Patent Publication Number: US-2016231026-A1

Title: Mounting system for solar panels

Description:
This application claims the benefit of priority of prior European application No. 13004752.5 filed on Oct. 2, 2013, and the entirety of this application is expressly incorporated herein by reference in its entirety and as to all its parts, for all intents and purposes, as if identically set forth in full herein. 
     The invention relates in general to a mounting system for plate-like members, also called panels, such as solar modules, solar collectors, hybrid collectors, esthetical elements or any combination thereof. The invention is especially suited for frameless solar modules and frameless hybrid collectors. The inventive system may also be used for mounting any other plate-like member especially when the benefits of the invention apply. 
     The inventive mounting system is especially suited for mounting plate-like members on slanted roofs, especially on top of weather proof roofs, as opposed to building integrated systems where the plate-like members form weather proof roofing. The inventive system is especially designed to be cost-effective, easy to use, to be modular and offer a new way of keeping the plate-like members clean near their bottom edge. 
     According to the state of the art mounting rails for holding solar panels are known as for example shown in  FIG. 1 . These systems are adapted for framed panels as will be described in conjunction with  FIG. 1  in the figure description. 
     In the EP 0 905 795 A2 a horizontal mounting rail is disclosed and shown in  FIGS. 5 and 6 , for holding framed solar panels on slanted roofs. This known horizontal rail has rectangular cross-section with an upper supporting surface for the solar panels parallel to its base or mounting surface which is to be secured to the roof. As shown in FIG. 6 of the EP 0 905 795 A2, a water-seal fitting together with upper supporting surface defines a mounting recess for the framed edges of the solar panels, with said mounting recess having an upper and a lower face in contact with the frame of the solar panel for holding it to the roof, with both faces being essentially parallel to each other, to the solar panel and to the roof itself. Water, molten snow, dirt or other contaminants entering into the space between said two faces will be collected there and cannot easily flow away because of the lower face, defined by the upper surface of the mounting rail, being slanted towards the center of the mounting arrangement, as can be gathered from FIGS. 8A and 8B of the EP 0 905 795 A2. Moisture 3D and dirt flowing down the slanted surface of the frame of the solar panels will likely get into the space between the frame and the mounting rail and will stay caught there. Draining structures are only provided in vertical mounting rails shown in FIG. 2 of the EP 0 905 795 A2, and even there only by a co-operation of the frame of the solar panels with a drain channel of the vertical rail. 
     Using such a system for frameless panels has the disadvantage that water will collect near the lower bottom edge of the panel. Even if a groove is provided for transporting the water away from the panel, water will collect. Moreover, since the rail, which normally consists of multiple rails placed next to each other, will not be mounted perfectly in one straight line, water will collected in lower portions of the rail. Even if the rails were perfectly straight, the water would have to travel a long way before it could leave the groove. 
     Wherever water collects, algae, small plants and other life forms will grow and dirt will collect, hindering the transport of the water, thus collecting more water to further stimulate growth of all kinds of life forms. 
     In the long run the water will not be able to run off as desired and start collecting near the module. 
     Water may thus penetrate the solar module, since frameless modules often have no edge sealing, meaning that the encapsulant of the module is not covered. Since the most common encapsulants (especially EVA) are hydroscopic, water will enter the module, causing delamination and oxidation of electrical parts. Also the water, life forms and dirt in it may cover the module, leading to shading and thus reduction of electrical and or thermal output. 
     Cleaning the module will resolve the latter problem, even if this comes at a cost. As will be described in more detail in relation to  FIG. 1 , cleaning of the groove or sides of the module is much more elaborate. The module must be lifted in order to gain access to the soiled parts. 
     It is the goal of the present invention to provide a mounting system, especially for frameless panels, that removes water from the module more readily. By doing so the need for cleaning of the panels and especially the mounting system itself is reduced drastically. 
     This goal is achieved by letting the water run off the mounting system in a direction perpendicular to the direction the rail extends in. Moreover, a slanted surface is provided, that allows the water to run off in direction of the roof top. A second surface may be provided for letting water run off towards the base of the roof. The surface is slanted relative to the horizontal, so that water runs off readily. Preferably the surface, or actually the parts of the surface defining the water level of water being collected by the mounting system, makes an angle to the horizontal larger than 1° even more preferred larger than 5°. 
     These goals are met by mounting systems according to the characterizing portions of the independent claims. Further features are defined by the dependent claims, the drawing figures and the detailed description of an embodiment of a mounting system according to the invention. 
