WO2017058086A1

WO2017058086A1 - Solar cell module

Info

Publication number: WO2017058086A1
Application number: PCT/SE2016/050920
Authority: WO
Inventors: Anna Svensson; Sara KLINGBERG
Original assignee: Soltech Energy Sweden Ab
Priority date: 2015-09-30
Filing date: 2016-09-28
Publication date: 2017-04-06
Also published as: SE1551255A1

Abstract

The invention relates to asolar cell module comprising a frame (12) with an upper elongated section (14), a lower elongated section (16), a first elongated side section (18') and a second elongated side section (18''); a first support layer (20) arranged in connection to the frame (12) and a solar cell layer (24) arranged on top of the first support layer (20), wherein the frame (12) surrounds the first support layer (20) and the solar cell layer (24) peripherally and wherein a fastening device (60) is arranged on the lower section (16) of the frame (12) for attachment of the solar cell module (10) to a batten (2). The invention further relates to a method for mounting a solar cell module (10).

Description

Solar cell module

TECHNICAL FIELD The present invention relates to a solar cell module and a method for mounting a solar cell module according to the appended claims.

BACKGROUND Solar cell modules or photovoltaic cell modules are commonly used for converting the energy of light into electricity. A solar eel! module comprises a plurality of solar cells connected in series. Multiple modules may be

interconnected in order to form an array of solar cell modules or they may be used individually. Solar cell modules may be ground mounted or roof or wall mounted. Roof mounted solar cell modules may be arranged either on top of the roof or integrated with the roof. It is important that an integrated solar cell module have enough structural strength to resist both for example snow load and the weight of an adult. It is also important that an integrated solar ceil module meets the same requirements for water runoff as a normal roof.

Solar cell modules mounted on roofs or walls may use wafer-based crystalline silicone ceils which have a high strength. However, such solar cell modules are relatively heavy and may thereby be difficult to mount on a roof. It is therefore desirable to achieve a lightweight solar cell module suitable for integration with a roof construction, which has enough structural strength, desired efficiency and which may be securely mounted on a roof.

SUMMARY OF THE INVENTION An object of the present invention is to achieve a solar cell module which is lightweight and which facilitates the mounting of the solar cell module. Another object of the invention is to achieve a solar cell module which may be securely mounted on a roof construction or a wall construction.

A further object of the invention is to achieve a solar cell module with optimized efficiency.

A further object of the invention is to achieve a solar cell module which is suitable for integration with a roof or wall construction. Another object of the invention is to achieve a new and advantageous method for mounting a solar cell module on a roof or wall construction.

The herein mentioned objects are achieved by a solar cell module and a method for mounting a solar cell module according to the herein disclosed independent claims.

According to an aspect of the present invention a solar cell module is provided, comprising a frame with an upper elongated section, a lower elongated section, a first elongated side section and a second elongated side section; a first support layer arranged in connection to the frame and a solar cell layer arranged on top of the first support layer, wherein the frame surrounds the first support layer and the solar cell layer peripherally and wherein a fastening device is arranged on the lower section of the frame for enabling attachment of the solar cell module to a batten. Roof tiles and solar cell modules replacing roof tiles in a roof construction or a wall construction are typically hanged on battens at an upper end of the roof tile/solar cell module. The lower end then typically overlaps and rests on top of roof tiles arranged below. With such an arrangement wind might flow underneath the lower end of the solar cell module and the pressure might, depending on the weight of the solar cell module, lift the lower end of the solar cell module. By arranging a fastening device in connection with the lower section of the frame the solar cell module may be attached to a batten at the lower end of the solar cell module. This way is ensured that the lower end of the solar cell module, and thus the whole solar cell module, is securely held in place.

The solar cell module is suitably adapted to be mounted on a roof construction or a wall construction. It is therefore to be understood that roof tiles, roofing felt and similar expressions mentioned herein applies for both roof constructions and wall constructions.

The fastening device is suitably removably attached to the lower section of the frame. This way, the fastening device may be arranged anywhere along the longitudinal extension of the lower section of the frame. It is thus possible to mount the solar cell module on an existing roof or wall construction

independently of the distance between the battens of the roof/wall construction. The fastening device may also be separately attached to a batten and the solar cell module may subsequently be mounted in engagement with the fastening device.

The first support layer preferably comprises at least one channel. The first support layer may comprise a plurality of channels. By configuring the first support layer with a plurality of channels the structural strength is increased. The channels suitably extend substantially perpendicularly to the longitudinal extension of the upper section and the lower section of the frame. Alternatively, the channels extend with an angle different from 90 degrees to the longitudinal extension of the upper section and the lower section of the frame. The channels suitably extend in parallel with each other. The at least one channel may be formed as a groove, slot or similar. The first support layer suitably comprises one or more plastic channels. The first support layer may comprise a multiwall plastic sheet. The first support layer may comprise a multiwall plastic sheet with channels extending substantially perpendicularly to the longitudinal extension of the upper section and the lower section of the frame. The first support layer may alternatively comprise molded plastic channels. By arranging the solar cell layer on top of a layer comprising plastic channels, such as a multiwall plastic sheet, the solar cell module achieves enough structural strength to resist both snow load and the weight of an adult. The first support layer thus enables the use of thin-film solar cells which have lower structural strength than the commonly known crystalline silicone ceils. The support layer comprising at least one channel also results in a lightweight solar cell module, which facilitates mounting of the solar cell module on a roof or a wall.

