DE102010027779A1 - Collector i.e. sunlight collector, for use in building roof for e.g. building-integrated photovoltaic power generation, has substrate units comprising substrate layers and fluorescent material and spatially separated from each other by gap - Google Patents

Abstract

The collector (10) has substrate units (12, 14, 16, 18) connected with a solar cell and comprising substrate layers (20, 22, 24, 26) and fluorescent material that is connected with the layers. The substrate units are spatially separated from each other by a gap (40), where end regions of the layers are connected by a spacer. A layer (38) filters the fluorescent material with noxious wavelengths of sunlight (36). The fluorescent material is designed as a dye film on a surface area of the layers, and exhibits gradated absorption or emission spectrum of the adjacent substrate units. An independent claim is also included for a collector arrangement comprising a receptacle.

Description

The invention relates to a collector, in particular solar collector for building-integrated photovoltaic energy production, as well as a collector assembly comprising the collector.

State of the art

There is a rapidly growing need for photovoltaic energy production or energy production by means of solar cells. This type of energy production is particularly resource-saving and low in emissions and therefore particularly environmentally friendly. Concentrators are often used, such as US 4,488,047 known.

Collectors for solar cells are traditionally installed by roof or in-roof installation obliquely on rooftops, so that the main direction of incidence of solar radiation as often as possible is perpendicular to the module surface. Since the increased emergence of low-cost thin-film modules, however, whole building fronts are increasingly covered with solar panels. From this practice, the so-called "building-integrated photovoltaics" (BIPV) or "Building Integrated Photovoltaics" (BIPV) is developing. In the GIPV functional building elements, such as roof tiles or the like, are replaced by solar cells. Although the solar cells then have reduced efficiency requirements, they may have to meet additional legal requirements for building elements, which are not required in classic on-roof installations.

For example DE 10 2007 015 472 A1 and DE 10 2006 010 646 A1 It is known to replace glass panes by thin-film modules or to integrate solar cells in glass panes. In such arrangements, it is possible to arrange the semiconductor layer between two glass plates, which may be semitransparent due to their small layer thickness. When using transparent materials for front and rear side conmacts, a semitransparent module could thus be produced.

The disadvantage here, however, is that thin-film cells have a specific structure on the glass, whereas the architect or the user usually desires a homogeneous coloring of the glass pane. This color is also not freely adjustable, but is fixed by the semiconductor material and the layer thickness. In addition, a thin-film production line is characterized in that usually only a defined size of the substrate can be produced. In contrast, however, especially in the GIPV often variable sizes and at best free-formable disc elements needed. Finally, today, thermal insulation for insulating buildings in building elements is an important feature. For a sufficiently high thermal resistance, therefore, the thickness of a thin-film cell must be chosen to be correspondingly large, which is disadvantageous in terms of weight and thus the handling of the cell.

Disclosure of the invention

It is therefore an object of the present invention to provide a collector, in particular solar collector for building-integrated photovoltaic energy production, which meets aesthetic requirements with good thermal insulation.

The object is achieved by the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims.

According to the invention, the collector comprises at least two substrate units which can be connected to a solar cell, each of which has a substrate layer and a fluorescent material connected to this substrate layer, the at least two substrate units being spatially separated from one another by a gap.

By such a spatial separation of the substrate units thermal insulation is achieved, which is comparable to known modern multiple glazing. However, when using lightweight substrate materials, the weight of the collector according to the invention can be reduced comparatively significantly, so that it is very easy to handle, in particular in the area of BIPIP.

By means of a defined selection of the fluorescent material, the coloration of the collector according to the invention can be adjusted as desired within certain limits during production. The color obtained is very homogeneous, which offers an aesthetic advantage.

Furthermore, such a collector arrangement is very inexpensive to manufacture.

In an advantageous embodiment of the present invention, the substrate layers are connected to one another at their end regions by spacers. As a result, a stable structure of the collector is realized without significantly increasing the weight. Furthermore, in this way there is an easy way to close the gap airtight. It is particularly advantageous if the Spacer comprises desiccant and / or a binder for oxygen. The degradation of the fluorescent material, caused by oxygen or moisture, can be reduced or avoided altogether. In addition, by providing a drying agent even accidentally entered into the gap humidity can not lead to condensation, aesthetic disadvantages can be avoided.

In a further advantageous embodiment of the present invention, the fluorescent material has an absorption spectrum which is substantially completely separated from its emission spectrum. This can prevent the radiation emitted from the fluorescent material from being absorbed again by the fluorescent material. In this way, the probability can be reduced that the radiation is emitted at an unfavorable angle and therefore leaves the collector again. The energy lost for energy conversion can be effectively reduced, which improves the efficiency of the collector of the invention.

