Abstract:
The invention relates to a photovoltaic concentrator module with multifunction frame and also to a method for production thereof. The concentrator module has a lens- and a base plate, between which a frame extends. Between the lens plate and the frame and/or the base plate and the frame, two sealing compounds and/or adhesive compounds extend, which compounds differ with respect to their hardening time and/or gas permeability.

Description:
BACKGROUND 
     The invention relates to a photovoltaic concentrator module with multifunction frame and also to a method for production thereof. Concentrator modules of this type are used in particular in the field of concentrating solar technology. 
     In photovoltaics, there have been approaches made already for many years to operate with concentrated solar radiation. The principle is simple: solar radiation is concentrated with mirrors and/or lenses and directed onto special concentrator solar cells. The required surface area of expensive cell material is hence reduced. A crucial breakthrough in concentrator technology is now imminent. This is the case not least because, with highly efficient concentrator PV solar cells on a III-V basis, efficiencies of the cells of over 37% have been achieved and hence efficiencies in the modules of significantly above 25% are possible. The application of III-V solar cells in concentrator systems has been investigated for a long time. Sunlight is hereby focused with the help of Fresnel lenses by a factor 300 to 1,000 on a tiny focal spot in which then a small solar cell of still merely 2 to 10 mm 2  is situated. The object of this procedure is to replace the expensive semiconductor surface of the III-V stacked cells for a comparatively economical lens system and consequently to make the application of this successful space technology also profitable on the ground. 
     Such concentrating photovoltaic systems serve for current generation, in particular in photovoltaic power plants. A large number of modules are mounted for this purpose on a tracking unit, a so-called tracker, which orientates the concentrator modules constantly towards the sun. The modules on a tracker are connected to each other electrically. This technology which is still very new has the advantages in the case of large-area use in particular, by enabling a cost reduction in photovoltaic current generation due to a high efficiency potential, of being able to be scaled into the gigawatt range without a shortage of raw materials and of having a short energy amortisation time. 
     Because of the higher complexity of concentrating photovoltaic systems in comparison with conventional flat modules, the former are suitable in particular for use in the power plant field. A certain amount of maintenance is required because of the controlled tracking and possible soiling of the lens system. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a photovoltaic concentrator module for current generation which is constructed from two planes. On the upper plane, subsequently termed lens plate, an optical concentrator is situated, which preferably contains an arrangement of point-focusing lenses in the plane of the lens plate, preferably in such a form that the lenses cover as large a part as possible of the surface of the concentrator. Fresnel lenses, but also spherical lenses, are possible as lenses. 
     On the lower plane, subsequently termed base plate, the solar cells including the electrical wiring thereof are situated. Each solar cell is disposed in the focus respectively of one lens. 
     It is essential in the construction of these concentrator modules that the spacing of the lens plane from the base plate is maintained very precisely so that the concentrating light impinges completely on the surface of the solar cell. 
     A typical concentrator is the FLATCON® concentrator with a lens plate with Fresnel lenses which concentrate the sunlight by a geometric factor of 500 onto stacked cells with 2-3 pn junctions of III-V semiconductors. 
     The components of the lens plate and of the base plate are carried respectively preferably by a glass plate, however other plate materials, such as for example acrylic or Plexiglass, are also possible. The two glass plates are glued according to the previous procedure by four rectangular glass plates with silicon or UV-hardening adhesive in such a manner that the four glass plates form a frame which extends round at the edge of the lens- and base plate or they are screwed together with metal profiles which extend round at the edge of the lens- and base plate. 
     This procedure has several disadvantages: the sealing surface is very small and has been glued merely with a single sealing compound made of silicon. Consequently, it is not possible to keep the module sealed over periods of time of 20 years and more, against the ingress of moisture from outside. This is very problematic since moisture can lead to corrosion of contacts on and between the solar cells and consequently impairs the durability of this product. The manufacture of such glass frames from a plurality of individual parts is economically very unfavourable and can only be automated with difficulty. Finally, the additional components indicated in this invention, such as filters for active ventilation, sorption agents, module mounting and electrical leadthrough, can be achieved in a glass frame only with difficulty or not at all. 
