module and its components, such as PV cells and their spacing, are only schematically illustrated in the figures and can be manufactured with additional components and structures in addition to those shown and described. Please also note that, due to their schematic nature, the figures are not to scale. Therefore, components and structures shown in the figures may be exaggerated or reduced in size for clarity.

[0030] In all embodiments, the PV module 1, 1A, 1B, 1C, 1D, and 1E comprises a front, transparent cover 2, a rear cover 3, and an arrangement or array of PV cells 4, which—as known in the art—are interconnected via an electrical connection structure in a circuit diagram to form so-called "strings" and which are arranged between the front cover 2 and the rear cover 3. The "strings" are, in turn, electrically interconnected to achieve the desired output voltage or current.

[0031] The front cover 2 is preferably flat or planar on the outer side of its main surface, through which the light radiation is coupled, so that the cover 2 is plate-shaped overall. However, the outer surface can also have small, regular or irregular elevations or corrugations, which preferably do not change the planar or flat and plate-shaped character of the cover 2.

[0032] The disclosure also encompasses a structure of a cover which is not entirely flat or planar, possibly with small elevations or corrugations, but which has an overall corrugated or angled outer surface which, for example, follows the inclination of the PV cells described later, but which, when viewed in relation to the entire cover, can still be regarded as plate-shaped.

[0033] In this sense, the outer side of the front cover 2 defines a flat reference plane 5 tangential to the main surface of the cover 2, which, in the case of a flat or planar cover, is congruent with the outer side and, in the case of an overall corrugated or angled outer surface, is parallel to an averaged main extension plane of the cover.

[0034] The rear cover 3 can have any shape on its outer surface, provided that no light coupling occurs through it and it is therefore not transparent. Otherwise, the rear cover can have the same plate-like shape and / or the same material as the front cover, especially, for example, when using bifacial PV cells.

[0035] If the PV module is as Fig. 2, the PV cells 4 are bifacial cells, the rear cover 3 is also preferably transparent. Fig. The variant shown in Figure 4 can, if bifacial PV cells are used, be designed with a transparent rear cover 3, unlike the one shown. For example, in this case, both covers 2, 3 can be made of glass or plastic, or one of the two covers, for example the front cover 2, can be a glass cover and the other of the two covers, for example the rear cover 3, can be a transparent film. If no bifacial PV cells are used, or if radiation coupling from the rear is not required even when using bifacial PV cells because the light radiation coupled in from the front is redirected within the PV module, the rear cover 3 can also be made of a light-impermeable metal or plastic material.

[0036] Furthermore, the PV cells 4 used in the PV module can - as is known per se in the prior art - have an anti-reflection layer and / or a macroscopically structured surface.

[0037] The PV cells 4 are arranged next to one another in the transverse and / or longitudinal or diagonal direction of the PV module, but are generally spaced apart from one another by gaps.

[0038] The electrical connection is established, as is known in the prior art, via electrical lines, so-called "busbars" or contact grids, but can also be achieved by so-called "stitch soldering," in which the ends of adjacent PV cells overlap, so that the desired circuit pattern and the desired output voltage and current are achieved by connecting the PV cells in parallel and series in "strings." The circuit diagram may also take into account the effects of partial shading of individual PV cells within the circuit arrangement, which, when connected in series, can limit the achievable voltage of an entire "string."

[0039] In order to increase the effective area of ​​the total photoelectrically active surface of the PV cells contained in the circuit arrangement accommodated in the PV module for a given size or given external dimensions of the PV module, the invention provides that at least some, preferably all, of the PV cells 4 of the arrangement are arranged in an inclined position of their respective photoelectrically active surfaces 4a, 4b relative to the flat reference plane 5 defined by the outer surface 2a of the front cover 2 (or a plane parallel thereto). The area share of the PV module occupied by the individual PV cells (in plan view) is thereby reduced by a factor of <1, corresponding to the cosine of the respective angle of inclination.This means that more PV cells, or more precisely a larger total photoelectrically effective surface, can be accommodated in a PV module of a given size through a comparatively simple mechanical measure and the performance of the PV module can be increased.

[0040] The PV cells 4 of the arrangement are arranged with their photoelectrically active surfaces 4a, 4b next to one another in the transverse direction of the PV module and / or in the longitudinal direction of the PV module and are preferably arranged inclined to one another, so that, as in Fig. 1 and Fig. 2, in cross-section an alternating V-arrangement and in the direction perpendicular to it a parallel, rib- or roof-like structure.

[0041] In a Fig. 4, these cells can also be arranged with their photoelectrically active surfaces 4a next to one another in a transverse direction of the photovoltaic module 1D and / or offset parallel to one another in the longitudinal direction of the photovoltaic module. This arrangement also achieves an increase in the total photoelectrically active surface for a given dimension of the PV module. This variant of this arrangement can also be combined with the Fig. 1 can be combined within a PV module, so that some PV cells can be aligned in the V arrangement and some PV cells in the parallel arrangement.