     The new and inventive mounting rail for plate-like elements such as solar panels, in particular for roofs extending in a slanted plane, has roof mounting means for being mounted on that roof and defining a mounting plane as well as an insert mounting recess to receive an edge of a plate-like element for being held in that first insert mounting recess, similar to prior art mounting rails for horizontal use. The mounting recess has a lower and an upper face opposing each other, as is also known. 
     For meeting the above-mentioned goal the lower face of the insert mounting recess is declining to the outside of the mounting rail forming an angle of at least 11°, preferably an angle of at least 41°, with the upper face and/or the mounting plane, according to the present invention. Thereby, a slanted water run off plane is defined that allows the water to flow to the roof surface in a direction towards a vertical plane containing the top or ridge of the roof. The above-given values are preferred for roofs with angles of inclination between 10° and 40° to provide a water run off plane slanted towards the surface of the roof and away from the insert holding recess. For roofs with other angles of inclination, mounting rails with steeper or less steep lower faces can be provided, as long as the lower face is slanted towards the roof surface at least with an angle of inclination at least 1° or more steeper than a horizontal plane. 
     Preferred, a plane is defined by the center edge and the outer edge of the lower face of the insert mounting recess, said plane slanted towards the outside of the mounting rail and forming an angle γ of at least 11°, most preferred an angle of at least 41°, with the upper face and/or the mounting plane. Again, said plane is defining the slanted water run off plane for preventing water and dirt to collect near the lower edge of the plate-like elements and flow away in the direction defined in the preceding paragraph. 
     To be able to hold plate-like elements at their lower edges, but with one and the same mounting rail holding elements adjacent and below the mounting rail, a second insert mounting recess is provided at the side opposite of the insert mounting recess. Although this second recess is depicted being deeper than the first insert mounting recess and is showing a second lower face being wider than the first lower face, embodiments with other dimensions of the second recess and its upper and lower faces are possible. Since the second insert mounting recess is open in the direction downward of the slanted roof, the second lower face can preferred form an angle with the second upper face and/or the mounting plane smaller than the angle of the lower face of the first insert mounting recess. 
     The mounting rail disclosed in the preceding paragraphs can be further characterized by an upper face of the insert mounting recess that extends mainly parallel to the mounting plane, in particular the side of the roof mounting means facing the roof. Preferred, the second upper face of the second insert mounting recess extends mainly parallel to the roof mounting means or the mounting plane. 
     While the mounting rail described in the preceding paragraphs can be used with plate-like elements with frames surrounding their edges at least partly or even all around, the goal of the present invention can be met even for plate-like elements without any frames or similar structures. For this reason, a mounting system according to the present invention is characterized by a mounting rail according to any of the preceding paragraphs and characterized further by a first member insert provided in the first insert mounting recess and showing a receiving groove for the plate-like element. 
     Preferred, this member insert additionally has a wedge-like part filling the gap between the plate-like element and the slanted lower face of the insert mounting recess. This wedge-like part fills the most of or even the whole space between the lower side of the element and the lower face of the recess, which space is opening up towards the outside of the mounting rail, thereby assuring a safe and reliable fixation of the edge of the plate-like element in the groove of the insert and also in the mounting recess. 
     Preferred, a second member insert is provided in the second insert mounting recess and showing a receiving groove for the plate-like element and a wedge-like part filling the gap between the plate-like element and the second lower face of the second insert mounting recess, with the same advantages as explained above. 
     To make easier the flowing away of water, molten snow, dirt and the like, the member inserts of a preferred embodiment of the invention are shorter than the mounting rail. Preferred, the member inserts are even shorter than the plate-like elements. For each of all possible embodiments of the member inserts there is a preferred embodiment having essentially constant cross-section over its length, which extends along the mounting rail. 
     For meeting the goal that separately produced member inserts can be inserted in the recesses of the mounting rail during the mounting process or during production of the mounting system, at least one of the member inserts or the insert mounting recesses have fixing means for fixing at least one of the inserts in the respective insert mounting recesses. Preferably, the fixing means can be disengaged for removal or replacement of the member inserts. 
     The member inserts can be made of flexible and/or resilient material. 
     A further advantageous embodiment of the mounting system is characterized by at least the first member insert having a protruding portion extending beyond the lower face of the insert mounting recess and preferably also extending beyond the upper face of the insert mounting recess. 
     The plane of the roof may also mean any plane parallel to the roof. 