     It is therefore the object of the present invention to produce a photovoltaic concentrator module which can be produced economically, is durable and which makes it possible to integrate simply and flexibly additional components which cannot be accommodated on the lens plate or the base plate or only with difficulty. Furthermore, a method is intended to be developed which enables the production of such concentrator modules. 
     The photovoltaic concentrator module according to the invention contains, as essential components, a lens plate, a base plate which is parallel to the lens plate, a frame which extends along the edge of the lens plate and of the base plate between the lens plate and the base plate, and also a first sealing compound and/or adhesive compound and a second sealing compound which are disposed adjacently extending at least partially along the frame between the lens plate and the frame and/or between the base plate and the frame, the two sealing and/or adhesive compounds differing with respect to their hardening times and/or gas permeabilities. Preferably, at least the second sealing compound forms a sealing line, but each sealing compound can in principle be configured as sealing line. The lens plate is hereby a transparent plate, for example made of glass, acrylic or Plexiglass on which at least one optical concentrator is disposed. The optical concentrator preferably contains point-focusing lenses, such as for example Fresnel lenses or spherical lenses. 
     This arrangement makes it possible to maintain the spacing between lens- and base plate very precisely so that it is ensured that the solar cells are illuminated completely by light focused by the lenses. 
     The base plate carries the solar cells and also parts of the wiring thereof, the module according to the invention being suitable above all for use with stacked cells. 
     At least one of the two sealing compounds which extend adjacently at least partially around as sealing lines parallel to the edge of the lens plate and/or of the base plate, is preferably permanently elastic. For the outer of these sealing compounds, an elastic silicone is suitable in particular, which is suitable for absorbing stresses and deformations of the different materials. The inner sealing compound is preferably a butyl cord which enables the air- and/or moisture-impermeable connection of the components of the concentrator module and fixing of the plates. 
     If for example mechanical stresses due to a different arrangement of the components of the module according to the invention occur on the inner sealing compound, then the inner sealing compound can also contain or consist of silicone and the outer sealing compound can be or consist of butyl cord. 
     Preferably, the second sealing compound, which contains for example silicone, extends next to the first sealing compound or adhesive compound. Hot-melt adhesive and/or UV-hardening adhesive are for example possible as adhesive compound. According to the invention, also merely a first sealing compound or a first adhesive compound can be used in portions. 
     The sealing compounds and/or adhesive compounds can be disposed extending around parallel to each other in the plane of the lens plate and/or the base plate. However also one or more sealing compounds for example can be accommodated between the edge of the lens plate and/or of the base plate and the frame. There are termed here as edge of the lens plate or base plate those sides of the lens- or base plate which delimit the respective plate between the surface which carries the lenses or the solar cells and the other side which is disposed respectively parallel thereto. 
     The frame of the concentrator module delimits the space containing the solar cells, subsequently termed the inside of the concentrator module or interior, from the exterior. Consequently, the solar cells can be protected permanently from moisture, dust, dirt and other environmental influences. The totality of all the components which connect lens- and base plate at the edge thereof in the above-described manner is termed frame. 
     Advantageously, the surfaces of the frame which abut against the lens plate and/or the base plate, such as for example the edge of the frame, are wide enough in order to receive at least two sealing lines comprising sealing compounds and/or adhesive compound. 
     The frame can be accommodated according to the invention completely between lens- and base plate. However, also parts of the frame or the entire frame can protrude beyond lens plate and/or base plate. On the other hand, the frame can however also be produced according to the invention such that it engages around the edge of the lens plate and/or the edge of the base plate so that the connection between the corresponding plate and the frame is produced on the side of the corresponding plate which is orientated towards the exterior of the module. In this case, a spacing can be produced between the edge of the lens plate and/or the base plate and the inside of the frame, which spacing can but need not be filled according to the invention with at least one sealing compound completely or partially on at least a part of the length of the frame. In particular, if the frame engages around the plates, a single sealing compound or an adhesive compound can be accommodated at the connection place between frame and the respective plate, which is orientated towards the exterior, whereas the other sealing compound is then accommodated, as described above, between the edge of the plate and the frame. Productions of one of the above-mentioned constructions of the frame in portions are also within the scope of the invention. 