[0042] The position of the PV cells, which is preferably inclined to the reference plane 5, is preferably selected such that an angle β between the photoelectrically active surfaces 4a, 4b of adjacent photovoltaic cells 4 within the PV module is between 30 and 105 degrees, and / or the angle of inclination α between the photoelectrically active surfaces 4a, 4b of the PV cells 4 and the reference plane 5 (or the plane parallel thereto) is between 15 and 75 degrees, preferably between 30 and 60 degrees, wherein not all PV cells of the arrangement need to have the same angle.

[0043] To limit the height of the PV module, the PV cells 4 are formed with a rectangular lateral contour with an aspect ratio different from one and preferably as elongated strips of a flat or planar semiconductor substrate whose long sides are oriented parallel to the reference plane 5. Such elongated strips of PV cells 4 are typically formed by physically subdividing larger, rectangular PV cells. Preferably, the length of the short side of the elongated strips is between 10 mm and 30 mm.

[0044] Adjacent PV cells 4 can be arranged in the same orientation or in an alternating manner, laterally reversed to each other and thus with spatially interchanged polarities.

[0045] To maintain the PV cells 4 in the inclined orientation, the PV cells 4 are preferably fixed in the inclined position by retaining elements (not shown) arranged within the PV module. Such retaining elements can be, for example, plastic strips with retaining sections at the desired intervals, into which the PV cells are inserted to achieve a geometrically defined position relative to one another.

[0046] Alternatively or in addition to the holding elements, a transparent embedding material 6 can be arranged between the PV cells 4 and the front cover 2 and / or the rear cover 3, as is known in the prior art. For example, the embedding material can be different on the front side (between the PV cells 4 and the front cover 2) and the rear side (between the PV cells 4 and the rear cover 3). However, a uniform material can also be used. In the invention, for example, polyurethane (PU), ethylene-vinyl acetate (EVA), polyethylene-octene elastomer (POE), or co-extrusion materials integrated with EVA and POE can be used for this purpose, as in the prior art.

[0047] In Fig. Figure 5 shows a variant of the PV module in which channels 8 are formed in the embedding material 6 between the PV cells, through which a fluid can pass, and in which the channels 8 are open on the outside of the PV module to enable passive cooling, or, for example, communicate with a peripheral collecting channel that leads to connections on the outside of the PV module, which in turn can be connected to an external cooling device, such as a heat exchanger. The PV cells inside the PV module can be cooled via this fluid, such as air, in order to counteract a reduction in efficiency associated with rising temperatures. The heat can then be extracted from the fluid outside the PV module through heat exchange, so that the PV module can be used for photoelectric and thermal energy conversion of the coupled solar energy, similar to a known hybrid module.

[0048] In another variant not shown, the PV module can have an optically effective lens arrangement between the front cover 2 and / or the rear cover 3 and the PV cells 4 in order to direct or diffract light rays coupled into the PV module towards the photoelectrically effective surfaces 4a, 4b of the inclined photovoltaic cells 4. This can increase the efficiency of the PV module and, to a certain extent, compensate for an alignment of the effective surface changed by the internal inclination of the PV cells compared to an alignment of the reference plane 5 of the PV module, if this serves as a reference plane for the alignment of the PV module at the installation site.

[0049] As indicated in the first to fifth embodiments, the PV module 1, 1A, 1B, 1C, 1D, 1E preferably has a module frame 7 in which the outer covers 2, 3 of the main surfaces are held with the PV cells 4 arranged therebetween in order to impart greater stability to the PV module or to improve the sealing and protection of the internal components, even in the region of the peripheral edge. The module frame 7 preferably surrounds an outer periphery of the PV module, including an outer periphery of the front cover 2 and the rear covers 3. For this purpose, the module frame 7 has, for example, a U-profile with a front section, a side section, and a rear section. The side section encloses the outer covers 2, 3 at their narrow sides.The front section rests on a peripheral edge section of the front cover 2, and the rear section rests on a peripheral edge section of the rear cover 3. The connections for the electrical power and, if provided, the supply and discharge of a cooling fluid are preferably integrated into the module frame.

[0050] The PV module with the embedding material 6 can be manufactured, for example, by a lamination process in which the embedding material 6, provided, for example, in the form of one or more films on the PV cells, is melted between the outer covers 2, 3. Subsequently, the composite created by lamination can be provided with the module frame 7 surrounding the outer covers and the embedding material.

[0051] At the Fig.In the embodiment shown in Figure 3, the PV cells 4 are not rigid, flat plates, but rather flexible foils bent into a semicircular shape, which may also be a flattened, curved shape, or a U-shape. The inventive concept is applied in this embodiment in that here too, at least sections of the PV cells are arranged with their respective photoelectrically active surfaces 4a, 4b inclined relative to a reference plane 5 defined by the flat outer surface 2a of the front cover 2, and the angle of inclination α can be determined with respect to a tangent to the curved surface in the respective sections. In this variant, too, bifacial or single-sided PV cells and the previously described embedding material, holding elements, and module frames can be used.

