Fastening arrangement for fastening a plurality of solar panels

Abstract

The invention provides a fastening arrangement (1000) for fastening at least two solar panels (1011-1018) on a substantially flat surface, each solar panel (1011-1018) having a bottom edge, a top edge, a first side edge, and a second side edge, wherein the fastening arrangement (1000) comprises: (I) a support arrangement (1700) configured to support the at least two solar panels (1011-1018) in an inclined position with respect to the substantially flat surface; (II) a transverse element (1210,1220) configured to support the bottom edge or the top edge of the at least two solar panels (1011-1018); and (III) at least two fastening elements (1510,1520), wherein each fastening element (1510,1520) secures a solar panel (1011,1018) to the transverse element (1210,1220).

Description

Fastening arrangement for fastening a plurality of solar panelsTechnical Field

[0001] The invention relates to a fastening arrangement for fastening one or more solar panels, a solar panel system comprising such a fastening arrangement, and a kit comprising a plurality of parts for assembling a fastening arrangement and / or solar panel system according to the invention.Background Art

[0002] With a drive towards transitioning to environmentally sustainable methods of power generation, solar panel systems on the roofs of buildings have become increasingly common. Furthermore, modern solar panel systems may have extended arrays of solar panels that can amount to tens of solar panels, hundreds of solar panels, or even more. Consequently, there has been a need for solar panel support and fastening arrangements. The solar panels in a solar panel system are typically fastened and supported at a predetermined inclined angle to the sun. Solar panels are used both on substantially flat as well as sloping roofs, both putting different requirements on the fastening arrangement.

[0003] Fastening arrangements that are known in the art are often modular and configured to fasten and support several different types of solar panels and in several different orientations (or positions) of solar panels. For instance, EP3865784B1 describes a system and a method for mounting at least one solar panel on a substantially flat mounting surface. The system comprises thereto a plurality of base elements and support structures configured for supporting the solar panels. The system further comprises a plurality of retaining elements for retaining at least part of a top edge of the solar panels, and clamping elements configured for clampingly engaging at least part of a bottom edge of the solar panels. Advantageously, the arrangement fastens rectangular solar panels in a landscape orientation along their long edge, thereby allowing for varying widths and / or lengths of the solar panels to be mounted while using the same components.

[0004] Disadvantageously, however, the fastening arrangement requires the use of two supports in the support structure per solar panel, whereas other prior art fastening arrangements that are used to fasten the solar panels along their short edges require only one support per solar panel and two additional supports at the end of an array. However, with the increasing size of the solar panels, arrangements wherein only the short edges are supported, are no longer sufficiently stable. An improved manner of supporting the solar panels along their long edge is therefore desired, yet without significantly increasing the number of components in the system and / or the material used for the support structure. Further arrangements are disclosed by US2014 / 083504A1 and DE202010008691 U1.

[0005] It is a goal of the invention to provide an improved fastening arrangement and / or a solar panel system that is cheaper and / or easier to be produced, transported, and / or installed compared to existing arrangements and / or systems. Alternatively, it is a goal of the presentinvention to provide a fastening arrangement and / or a solar panel system that otherwise is an improvement over existing systems.Summary of Invention

[0006] Therefore, according to a first aspect, the invention provides a fastening arrangement for fastening at least two solar panels on a substantially flat surface. Each solar panel has a bottom edge, a top edge, a first side edge, and a second side edge. The fastening arrangement comprises a support arrangement, a transverse element and at least two fastening elements. The support arrangement is configured to support the at least two solar panels in an inclined position with respect to the substantially flat surface. The transverse element is configured to extend along the bottom edge or the top edge of at least two solar panels. Each fastening element secures a different solar panel of the at least two solar panels to the transverse element.

[0007] In this context, the inclined position of a solar panel refers to any position wherein the light receiving surface of a solar panel makes a non-zero angle with respect to the horizon. For the sake of explanation of the invention, it is considered that solar panels have a rectangular shape with a length larger or equal to their width. Each solar panel has two long opposing edges defined in their length direction (e.g., the bottom edge and the top edge), and two short opposing edges defined in their width direction (e.g., the first side edge and the second side edge). Typically, the solar panels are mounted in a landscape configuration, such that the long edges extend at a single substantially vertical level along a transverse axis, whereas the short edges extend from a relatively higher position to a lower position (e.g., from the top edge to the bottom edge) in the inclined plane and along a longitudinal axis perpendicular to the transverse axis. As such, the transverse element is typically arranged to extend in a direction or plane parallel to the substantially flat surface. Nevertheless, it will be understood that solar panels are not necessarily rectangular, and / or that occasionally also a portrait configuration may be used. The interpretation of rectangular solar panels that are mounted in a landscape configuration should therefore only be considered as illustrative and not limiting for the invention. Here the term “substantially flat surface” is used to indicate any surface with an inclination that is less than the preferred support position of the solar panels, e.g., less than 5 degrees or less than 3 degrees.

[0008] Advantageously, with such a fastening arrangement, the transverse element may fulfill several functions simultaneously while in other systems separate elements are used for every function and / or additional supports are required. Firstly, due to its extension along the bottom edge or top edge of at least two solar panels, the at least two solar panels may be supported simultaneously by a single support structure through the transverse element. This reduces the number of support structures that are required and thereby saves material expenses.Furthermore, assembly of the fastening arrangement is generally faster as less components need to be transported to the installation site.

[0009] Alternatively and / or in addition, the transverse element may be used to interconnect adjacent solar panels in an array of solar panels, thereby preventing the movement of solarpanels along a length direction of the array. As such, it is not needed to provide separate or additional elements in the fastening arrangement to prevent a movement in that direction.

[0010] Alternatively, or in addition, the transverse elements may provide flexibility for the positioning of the at least two fastening elements with respect to the support arrangement. The latter allows to independently select positions for the support arrangement and the at least two fastening elements that are optimal in a particular situation. For example, for supporting the solar panel at a position that is best for the distribution of ferees, or at a position that is considered best for its placement on the underlying substantially flat surface.

[0011] In an embodiment, the transverse element has a length at least equal to 20% of the length of the bottom edge of one solar panel of the at least two solar panels. The fastening arrangement may comprise at least two solar panels. The at least two solar panels may be positioned adjacent to each other in the transverse direction. This allows the transverse element to not only extend along the top edge or bottom edge of the at least two solar panels, but also engage therewith over a longer length and / or at different positions along the respective edge. Preferably, the transverse element has a length at least equal to 25% of the length, or at least 35% of the bottom edge or top edge of one solar panel of the at least two solar panels. Typically, the at least two solar panels in an solar panel system or array of a solar panel system have substantially similar dimensions. Advantageously, with a minimum length of at least 20%, or at least 25%, or at least 35% of the length of the bottom edge, the transverse element may be able to (adequately) support the at least two solar panels. Moreover, sufficient space is typically provided to arrange the at least two fastening elements along the bottom edge and / or the top edge of the at least two solar panels.