A second support layer may be arranged underneath the first support layer such that the second support layer forms a back layer. The first support layer is suitably thicker than the second support layer. The second support layer preferably comprises one or more channels extending substantially

perpendicularly to the longitudinal extension of the upper section and the lower section of the frame. The second support layer suitably comprises a multiwall plastic sheet. This way, the structural strength of the solar cell module may be increased while minimizing the weight of the solar cell module. The second support layer comprising channels suitably prevents leakage on the underlying roofing felt and leads water away from the solar cell module. In the case where the first support layer and/or the second support layer comprise multiwall plastic sheets, the multiwall plastic sheets may have any profile, for example rectangular, honeycomb, latticework or similar. The cross-section of the channels of the first support layer and/or the second support layer may have any shape. The solar cell layer preferably comprises a thin-film solar cell. The thin-film solar cell layer suitably comprises a thin film of photovoltaic material on a glass substrate. Alternatively, the thin film of photovoltaic material is sandwiched between two glass substrates. The glass substrate suitably consists of heat treated or tempered glass. The solar cell layer is preferably a rigid thin-film solar cell layer. The thin-film solar cell may comprise cadmium telluride or any other type of solar cells. By using a thin-film solar cell the thickness of the solar cell module is minimized which makes the solar cell module suitable for integration with a roof construction. The at least one channel of the first support layer render the first support layer flexible. The first support layer will thus provide a damping function when the solar cell module is subjected to loads. This way the thin-film solar cell layer can move and the risk that the solar cell layer cracks or breaks under load is minimized. Alternatively, the solar ceil layer comprises crystalline silicon.

By using a the first support layer comprising channels and alternatively a second support layer comprising channels and by using a thin-film solar cell in the solar cell layer a lightweight solar cell module is achieved. This facilitates the mounting of the solar cell module on a roof or a wall. However, since the solar cell module is lighter than ordinary roof tiles there is a risk that the pressure from wind acting underneath the solar cell module might displace the solar cell module. By arranging the fastening device on the lower section of the frame it is ensured that the solar cell module is held in place.

According to an aspect of the invention the solar cell module is adapted to constitute an integrated part of a roof or wall construction. This means that the solar cell module is adapted to be arranged flush with neighbouring roof tiles and thus constitute a part of the roof or the wall. By using a thin-film solar cell the solar cell module is particularly suitable for integration with a roof or wall construction. Furthermore, the first side section and the second side section of the frame each suitably comprises a retention portion adapted to engage with a neighbouring roof tile. The first side section of the frame suitably comprises a retention portion adapted to engage with a right side of a roof tile. The second side section of the frame suitably comprises a retention portion adapted to engage with a left side of a roof tile. The retention portions of the respective side section are thus adapted to hold the solar cell module in place when being integrated with a roof construction. This way, the solar cell module is retained in place by interaction with neighbouring roof tiles. The solar cell module is essentially flat and is thus suitable for engagement with essentially flat roof tiles. However, the retention portions of the solar cell module may be adapted to engage with any type of roof tile. The first side section of the frame suitably comprises a lower retention portion which is adapted to engage with an upper part of the right side of a roof tile. The first side section thus comprises a retention portion adapted to be placed underneath a neighbouring roof tile. The weight of the neighbouring roof tile thus holds the first side section in place. The second side section of the frame suitably comprises an upper retention portion which is adapted to engage with a lower part of the left side of a roof tile. The second side section thus comprises a retention portion adapted to be placed on top of the neighbouring roof tile. The weight of the solar cell module thus holds the neighbouring roof tile in place. This way, the solar cell module constitutes an integrated part of the roof construction.

The solar cell module suitably has a front side and a back side. The front side is suitably facing outwards, towards the sun. The back side is suitably facing inwards, away from the sun. The back side is suitably facing the battens and the roofing felt of a roof construction or a wall construction. The solar cell layer is thus arranged on the front side and the first support layer is arranged on the back side. The fastening device is suitably arranged on the back side of the solar cell module.

The fastening device is suitably arranged adjacent the second side section of the frame. The fastening device suitably comprises an elongated strip. The fastening device may comprise metal and/or plastics. The fastening device is suitably adapted to be arranged in engagement with the lower section of the frame on the back side of the solar cell module. The fastening device suitably comprises a plurality of attachment points arranged along the extension of the fastening device. The attachment points are adapted for interaction with at least one fastener. The attachment points are suitably attachment holes and the at least one fastener may be a screw, nail or similar. The fastening device may further comprise a hook portion adapted to engage with the lower section of the frame. The hook portion is suitably adapted to engage with a back portion of the lower section of the frame on the back side of the solar cell module. Suitably, the fastening device comprises an elongated portion with a plurality of attachment points and a projecting hook portion at an end of the elongated portion. During mounting of the solar cell module the fastening device is suitably adapted to be attached to an underlying roof tile and/or batten first, whereafter the solar cell module is adapted to be arranged such that a back portion of the lower section of the frame is slid underneath the hook portion of the fastening device. The back portion of the lower section of the frame is thus adapted to be clamped between the hook portion and the underlying roof tile/batten. The fastening device may thus comprise a Z bend strip. Since the solar cell module overlaps an underlying roof tile when being integrated in a roof or wall construction, the solar cell module is attached to the batten through the underlying roof tile. The fastening device is thus arranged on the roof tile and the fastener penetrates the underlying roof tile and the batten. By having a fastening device comprising a plurality of attachment points the solar cell module can be attached to different roof or wall