[0052] Although partial aspects such as the shape of the PV modules, the cooling channels in the embedding material, the transparent rear cover, etc. are only shown in individual embodiments, these features can also be combined with one another.

Claims

[1] A photovoltaic module (1;1A;1B;1C;1D;1E) with a front, transparent cover (2), a rear cover (3), an arrangement of photovoltaic cells (4) which are connected to one another in a circuit diagram via an electrical connection structure and which are arranged between the front cover (2) and the rear cover (3), wherein at least some, preferably all, of the photovoltaic cells (4) of the arrangement are arranged in an inclined position of their respective photoelectrically active surfaces (4a, 4b). [2] The photovoltaic module (1; 1A; 1B; 1E) according to claim 1, wherein the photovoltaic cells (4) with their photoelectrically active surfaces (4a, 4b) are arranged next to one another in a transverse direction of the photovoltaic module (1; 1A; 1B) and / or in a longitudinal direction and / or a diagonal direction of the photovoltaic module (1; 1A; 1B) offset and inclined to one another. [3] The photovoltaic module (1; 1C; 1D) according to claim 1 or 2, wherein the photovoltaic cells (4) with their photoelectrically active surfaces (4a, 4b) are arranged offset parallel to one another in a transverse direction of the photovoltaic module (1; 1A; 1B) and / or in a longitudinal direction and / or in a diagonal direction of the photovoltaic module (1; 1A; 1B). [4] The photovoltaic module (1;1A;1B;1E) according to claim 1 or 2, wherein an angle (β) between the photoelectrically active surfaces (4a,4b) of adjacent photovoltaic cells (4) is between 30 and 105 degrees. [5] The photovoltaic module (1; 1A; 1B; 1D; 1E) according to one of claims 1 to 4, wherein the angle of inclination (α) between the photoelectrically active surfaces (4a, 4b) of the photovoltaic cells (4) and the reference plane (5) is between 15 and 75 degrees, preferably between 30 and 60 degrees. [6] The photovoltaic module (1;1B;1C) according to any one of claims 1 to 5, wherein the photovoltaic cells (4) are bifacial cells and the back cover (3) is transparent. [7] The photovoltaic module (1;1A;1B;1C;1D;1E) according to one of claims 1 to 6, wherein the photovoltaic cells (4) are fixed in the inclined position by holding elements arranged within the photovoltaic module. [8] The photovoltaic module (1;1A;1B;1C;1D;1E) according to one of claims 1 to 7, wherein a transparent embedding material (6) is arranged between the photovoltaic cells (4) and the front cover (2) and / or the rear cover (3). [9] The photovoltaic module (1; 1E) according to claim 8, wherein channels are formed in the embedding material (6) through which a fluid can pass, and the channels (6) are open on the outside of the photovoltaic module or communicate with a peripheral collecting channel. [10] The photovoltaic module (1;1A;1B;1C;1D;1E) according to one of claims 1 to 9, wherein the photovoltaic cells (4) are elongated strips of a flat semiconductor substrate whose long sides are oriented parallel to the reference plane (5). [11] The photovoltaic module (1;1A;1B;1C;1D;1E) according to claim 10, wherein the strips of photovoltaic cells (4) are formed by physically dividing larger photovoltaic cells. [12] The photovoltaic module (1;1A;1B;1C;1D;1E) according to claim 10 or 11, wherein the length of the short side of the elongated strips is between 10mm and 30mm. [13] The photovoltaic module (1) according to one of claims 1 to 12, wherein the photovoltaic cells (4) have an anti-reflection layer and / or a macroscopically structured surface. [14] The photovoltaic module (1) according to one of claims 1 to 13, wherein the photovoltaic module (1) has a lens arrangement between the front cover (2) and / or the rear cover (3) and the photovoltaic cells (4) in order to direct / diffract light rays coupled into the photovoltaic module in the direction of the photoelectrically active surfaces (4a, 4b) of the inclined photovoltaic cells (4). [15] The photovoltaic module (1;1A;1B;1C;1D;1E) according to any one of claims 1 to 14, wherein the photovoltaic module (1;1A;1B) comprises a frame (7) surrounding an outer periphery of the photovoltaic module (1;1A;1B;1C;1D;1E), preferably including an outer periphery of the front cover (2) and the rear covers (3). [16] The photovoltaic module (1;1A;1B;1C;1D;1E) according to one of claims 1 to 15, wherein the front transparent cover (2) defines a flat reference plane (5) tangential to a main surface of the cover (2) on the outside, and wherein at least some, preferably all, of the photovoltaic cells (4) of the arrangement are arranged in a position of their respective photoelectrically active surfaces (4a, 4b) inclined relative to the reference plane (5) defined by the outer surface (2a) of the front cover (2).

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