     The frame can consist of according to the invention entirely or partially hollow profiles which can be empty or filled with sorption agent, there being possible inter alia as sorption agent SiO 2 , silica gel, calcium chloride, calcium fluoride, magnesium sulphate, sodium sulphate and/or calcinated alumina. 
     These hollow profiles can thereby be of any shape. They can for example fill the entire width of the frame, i.e. the entire spacing between lens plate and base plate. However they can also fill only a part of the width of the frame, the remainder of the width being formed by spacer frames. These spacer frames are disposed between the hollow profiles and also between the hollow profiles and the lens plate or the base plate such that the frame, consisting of one or more hollow profiles and spacer frames, extends at least over the entire spacing between lens plate and base plate. 
     The frame can however also consist of one or more hollow profiles only along a part of its length. There may be understood here by the length of the frame, as in the following, its extension parallel to the edge of lens plate or base plate. 
     According to the invention, a frame which contains one or more hollow profiles over a part of its length on a part of its width or on its entire width is also possible, the resulting remainder of the width of the frame then being formed by one or more spacer frames. On portions of the frame length which have no hollow profiles, the frame consists of a spacer frame on its entire width. 
     Advantageously, the spacer frames and/or hollow profiles are produced such that their edge faces which are situated in the plane of the frame are sufficiently wide to provide room for the at least two sealing compounds and/or adhesive compounds in order to enable sealing of the module. There are possible here all different combinations of sealing compounds and adhesive compounds and also individual use thereof. The sealing and/or adhesive compounds extend preferably along the connection place of the hollow profiles with other hollow profiles, the frame, the spacer, the lens plate or the base plate. In principle, all connection places between the individual elements of the module can be sealed with sealing and/or adhesive compounds individually or adjacently. 
     In a further advantageous embodiment of the invention, the frame and/or at least one hollow profile and/or at least one spacer frame is provided with one or more openings. These openings can be accommodated on the side of hollow profiles which are orientated towards the interior of the module, subsequently termed inside, or on the side which is orientated towards the exterior, subsequently termed outside. 
     As simple holes in the inside, they serve for conveying away moisture into the interior of the hollow profile where the moisture can be absorbed by the one or more sorption agents. 
     The openings can also serve at each of the above-mentioned positions for the purpose of integrating further components in the concentrator module. According to the invention, one or more filters can be accommodated in suitably configured openings such that they fill the respective opening completely and enable controlled exchange of air or other gases between the interior and exterior. The filters can thereby contain or comprise for example a sintered metal and/or a metal grating and/or a plastic material net and/or a plastic material membrane. An arrangement of filters according to the preceding description may be mentioned in particular, in which one or more filters are accommodated in the inside of a hollow profile and one or more filters in the outside of the same hollow profile so that air or a different gas can flow through the filters and the hollow profile into the interior of the module or out of the module. In this way, a pressure equalisation between interior and exterior can be achieved, by means of which buckling of the lens plate and/or of the base plate is prevented during heating of the module. The inflowing air can thereby be dried by means of the sorption agent in the hollow profile so that the ingress of moisture into the concentrator module is avoided. Advantageously, coarser structures are chosen for the outer filters and finer structures for the inner ones. For example, the outer filter can be designed to exclude particles which are larger than 50 μm. The finer, inner filter could let for example particles up to a size of 5 μm pass through. 
     The process of gas exchange with the exterior can be controlled by targeted heating of at least parts of the concentrator module. Heating at the suitable point in time can take place according to the invention by means of a light-absorbing colouration of a part of the concentrator module so that, with sun irradiation commencing, air flows out of the concentrator module and, with the absence of sun irradiation, air dried by the sorption agent flows into the interior. 