constructions with different distances between the battens. The fastening device is suitably configured such that the solar cell module can be attached to roof or wall constructions with a distance between the battens around 250-400 millimetres, preferably around 300-380 millimetres.

According to an aspect of the invention the frame comprises at least one opening in fluid connection with the at least one channel of the first support layer. Suitably, the frame comprises at least two openings in fluid connection with the at least one channel of the first support layer. According to an aspect of the invention the frame comprises a plurality of openings in fluid connection with the channels of the first support layer. Suitably, the upper section and/or the lower section of the frame each comprise at least one opening in fluid connection with the at least one channel of the first support layer. Suitably, the upper section and/or the lower section of the frame each comprise a plurality of openings in fluid connection with the channels of the first support layer. It is common knowledge that the efficiency of solar cells decrease when the temperature increases. It is therefore desirable to be able to cool the solar cell module. By arranging openings in fluid connection with the channels of the channels of the first support layer, air is able to flow through the solar cell module. Since the solar cell layer is arranged in contact with the first support layer the solar cell layer is cooled by the air flowing through the channels. A solar cell module with improved efficiency is thereby achieved. Each channel of the first support layer suitably extends between an opening in the upper section of the frame and an opening in the lower section of the frame. The channels of the first support layer are thus adapted for cooling of the solar cell layer. The openings in the upper section of the frame are suitably arranged on an upper end portion. The openings in the lower section of the frame are suitably arranged on a lower end portion.

The upper section of the frame may further comprise attachment holes for attachment of the solar cell module to an underlying batten by means of fasteners.

The frame of the solar cell module is preferably essentially rectangular, where the upper section and the lower section are longer than the first and the second side section. The upper section and the lower section of the frame thus define the length of the solar cell module whereas the first and the second side section define the height of the solar cell module. The upper section and the lower section of the frame are arranged in parallel opposite each other and the first side section and the second side section are arranged in parallel opposite each other. The frame, and thus the solar cell module, suitably has the same size (length and height) as a plurality of adjacently arranged roof tiles. The solar cell module may have the size of one or more roof tiles arranged next to each other. This way, a plurality of roof tiles may easily be replaced by the solar cell module.

The frame preferably comprises metal, such as steel, aluminium or similar. The frame may alternatively comprise a plastic material. The frame may further comprise a surface coating or similar for protection against corrosion. The upper section, the lower section, and the side sections are suitably adapted to mechanically hold the first support layer and the solar cell layer. The frame is thus not fixedly adhered to the various layers. The upper section, the lower section, the first side section and the second side section of the frame may comprise bent sheet metal, extruded metal or extruded plastic. Alternatively, the frame sections are molded as separate pieces which are mechanically attached to each other, or the frame sections are molded as one piece. For example, the frame may be a solid plastic frame where the upper section, the lower section, the first side section and the second side section are molded as one piece. The frame may alternatively be a solid frame molded in one piece comprising the upper section, the lower section, the first side section, the second side section and a back section. The back section may be the first support layer or the second support layer integrated with the frame. By using a frame which is adapted to mechanically hold the various layers the

manufacturing of the solar cell module is facilitated. The manufacturing is less time consuming and thus more cost-efficient. By using a metal frame to mechanically hold the different layers in place, vibrations between the different parts of the solar cell module may occur. Vibrations between the glass of the solar cell layer and the metal frame sections may cause undesired noise. However, since the first support layer of the solar cell module comprises channels and thereby provide a damping function, the vibrations between the solar cell layer and the frame are minimized. . Alternatively, silicone or similar may be applied between the metal frame and the solar cell layer in order to achieve a damping function. The occurrence of undesired noise is thereby minimized. Also, the support layer comprising plastic channels is flexible which enables the use of press fit between the support layer and the metal frame. The frame sections are suitably connected by rivets, particularly blind rivets. Alternatively, the frame sections are connected by screw joints. This way, the frame sections are mechanically connected to each other and recycling of worn out solar cell modules is facilitated. The rivets/screw joints may also act as spacers holding the different layers in place. At least one support member may be arranged between the upper section and the lower section of the frame in order to retain the shape of the frame. The at least one support member is suitably attached to the upper section and the lower section of the frame. The support member preferably extends