[0012] In an embodiment, the fastening arrangement is configured to support the solar panels in one or more arrays. Each array may comprise a row wherein one or more solar panels are arranged in series. Alternatively, an array may also be configured as a grid having a plurality of rows, each row comprising a series of one or more solar panels. Within a series, the second side edge of a first solar panel is adjacent to the first side edge of a second solar panel. The support arrangement is typically configured to support all solar panels within a series in the same inclined plane or an alternating inclined plane with respect to the substantially flat surface.

[0013] In an embodiment, the fastening arrangement comprises a first transverse element configured to be arranged along the bottom edge of the at least two solar panels and a second transverse element configured to be arranged along the top edge of the at least two solar panels. In some embodiments, it may be sufficient that the bottom edge of the solar panels rest on one of the transverse elements without the use of additional fastening elements. In other embodiments, a pair of first fastening elements may be provided to secure the bottom edge to the first transverse element, and a pair of second fastening elements may be provided to secure the top edge to the second transverse element. In further embodiments, the transverse element may only support the top edge of the at least two solar panels without the use of fastening elements. For instance, the first or second transverse element may be an “insert type” of profile. In such a type of profile, noseparate fastening element is provided to secure the solar panel edge to the transverse element. Instead, the solar panel is inserted into the transverse element and secured by an edge or feature of the transverse element that is configured to protrude over a top surface of the solar panel, thereby securing the solar panel directly in the transverse element.

[0014] In an embodiment, the transverse element has a maximum length of at most 150% of one of the at least two solar panels, such as a maximum length of at most 100% of the solar panel, or a maximum length of at most 80% of the solar panel. Such length restrictions provide the benefit of using a relatively low amount of material in the manufacturing of the fastening arrangement while providing sufficient support in the transverse direction. Hence, in a further embodiment, the transverse element may comprise a length in the range of 20%-150% of the length of one of the at least two solar panels, such as 25%-100% of the length of one of the at least two solar panels, preferably 30%-80% of the length of the at least two solar panels. For equally sized solar panels, this corresponds to a length in the range of 10%-75% of the combined length of the at least two solar panels, such as 12,5%-50% of the combined length of the at least two solar panels, or 15%-40%. The fastening arrangement may comprise at least two solar panels. The at least two solar panels may be positioned adjacent to each other in the transverse direction.

[0015] The fastening arrangement according to the invention comprises at least two fastening elements, wherein each fastening element secures a different solar panel to the transverse element. In embodiments wherein the fastening arrangement comprises both a first and second transverse element, the fastening arrangement may further comprise a second pair of fastening elements for fastening the second transverse element. In such embodiments, the at least two fastening elements are first fastening elements, and the fastening arrangement further comprises at least two second fastening elements for securing a solar panel to the second transverse element. The first fastening elements are configured to be fastened to the first transverse element and the second fastening elements are configured to be fastened to the second transverse element. In total, the fastening arrangement thus comprises at least four fastening elements for securing the at least two solar panels at their respective bottom edges and top edges. Advantageously, movement of the solar panels in all directions may be prevented when suitable fastening elements are used.

[0016] In an embodiment, the fastening elements are configured to be fastened to the respective transverse element at a limited number of predetermined locations. Here the term “fastening elements” is used to refer to the first fastening elements and / or the second fastening elements in embodiments wherein both are present. The term “limited number” refers to any number less than an infinite amount of different locations. In embodiments, the limited number of predetermined locations may be at most 5 locations, or at most 3 locations, preferably only one or two different fastening locations are provided per solar panel. The presence of predetermined locations eliminates the need for any on-site configuration and eases the assembly. The predetermined locations for the fastening elements may for instance be selected for optimalweight distribution of a series of (at least two) solar panels.

[0017] In an embodiment, the fastening elements are configured to be fastened to the transverse element without the need for any additional tools. Again, the term “fastening elements” may refer here to some or all fastening elements, first fastening elements and / or second fastening elements that are present. The feature that the fastening elements may be fastened without the need for any additional tools can considerably speed up the installation process as during assembly one does not need to continuously pick up a tool to fasten the fastening elements. In addition, it may be advantageous for home-owners for installing solar panels without the need for skilled labor or specialized tools. Moreover, in roofs that are difficult to access, there may not be sufficient space for assembly and it may be advantageous to have a fastening arrangement that can be assembled with ease and without any specific tools.

[0018] In an embodiment, the transverse element comprises a plurality of engagement features for the fastening elements, and the at least two fastening elements comprise complementary engagement features. For example, the engagement features and complementary engagement features may comprise a pin and slot, a groove and clamp configured to engage in the groove, a screw thread and screw hole, a first and second jaw of a clamp, etc. In accordance with the advantages described above, the engagement features may be provided at a limited number of pre-determined positions and / or allow for a fast assembly, preferably without the required used of additional tools.

[0019] In an embodiment, the engagement features may be spaced from each other along the transverse element at a distance of at least 10% of a length of a solar panel or at least 20% of a length of a solar panel. Typically, a solar panel manufacturer provides guidance of optimal engagement positions for solar panels to a support arrangement. By arranging the engagement features 10% from each other enough flexibility is provided to engage the fastening elements close enough to the suggested positions. Advantageously, the person installing the solar panels does not need to measure where to apply the fastening element, but instead count where to engage it, e.g., in the third, fourth, or fifth position when counting from a certain side.

[0020] In an embodiment, the fastening elements or engagement features may be spaced at most 25 cm apart, preferably at most 15 cm apart, or at most 10 cm apart along the transverse element. Furthermore, the second fastening elements may be spaced at most 25 cm apart, at most 15 cm apart, or at most 10 cm apart along the transverse element. The predetermined locations are calculated a-priori during the design and manufacture of the support and fastening arrangement so that the end user may assemble the arrangements without significant effort. This may be particularly useful when supporting an array of several solar panels, wherein the optimal locations to support the solar panel are already known. Additionally, the predetermined positions avoid any user error during the assembly of the fastening arrangement, ensuring an equal weight distribution and avoiding any disproportionate straining of the fastening elements.

[0021] In an embodiment, the fastening elements may be or include an element that actively exerts a force on a surface of a solar panel, e.g., the top surface of the solar panel, to secure therespective solar panel to the transverse element. Alternatively, the fastening element may be an element that merely blocks or prevents movement of the solar panel in one or more direction.