     According to the invention, one or more connection elements can also be integrated in the frame of the module, said connection elements enabling the mechanical connection of the concentrator module to other modules. These connection elements can also be produced to be put together and/or accommodated in one or more of the above-described openings in the frame. 
     The connection elements can be produced to be gas-permeable so that externally dried air or another gas can be introduced into the interior of the module. A plurality of modules of the type described here can also be connected to each other via such a connection so that externally dried air can be conducted through the entire system of concentrator modules. 
     In a further embodiment of the module according to the invention, an electrical leadthrough, preferably moisture- and/or gas-impermeable, is integrated in the frame. A simple embodiment is described in the patent specification WO 03/028114. This electrical leadthrough can be connected by a wire for example in the interior to the solar cells and then serves for electrical wiring of the solar cells with devices in the exterior. 
     The frame can serve furthermore for mounting of devices which assist operation of the solar cell module by itself or in conjunction with other modules. Thus a mounting for example can be welded onto the frame or screwed on, with which the solar cell module for example can be mounted on a tracker and/or adjusted. The mounting can have a screw connection. However it can also be configured in such a manner that it permits the rapid connection of modules for example by managing. The mounting can contain in addition electrically conductive components so that it enables earthing of the concentrator module. 
     There are suitable as material for the frame, the hollow profiles and the spacer frame, steel, zinc-plated steel, stainless steel, aluminium and/or other metals and also composite materials, Plexiglass, polymethylmethacrylate (PMMA), acrylic glass, other plastic materials and glass. The materials can be used alone or in combination. 
     In an advantageous embodiment of the invention, the interior of the concentrator module has spacers which connect the lens plate and the base plate to each other. These spacers can have any shape. For example, the spacers placed between the lens- and base plate can be cylinders or cubes. However, a shape (termed double-T shape) is particularly advantageous, which has two parallel portions in cross-section, which are connected to each other via a third portion in the centre thereof. The two parallel portions thereby abut against the lens- or base plate. 
     In a further embodiment of the module according to the invention, the lens plate and/or the base plate can comprise a plurality of neighbouring partial plates which are situated in one plane. This enables the production of large modules with a large number of lens- and base plates, the size of which exceeds the technically achievable size of one individual lens- or base plate. Between the edges of the partial plates, a boundary region can thereby be produced which extends in the direction of the edges of the respective partial surfaces. Since this boundary region represents a spacing between the partial plates, it can serve for the purpose of taking up mechanical loads on the respective plate. For this purpose, it is advantageously filled with a sealing compound, containing or consisting of for example elastic silicone. Expediently, among at least a part of the resulting boundary regions between partial plates, spacers are fitted between lens- and base plate over a part of their length. The spacers can thereby have, in their cross-section perpendicular to the longitudinal extension of the boundary region, the above-described double-T shape, so that the spacer per se is relatively narrow but contributes a broad surface to the boundary region. On this relatively broad surface, at least one sealing compound and/or adhesive compound can be accommodated between the spacer and the lens- or base plate along each side of the boundary region, so that the interior of the module is sealed against the exterior. 
     In the method according to the invention for the production of the photovoltaic concentrator module, lens plate and base plate are pressed together in such a manner that the spacing between the lens plate and the base plate is maintained with a tolerance &lt;1 mm, preferably &lt;500 μm. For this purpose, a spacer can be placed between lens plate and base plate. Lens plate and base plate are then pressed against the frame of the concentrator module until they touch the spacer. In addition, it is also possible to delimit the spacing between lens plate and base plate during the process of pressing together lens plate and base plate with the frame by the elasticity of the butyl cord or of the corresponding adhesive compound. Lens plate and base plate are hereby pressed against the frame with a force until the force exerted by the butyl cord on lens plate and base plate is equal to the application pressure force. 
     The pressing-on can take place by means of exerting force from outside but it is also possible to press the lens plate and the base plate against the frame in that a vacuum is generated in the interior of the concentrator module, i.e. in the region between lens plate and base plate which is surrounded by the frame. Lens plate and base plate are then suctioned thus against the frame. 