     The mounting system normally is mounted on a vertical rail, rafter or counter batten, extending vertically on the slanted roof. 
     According to the invention, the water run off plane is slanted towards the surface of the roof for any of its angles of inclination, as becomes clear from the specification and the drawing figures. The run off plane is declining towards the outside of the mounting rail or the mounting system, respectively, such that the water can run off in a direction towards a vertical plane containing the top or ridge of the roof. This slanted surface allows the water to run off from the insert holding recess of the mounting rail onto the roof. The water can run off more readily because the slope of the plane it runs over can be made large. Previously this angle was limited because mounting the rail under an angle is not optically pleasing. Alternatively the rail could be given a cross-section that is not constant over its length, requiring the rail to be worked over. Moreover, it can no longer be manufactured in a die casting process, what would make the rail expensive. 
     Also the way the water has to travel to leave the mounting system is much shorter and independent of the location of the module in the mounting system. 
     In addition to those advantages, the mounting system remains cost-effective, easy to mount, not requiring additional labor to be installed. 
     The water run off plane may be defined by the surface of water standing still on the lower recess face, ignoring adhesion and cohesion so that the surface of the water extends in a flat plane. According to the invention this plane does not intersect with the module, so that the edge of the module is not in direct contact with any accumulated water. The effective distance from the module edge to the water level depends on the relation between the slope of the roof and the angle of inclination of the lower face of the mounting rail or the water run off plane, and is preferably more than 1 mm. Preferably the minimum distance from this plane to the module or the module holding recess for holding the same is at least 1 mm, preferably more than 5 mm and even more preferred more than 10 mm. Note that this distance also depends on the on the relation between the slope of the roof and the angle of inclination of the lower face of the mounting rail or the water run off plane. The mounting recess extends in the direction of the rail. 
     Alternatively the water run off plane may be defined as the steepest plane from the lower edge of the module or the module holding recess for holding the same tangentially touching on the upper side of a portion of the lower part of the insert mounting recess, such as the lower recess face or the insert holding means, the plane extending in the direction of the mounting rail or in the direction of the smallest slope of the roof. “Steepest” is meaning “less parallel to the module or the upper recess face”. 
     The means for holding the plate-like member may be any suitable means for holding for example a solar module. In the simplest case, the means for holding the plate-like member are formed by faces of the module holding recess, preferably the insert mounting recess having a lower and an upper face opposing each other for clamping the module. Moreover, the lower and upper face would be on opposite sides of the module. 
     Preferably, the water removal plane starts not in the lower module edge or the corresponding portion of its holding means, but at certain, when mounted preferably more or less vertical distance therefrom, so that water is even less likely to come into contact with the module. The minimum distance is larger than 2 mm, preferably more than 5 mm and even more preferred more than 10 mm. 
     Preferably, the upper face of the insert mounting recess extends mainly parallel to the plate like member when being held. In that way the mounting means are less visible and thus more esthetically pleasing. 
     Since a solar panel roof normally extends in a plane parallel to the roof it is mounted on, it typically extends under the same slope as the roof. Therefore, the water removal plane may also be defined relative to the modules and thus the upper recess face. The angle δ is equal to angle γ if the water removal plane extends horizontally. Therefore, for δ the same conditions hold as for γ: δ should be larger than the slope α of the roof, preferably at least by an amount β of 1°. 
     Preferably, the member insert has a mainly constant cross-section. In this way the insert can be made by die casting. After the casting it only needs to be cut to the desired length. 
     Preferably, the member insert, the insert mounting recess or both have means for fixing the position of the insert in the insert mounting recess so that the insert stays in place, especially when the module is being inserted. In that way installation can be done more easily: The insert is first placed in the insert mounting recess. By making the member insert of a flexible material, the insert not only serves to hold the module, it also protects the module against the rail, which is normally made of a hard material such as a metal like aluminum or a fiber reinforced plastic. Making the insert compressible facilitates the fixing of the insert in the insert mounting recess. 
     Preferably, the member insert has a protruding portion extending beyond the lower module holding face and preferably also extending beyond the upper face of the insert mounting recess when placed in the insert mounting recess. The insert thus facilitates the mounting of the module by guiding its lower part into the insert and thus the mounting rail. 
     Further embodiments of the invention are indicated in the figures and in the dependent claims. The list of reference numerals and symbols forms part of the disclosure. 
    