[0022] In an embodiment, the fastening arrangement comprises at least four fastening elements for securing the bottom edges or top edges of a solar panel to the respective transverse elements. The choice of the type, design, and number of fastening elements may be determined based on the conditions where the solar panels are installed, in particular the wind climate. For instance, in a gentle wind climate, the fastening elements may simply support the solar panel at the bottom edge (instead of clamping the solar panel). Alternatively, in particularly windy environments, more than two fastening elements per solar panel may be required to prevent a solar panel from getting loose. In embodiments, more fastening elements may be provided per solar panel, for example 6, 8, 10, or 12 fastening elements per solar panel.

[0023] In an embodiment, the fastening elements may be clamps configured to clamp the solar panels to one or more transverse elements. It will further be understood by the skilled person that any combination of fastening elements may be made, wherein one long edge of the solar panel, e.g., the bottom edge, is clamped using any number of fastening elements, whereas the other long edge is only retained, or vice versa.

[0024] In an embodiment, the first fastening elements and / or the second fastening elements are panel clamps. Here, the panel clamp may in some embodiments be a clamp that applies a force from two opposite sides of the solar panel to hold / secure the solar panel to the transverse element. In other embodiments, the clamp may only be attached to a part of the solar panel and may aid in preventing relative movement of the solar panel (as opposed to fixing the solar panel to the transverse element). The choice of fastening element will be apparent to the skilled person in dependence of the environment where the solar panels are installed.

[0025] In an embodiment, the panel clamp may be selected from the group of a snap-and- swing clamp. Here, the snap-and-swing clamp refers to a clamp that comprises two elements, a top jaw configured to contact an upper surface of the solar panel and a rotatable element that contacts a lower surface of the solar panel directly or indirectly via a portion of the transverse element upon which the solar panel rests. In this way, the snap-and-swing clamp may contact the upper and lower surface of the solar panel. More precisely, the snap-and-swing clamp may typically contact the upper and lower surface of a frame member of the solar panel. The clamp may be engaged by rotating a part of the clamp about the rotatable element. The rotatable element may also be referred to as an engagement element. The clamp is engaged by rotating the clamp, typically from a first position to a second position, about the rotatable element, wherein the clamp is at least partially deformed at a point between the first position and the second position upon the application of the torque. As a result of this deformation, the clamp cannot be disengaged without the application of a similar torque in the opposite direction. Hence, in this way, the snap-and-swing clamp may secure the solar panel by simply engaging the clamp without the need for additional tools.

[0026] In an embodiment, the panel clamp may be an inclined screw cap. The inclined screwcap has a locking element functioning as a top jaw that may extend over the upper surface of the solar panel and contact it. The lower surface of the solar panel rests on a portion of the transverse element. In embodiments, the transverse element and the inclined-screw cap may comprise screw holes or other openings through which a screw may be inserted. The inclination of the screw hole relative to the transverse element may be varied. Hence, the inclination of the inclined- screw cap may be fixed at a predetermined inclination. The head of the screw abuts the locking element and a nut secures the panel clamp to the transverse element. Here, the solar panel may be secured between the locking element (of the inclined-screw cap) and the transverse element by partial deformation of the inclined-screw cap. The nut may be further tightened or loosened for finetuning the fit of the solar panel between the panel clamp and the transverse element. Hence, in this way, the panel clamps may facilitate the ease of assembly by allowing the solar panels to be secured and released from the transverse element without any additional tools.

[0027] In an embodiment, the fastening arrangement is configured to support any solar panel having a length selected from the range of 100-300 cm, preferably 150-250 cm in a landscape orientation. Typically solar panels have a length between 175-225 cm and for solar panels longer than approximately 200 cm, support along the long edge is required to prevent bending of the solar panel. Nevertheless, it will be understood by the skilled person that the stiffness of a solar panel frame is also relevant in this respect, and that also for smaller panels it may be required to support them along their long edge. In alternative embodiments, the fastening arrangement may also be configured to support the solar panel in a portrait orientation, optionally in dependence of the dimensions of the roof or substantially flat surface the solar panels are supported on. The fastening arrangement can be configured in many different ways, allowing for the accommodation of solar panels within the aforementioned dimensions and configurations.

[0028] In an embodiment, the transverse element has a width of at least 5%, or at least 10%, or at least 15% of the width of the solar panel. Here the width is measured as a maximum width of the transverse element in the inclined plane and extending in the longitudinal direction. A wider transverse element may be beneficial in accommodating a range of variability in the width of the solar panels. Furthermore, in embodiments, the position of the one or more fastening elements on the transverse element may be varied over the width of the transverse element. Especially, the position of the at least two fastening elements may be varied over the width of the transverse element. In this way, adjustments may be made during assembly (should they be necessary) to accommodate for variations in the width of the solar panel.

[0029] In an embodiment, the support arrangement comprises an elongated element extending in a longitudinal direction substantially perpendicular to the transverse element, a low support connected to the elongated element and a high support connected to the elongated element. The high support and the low support are configured for supporting the solar panel at an inclined position, wherein the high support has a larger height than the low support. Here the height of the high and low support refers to a maximum supporting height of the solar panel. Advantageously, the support arrangement is modular, thereby saving material expenses in comparison to integrallyformed support arrangements.

[0030] In an embodiment, the transverse element is attached to the high support or the low support. The other support of the high support or low support may have an integrally formed fastening element or retainer, or a separately formed fastening element or retainer that is directly secured to the respective transport without the use of a transverse element. Advantageously, the single transverse element ensures that adjacent solar panels are interconnected and material expenses are saved by not providing a second transverse element. Alternatively, in embodiments, the first transverse element may be attached to the low support and the second transverse element may be attached to the high support.

[0031] In an embodiment, the high support has a maximum height Hi and the low support has a maximum height H2. Here, the distance between the maximum height of the high support and the maximum height of the low support is Li. The inclination angle of the solar panel is defined as a = arctan ((HI-H2) / LI), where a is selected from the range of 5°-15°, preferably at an angle selected from the range of 8°-12°. The inclination of the solar panel is selected to improve the efficiency of the power generated by the solar panel based on the geographic location where the solar panel is installed. Typically, the solar panels in a solar panel installation system are configured to make an angle between 5 and 35 degrees with respect to the horizon, as this optimizes the energy yield in most European countries. It will be understood by the skilled person that the optimal angle is dependent on the geographical position and specifically the latitude of the location where the solar panel system is installed. The fastening arrangement is structurally not limited to any angle and the height of the supports may be adjusted for supporting the solar panels at any angle. In embodiments, the fastening arrangement may be designed to support a solar panel at a certain predefined angle dependent on the location of the solar panel system.