It is also advantageous if the fluorescent material of two adjacent substrate units has a graduated absorption or emission spectrum. In other words, the fluorescent material of a first substrate unit absorbs or emits radiation of a different wavelength than the fluorescent material of an adjacent substrate unit. As a result, a specific part of the incident spectrum can in each case be absorbed and concentrated in each substrate unit. In this way, the use of specially adapted to these parts of the spectrum solar cells for energy conversion is possible, which significantly increases the efficiency of the collector.

In a further advantageous embodiment of the present invention, a layer is provided which filters out harmful wavelengths of the sunlight for the fluorescent material. As a result, the fluorescent material is protected and thus more durable. Costs that cause the replacement of a degraded fluorescent material can thus be reduced or avoided altogether.

In a further advantageous embodiment of the present invention, the fluorescent material is formed as a dye film on the surface of the substrate layer. As a result, a particularly effective absorption of the incident light can be achieved.

The invention further relates to a collector arrangement comprising a receptacle in which a collector according to the invention can be fastened, wherein at least one semiconductor cell is arranged in the receptacle for each substrate layer. Such an arrangement is particularly advantageous to use in the GIPV, since the arrangement as such is well usable as a building element. Furthermore, such an arrangement has the advantages of a collector according to the invention.

In an advantageous embodiment of the present invention, the receptacle is designed as a window frame. As a result, an arrangement according to the invention is particularly easy to use as a building element and thus in the GIPV.

In a further advantageous embodiment of the present invention, the semiconductor cell is formed as a semiconductor cell strip. As a result, a particularly large variability in the structural design of the arrangement according to the invention can be achieved.

In a further advantageous embodiment of the present invention, radiation sources are arranged in the receptacle, by means of which radiation can be introduced into the substrate units. With this configuration, the arrangement according to the invention can be used equally as an energy supplier, as well as a flat luminous element. This is particularly advantageous in the GIPV, since a component to be provided in any case can solve a plurality of tasks at the same time.

Further advantages and advantageous embodiments of the subject invention are illustrated by the drawings and explained in the following description. It should be noted that the drawings have only descriptive character and are not intended to limit the invention in any way.

Show it:

1 a schematic partial view of a collector according to the invention;

2 a schematic representation of the spacer-connected end portion of the collector according to the invention;

3 a schematic representation of a receptacle for a collector assembly according to the invention;

4 a schematic representation of the receptacle for a collector assembly according to the invention;

5 a schematic representation of another embodiment of the receptacle for a Collector arrangement according to the invention with radiation sources.

1 schematically shows a partial view of a collector 10 , in particular solar collector for building-integrated photovoltaic power generation, according to the present invention. The collector 10 has at least two, but advantageously a plurality of substrate units 12 . 14 . 16 . 18 on. In the following, the collector according to the invention will be used in a non-limiting manner in an embodiment with four substrate units 12 . 14 . 16 . 18 described. However, there are also embodiments with only two substrate units 12 . 14 and the features described herein possible.

According to 1 include the four substrate units 12 . 14 . 16 . 18 one substrate layer each 20 . 22 . 24 . 26 and a fluorescent material.

The substrate layers 20 . 22 . 24 . 26 are suitably transparent. They can be made of plastic or glass, for example. Suitable plastics include polymethylmethacrylate or polycarbonate. Preferably, the substrate layers 20 . 22 . 24 . 26 just trained and arranged parallel to each other.

The fluorescent material may be used, for example, as a dye in the substrate layers 20 . 22 . 24 . 26 be finely distributed. Preferably, however, the fluorescent material forms a fluorescent layer 28 . 30 . 32 . 34 from, which directly at the respective substrate position 20 . 22 . 24 . 26 is arranged such that the substrate layer 20 . 22 . 24 . 26 on its surface completely with the fluorescent layer 28 . 30 . 32 . 34 is covered. The fluorescent layer 28 . 30 . 32 . 34 is advantageously a dye film. Only end portions may be excluded from coverage, as with reference to FIG 2 is described. In this case, the substrate layers 20 . 22 . 24 . 26 preferably the same area. The fluorescent layer 28 . 30 . 32 . 34 may for example consist of organic dyes, quantum dots, or quantum dots, or more complex systems. Quantum dots are advantageous here because their optical properties are very precisely adjustable. Exemplary dyes are organic dyes such as rhodamine dyes, coumarin dyes or fluorescein.