substantially perpendicularly to the longitudinal extension of the upper section and the lower section of the frame. The support member is suitably attached to the upper section and the lower section by rivets. The support member may be arranged on the back side of the solar cell module. The frame preferably comprises at least one hanging portion. The at least one hanging portion may be arranged on the upper section of the frame. The hanging portion may be a protruding portion on the back side of the upper section. Alternatively, the first side section and the second side section of the frame each comprise a hanging portion. The hanging portions may be arranged at the upper end of the respective side section, adjacent the upper section of the frame. Each hanging portion suitably comprises an upper portion protruding perpendicularly to the longitudinal extension of the respective side section. The protruding upper portions are on the back side of the solar cell module and are adapted for hanging the solar cell module on a batten. The protruding upper portions are thus adapted to abut an edge of a batten. When the solar cell module is integrated in a roof or wall construction the solar cell module hangs on a batten by means of the hanging portions and the first support layer abuts the batten. The lower section of the solar cell module rests on roof tiles arranged below the solar cell module. The first support layer and the lower section of the frame thereby abut roof tiles arranged below the solar cell module. The first support layer is thus a load carrying layer.

According to an aspect of the invention the solar cell module comprises a connection box for electronics. The connection box may be arranged adjacent the first support layer underneath the solar cell layer. The connection box may be arranged coplanar with the solar cell layer underneath the upper section of the frame. The connection box may be arranged adjacent the first side section or the second side section of the frame, adjacent the first support layer.

Alternatively, the first support layer comprises two or more separate parts arranged in parallel, wherein the connection box is arranged between two parts. Alternatively, the connection box is arranged in an opening in the first support layer. By arranging the connection box coplanar with the first support layer wires from the connection box are accessible on the back side of the solar cell module. This way, the solar cell module may easily be connected to other solar cell modules. The connection box may alternatively be arranged coplanar with the solar cell layer, for example between the first support layer and the upper section of the frame.

In the case where a second support layer is arranged on the back side of the frame the second support layer is suitably shorter than the first support layer and shorter than the longitudinal extension of the side sections of the frame. The second support layer is preferably held by the lower section of the frame, the first side section and the second side section. The second support layer is thus not held by the upper section of the frame. The upper part of the second support layer may alternatively be adhered to the back side of the first support layer. The first support layer thus extends beyond the second support layer in direction towards the upper section of the frame. This means that when the solar cell module is integrated in a roof or wall construction the first support layer still abuts the batten. The first support layer is thus still the load carrying layer. By having a shorter second support layer, wires from the connection box are still easily accessible on the back side of the solar cell module.

The upper section of the frame preferably comprises a first elongated portion on the front side of the solar cell module, a second elongated portion on the back side of the solar cell module arranged in parallel with the first portion, and an upper end portion connecting the first and the second elongated portion. The upper section of the frame thus suitably comprises a first elongated portion abutting the solar cell layer on the front side of the solar cell module and a second elongated portion abutting the back side of the first support layer on the back side of the solar cell module. The first portion partly overlaps the solar cell layer on the front side of the solar cell module and holds the solar cell layer in place. The second portion partly covers the first support layer on the back side of the solar cell module. When the solar cell module is integrated in a roof construction, roof tiles might overlap the upper part of the front side of the solar cell module. The first portion of the upper section of the frame may thereby be configured such that only the upper section of the frame is overlapped and not the uncovered solar cell layer. The upper section of the frame further comprises side portions adapted to be connected to the side sections. The cooling openings arranged in fluid connection with the channels of the first support layer are suitably arranged on the upper end portion. The lower section of the frame suitably comprises a U-section with two parallel portions and a lower end portion connecting the two parallel portions. The cooling openings arranged in fluid connection with the channels of the first support layer are suitably arranged on the lower end portion of the lower section of the frame

The first side section and the second side section of the frame preferably each comprises a drainage portion. The drainage portion is adapted to lead water from the underlying roofing felt. The drainage portions of the first side section and the second side section respectively suitably comprises a drainage channel, through which water may be lead away from the solar cell module. The drainage portions are arranged on the back side of the solar cell module. The drainage portions may each comprise a bent/curved portion forming the drainage channel. The drainage portion of the first side section suitably comprises a drainage channel formed underneath the retention portion of the first side section. The drainage portion of the second side section suitably comprises a drainage channel formed underneath the first support layer. The lower section of the frame preferably comprises at least one drainage opening arranged in fluid connection with each drainage channel. This way, the water is lead away from the solar cell module. Further objects, advantages and novel features of the present invention will become apparent to one skilled in the art from the following details, and also by putting the invention into practice. Whereas the invention is described below, it should be noted that it is not restricted to the specific details described. Specialists having access to the teachings herein will recognise further applications, modifications and incorporations within other fields, which are within the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For fuller understanding of the present invention and further objects and advantages of it, the detailed description set out below should be read together with the accompanying drawings, in which the same reference notations denote similar items in the various diagrams, and in which:

Figure 1 schematically illustrates a roof construction comprising a solar cell module according to an embodiment of the invention; Figure 2 schematically illustrates a solar cell module according to an

embodiment of the invention:

Figure 3a-c schematically illustrates cross-sections of a solar cell module

according to embodiments of the invention;