[0032] In an embodiment, the support arrangement may be configured for solar panels having a variable width in a landscape orientation. A fastening position of the transverse element with respect to the support arrangement may be adjustable in the longitudinal direction. This provides optimal flexibility for the use of the fastening arrangement in many different situations. Nevertheless, in other embodiments, the support arrangement may also be designed for panels having a specific width only. Since, the shape and / or dimensions of solar panels are nowadays to a large extent standardized, the fastening arrangement may also be manufactured to hold solar panels with specific dimensions only. This significantly reduces the complexity in manufacturing the fastening arrangement, thereby also reducing the associated costs.

[0033] In an embodiment, the high support and / or the low support may comprise one or more engagement features, for example grooves or notches, for fastening the transverse element(s) thereto. Preferably, the one or more engagement features on the high support and / or the low support may extend in a continuous range along the longitudinal direction, or a plurality of different engagement features may be provided at different positions along the longitudinal direction to provide different engagement positions for the one or more transverse elements. In this way, the fastening position of the transverse element, or the first transverse element and / orthe second transverse element to the support arrangement may be varied in the longitudinal direction. This provides the advantage of adjusting the position of the transverse element, or the first transverse element and / or the second transverse element dependent on the width of the solar panel.

[0034] In an embodiment, the fastening arrangement is configured to fasten the at least two solar panels in an east-west orientation or in a south orientation. Here, an east-west orientation refers to an array of solar panels comprising rows with solar panels facing in alternating directions. That is, a first solar panel and a second solar panel both) oriented with their long edges adjacent to one another are configured to be in east-facing and west-facing directions, respectively. In this way, power generation may be optimized over the arc of the sun’s trajectory over the course of the day, from sunrise to sunset. Alternatively, it may be desired to have all the solar panels in the array face one direction. For example, all the solar panels in the array may be approximately south facing, or in another direction dependent on the specifics of the installation site.

[0035] In an embodiment, the fastening arrangement may comprise one or more foot-elements for supporting the support arrangement above a surface or a roof. These foot-elements may comprise fastening features such as screw threads or securing holes to secure the support arrangement to the flat surface or the roof. However, typically, the fastening arrangement is “fastened” to the roof or other substantially flat surface using heavy weights such as bricks or stones that may be placed on the foot-elements or other parts of the support arrangement as a ballast to immobilize the fastening arrangement. The foot-elements can compensate for unevenness in the surface of the roof or other substantially flat surface.

[0036] It will be apparent to the skilled person to include other advantageous features to the fastening arrangement to optimize the on-site performance of the solar panel array. For instance, side plates for preventing the side-entry of wind, plates for preventing the propagation of fire, back plates in a south orientation of the solar panel system, cable holders, and / or ballast holders may be connected to the fastening arrangement. In embodiments, the fastening arrangement may include such components.

[0037] In an embodiment, the high support and the low support both comprise complementary coupling elements for attaching the high support and the low support to the elongated longitudinal support element. Preferably, the complementary coupling elements allows for a quick assembly and fastening without the need to use tools or other elements. More preferably, such coupling elements are provided at a plurality of different positions on the elongated longitudinal support element to be able to configure the position where a low support and high support are fastened. In this way, the distance between a low support and high support can be configured. The skilled person will understand that the spacing of the complementary coupling elements on the elongated longitudinal support element can be made in consideration of the desired angle of inclination of the solar panel. Coupling elements together also provide a rigid connection between all the elements of the support arrangement. This improves the structural integrity of the supportarrangement and hence also the structural integrity of the fastening arrangement.

[0038] In an embodiment, the transverse element comprises an angular profile. Here the term “angular profile” is used to describe a profile comprising at least two major surfaces configured to extend in the transverse direction, the two major surfaces making an angle of substantially 90 degrees with respect to each other. Advantageously, one surface may be arranged in parallel to the inclined plane, while the other surface may be arranged substantially perpendicular to the inclined plane and in parallel to the bottom edge or top edge of the solar panel. Such a configuration enables an easy engagement of the transverse element to both the support arrangement and the solar panels. It is noted that the transverse element is typically formed of an angular profile or comprises an angular profile. Protrusions, cut-outs, and bend portions may be provided in the angular profile to form specific features, for example, the engagement features for the fastening elements may be included in one of the two major surfaces.

[0039] In an embodiment, the transverse element is made of metal, preferably steel or aluminum. Metallic structures have a sufficiently high Young’s modulus to retain their structure under loading of one or more solar panels. Furthermore, the material is easy to manufacture using conventional methods known in the art such as rolling a steel profile and cutting it to size. In embodiments, the fastening elements are also made of metal. The fastening elements may be manufactured through rolling, extrusion, from folding of metallic sheets, or using any other type of method known in the art. It will be understood by the skilled person that this may depend on the specific design of the fastening element.

[0040] According to an important advantage of the invention, the transverse elements may interconnect adjacent solar panels in a series of solar panels. As such, the invention is directed at a fastening arrangement for at least two solar panels. Nevertheless, it will be apparent to the skilled person that the components of the fastening arrangement may just as well be configured to support a single solar panel only.

[0041] In an embodiment, the transverse elements are long transverse elements and the fastening arrangement further comprises one or more short transverse elements and / or end fasteners for securing one or more solar panels at the end of a series of solar panels. The long transverse element is configured to support at least two solar panels. In order to support the solar panels positioned at the ends of rows in the array, the fastening arrangement may further comprise short transverse elements or end fasteners configured to support the short edge of a solar panel at the end of a row of solar panels. Here, the short transverse element may support the solar panel at the bottom edge or the top edge at a distance from the edge of at least 20% or at least 25% of the length of the solar panel. Alternatively, the end fasteners may support the solar panels at the end of a row by supporting the solar panel at the first side edge or the second side edge. For example, a series of “n” solar panels may be supported by the fastening arrangement comprising “(n-1 )” long transverse elements and two end fasteners or short transverse elements. In embodiments wherein transverse elements are provided along both the top edge and the bottom edge, “2*(n-1)” long transverse elements are used, and four endfasteners or short transverse elements. It will be understood by the skilled person, however, that many different configurations of the modular system are possible and therefore that the number of elements may differ per embodiment.

[0042] According to another aspect of the invention, and in accordance with the effects and advantages as described herein above, there is provided a solar panel system comprising the fastening arrangement and a plurality of solar panels fastened to the substantially flat surface using the fastening arrangement. In an embodiment, the system comprises at least three solar panels.