     The described invention has the following advantages relative to the state of the art:
         The claimed invention makes it possible to specify exactly the spacing between lens plate and base plate so that the best possible illumination of the solar cell surface is achieved.   The claimed photovoltaic concentrator module can be produced economically and flexibly. In contrast to the glass frames or screwed-on metal profiles, known from the state of the art, the frame can be readily adapted to any possible requirements.   The module is air- and/or moisture-impermeable and maintains this property over a significantly longer period of time than concentrator modules known according to the state of the art.   The frame of the concentrator module can consist of hollow profiles entirely or partially which can receive sorption agents, as a result of which air located in the module and air flowing into the module can be dried.   Openings can be accommodated in the frame of the module without great complexity and of any shape. The openings can contain for example filters.   The claimed concentrator module can consequently be ventilated in a controlled manner. Dried air can be conducted into the interior or moist air can be suctioned out of the interior.   The claimed concentrator module makes it possible to integrate in the frame electrical leadthroughs between the inside of the concentrator module and the outside in an air- and/or moisture-impermeable manner.   A large number of the claimed concentrator modules can be connected to each other via connection units so that for example a plurality of concentrator modules can be provided together with externally dried air.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       A few examples of concentrator modules according to the invention are now provided in the following. The same and similar reference numbers are thereby used for the same and similar elements. 
         FIG. 1  shows the part of a section through a concentrator module according to the invention. 
         FIG. 2  shows the part of a section through a concentrator module according to the invention, having a frame which comprises a hollow profile filled with sorption agent over the entire width. 
         FIG. 3  shows the part of a section through a concentrator module according to the invention, having a frame which contains two hollow profiles separated by a spacer frame. 
         FIG. 4  shows the part of a section through a concentrator module according to the invention like  FIG. 2 , filters being integrated in the hollow profile. 
         FIG. 5  shows the part of a section through a concentrator module according to the invention, having a frame on which a mounting is fitted and in which a filter and an electrical leadthrough are integrated. 
         FIG. 6  shows the part of a section through a concentrator module according to the invention, having a frame in which an electrical leadthrough is integrated. 
         FIG. 7  shows a part of a side view of a concentrator module according to the invention with a cable leadthrough which has an oval edge. 
         FIG. 8  shows the part of a section through a concentrator module according to the invention, the frame of which contains a plurality of hollow profiles and also an electrical leadthrough. 
         FIG. 9  shows the part of a section through a concentrator module according to the invention, in the frame of which a mounting is integrated for suspending the module. 
         FIG. 10  shows the part of a section through two concentrator modules according to the invention which are connected to each other via a connection unit. 
         FIG. 11  shows the plan view on a concentrator module according to the invention, the lens plate and/or base plate of which comprises a plurality of partial plates. 
         FIG. 12  shows a spacer between one part of the lens plate and one part of the base plate. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows the part of a section through a concentrator module according to the present invention. A transparent lens plate  1  which carries the focusing lenses  7   a ,  7   b  and  7   c  and is parallel to the optical plane of the lenses  7   a ,  7   b  and  7   c  is situated parallel to a base plate  2  which carries the solar cells  8   a ,  8   b  and  8   c . Between the lens plate  1  and the base plate  2 , a frame  3  is disposed along the edge of lens plate  1  and base plate  2 , said frame covering the entire spacing between the lens plate  1  and the base plate  2 . In the shown example, the cross-section of the frame  3  describes a U-shape, a short member  3   a  and  3   b  respectively being orientated towards the lens plate  1  or base plate and a long side  3   c  extending between lens plate  1  and base plate  2 . The corners of the frame  3   d  and  3   e  are bevelled over a short piece in the illustrated example so that the long side  3   c  of the frame  3  does not span the entire spacing between lens plate  1  and base plate  2  but leaves a small space for respectively an outer sealing compound  5   a  and  5   b.    
     The contact points between the lens plate  1  and the frame  3  and also between the base plate  2  and the frame  3  are sealed by respectively two sealing compounds  4   a  and  4   b  and also  5   a  and  5   b . The sealing compounds  4   a  and  4   b  can be replaced according to the invention also by adhesive compounds  4   a  and  4   b.    