Figure 4 schematically illustrates the back side of a solar cell module

according to an embodiment of the invention;

Figure 5a-b schematically illustrates a solar cell module according to an

embodiment of the invention; and

Figure 6 illustrates a flow chart of a method for mounting a solar cell

module according to an embodiment of the invention. DETAILED DESCRIPTION OF THE DRAWINGS

Figure 1 schematically shows a roof construction 1 comprising a solar cell module 10 according to an embodiment of the invention. The solar cell module 10 constitutes an integrated part of the roof construction 1 and is arranged on battens 2 arranged in parallel. The roof construction 1 may be a wall construction. The solar cell module 10 is here illustrated in engagement with a roof tile 4 on the right side. Another roof tile 4 is arranged below the solar cell module 10 in order to illustrate how the solar cell module 10 overlaps the upper end of roof tiles 4 arranged below the solar cell module 10. The solar cell module 10 comprises a frame 12 with an upper elongated section 14, a lower elongated section 16, a first elongated side section 18' and a second elongated side section 18"; a first support layer 20 (not shown) arranged inside the frame 12 forming a back layer and a solar cell layer 24 arranged on top of the first support layer 20, wherein the frame 12 surrounds the first support layer 20 and the solar cell layer 24 peripherally. The first support layer 20 comprises at least one channel (not shown). The first support layer 20 preferably comprises a plurality of channels. The channels suitably extend substantially perpendicularly to the extension of the upper section 14 and the lower section 16 of the frame 12. The first support layer 20 may comprise a multiwall plastic sheet with channels. The first support layer 20 may

alternatively comprise moulded plastic channels. The first support layer 20 suitably comprises an arbitrary number of channels. The channels are illustrated in Figure 3c. The solar cell module 10 may comprise a second support layer 22 underneath the first support layer 20. The second support layer 22 may thus form the back layer and suitably also comprises channels extending substantially perpendicularly to the longitudinal extension of the upper section 14 and the lower section 16 of the frame 12. The solar cell layer 24 may comprise a thin-film solar cell or any other type of solar cells.

The solar cell module 10 has a front side 26 and a back side 28. The front side 26 is facing outwards, towards the sun and the back side 28 is facing inwards, away from the sun. The back side 28 is thus facing the battens 2 and the roofing felt of the roof construction 1. The solar cell module 10 is in direct contact with a batten 2 at the upper section 14 of the frame 12 and typically rests on roof tiles 4 at the lower section 16 of the frame 12.

The frame 12 of the solar cell module 10 is essentially rectangular. The upper section 14 and the lower section 16 of the frame 12 thus define the length of the solar cell module 10 whereas the first and the second side section 18', 18" define the height of the solar cell module 10. The first side section 18' is on the left side of the solar cell module 10 and the second side section 18" is on the right side of the solar cell module 10, when the solar cell module 10 is arranged for use. The frame 12, and thus the solar cell module 10, may have the size of one or more roof tiles 4 arranged next to each other. The frame 12 preferably comprises metal, such as steel, aluminium or similar. The frame 12 may alternatively comprise a plastic material. The upper section 14, the lower 16 section, and the side sections 18', 18"are suitably adapted to mechanically hold the first support layer 20 and the solar cell layer 24. The upper section 14, the lower section 16, the first side section 18' and the second side section 18" of the frame 12 may comprise bent sheet metal, extruded metal or extruded plastic. The frame sections 14, 16, 18', 18" are suitably connected by rivets, particularly blind rivets. . Alternatively, the frame sections 14, 16, 18', 18" are connected by screw joints. This way, the frame sections 14, 16, 18', 18" are mechanically connected to each other and recycling of worn out solar cell modules is facilitated. The rivets/screw joints may also act as spacers holding the different layers in place.

The upper section 14 and the lower section 16 of the frame 12 may each comprise a plurality of openings 30 in fluid connection with the channels of the first support layer 20. By arranging openings 30 in fluid connection with the channels of the first support layer 20, air is able to flow through the solar cell module 10. Since the solar cell layer 24 is arranged in contact with the first support layer 20 the solar cell layer 24 is cooled by the air flowing through the channels. The channels suitably extend between the openings 30 in the upper section 14 of the frame 12 and the openings 30 in the lower section 16 of the frame 12. The upper section 14 of the frame 12 may further comprise attachment holes 31 for attaching the solar cell module 10 to a batten by means of fasteners.

The first side section 18' and the second side section 18" of the frame 12 each suitably comprises a retention portion 56 adapted to engage with a

neighbouring roof tile 4. The first side section 18' of the frame 12 suitably comprises a retention portion 56 adapted to engage with a right side of a roof tile 4. The second side section 18" of the frame 12 suitably comprises a retention portion 56 adapted to engage with a left side of a roof tile 4. The retention portions 56 of the respective side section 18', 18" are thus adapted to hold the solar cell module 10 in place when being integrated with a roof construction 1. This way, the solar cell module 10 is retained in place by interaction with neighbouring roof tiles 4. The solar cell module 10 is

essentially flat and is thus suitably adapted to engage with essentially flat roof tiles 4. The first side section 18' of the frame 12 suitably comprises a lower retention portion 56 which is adapted to engage with an upper part of the right side of a roof tile 4. The first side section 18' thus comprises a retention portion 56 adapted to be placed underneath a neighbouring roof tile 4. The weight of the neighbouring roof tile 4 thus holds the first side section 18' in place. The second side section 18" of the frame 12 suitably comprises an upper retention portion 56 which is adapted to engage with a lower part of the left side of a roof tile 4. The second side section 18" thus comprises a retention portion 56 adapted to be placed on top of the neighbouring roof tile 4. The solar cell module 10 thus holds the neighbouring roof tile in place. The solar cell module 10 will be further described in Figures 2-5.