[0043] According to yet a further aspect of the invention, and in accordance with the effects and advantages as described herein above, there is provided a kit of parts comprising a transverse element and at least two fastening elements. The transverse element and at least two fastening elements may be used in combination with components of an existing solar panel fastening arrangement. For example, a panel clamp clamping the short edges of two adjacent panels in an existing solar panel system may be replaced by a transverse element and two fastening elements according to the invention to provide support along the long edges of the solar panel.

[0044] In an embodiment, the kit of parts further comprises components of a support arrangement.

[0045] In a further embodiment, the kit of parts further comprises one or more of an elongated longitudinal support element, a high support, a low support, a plurality of foot-elements, and / or a plurality of solar panels.Brief Description of Drawings

[0046] Embodiments will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts.

[0047] Figure 1 A schematically shows a perspective view of a first embodiment of a solar panel system supported by a fastening arrangement according to the invention.

[0048] Figure 1 B schematically shows a different configuration of the fastening arrangement according to the embodiment in Fig. 1 A when used for a single solar panel only.

[0049] Figures 2A and 2B schematically depict a top view and perspective view of an alternative embodiment of a fastening arrangement.

[0050] Figure 2C shows a detail of a side view of a high support in the fastening arrangement in Fig. 2A.

[0051] Figure 2D shows a detail of a side view of a low support in the fastening arrangement in Fig. 2A.

[0052] Figure 3A shows a side view according to a first embodiment of a transverse element and fastening element for use in the fastening arrangement according to the embodiments in Figs. 1A-2D.

[0053] Figure 3B shows an exploded perspective view of the transverse element and fastening element in Fig. 3A.

[0054] Figure 4A shows a side view according to an alternative embodiment of a transverse element and fastening element for use in the fastening arrangement according to the embodiments in Figs. 1A-2D.

[0055] Figure 4B shows a perspective view of the transverse element and fastening element for use in the fastening arrangement according to the embodiments in Figs. 1A-2D.

[0056] Figure 5 shows a top view of a fastening arrangement according to another embodiment of the invention.

[0057] Figure 6 shows a top view of a fastening arrangement according to yet another embodiment of the invention.

[0058] The depicted figures are schematic representations of some embodiments of the invention, and do not serve as restriction of the scope or the protection laid down by the claims. The figures are intended to provide an illustration only, and are not necessarily to scale.Detailed Description of Drawings

[0059] The following is a description of certain embodiments of the invention, given by way of example only and with reference to the figures.

[0060] Figure 1 A schematically shows a perspective view of a first embodiment of a solar panel system 1001 in an east-west orientation. The solar panel system 1001 comprises a plurality of equally-sized solar panels 1011-1018 that are supported and fastened by the fastening arrangement 1000 in a landscape orientation.

[0061] The solar panel system 1001 comprises an array 1170, which is organized into four rows 1191-1194 of two solar panels each. Each solar panel has a bottom edge 1161 , a top edge 1162, a first side edge 1163, and a second side edge 1164. The width of the solar panels is approximately 100 cm. Each solar panel has a length L of approximately 170 cm and is not sufficiently stiff to be supported only on the short side edges 1163, 1164 of the solar panel. As such, the fastening arrangement 1000 is configured to support and fasten the solar panels 1011- 1018 along each of their long bottom edge 1161 and long top edge 1162.

[0062] The fastening arrangement 1000 comprises a support arrangement 1700, a first transverse element 1210 (schematically indicated), a second transverse element 1220 (schematically indicated), a first pair of fastening elements 1510 and a second pair of fastening elements 1520. The first transverse element 1210 and the second transverse element 1220 are long transverse elements. In addition, the fastening arrangement 1000 comprises a plurality of short transverse elements 1261 ,1262,1263,1264 (schematically indicated) to support the solar panels 1011 ,1012 at the ends of each row 1191 , 1192, 1193, 1194 in the array 1170.

[0063] The first transverse element 1210 is arranged to extend in a transverse direction Y and configured to support the bottom edge 1161 of two adjacent solar panels 1011 , 1012. The transverse direction Y is defined perpendicular to a longitudinal direction X in a plane parallel tothe substantially flat surface. Similarly, the second transverse element 1220 is configured to support the top edge 1162 of the two adjacent solar panels 1011 , 1012. The transverse elements 1210, 1220 have a length equal to approximately 50% of the length L of a solar panel 1011 thereby allowing for a support of the solar panels 1011 , 1012 at a position away from their short edge 1163,1164. The fastening arrangement 1000 further comprises two first fastening elements 1510 and two second fastening elements 1520 for securing the solar panels 1011 , 1012 to the first transverse element 1210 and second transverse element 1220, respectively.

[0064] Due to the use of the first and second transverse elements 1210, 1220, adjacent solar panels 1011 , 1012 in a row 1191 are interconnected with each other and it is not needed to provide a connection between the panels at the side edges 1163,1164. In addition, it is not needed to provide an end fastener at the end of the row, and fastening the solar panels only along their long edges 1161 , 1162 suffices. The transverse elements 1210, 1220 thereby allow the support arrangement 1700 to support the solar panels 1011 , 1012 at a position ideal for minimizing the bending of the respective solar panel under the own weight of the solar panel 1010. Simultaneously, the transverse elements 1210, 1220 also prevent sliding or other movement of the solar panels 1010 along the transverse direction Y. As such, the number of support points in the support arrangement 1700 may be kept to a minimum and no additional elements are needed to prevent the movement along the transverse direction Y.

[0065] Two short transverse element 1261 ,1263 are positioned on the bottom edge 1161 and top edge 1162 at a distance of approximately 25% of the solar panel length L from the first side edge 1163 of the first solar panel 1011. Similarly, the second solar panel 1012 at the end of the row 1191 is supported and fastened by the short transverse elements 1262,1264 arranged at a distance of approximately 25% of the solar panel length L from the second side edge 1164 of the second solar panel 1012. As explained above, this positioning provides optimal support and prevents bending of the solar panels 1011 , 1012.

[0066] According to an important advantage of the invention, the fastening arrangement 1000 is modular and therefore may be arranged in a different configuration dependent on the preferred use. Figure 1 B illustrates how the components of the fastening arrangement 1000 may be used to mount a single solar panel 1010. Although this is not specifically what the invention is intended for, occasionally space may be so limited that an array 1170 of solar panels comprises a row 1190 consisting of a single solar panel 1010 only. Advantageously, the same components may be used for supporting such a solar panel 1010. A first transverse element 1210 and second transverse element 1220 are connected to the support arrangement 1700 and arranged to support the bottom edge 1161 and top edge 1162 of the solar panel 1010.