    
     
       A preferred embodiment of the invention will now be explained in detail with reference to the drawings. In the drawings: 
         FIG. 1  schematically shows a mounting system for frameless modules according to the state of the art. 
         FIG. 2  schematically shows a cross sectional view of an embodiment of two solar modules being held by a mounting system according to the invention; 
         FIG. 3  shows a 3D view of the mounting system of  FIG. 2 ; 
         FIG. 4  shows the water removal plane and the way the water runs off the modules. 
     
    
    
     The present invention will be described with reference to exemplary embodiments and the present invention is not limited to a particular embodiment or component parts thereof, except as defined in the appended claims. Embodiments of the present invention may be used with a variety of methods and systems. It will be apparent to one skilled in the art that the present invention may be practiced in a variety of ways within the scope of the claims. Any feature shown in relation to the figures may be applied in general to the invention as described in the claims. 
     As used herein, the indefinite article (“a”, “an”) denotes the presence of at least one of the referenced item, and the terms multiple and ‘a plurality’ denotes the presence of more than one. 
       FIG. 1  schematically shows a mounting system  1 ′ according to the state of the art as available from Creotecc Solar mounting systems (www.creotecc.de) under the name Alutec 42 FL. 
     A mounting rail  3 ′ to be placed essentially horizontally on a slanted roof  2 ′ is shown, holding a frameless module  6 ′ with insert  4 ′. The rail  3 ′ is made for holding two modules, only the upper one being shown. The mounting rail  3 ′ has roof mounting means  5 ′ defining a mounting plane  22 ′: the plane defining the orientation of the mounting rail  3 ′ when attached to the roof in normal fashion. The plane  22  being drawn slightly offset for clarity, the plane still extending in parallel to the roof  2 ′. 
     A groove or channel  24  is provided for collecting rain water falling on module  6 ′. As described previously, the water will assemble in this groove and collect dirt and life forms. Moreover, since for esthetical reasons the groove cannot be too slanted to the plane of the roof (=rotated around line of greatest slope of the roof), water will remain in it. During rainfall the groove will completely fill and water and dirt will gather to the level indicated with the dashed line  29  and come in contact with the side of the module that normally is not protected. 
     Encapsulants, especially EVA, are hydroscopic. Thus water will enter the module causing it to delaminate. As more and more water enters the module, electrical components in the module (cells, interconnectors, diodes, etc.) will be impaired. 
       FIG. 2  shows a mounting system  1  according to the present invention for mounting solar panels or modules  6 ,  7  on a slanted roof  2 . The parts of the mounting system  1  shown (the parts holding the upper and lower part of the solar modules  6 ,  7  respectively and additional inserts holding the lower edge of the module are not shown) mainly consist of a mounting rail  3  holding a module insert  4  and extending essentially horizontally over the surface of the roof  2 . The module insert  4  has means  27   a ,  27   b  for holding the modules  6 ,  7 , respectively. In this embodiment the holding means consist of module holding surfaces  27   a ,  27   b . The rail  3  is held in place by a climber or more general rail fixing means  13 , normally fixing it to a vertical rail, rafter or counter batten. 
     Each module  6 ,  7  may on both its lower and its upper side be held by multiple inserts  4 . By using multiple inserts  4  for holding one module, placing them next to each other at an distance in one mounting rail, that module is held more firmly and will bend less, for example under influence of wind or its own weight. 
     The module insert  4  is held by an insert mounting recess  8  in the mounting rail  3 . The module  6  is held by a first module holding recess  10  in that first module insert  4 . In this way the module  6  is protected against the mounting rail  3  that is normally made of a hard material such as metal or reinforced plastic. Especially when mounting the module  6 , insert  4  protects it so that module  6  is not damaged when it slides into the recess  10  in the rail  3 . In the embodiment shown in  FIG. 4 , the module holding surface  27   a  (in this embodiment forming part of the means for holding the plate-like member) of the module insert  4  extends beyond the upper face  19  of the insert mounting recess  8 . When mounting the module, the first module inserts  4  preferably are placed in the mounting recess  8 . Then the lower edge of the module  6  may be placed on the protruding portion  17  of the first module insert  4  before it is slid into the first module holding recess  10 . 