To a degradation of the fluorescent layers 28 . 30 . 32 . 34 by atmospheric oxygen or humidity, these are preferably all within the collector 10 arranged. Therefore, the fluorescent layers 28 . 30 the with respect to the sunlight 36 top substrate units 12 . 14 Be arranged facing each other. The following fluorescent layers 32 . 34 are each by a substrate layer 22 . 24 separated from the adjacent fluorescent layer. Such an arrangement ensures that the collector 10 incident solar radiation 36 first at least once a substrate layer 20 must penetrate before going to the first fluorescent layer 28 meets. This has the advantage of being in the sunlight 36 contained UV components which are harmful to the fluorescent material and can lead to a degradation of the same, are filtered out. The life of the collector according to the invention 10 can be extended so clearly.

To further enhance this effect, an additional outer protective layer can also be used 38 be provided, which is designed to filter out the harmful for the fluorescent material wavelengths of sunlight. The protective layer can be designed, for example, as an optical filter. The protective layer 38 For example, it can be directly on the top, the sunlight 36 facing substrate layer 20 be upset. Harmful wavelengths are wavelengths of this type which lead to a degradation of the fluorescent material or cause it to be particularly strong.

The fluorescent material, such as the fluorescent layers 28 . 30 . 32 . 34 This is for the collector 10 striking sunlight 36 absorb a certain wavelength and then emit fluorescence radiation or fluorescent light with a longer wavelength. It is advantageous if a large proportion of the emitted light or the emitted radiation in the substrate layer 20 . 22 . 24 . 26 trapped by total reflection and thus migrates comparable to a light guide to a first end portion. At this end portion of a solar cell can be arranged, whereby the emitted radiation is convertible into electrical energy.

The efficiency of a collector according to the invention 10 is particularly high when a first substrate unit 12 a fluorescent material that absorbs and re-emits sunlight of a first wavelength range and a second substrate unit 22 having a fluorescent material that absorbs and re-emits sunlight of a second wavelength range, and so on. In other words, it is advantageous if the fluorescent material of two adjacent substrate units has a graduated absorption or emission spectrum. Thereby, especially if for each substrate unit 12 . 14 . 16 . 18 a separate solar cell is provided, this adapted exactly to the radiation emitted by the fluorescent material radiation and thus be particularly effective.

The substrate units 12 . 14 . 16 . 18 are according to the invention by a gap 40 . 42 . 44 spatially separated from each other. The resulting gaps or gaps 40 . 42 . 44 can be filled with an inert gas, such as nitrogen, argon or krypton. Especially with the use of Qauntendots as a fluorescent, material in the fluorescent layer 28 . 30 . 32 . 34 the use of an inert gas is essential. Because quantum dots are particularly unstable to atmospheric oxygen. However, this is true for most fluorescent materials.

Due to the structure of alternating substrate layers 12 . 14 . 16 . 18 and columns 40 . 42 . 44 , In particular, the resulting alternating structure of plastic or glass and gas layers, an effect of good thermal resistance is achieved, which is comparable to that of a multiple glazing. By the aforementioned structure can thus be achieved excellent thermal insulation. Such thermal insulation is particularly advantageous for collectors used in BIPV, where collectors are building elements. For example, this can save heating costs and thus relieve the burden on the environment.

The multilayer structure according to the invention also makes it possible to control the incident light 36 through several layers of different substrate units 12 . 14 . 16 . 18 to filter. By appropriate selection, in particular, of the dye combinations in the fluorescent materials, such as in the fluorescent layers 28 . 30 . 32 . 34 , the overall color effect of the collector according to the invention 10 to be influenced. This is the perceived colouration of the collector 10 at least within certain limits variable during their production, with a highly homogeneous color is achieved.

The collector 10 has a first end portion 46 on, which is schematically in 2 is shown. At this end section 46 close the substrate units 12 . 14 . 16 . 18 flush with each other and are here connected to a solar cell. In this case, a common solar cell for all substrate layers 12 . 14 . 16 . 18 be provided. However, it is convenient for each substrate unit 12 . 14 . 16 . 18 to provide a separate solar cell, as with respect to the collector assembly according to 3 and 4 is described. As a result, as already stated, each of the substrate units 12 . 14 . 16 . 18 be adapted to a specific wavelength along with the solar cell to increase the effectiveness of the collector 10 to increase. This first end area 46 opposite are the substrate layers 20 . 22 . 24 . 26 each have a further end region, which may be provided with a mirror. In this way, the radiation emitted by the fluorescent material becomes the end portion connectable to the solar cell 46 bundled. Radiation losses are reduced.