[0067] The transverse elements 1210, 1220 are provided with a plurality of engagement features 1710 for the fastening elements (see Fig. 3A-4D for more detail). The engagement features 1710 are formed by slots in the transverse elements for insertion of a fastening element 1510, 1520. The slots are equidistantly spaced from each other at a spacing distance Di of approximately 25 cm each. Such a spacing provides enough flexibility for fastening the fasteningelements 1510 at a preferred position. The provision of the engagement features 1710 enhances the installation speed. No fastening elements are indicated on the top edge, nevertheless, the skilled person will understand that these may be provided to further secure the solar panels. Alternatively, the transverse element 1220 may be replaced by an insert type profile that secures the solar panel near its top edge 1162 without the use of a fastening element.

[0068] Figures 2A-2D schematically depict an embodiment of a solar panel installation 2001 fastened using a fastening arrangement 2000 with support arrangement 2700 according to an alternative embodiment. One of the solar panels has been removed to better show the support arrangement 2700. Features of the solar panel installation 2001 and fastening arrangement 2000 that have already been described above with reference to the embodiment above may also be present in the system shown in Fig. 2A-2D and will not all be discussed here again. For the discussion with reference to Fig. 2A-2D, like features are designated with similar reference numerals preceded by 2000 to distinguish the embodiments.

[0069] Fig. 2A shows a top view of the solar panel installation 2001 . Figure 2B shows an isometric zoomed in view of the embodiment shown in Fig. 2A. The support arrangement 2700 comprises a plurality of longitudinal support elements 2701 , high supports 2102, low supports 2103, and feet 2104,2105. The longitudinal direction X is defined as the direction wherein the longitudinal support elements 2701 extend. Four elongated longitudinal support elements 2701- 2704 are each provided with feet 2104,2105 to which the high supports 2102 and the low supports 2103 are connected thereto.

[0070] First transverse elements 2210 extends along the bottom edge 2161 of the solar panel 2012. On each end of the transverse elements 2210, a plurality of engagement features 2710 are provided for engaging a fastening element (not shown) thereto. The engagement features 2710 are spaced from each other over a distance of approximately 10 cm, such that a limited number of different fastening positions for the fastening elements are provided. This is advantageous as the person installing the solar panel installation 2000 will be guided in where to place the fastening elements in dependence of the specifics of the solar panel installation, e.g., the size of the panels, or the positioning of the elongated longitudinal support profiles on the substantially flat surface. Similarly, a plurality of engagement features 2720 are provided on the second transverse elements 2220.

[0071] At the row end, small transverse elements 2261 ,2262 are provided to support and secure the solar panels. Engagement features 2710,2720 similar to those in the first and second transverse elements 2210, 2220 may be provided for engaging a fastening element. Nevertheless, it will be understood that alternatives, such as panel clamps may also be used.

[0072] Figure 2C shows a partial side view of the solar panel system 2001 at the position of a high support 2102 as indicated in Fig. 2A. Likewise, Figure 2D shows a partial side view of the solar panel system 2001 at the position of a low support 2103 as indicated in Fig. 2A.

[0073] The high support 2102 and low support 2103 are both fastened to the elongated longitudinal support element 2701 and extend in a vertical direction Z perpendicular to thesubstantially flat surface. A lower side of the second transverse element 2220 is arranged on the high support 2102 at an approximate maximum height Hi. A lower side of the first transverse element 2210 is arranged at an approximate maximum height H2. The height difference and the spacing between the high support 2102 and the low support 2103 facilitates supporting the solar panel 2010 at a predetermined angle of inclination. The distance between the maximum height of the high support 2102 and the maximum height of the low support 2103 can be adjusted to set a preferred inclination angle of the solar panel. The inclination angle of the solar panel is defined as a = arctan ((HI-H2) / LI), wherein in the depicted embodiment, a can be selected as any number from the range of 8°-12°. It will be understood that the design of the support arrangement 2700 may easily be adjusted to also accommodate different angles.

[0074] The first and second transverse elements 2210, 2220 are identically shaped and comprise an angular profile. The transverse elements 2210, 2200 have a first major surface 2231 , a second major surface 2232, a first connective portion 2233, second connective portion 2234, first abutment surface 2235 and second abutment surface 2236. The first major surface 2231 and second major surface 2232 are connected to each other at an angle of 90 degrees. The first abutment surface 2235 extends in parallel to the first major surface 2231 and is connected thereto through the first connective portion 2233. The second abutment surface 2236 extends in parallel to the second major surface 2232 and is connected thereto through the second connective portion 2234.

[0075] The first major surface 2231 may abut a supporting surface of the high support 2102 or low support 2103. Advantageously, due to the abutting surface, the transverse element may be easily engaged to the respective support 2102, 2103. The first abutment surface 2235 extends in parallel thereto and therefore can support a lower side of a solar panel over the full length of the transverse element. Advantageously, the lower side of the solar panel is well supported over the full length of the transverse element, and not only at the position of the high support 2102, or low support 2103 as in most conventional systems. The second abutment surface 2236 may be arranged to abut the bottom edge 2161 or top edge 2162 of the solar panel. Nevertheless, even though the term abutment surface is used, there is no requirement of the surfaces actually contacting each other. Advantageously, the second abutment surface 2236 may functions as a stop edge is provided when the transverse element is used at the low support 2103. The

[0076] Further, as mentioned above, the elongated longitudinal support element 2701 is provided with feet 2104,2105 to which the high supports 2102 and the low supports 2103 are connected thereto.

[0077] The first and second transverse elements 2210, 2220 further comprise engagement features 2710 (see Fig. 2B) for engaging the first fastening elements 2510 and second fastening elements 2520 thereto. The first fastening elements 2510 and second fastening elements 2520 are panel clamps that can be fastened by tightening a bolt with a nut. Screw holes are provided as engagement features 2710 on the transverse elements 2210, 2220 at predetermined positions for ease of installation.

[0078] Figure 3A and 3B depict a side view and isometric view of an alternative embodiment of a fastening element 3510 and transverse element 3200 that could be used, for instance instead of the fastening element 2510 and transverse element 2210. The fastening element 3510 is a panel clamp having an upper jaw 3036 that can be used to secure a solar panel by tightening a bolt with a nut. Advantageously, the transverse element 3200 allows for pre-assembly of the fastening element 3510 as illustrated in Fig. 3A. Features of the fastening element 3510 and transverse element 3200 that have already been described above with reference to another embodiment may also be present in the embodiment shown in Fig. 3A-3B and will not all be discussed here again. For the discussion with reference to Fig. 3A-3B, like features are designated with similar reference numerals preceded by 3000 to distinguish the embodiments.