     By making the insert  4  much shorter than the width of the module (width extending perpendicular to the plane of  FIG. 2  and normally perpendicular to the line of greatest slope of the roof and parallel to the surface of the roof) gaps exist between neighboring inserts and rain water falling on the module  6  and molten snow running off module  6  is free to flow from the module onto the roof  2  below it. This is shown in  FIG. 4 . The arrows roughly indicate the path the water will follow, unhindered by any obstacles. The arrows extend in a plane parallel to the plane of the drawing, but in a plane next to the insert  4 . In planes where the insert  4  extends in, the water is hindered, but may run off sideways (direction perpendicular to the plane of the drawing). Since the inserts  4  are relatively short, typically between 5 and 20 cm, water will run off easily. 
     Returning to  FIG. 2 , insert  4  is held in place by insert holding means  12 . The insert  4  is made of a flexible, resilient material such a polymer and its structure allows it to deform slightly. Its walls are not too thick so that its protruding portion  17  can be pressed towards the upper module holding face  27   a , thus allowing the module insert  4  to be inserted into the insert mounting recess  8 . In this way the insert  4  also makes it possible for the module  6  to bend, especially towards the roof  2 , without the rail  3  exerting too large forces the module, what may damage the latter. 
     As water runs off the module  6  it will flow as shown in  FIG. 4 , the arrows indicating the flow. Depending on the exact shape of the mounting rail  3  and the slope of the roof, a water run off plane  23  will form/be formed. In general this plane mainly is the lower recess face  16 . In the shown embodiment, the insert holding means  12  extends such that the water run off plane  23  is also defined by it. In general the water run off plane  23  may be defined by the surface of water standing still on the lower recess face  16 , ignoring adhesion and cohesion of the water so that the surface of the water forms an essentially ideally even plane. According to the invention this plane  23  does not intersect with the module  6  due to the mutual relation of the angles of inclination of the water run off plane  23  or the lower recess face  16 , the height of the module  6 , the height and thickness of the insert  4  and the width of the lower recess face  16 . Preferably the minimum distance from this plane to the module  6  or the module holding recess  10  is at least 2 mm, preferably more than 5 mm and even more preferred more than 10 mm. Note that this distance also depends on the slope of the roof. 
     Alternatively the water run off plane  23  may be defined as the steepest plane from lower edge of the module  6  or the inserts  4  and tangentially touching on the upper side of a portion of the lower part of the insert mounting recess  8 , such as the lower recess face  16  or the insert holding means  12 . This the plane  23  is extending in the direction of the mounting rail  3  or in the direction of the smallest slope of the roof  2 . “Steepest” is meaning or could be replaced by “at least less parallel to the module or the upper recess face  19 ”. Ideally the water removal plane  23  starts not in the lower module edge  9  or the corresponding portion of the inserts  4 , but at a certain distance, when mounted preferably vertical distance therefrom, so that water is even less likely to come into contact with the module. The minimum distance being larger than 2 mm preferably more than 5 mm and even more preferred more than 10 mm. 