Figure 2 schematically shows a top view of the solar cell module 10 according to Figure 1 , this figure does however not show the solar cell layer 24, the first support layer 20 or the optional second support layer 22. The solar cell module 10 comprises a fastening device 60 arranged on the lower section 16 of the frame 12. The fastening device 60 is suitably removably arranged on the lower section 16 of the frame 12. The fastening device 60 is adapted for attachment of the solar cell module 10 to a batten 2 and thereby ensuring that the solar cell module 10 is not displaced by the wind. The fastening device 60 will be further described in Figure 5a and 5b.

Figure 3a and 3b schematically shows cross-sections of a solar cell module 10 according to embodiments of the invention. The solar cell module 10 is configured as described in Figure 1 and Figure 2 but the frame 12 is omitted, such that the layers of the solar cell module 10 are shown. Figure 3a shows a solar cell module 10 comprising a first support layer 20 and a solar cell layer 24. Figure 3b shows a solar cell module 10 comprising a first support layer 20, a second support layer 22 and a solar cell layer 24. The first support layer 20 may comprise one or more rows of channels. The first support layer 20 is thicker than the second support layer 22. The first support layer 20 is a load carrying layer. The second support layer 22 is arranged underneath the first support layer 20 and may likewise comprise one or more rows of channels. The second support layer 22 prevents leakage on the underlying roofing felt and leads water away from the solar cell module 10. The channels of the first support layer 20 and the second support layer 22 may have any cross-section, for example rectangular, honeycomb latticework or similar. This is however not shown in the figures. By using layers comprising channels the weight of the solar cell module 10 is reduced and the mounting of the solar cell module 10 is facilitated.

The solar cell module 10 further comprises a connection box 32 for electronics. The connection box 32 may be arranged adjacent the first support layer 20 underneath the solar cell layer 24. In the case where the solar cell module 10 comprises a second support layer 22 the connection box 32 may be arranged on top of the second support layer 22, flush with the first support layer 20. The connection box 32 may be arranged in an opening in the first support layer 20. Alternatively, the first support layer 20 comprises two or more separate parts arranged in parallel, wherein the connection box 32 is arranged between two parts, underneath the solar cell layer 24. Alternatively, the connection box 32 is arranged underneath the upper section 14 of the frame 12, on the same level as the first support layer 20. Alternatively, the connection box 32 is arranged underneath the upper section 14 of the frame 12, on top of the first support layer 20 and thus coplanar with the solar cell layer 24. The solar cell layer 24 comprises a thin film of photovoltaic material on a glass substrate. Alternatively, the thin film of photovoltaic material is sandwiched between two glass substrates. The glass substrate suitably consists of heat treated or tempered glass. The solar cell layer 24 may be a rigid thin-film solar cell layer. The thin- film solar cells suitably comprise cadmium telluride. The first support layer 20 and the second support layer 22 comprising a plurality of channels will both provide a damping function when the solar cell module 20 is subjected to loads. This way the thin-film solar eel! layer 24 can move and the risk that the solar cell layer 24 cracks or breaks under load is minimized.

Figure 3c schematically shows cross-sections of a solar cell module 10 according to embodiments of the invention. The solar cell module 10 is configured as described in Figure 3a. The first support layer 20 comprises a plurality of channels 25 extending essentially perpendicularly to the

longitudinal extension of the upper section 14 and the lower section 16 of the frame 12. In the upper figure the first support layer 20 comprises a multiwall plastic sheet with channels 25. In the lower figure the first support layer 20 comprises moulded plastic channels 25. The moulded channels 25 of the first support layer 20 may lack a top portion and the solar cell layer 24 may thus rest on the walls of the channels 25. The first support layer 20 suitably comprises an arbitrary number of channels 25.

Figure 4 schematically illustrates the upper part of a back side 28 of a solar cell module 10 according to an embodiment of the invention. The solar cell module 10 is configured as described in Figure 1 , Figure 2, Figure 3a and/or Figure 3c. The upper section 14 of the frame 12 comprises a first elongated portion 40 arranged on the front side 26 of the solar cell module 10, a second elongated portion 42 arranged on the back side 28 of the solar cell module 10 and an upper end portion 41 connecting the first and the second portion 40, 42. The first portion 40 partly overlaps the solar cell layer 24 on the front side 26 of the solar cell module 10 and holds the solar cell layer 24 in place. The second portion 42 partly covers the first support layer 20 on the back side 28 of the solar cell module 10. When the solar cell module 10 is integrated in a roof construction 1 , roof tiles 4 will overlap the upper part of the front side 26 of the solar cell module 10. The first portion 40 of the upper section 14 of the frame 12 may be configured such that only the upper section 14 of the frame 12 is overlapped and not the uncovered solar cell layer 24. The upper section 14 of the frame 12 further comprises side portions adapted to be connected to the side sections 18', 18" of the frame 12. The upper end portion 41 may comprise openings 30. The openings 30 are adapted to be in fluid connection with the channels 25 of the first support layer 20 for cooling of the solar cell layer 24. The lower section 16 of the frame 12 is suitably an essentially U-shaped profile element.