According to 2 are the substrate units 12 . 14 . 16 . 18 at the end area 46 attached to each other. These are spacers or spacers 48 . 50 . 52 , provided that the substrate layers 20 . 22 . 24 . 26 connect with each other. By providing the spacers 48 . 50 . 52 can be a defined size of the gap 40 . 42 . 44 be created. In addition, a very stable construction is created with which the collector 10 safe and easy to handle. Furthermore, the spacers allow 48 . 50 . 52 an airtight seal of the column 40 . 42 . 44 , so that the entry of air and moisture, especially humidity, can be avoided.

In particular, with slight damage, such as cracking, however, the ingress of atmospheric oxygen or atmospheric moisture can not always be safely avoided, which leads to an accelerated degradation of the fluorescent material in particular. To prevent this is in the spacers 48 . 50 . 52 preferably a drying agent 54 . 56 . 58 and / or a means for absorbing oxygen 55 . 57 . 59 intended. This can cause humidity or oxygen, which inadvertently enters the column 40 . 42 . 44 have penetrated, safely removed from these. Although such absorption and / or drying media 54 - 59 not limited shelf life. However, degradation of the fluorescent material for at least a limited period of time, such as from the occurrence of the damage to the replacement of the damaged element, can be prevented. That way, not the entire collector 10 or an entire substrate unit 12 . 14 . 16 . 18 but only the respective damaged element to be replaced, which can significantly reduce the cost of such exchange.

As described, the spacers can 48 . 50 . 52 be advantageously arranged so that free end portions of the substrate layers 20 . 22 . 24 . 26 arise. At these end regions, a fluorescent material is not necessary. Instead, the transition to the semiconductor or to the solar cell can be realized here. The collector according to the invention 10 thus finds advantageous use in a collector arrangement, such as a collector arrangement for building-integrated photovoltaic energy.

Such a collector arrangement according to the invention comprises a receptacle 60 in which the collector 10 is attachable, as in 3 is shown. In the event that the collector 10 when Window pane of a building is intended to serve the recording 60 be designed as a window frame. The recording 60 However, it does not have to be in the form of a fixed framework if the collector 10 in itself has a sufficiently high structural stability.

The recording 60 comprises a solar cell or semiconductor cell, which in particular comprises crystalline silicon. The semiconductor cell may be formed as a semiconductor cell strip. It is for each substrate unit 12 . 14 . 16 . 18 one semiconductor cell strip each 62 . 64 . 66 . 68 intended. The semiconductor cell strips 62 . 64 . 66 . 68 have a lateral distance from each other, the exact size of the column 40 . 42 . 44 equivalent. This is the collector 10 exactly in the picture 60 positionable. Furthermore, a modular construction of concentrator and converter is possible by forming the semiconductor cells as cell strips.

The semiconductor cell strips 62 . 64 . 66 . 68 are preferably manufactured in a mass production in one size. In the event that the size of the substrate layer projects beyond the length of the semiconductor cell strips, substantially the entire length of the substrate layers may be used 20 . 22 . 24 . 26 to provide with a solar cell, the semiconductor cell strips 62 . 64 . 66 . 68 with further semiconductor cell strips 70 . 72 . 74 . 76 via an electrical connection 78 . 80 . 82 . 84 be connected to each other. To avoid radiation losses is in the range of electrical connections 78 . 80 . 82 . 84 a mirrored area 86 intended.

Emitted radiation, outside the solar cells from the substrate layers 20 . 22 . 24 . 26 exit, so through the mirrored area 86 reflected. In the event that a plurality of semiconductor cell strips is arranged one behind the other, a plurality of mirrored areas is expediently provided. In any case, the semiconductor cells are switchable in series to produce a corresponding module voltage and to provide via a transducer.

In addition, through the use of the mirrored area 86 the size of the recording 60 be made variable. For the size does not necessarily have to amount to a multiple of the length of a semiconductor cell or of a semiconductor cell strip. Deviations of a multiple of the length of the semiconductor cell strips can thus be compensated for by the mirrored region (s). Especially in the design of the recording 60 As a window frame, this embodiment is advantageous because a very large variability is given with respect to a window size to be realized, as well as the shape of the collector 10 in itself within certain limits is freely selectable.

It is particularly advantageous if the semiconductor cells are detachable in the receptacle 60 be attached. As a result, the semiconductor cells or the solar cells can be exchanged in a simple manner. On the one hand, it can react to new developments and integrate more efficient cells. Furthermore, the replacement of defective cells is so easy.