     As can be seen from  FIG. 2 , if the water run off plane  23  extends horizontally, the angle γ is equal to the slope of the roof α. Since the water will not run off easily in this situation, γ should be larger than α. If γ is larger than α, the water removal plane  23  will make an angle of β with the horizontal  21 . By making sure that γ is larger than the slope of the roof α by amount β, and as is understood declining in the opposite direction with respect to the inclination of the roof  2 , and towards a vertical plane comprising the top or ridge of the roof  2 , the water will run off readily. Preferably β is larger than 1° and more preferably is larger than 2°. With typical roofs having a slope of 10° to 30°, γ typically should be larger than 30°. Also shown in  FIG. 2  is a second module  7  being held by more or less the same structures as described above for the side of the mounting rail  3  holding the lower edge of a solar panel  6  or similar plate-like elements. Since the problem of water not running off properly is not an issue near the top of the module (water simply runs over the module), this part of the holding systems is not described in the same detail as the firstly disclosed features. The mounting system  3 ,  4   b  for an upper edge of a solar panel  7  or the like comprises a second insert mounting recess  8   b  at the side opposite of the insert mounting recess  8  of the same mounting rail  3 . This second recess  8   b  is deeper than the first insert mounting recess  8  and showing a second lower face  16   b  being wider than the first lower face  16 . Since there is no real problem with water not running off the upper edge of the panel  7 , the second lower face  16   b  can form an angle with the second upper face  19   b  and/or the side of the roof mounting means  5  facing the roof  2  smaller than the angle of the lower face  16  of the first insert mounting recess  8 . Here and every time in this description where the “side of the roof mounting means  5  facing the roof  2 ” is mentioned this expression could be replaced by “the side of the mounting rail  3  facing the roof  2  when mounted thereon” or “a plane through the mounting rail  3  parallel to the surface of the roof  2 ”. 
       FIG. 3  shows a 3D view of a mounting rail  3  holding two modules  6 ,  7 . One module insert  4  holding module  6  can be seen. The lower recess face  16  and its insert holding means  12  are also visible. The roof mounting means  5  are formed by the bottom of the rail  3 . The rail is held in place by a climber as shown in  FIG. 2 . This climber  13  thus may also be part of the mounting means  5 . 
     Angle α is formed between the plane of the roof  26  and the horizontal  21  (in a plane perpendicular to a horizontal straight line at the respective location along the mounting rail  3 . Normally a is a given in particular by the type and/or construction of the roof ( 2 ) and typically lies in the range from 10° to 40°. 
     The rail  3  may be as short as the width of one module  6 ,  7 . In that case the rail is easy to transport and to bring onto the roof. Connection parts may be inserted from the side into two adjacent rails  3  in order to couple them in longitudinal direction. These connection parts may also have protruding portions protruding between adjacent modules, guaranteeing a distance between them. The connection parts are preferably made of a relatively soft material such polymer. In this way the modules  6 ,  7  adjacent to each other in horizontal direction will not touch each other what could lead to damage to the modules. 
     Referring to  FIG. 4 , it is important that no or very little water is collected in the range indicated with triangle  20 . In all figures the insert holding means  12  are shown larger than they need to be for clarity. Reducing their size will still hold the insert  4 ,  4   b  tightly (especially when the module  6 ,  7  is present) while letting almost all water drain off. According to the invention, water that collects will not reach the module, thus not impairing its efficiency or life-time. 
     Since a solar panel roof normally extends in a plane  15  parallel to the roof  2  it is mounted on, it typically extends with the same slope as the roof. Therefore the water run off plane  23  may also be defined relative to the modules  6 ,  7  and/or the upper recess face  19 . The angle δ is equal to angle γ if plane  23  extends horizontally. Therefore for δ the same conditions hold as for γ: δ should be larger than the slope α of the roof  2 , preferably at least by an amount β of 1°. 
     Even though not shown, it is clear the modules  6 ,  7  must be supported near their upper edge, too. Preferably this is done by a second similar mounting rail  3  with similar inserts  4 ,  4   b . Near the top or bottom of the slanted roof  2  alternative mounting means may be used. 
     The invention is not restricted to the embodiments shown. Single or multiple combinations thereof are possible. Features of the shown embodiment may also be applicable to other concepts and embodiments, shown and not shown in the figures, and more particularly to the invention as described in the claims. 
     LIST OF REFERENCE SIGNS 
       