The solar cell module suitably comprises at least one hanging portion 52. The first side section 18' and the second side section 18" of the frame 12 may each comprise a hanging portion 52. The hanging portions 52 are arranged at the upper end of the respective side section 18', 18", adjacent the upper section 14 of the frame 12. Each hanging portion 52 suitably comprises an upper portion 54 protruding perpendicularly to the longitudinal extension of the respective side section18', 18". The protruding upper portions 54 are on the back side 28 of the solar cell module 10 and are adapted for hanging the solar cell module 10 on a batten 2. The protruding upper portions 54 thus abut an edge of a batten 2 when the solar cell module 10 is integrated in a roof construction 1 . Alternatively, the hanging portion 52 is arranged on the upper section 14 of the frame 12. The upper section 14 and the lower section 16 of the frame 12 may be connected by support members 58 arranged on the back side 28 of the solar cell module 10. The solar cell module 10 may comprise one or more support members 58. The support members 58 are suitably attached to the upper section 14 respectively the lower section 16 by rivets.

Figure 5a schematically illustrates a top view of a solar cell module 10 according to an embodiment of the invention. The solar cell module 10 is configured as described in any of the Figures 1 -4 but in this figure the solar cell layer 24, the first support layer 20 and the second support layer 22 are omitted in order to illustrate the fastening device 60. As described in Figure 1 , the second side section 18" of the frame 12 typically comprises a retention portion 56 which is adapted to be arranged on top of a neighbouring roof tile 4. This means that this side of the solar cell module 10 holds the neighbouring roof tile 4 in place by the weight of the solar cell module 10 and possibly by fasteners attached to a batten 2 through attachment holes 31 in the upper section 14 of the frame 12. Should wind flow underneath the solar cell module 10 the pressure might, due to the low weight and the relatively large area of the solar cell module 10, lift this side of the solar cell module 10. Thus, in order to ensure that the solar cell module 10 is held in place despite its low weight, and thereby retain the neighbouring roof tiles 4 in place the fastening device 60 is suitably arranged adjacent the second side section 18" of the frame 12. The fastening device 60 is suitably an elongated metallic strip. The fastening device 60 is suitably arranged in engagement with the lower section 16 of the frame 12 on the back side 28 of the solar cell module 10. The fastening device 60 comprises a plurality of attachment points 62 arranged along the extension of the fastening device 60. The attachment points 62 are adapted for interaction with at least one fastener 64. The attachment points 62 are suitably through holes and the at least one fastener 64 may be a screw, nail or similar. The fastening device 60 further comprises a hook portion 66 adapted to engage with the lower section 16 of the frame 12. Suitably, the fastening device 60 comprises an elongated portion with a plurality of fastening points 62 and a projecting hook portion 66 at an end of the elongated portion. The fastening device 60 may thus comprise a Z bend strip. Figure 5b schematically shows a cross section of a solar cell module 10 through a fastening device 60 according to an embodiment of the invention. The solar cell module 10 is configured as described in any of the Figures 1 -5a. Here is illustrated how the solar cell module 10 is attached to a batten 2 by means of the fastening device 60. Since the solar cell module 10 overlaps an underlying roof tile 4 when being integrated in a roof or wall construction 1 , the solar cell module 10 is attached to the batten 2 through the underlying roof tile 4. The at least one fastener 64 thus penetrates the underlying roof tile 4 and the batten 2. By having a fastening device 60 comprising a plurality of attachment points 62 the solar cell module 10 can be attached to different roof or wall constructions 1 with different distances between the battens 2. The fastening device 60 is suitably configured such that the solar cell module 10 can be attached to roof constructions 1with a distance between the battens 2 around 250-400 millimetres, preferably around 300-380 millimetres. This way, the solar cell module 10 may easily replace roof tiles 4 in roof or wall constructions 1 without the need of modifying for example the battens 2 of the roof/wall construction 1 .

Figure 6 shows a flow chart of a method for mounting a solar cell module 10 according to an embodiment of the invention. The solar cell module 10 is configured as described in any of the figures 1 -5. The solar cell module thus comprises a frame 12 with an upper elongated section 14, a lower elongated section 16, a first elongated side section 18' and a second elongated side section 18"; a first support layer 20 arranged in connection to the frame 12 and a solar cell layer 24 arranged on top of the first support layer 20, wherein the frame 12 surrounds the first support layer 20 and the solar cell layer 24 peripherally and wherein a fastening device 60 is removably arranged on the lower section 16 of the frame 12 for attachment of the solar cell module 10 to an underlying batten 2. The method comprises the steps of:

- attaching s101 the fastening device 60 to the underlying batten 2 by means of at least one fastener 64; and

- arranging s102 the solar cell module 10 such that the lower section 16 of the frame 12 engage with the fastening device 60.