     The sealing or adhesive compounds  4   a  and  4   b  and also the sealing compounds  5   a  and  5   b  are disposed parallel to each other between the edge  3   a  of the frame  3 , orientated towards the lens plate  1 , and lens plate  1 , and also between the edge  3   b  of the frame  3 , orientated towards the base plate  2 , and the base plate  2 , in the plane of the lens plate  1  or of the base plate  2  and extend parallel to the frame  3  over its entire length. As outer sealing compounds  5   a  and  5   b , for example elastic silicone can be used, butyl cords for example are suitable as inner sealing compounds  4   a  and  4   b . If, instead of the sealing compounds  4   a  and  4   b , adhesive compounds  4   a  and  4   b  are located between the frame and the corresponding plate, then hot-melt adhesive or UV-hardening adhesive for example are suitable here. 
     In the example illustrated here, the sealing compounds or adhesive compounds  4   a  and  4   b  and also the sealing compounds  5   a  and  5   b  extend over the entire depth of the frame  3 , i.e. its entire extension in the direction of the interior  6  of the module. The sealing or adhesive compounds  4   a  and  4   b  are thereby situated towards the interior  6  whilst the sealing compounds  5   a  and  5   b  to the outside fill the remaining space between the frame  3  and the lens plate  1  or the base plate  2  which is not filled by the inner sealing or adhesive compounds  4   a  and  4   b.    
     The solar cells  8   a ,  8   b  and  8   c  are situated in the focus of the lenses  7   a ,  7   b  or  7   c  which are disposed adjacently on the lens plate  1  in such a manner that they cover the surface of the lens plate  1  preferably as completely as possible. For example, the lenses  7   a ,  7   b  and  7   c  can be rectangular and of the same surface area so that they can be disposed adjacently in such a manner that the surface of the lens plate is covered without a gap. Each lens  7   a ,  7   b  and  7   c  focuses the light  18   a ,  18   b  or  18   c  on respectively one solar cell  8   a ,  8   b  or  8   c.    
       FIG. 2  shows the part of a section through a concentrator module analogously to  FIG. 1  with the difference that here the frame  3  consists of, on its entire width, a hollow profile  10  which is filled with one or more sorption agents  11 . The hollow profile  10  can, as long as it meets the described requirements, be of any shape. The hollow profile  10  shown in  FIG. 2  has for example a rectangular cross-section, the two corners of the cross-section situated towards the exterior being bevelled so that both the inwardly-  10   i  and the outwardly-directed side  10   a  of the hollow profile  10  are situated vertically on lens plate  1  and base plate  2  but the outside  10   a  of the hollow profile  10  is somewhat shorter than the inside  10   i . The sides of the hollow profile  10  which are orientated in the direction of the lens plate  1  and the base plate  2  are bevelled in this example on a part of their length parallel to the lens plate  1  or base plate  2  and over the remainder of the spacing between inside  10   i  and outside  10   a  of the hollow profile  10 . 
     The connection places of the hollow profile  10  to the lens plate  1  and the base plate  2  are sealed respectively, as in  FIG. 1 , with two sealing or adhesive compounds  4   a  and  4   b  and also sealing compounds  5   a  and  5   b  which extend along the length of the frame. In the example shown here, the sealing or adhesive compounds  4   a  and  4   b  and also  5   a  and  5   b  extend over the entire depth of the hollow profile  10 , i.e. its entire extension in the direction of the interior  6  of the module. The sealing or adhesive compounds  4   a  and  4   b , for example butyl cords in the case of sealing compounds or hot-melt adhesive or UV adhesive in the case of adhesive compounds, are thereby situated towards the interior  6 , whilst the sealing compounds  5   a  and  5   b , for example elastic silicone, fill the remaining space between the hollow profile  10  and the lens plate  1  or base plate  2  which is not filled by the butyl cords or the adhesive compounds. 