[0079] The transverse element 3200 has a first major surface 3231 , a second major surface 3232, a first connective portion 3233, a second connective portion 3234, a first abutment surface 3235, and a pre-assembly flange 3237. Advantageously, due to the provision of the pre-assembly flange 3237, the fastening element 3510 may be provided pre-assembled to the transverse elements 3200 before being arranged in the solar panel system 3001 . The second connective portion 3234 comprises an engagement feature 3710 shaped as a cut-out portion. Conveniently, lateral access is provided for quick insertion of the fastening element and allowing a rotation from a first position for pre-assembly to a second position for tightening. In the pre-assembly position, a transverse element 3200 having a fastening element 3510 pre-assembled thereto may be arranged on a support arrangement 3700. In the pre-assembly position, sufficient space is provided for placement of the solar panel. Then, the fastening element 3510 may be rotated using the space provided by the cut-out portion to the second position for tightening. Finally, after tightening, the top jaw 3036 may be moved downward to a third position by tightening the bolt.

[0080] A solar panel may be clamped between the top jaw 3036 and the transverse element 3200, which forms a lower jaw. The bolt and nut may be tightened to adjust the fit in dependence of the specifications of the solar panel 3010, in particular a height of the solar panel frame.

[0081] Figure 4A and 4B depict a side view and isometric view of another embodiment of the fastening element 4510 and transverse element 4200. Features of the fastening element 4510 and transverse element 4200 that have already been described above with reference to another embodiment may also be present in the embodiment shown in Fig. 4A-4B and will not all be discussed here again. For the discussion with reference to Fig. 4A-4B, like features are designated with similar reference numerals preceded by 4000 to distinguish the embodiments.

[0082] The transverse element 4200 has a first major surface 4231 , a second major surface 4232, a first connective portion 4233, a first abutment surface 4235, and a sloping flange 4238. Advantageously, due to the provision of a sloping flange 4238 that extends in a direction away from the solar panel, an edge is provided which can be used to lock a fastening element 4510, 4520 thereto without the use of any tools.

[0083] The fastening element 4510 has a top jaw 4036 and an engagement element 4037 configured to be engaged to the opening 4710 in the transverse element 4200. The top jaw 4036extends over the transverse element 4200 and solar panel when fastened. The engagement element 4037 abuts the bottom of the transverse element at an abutting point 4211 . To engage the fastening element 4510, the lower part 4511 of the fastening element 4510 is pushed against the transverse element 4200 at the abutting point 4211 such that the engagement feature 4037 rotates about the abutting point 4211 on the transverse element 4200, thus, locking the solar panel between the top jaw 4036 and the transverse element 4200. In the depicted embodiment, the fastening element 4510 undergoes (partial) deformation during engagement, which is realized by a hinged connection 4512 in two fastener portions in the lower part 4511 . Typically, the solar panel may be clicked or snapped onto the transverse element 4200 by a simple toggle or clicking movement. It is advantageous that this action can be performed by a single person, without the assistance of colleagues, or the use of additional tools as it speeds up the installation process. Moreover, it reduces the amount of equipment that the person installing the solar panel system 4001 needs to carry onto the roof. In addition, the assembly of the solar panel system 4001 is intuitive such that no training or specialized personnel is required for the installation. The fastening elements 4510 may be pre-assembled to the transverse elements 4200.

[0084] Figure 5 shows an embodiment of a solar panel installation 5001 and fastening arrangement 5000 according to yet another embodiment of the invention. Features of the solar panel installation 5001 and fastening arrangement 5000 that have already been described above with reference to any of the other embodiments shown above may also be present in the system shown in Fig. 5 and will not all be discussed here again. For the discussion with reference to Fig. 5, like features are designated with similar reference numerals preceded by 5000 to distinguish the embodiments.

[0085] Four solar panels 5011 ,5012,5013,5014 are supported by the fastening arrangement5000. The fastening arrangement 5001 comprises first transverse elements 5211-5215, and second transverse elements 5221-5225 of a length of approximately 20% of the length L of a solar panel only, yet still supports at least two solar panels such that the solar panels can be interconnected through fastening elements (not shown) that can be engaged to the transverse elements. Due to the relatively short length of the transverse elements, a minimal amount of material is used, thus, reducing material costs.

[0086] It is noted that such an arrangement is only applicable for solar panels having a sufficient stiffness for being supported only at a position adjacent to their short edges. It will be understood that the length of the transverse elements may be adjusted to provide a better support and / or that a configurations as depicted in Fig. 1A-2D may alternatively be used if needed.

[0087] Figure 6 shows an embodiment of a solar panel installation 6001 and fastening arrangement 6000 according to yet another embodiment of the invention. Features of the solar panel installation 6001 and fastening arrangement 6000 that have already been described above with reference to any of the other embodiments shown above may also be present in the system shown in Fig. 6 and will not all be discussed here again. For the discussion with reference to Fig.6, like features are designated with similar reference numerals preceded by 6000 to distinguish the embodiments.

[0088] Four solar panels 6011 ,6012,6013,6014 are supported by the fastening arrangement 6000. The fastening arrangement 6001 comprises a first transverse element 6210 and second transverse element 6220 that extend over the full length of the four solar panels. One or more first fastening elements (not shown) are arranged on the first transverse element 6210 to secure the solar panels 6011 ,6012,6013,6014 thereto. Advantageous to providing continuous transverse elements 6210, 6220 is that optimal flexibility is obtained for positioning the support arrangement 6700. Although Fig. 6 displays equidistantly spaced longitudinal support elements 6701-6707, it will be understood that this is not necessarily required. The precise positioning of supports in the support arrangement 6700 may for instance be determined in dependence of structural features of the substantially flat surface that the solar panel installation is positioned on.

[0089] Although the depicted embodiments all show a very limited number of solar panels, it will be understood that the fastening arrangements can be extended to any desired size. An array 1170 of solar panels may for instance comprise approximately 100 solar panels, or 1000 solar panels or even more. Advantageously, the fastening arrangement according to the invention is modular and can be used in many different configurations, for arrays of different shapes, orientations and solar panels of different dimensions. The same transverse profiles may be used in many of those, thereby limiting the number of components that need to be produced and / or kept in stock.