Roof tiles 4 of a roof or wall construction 1 on which the solar cell is to be mounted is suitably first removed in order to mount the solar cell module 10. This way, the solar cell module 10 becomes an integrated art of the roof/wall construction 1 .

The fastening device 60 is suitably first removed from the solar cell module 10, such that it can be separately attached to the batten 2.

The step to attach the fastening device 60 to the batten 2 suitably comprises to arrange the fastening device 60 on a roof tile 4 and attach the fastening device 60 to the underlying batten 2 through the roof tile 4. This way, there is no need to move or modify an underlying roof tile 4 before attaching the fastening device 60.

The step to arrange the solar cell module 10 such that the lower section 16 of the frame 12 is engaged with the fastening device 60 suitably comprises to engage the lower section 16 of the frame 12 with a hook portion 66 of the fastening device 60. Suitably, a back portion of the lower section 16 of the frame 12 is slid underneath the hook portion 66 of the fastening device 60. The lower section 16 of the frame 12 is thus clamped between the hook portion 66 of the fastening device 60 and the underlying roof tile 4.

It is to be understood that instead of an underlying roof tile 4 it may be another solar cell module being arranged below the solar cell module 10 to be mounted. By designing the fastening device 60 with a hook portion 66 the solar cell module 10 may be slid into place, in engagement with the fastening device 60. This way, the fastening device 60 may be attached to the batten 2 prior to arranging the rest of the solar cell module 10. Mounting of the solar cell module 10 on a roof or wall construction 1 is thereby facilitated.

The foregoing description of the preferred embodiments of the present invention is provided for illustrative and descriptive purposes. It is not intended to be exhaustive or to restrict the invention to the variants described. Many modifications and variations will obviously be apparent to one skilled in the art. The embodiments have been chosen and described in order best to explain the principles of the invention and its practical applications and hence make it possible for specialists to understand the invention for various embodiments and with the various modifications appropriate to the intended use.

Claims

1 . A solar cell module, comprising a frame (12) with an upper elongated section (14), a lower elongated section (16), a first elongated side section (18') and a second elongated side section (18"); a first support layer (20) arranged in connection to the frame (12) and a solar cell layer (24) arranged on top of the first support layer (20), wherein the frame (12) surrounds the first support layer (20) and the solar cell layer (24) peripherally and wherein a fastening device (60) is arranged on the lower section (16) of the frame (12) for attachment of the solar cell module (10) to a batten (2).

2. A solar cell module according to claim 1 , wherein the solar cell layer (24) comprises a thin-film solar cell.

3. A solar cell module according to claim 1 or 2, wherein the first support layer (20) comprises at least one channel (25).

4. A solar cell module according to claim 3, wherein the at least one channel (25) extends substantially perpendicularly to the extension of the upper section (14) and the lower section (16) of the frame (12).

5. A solar cell module according to any of the preceding claims, wherein a second support layer (22) is arranged underneath the first support layer (20) forming a back layer.

6. A solar cell module according to claim 4, wherein the second support layer (22) comprises channels extending substantially perpendicularly to the extension of the upper section (14) and the lower section (16) of the frame (12).

7. A solar cell module according to any of the preceding claims, wherein the fastening device (60) comprises a plurality of attachment points (62) adapted for interaction with at least one fastener (64).

8. A solar cell module according to any of the preceding claims, wherein the fastening device (60) comprises a hook portion (66) adapted to engage with the lower section (16) of the frame (12).

9. A solar cell module according to any of the preceding claims, wherein the solar cell module (10) is adapted to constitute an integrated part in a roof or wall construction (1 ).

10. A solar cell module according to any of the preceding claims, wherein the frame (12) comprises metal.

1 1 . A solar cell module according to any of the preceding claims, wherein the frame (12) comprises at least one hanger portion (52).

12. A method for mounting a solar cell module (10)comprising a frame (12) with an upper elongated section (14), a lower elongated section (16), a first elongated side section (18') and a second elongated side section (18"); a first support layer (20) arranged in connection to the frame (12) and a solar cell layer (24) arranged on top of the first support layer (20), wherein the frame (12) surrounds the first support layer (20) and the solar cell layer (24) peripherally and wherein a fastening device (60) is removably arranged on the lower section (16) of the frame (12) for attachment of the solar cell module (10) to a batten (2), the method comprises the steps of:

- attaching (s101 ) the fastening device (60) to the batten (2) by means of a fastener (64); and

- arranging (s102) the solar cell module (10) such that the lower section (16) of the frame (12) engages with the fastening device (60).

13. A method for mounting a solar cell module (10), wherein the step to arrange (s102) the solar cell module (10) such that the lower section (16) of the frame (12) engages with the fastening device (60) comprises to engage the lower section (16) of the frame (12) with a hook portion (66) of the fastening device (60).