       FIG. 3  shows the part of a section through a concentrator module, the frame  3  of which has two hollow profiles  10   o  and  10   u  filled with sorption agents  11 , one  10   o  of which abuts against the lens plate  1  and one  10   u  of which abuts against the base plate  2 , and between which a spacer frame  12  constructs the frame  3  on its remaining width. The connection points between the hollow profiles  10   o  and  10   u  and the spacer frame  12  and also between the hollow profiles  10   o  and  10   u  and also the lens plate  1  or the base plate  2  are hereby sealed respectively by two sealing compounds  4   a  and  4   b  or adhesive compounds  4   a  and  4   b  and also sealing compounds  5   a  and  5   b  which extend parallel to the length of the frame  3  as two sealing lines. In the illustrated example, the cross-section of the hollow profiles  10   o  and  10   u  has the shape described for the preceding Figures but the side directed inwards and the one directed outwards is significantly shorter. The cross-section of the spacer frame  12  in the illustrated example has a U-shape, the two members of the U being directed inwards. The other elements shown correspond to those of the preceding Figures. 
       FIG. 4  shows the part of a section through a concentrator module, the frame  3  of which, over the full width, comprises a hollow profile  10  filled with sorption agent  11 , in the outside  10   a  and inside  10   i  of which respectively a filter  9   a  or  9   b  is integrated so that air can flow past the sorption agent  11  into the interior  6  of the concentrator module or out of the concentrator module. One of the filters  9   a  in this Figure is situated closer to the lens plate  1 , whilst the other filter  9   b  is situated closer to the base plate  2  so that the gas which flows through the hollow profile  10  covers as wide a path as possible in the sorption agent  11 . The filters  9   a  and  9   b  can furthermore be disposed also offset along the length of the frame  3  so that the path of the gas through the sorption agent  11  is further extended. The other shown elements correspond to those of the preceding Figures. 
       FIG. 5  shows a section from a concentrator module, on the frame  3  of which a mounting  13  is mounted for example in order to mount the concentrator module on a tracker. The mounting  13  can be for example a welded-on screw connection. Furthermore, the frame  3  illustrated here has an opening in the broad side which is filled completely by a filter  9 . There is termed broad side of the frame that side of the frame which stands perpendicular to the plane of the lens plate  1  and of the base plate  2 . Through the filter  9 , gas can be conducted or flow directly from the exterior into the interior  6  of the concentrator module without passing through a sorption agent  11 . 
     In addition,  FIG. 5  shows an electrical leadthrough  14 , which is accommodated in the broad side of the frame, between the interior  6  of the module and the exterior, which is connected via an electrical connection  15  to the solar cells  8   a ,  8   b  and  8   c  which are wired on the base plate  2 . This leadthrough  14  can be configured for example as described in WO 03/028114. The other shown elements correspond to those of the preceding Figures. 
       FIG. 6  shows the part of a section through a concentrator module according to the invention, in the frame of which an electrical leadthrough  14  is incorporated. The electrical leadthrough  14  is incorporated here in a concavity  200  in the frame  3 . The space of the concavity  200  which is not filled by the leadthrough  14  is filled here with a sealing compound  201 , for example silicone, so that the connection points between frame  3  and leadthrough  14  are sealed. The leadthrough  14  has in addition a plastic material bush  202  which protrudes into the interior of the module  6 . Such a leadthrough  14  is distinguished by simple, rapid assembly and also low costs and can serve at the same time for strain relief. Furthermore, the frame  3  in  FIG. 6  is not accommodated completely between the lens plate  1  and the base plate  2  but engages around the base plate  2  so that the latter is supported on a part  101  of the frame  3 . Between the base plate  2  and the frame  3 , a sealing compound  4   b  for sealing the module is accommodated along the support surface. In addition,  FIG. 6  shows a sealing compound  5   b  between the edge of the base plate  111  and the frame  3 . The other illustrated components correspond to those of the preceding Figures. 