A detachable attachment of the solar cells or semiconductor cells in the recording 60 is in particular realized by a clip mechanism. For this purpose, the collector 10 Cliplaschen have, the corresponding counter-elements on the recording 60 behind, or vice versa. This makes it possible to obtain the efficiency of the arrangement according to the invention when the fluorescent material is of only limited durability. Replacement of the collector 10 is so easily possible. Furthermore, it can be responded to changing aesthetic demands. If the taste of the user changes, can through an easy-to-design exchange of the collector 10 to get a new coloring.

Especially with a releasable attachment of the collector 10 at the reception 60 can be a protective layer 88 be provided, as in 4 can be seen. The protective layer 88 is for example between the collector 10 , or between the end regions of the substrate layers 20 . 22 . 24 . 26 and the semiconductor cells arranged. This can damage the semiconductor cells at the onset of the collector 10 in the recording 60 be prevented. In order not to impair the effectiveness of the arrangement, the protective layer is made transparent. Emitted radiation can be the protective layer 88 so easily penetrate and get to the semiconductor cells.

In all this, a seal is expedient which seals the arrangement with respect to the environment and thus prevents atmospheric moisture or oxygen from reaching the semiconductor cell, for example. This can be a sealing material 90 be provided that between the recording 60 and the collector 10 is arranged.

Another embodiment of the present invention is in 5 shown. According to 5 are in the recording 60 Radiation sources arranged. These are preferably light sources 92 , wherein each substrate unit 12 . 14 . 16 . 18 a radiation or light source should be assigned. These light sources 92 For example, they may be formed as LEDs (Light Emitting Diodes). The light sources 92 are powered by an electrical outlet that is in the receptacle 60 can be arranged. The LEDs direct radiation into the substrate units 12 . 14 . 16 . 18 one. The radiation transition can be achieved by providing a light guide 94 be supported between the substrate unit 12 and the light source 94 is arranged. In this way, the individual substrate units 12 . 14 . 16 . 18 or the fluorescent material contained in these particular when no sunlight on the collector 10 falls, be excited to shine. As a result, a pleasant tone that is pleasant for the user can be generated. The arrangement according to the invention can thus work equally well as a flat light source.

If an additional energy storage, such as an accumulator provided, thus the energy for the illumination of a room can be collected in sunlight and delivered in the dark. In this way, an independent lighting system is created in which the consumed energy is generated equally. As a rule, significantly more energy is stored than is consumed by the lighting, so that the use for energy production is still possible.

In an alternative embodiment, it would also be conceivable to use the semiconductor cell on the sides of the collector, ie at the end region of the substrate units 12 . 14 . 16 . 18 to realize in thin-film technology. This would create a collector arrangement in which an even greater variability in the design of the shape of the collector, or its arrangement is possible.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4488047 [0002]
• DE 102007015472 A1 [0004]
• DE 102006010646 A1 [0004]

Claims (10)

Collector, in particular solar collector for building-integrated photovoltaic energy production, comprising at least two substrate units connectable to a solar cell ( 12 . 14 ), each having a substrate layer ( 20 . 22 ) and a fluorescent material associated with said substrate layer, said at least two substrate units ( 12 . 14 ) through a gap ( 40 ) are spatially separated from each other. Collector according to claim 1, characterized in that the substrate layers ( 20 . 22 ) at their end regions by a spacer ( 48 ) are interconnected. A collector according to claim 1 or 2, characterized in that the fluorescent material has an absorption spectrum which is substantially completely separated from its emission spectrum. Collector according to one of claims 1 to 3, characterized in that the fluorescent material of two adjacent substrate units ( 12 . 14 ) has a graded absorption or emission spectrum. Collector according to one of claims 1 to 4, characterized in that a layer ( 38 ) which filters out harmful wavelengths of the sunlight for the fluorescent material. Collector according to one of claims 1 to 5, characterized in that the fluorescent material as a dye film ( 28 . 30 ) on the surface of the substrate layer ( 12 . 14 ) is trained. Collector arrangement, in particular solar collector arrangement, comprising a receptacle ( 60 ), in which a collector ( 10 ) can be fastened according to one of claims 1 to 6, wherein in the receptacle ( 60 ) for each substrate layer ( 20 . 22 ) at least one semiconductor cell is arranged. Collector arrangement according to claim 7, characterized in that the receptacle ( 60 ) is designed as a window frame. Collector arrangement according to Claim 7 or 8, characterized in that the semiconductor cell is in the form of a semiconductor cell strip ( 62 . 64 ) is trained. Collector arrangement according to one of claims 7 to 9, characterized in that in the receptacle ( 60 ) Radiation sources ( 94 ) are arranged by the radiation in the substrate units ( 12 . 14 ) can be introduced.

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