     
       
         
           
               
               
               
             
               
                   
                   
               
             
            
               
                   
                  1, 1′ 
                 Mounting system 
               
               
                   
                  2, 2′ 
                 Slanted roof 
               
               
                   
                  3, 3′ 
                 Module mounting rail 
               
               
                   
                  4, 4′, 4b 
                 Module or member insert 
               
               
                   
                  5, 5′ 
                 Roof mounting means 
               
               
                   
                  6, 6′ 
                 First module 
               
               
                   
                  7 
                 Second module 
               
               
                   
                  8, 8b 
                 Insert mounting recess 
               
               
                   
                  9 
                 Lower module edge 
               
               
                   
                 10 
                 Module holding recess 
               
               
                   
                 12, 12b 
                 Insert holding means 
               
               
                   
                 13 
                 Climber 
               
               
                   
                 15 
                 Plane of modules 
               
               
                   
                 16, 16b 
                 Lower face of the insert 
               
               
                   
                   
                 mounting recess 
               
               
                   
                 17, 17b 
                 Protruding portion 
               
               
                   
                 19, 19b 
                 Upper face of the insert 
               
               
                   
                   
                 mounting recess 
               
               
                   
                 20 
                 Water collecting in the 
               
               
                   
                   
                 mounting rail 
               
               
                   
                 21 
                 Horizontal plane 
               
               
                   
                 22, 22′ 
                 Mounting plane 
               
               
                   
                 23 
                 Water removal or run off 
               
               
                   
                   
                 plane 
               
               
                   
                 24 
                 Groove 
               
               
                   
                 26 
                 Plane roof extends in 
               
               
                   
                 27a 
                 Upper module holding face 
               
               
                   
                 27b 
                 Upper module holding face 
               
               
                   
                 29 
                 Water level 
               
               
                   
                 α 
                 Angle between horizontal 
               
               
                   
                   
                 and mounting plane 
               
               
                   
                 β 
                 Angle between mounting 
               
               
                   
                   
                 plane and second water 
               
               
                   
                   
                 plane removal 
               
               
                   
                 γ 
                 Angle between mounting 
               
               
                   
                   
                 plane and first water removal plane 
               
               
                   
                 δ 
                 Angle between water run 
               
               
                   
                   
                 off plane and plane of the 
               
               
                   
                   
                 modules