       FIG. 7  shows a part of the side view of a concentrator module according to the invention with a view on the surface of the frame  3 . The cable leadthrough  14  can be seen here in the direction of the leadthrough channel  203  thereof which extends through the plastic material bush shown in  FIG. 6 . Next to the leadthrough  14 , a sliding block without a hole boring  204  is disposed on the right and on the left a sliding block with a hole boring  205 . The sliding block with hole boring  205  is pushed over a connection cable  206  for connection of the solar module and then serves for guiding and/or strain relief of the cable  206 . The two sliding blocks  204  and  205  are pushed into the convexity  200  of the frame  3  so that the region of the convexity  200  which surrounds the leadthrough  14  can be filled with sealing compound  201  without running into other regions of the convexity  200 . 
       FIG. 8  shows the part of a section through a concentrator module according to the invention, the frame  3  of which contains a plurality of hollow profiles  10   a ,  10   b ,  10   c  and  10   d . The hollow profiles  10   a ,  10   b ,  10   c  and  10   d  are thereby disposed adjacently such that they form the frame  3  at the same spacing between lens plate  1  and base plate  2 . Furthermore,  FIG. 8  shows an electrical leadthrough  14  through a hollow profile  10   d . It is configured here as a channel with a plastic material bush  202  which leads through the hollow profile  10   d  in such a manner that the interior of the hollow profile  10   d  is open neither to the exterior nor to the interior  6  but a connection between interior  6  and exterior is produced. The other illustrated components correspond to those of the preceding Figures. 
       FIG. 9  shows the part of a section through a concentrator module according to the invention, in the frame  3  of which a mounting  13  is integrated. The retaining element  13  hereby sits in a convexity  102  with a rectangular cross-section of the frame  3  in such a manner that the concentrator module can be suspended on the mounting  13 . The convexity  102  on the edge which is orientated outwards towards the lens plate  1  has a projection  103  for this purpose in the plane of the frame outside, which projection presses against a corner  104  in the mounting  13  which engages in the convexity  102 , whilst at the same time the edge  105  of the convexity  102  which is orientated outwards towards the base plate presses against the mounting  13  by the weight of the concentrator module. The other illustrated components correspond to those in the preceding Figures. 
       FIG. 10  shows parts of a section through two concentrator modules which are connected to each other via a connection element. The connection element is a plug-in connection comprising a plug  17  and a socket  16 . Plug  17  and socket  16  can be inserted into the corresponding module, be welded on it or connected to it in another manner. The plug  17  of the one module is inserted into the socket  16  of the other module and the contact point between plug  17  and socket  16  is sealed by a sealing compound  19  which extends along at the contact point in the plane perpendicular to the connection axis. The plug-in connection comprising plug  17  and socket  16  can be gas-permeable according to the invention so that gas can be conducted from one module into the other. Each module can have a plurality of plugs  17  and/or sockets  16  via which it can be connected to a plurality of other modules so that for example externally dried air can be conducted actively through a plurality of concentrator modules. The other illustrated elements correspond to those of the preceding Figures. 
       FIG. 11  shows the plan view on a concentrator module according to the invention, the lens plate  1  and/or base plate  2  of which consists of a plurality of partial plates  106   a  to  106   e . The partial plates here have a rectangular configuration and are disposed adjacently in parallel along the longitudinal side thereof. However other forms are also possible. Between the partial plates  106   a  to  106   e , boundary regions  107   a  to  107   d  are produced. 
       FIG. 12  finally shows a spacer  108  in the manner in which it can be fitted in the interior  6  of the concentrator module between lens plate  1  and base plate  2 . The illustration does not show the longitudinal extension of the spacer  108 . Preferably, it follows the longitudinal course of the boundary region  107 . A spacer  108  as shown can be disposed under each boundary region  107  along the entire length thereof or along a part of its length. In illustration  12 , it can be detected in addition how a first sealing compound  109  fills the boundary region  107  and two second sealing compounds or adhesive compounds  110  extend along the contact surface of lens plate  1  and spacer  108  and also of base plate  2  and spacer  108  on both sides of the boundary region  107  parallel to the length thereof.