Claims

Claims1 . A fastening arrangement (1000) for fastening at least two solar panels (1011 -1018) on a substantially flat surface, each solar panel (1011-1018) having a bottom edge, a top edge, a first side edge, and a second side edge, wherein the fastening arrangement (1000) comprises: a support arrangement (1700) configured to support the at least two solar panels (1011- 1018) in an inclined position with respect to the substantially flat surface; a transverse element (1210, 1220) configured to extend along the bottom edge or the top edge of the at least two solar panels (1011-1018) ; the fastening arrangement (1000) further comprising: at least two fastening elements (1510, 1520) , wherein each fastening element (1510, 1520) secures a different solar panel (1011-1018) of the at least two solar panels (1011 -1018) to the transverse element (1210, 1220) .

2. The fastening arrangement (1000) according to claim 1 , wherein the fastening arrangement comprises at least two solar panels (1011-1018), wherein the transverse element (1210, 1220) has a length at least equal to 20% of the length of the bottom edge of one solar panel (1011-1018) of the at least two solar panels (1011-1018) .

3. The fastening arrangement (1000) according to claim 1 or 2, wherein the fastening arrangement (1000) comprises at least two solar panels (1011-1018), wherein the transverse element (1210, 1220) has a maximum length of 80% of the length of the bottom edge of one solar panel (1011-1018) of the at least two solar panels (1011-1018), preferably a maximum length of 50% of the solar panel .

4. The fastening arrangement (1000) according to any of the preceding claims, wherein the transverse element is a first transverse element (1210) configured to be arranged along the bottom edge of the at least two solar panels (1011-1018) , the fastening arrangement (1000) further comprising a second transverse element (1220) configured to be arranged along the top edge of the at least two solar panels (1011-1018) .

5. The fastening arrangement (1000) according to claim 4, wherein the at least two fastening elements are first fastening elements (1510), the fastening arrangement (1000) further comprising at least two second fastening elements (1520) for securing a solar panel (1011-1018) to the second transverse element (1220).

6. The fastening arrangement (1000) according to any of the preceding claims, wherein the fastening elements (1510, 1520) are configured to be fastened to the respective transverse element (1210, 1220) at a limited number of predetermined locations.

7. The fastening arrangement (1000) according to any of the preceding claims, wherein the fastening elements (1510, 1520) are configured to be fastened to the transverse element (1210, 1220) without the use of any additional tools.

8. The fastening arrangement (1000) according to any of the preceding claims, wherein the transverse element (1210, 1220) comprises a plurality of engagement features (2710, 2720) for the fastening elements (1510, 1520), and wherein the fastening elements (1510, 1520) comprise complementary engagement features.

9. The fastening arrangement (1000) according to any of the preceding claims, wherein the fastening elements (1510, 1520) or engagement features (2710, 2720) are positioned at a distance of at most 15 cm apart along the transverse element (1210, 1220), preferably at most 10 cm apart.

10. The fastening arrangement (1000) according to any one of the preceding claims, wherein the second fastening elements (1520) or engagement features (2720) are positioned at a distance of at most 15 cm apart along the second transverse element (1220), preferably at most 10 cm apart.11 . The fastening arrangement (1000) according to any one of the preceding claims, wherein the fastening arrangement (1000) supports a solar panel (1011-1018) in a landscape orientation, the solar panel (1011-1018) having any length selected from the range of 150 - 250 cm, or supports two solar panels (1011-1018) in a landscape orientation, the respective solar panels (1011-1018) having any length selected from the range of 150 - 250 cm.

12. The fastening arrangement (1000) according to any one of the preceding claims, wherein the fastening elements (1510, 1520) and / or second fastening elements (1510, 1520) are panel clamps.

13. The fastening arrangement (1000) according to claim 12, wherein the panel clamp is selected from the group of a snap-and-swing clamp and an inclined-screw cap.

14. The fastening arrangement (1000) according to any of the preceding claims, wherein the fastening arrangement comprises at least two solar panels (1011-1018), wherein the transverse element (1210, 1220) has a width of at least 5%, such as at least 10%, especially at least 15% of the width of one of the at least two solar panels (1011-1018).

15. The fastening arrangement (1000) according to any one of the preceding claims, wherein the support arrangement (1700) comprises an elongated element extending in a longitudinal direction substantially perpendicular to the transverse element (1210, 1220), a low support (2103) connected to the elongated element and a high support (2102) connected to the elongated element , wherein the high support (2102) and the low support (2103) are configured for supporting the solar panel (1011-1018) at an inclined position, wherein the high support (2102) has a larger height than the low support (2103).

16. The fastening arrangement (1000) according to claim 15, wherein the high support and / or the low support may comprise one or more engagement features for fastening the transverse element(s) (1210, 1220) thereto.

17. The fastening arrangement (1000) according to claim 15 or 16, wherein the high support (2102) has a maximum height Hi and the low support has a maximum height H2, wherein the distance between the maximum height of the high support (2102) and the maximum height of the low support (2103) is Li , wherein the inclination angle of the solar panel (1011-1018) is defined as a = arctan ((HI-H2) / LI), wherein a is selected from the range of 5°-15°, preferably at an angle selected from the range of 8°-12°.

18. The fastening arrangement (1000) according to any of the preceding claims, further comprising one or more foot-elements for supporting the support arrangement (1700) above a surface or a roof.

19. The fastening arrangement (1000) according to any one of the preceding claims, wherein the transverse element (1210, 1220) is made of metal, preferably steel or aluminum.

20. The fastening arrangement (1000) according to any one of the preceding claims, wherein the fastening arrangement (1000) is configured to support an array of solar panels (1011-1018) , wherein the array of solar panels (1011-1018) comprises at least 3 solar panels (1011-1018), preferably at least 5 solar panels (1011-1018).

21. The fastening arrangement (1000) according to any one of the preceding claims, wherein the fastening arrangement (1000) further comprises end fasteners configured to support the side of the solar panel (1011 -1018) at the end of an array.

22. The fastening arrangement (1000) according to any of the preceding claims, wherein the transverse element (1210, 1220) comprises an angular profile.

23. A solar panel system comprising the fastening arrangement (1000) according to any one of the preceding claims and a plurality of solar panels (1011-1018) fastened to the substantially flat surface using the fastening arrangement (1000).

24. A kit of parts comprising a transverse element (1210, 1220) for use in a fastening arrangement (1000) according to any one of claims 1 -22, and at least two fastening elements (1510, 1520) for use in a fastening arrangement (1000) according to any one of claims 1-22.

25. The kit of parts according to claim 24 further comprising a support arrangement (1700) for use in a fastening arrangement (1000) according to any one of claims 1 -22.

26. The kit of parts according to claim 25, further comprising one or more of the following: an elongated longitudinal support element ; and / or a high support (2102); and / or a low support (2103); and / or a plurality of foot-elements; and / or a plurality of solar panels (1011-1018).

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