DE102009055432A1 - Concentrating device for use in photovoltaic array or solar panel for concentrating incident light, particularly sunlight, has statically mounted gutter or trough-shaped mirror body - Google Patents

Abstract

The concentrating device (100) has a statically mounted gutter or trough-shaped mirror body (10). The photovoltaic absorbing agent is arranged in or under the wandering focal point or focal plane or focal plane of the mirror body or between the focal point or focal plane or focal plane of the mirror body and the vertex of the mirror body. An independent claim is also included for a method for concentrating incident light, particularly sunlight.

Description

Technical area

The present invention relates to a device for concentrating incident light, in particular of sunlight, provided, comprising at least one statically mounted trough or trough-shaped mirror body, by means of which the incident light on at least one photovoltaic absorber means, in particular at least one solar cell, for example at least a solar cell plate or at least one solar cell latch, is deflectable. (see document DE 202 20 390 U1 from the prior art).

The The present invention further relates to a corresponding method for concentrating incident light, in particular sunlight.

in this connection is intended above and below under incident light that Be understood by the outside of the light Device incident light rays, in particular by the of outside incident sunbeams, is formed.

• – der I[nfra]R[ot]-Bereich (Wellenlängenbereich bis zu etwa 2.000 Nanometer bzw. Frequenzbereich bis herab zu etwa 150 Terahertz) und
• – der U[ltra]V[iolett]-Bereich (Wellenlängenbereich bis herab zu etwa einem Nanometer bzw. Frequenzbereich bis zu etwa 300 Petahertz).

In this context, however, in the context of the present invention, the term light is understood to mean not only the visible to the eye region of the electromagnetic radiation, which extends in a wavelength range from about 380 nanometers to about 780 nanometers (which corresponds to a frequency of about 789 terahertz down to about 385 terahertz); Rather, the term light is understood to mean the entire, ie also the electromagnetic wavelength or frequency spectrum not visible to the eye, in particular

• The I [nfra] R [ot] region (wavelength range up to about 2,000 nanometers or frequency range down to about 150 terahertz) and
• - The U [ltra] V [iolett] range (wavelength range down to about one nanometer or frequency range up to about 300 petahertz).

State of the art

conventional Planar photovoltaic systems in use today have large-area silicon modules and are very expensive to manufacture, with production costs currently determined by the cost of silicon.

• – bei monokristallinem Silizium (mit einem Wirkungsgrad von etwa sechzehn Prozent bis etwa zwanzig Prozent und mit einem Marktpreis von etwa 500 EUR pro Quadratmeter) etwa sechzig Prozent,
• – bei polykristallinem Silizium (mit einem Wirkungsgrad von etwa zehn Prozent bis etwa fünfzehn Prozent und mit einem Marktpreis von etwa 350 EUR pro Quadratmeter) etwa vierzig Prozent und
• – bei amorphem Silizium (mit einem Wirkungsgrad von etwa acht Prozent bis etwa zehn Prozent und mit einem Marktpreis von etwa 250 EUR pro Quadratmeter) oder bei anderen Halbleiter-Dünnschichtmaterialien etwa zwanzig Prozent.

Here, the cost portion of the photovoltaic material (with a comparable mechanical structure and a comparable mass of about ten kilograms per square meter) at the modules

• - for monocrystalline silicon (with an efficiency of about sixteen percent to about twenty percent and a market price of about € 500 per square meter) about sixty percent,
• - For polycrystalline silicon (with an efficiency of about ten percent to about fifteen percent and a market price of about 350 euros per square meter) about forty percent and
• - For amorphous silicon (with an efficiency of about eight percent to about ten percent and a market price of about 250 EUR per square meter) or about twenty percent for other semiconductor thin-film materials.

Out For this reason, photovoltaic concentrators are increasing in recent times for use; Here, as concentrators of the light bundling serving devices of geometric optics, means derer a multiplication of the radiation density and thus a minimization the absorber surface is achievable.

by virtue of the increased efficiency of photovoltaic systems can reduce the silicon cost by a reduced area of solar cells and thus the ratio of solar cell costs to the total costs be lowered; as a solar cell material can hereby apart from silicon also III / IV semiconductors, such as gallium arsenide (GaAs) or indium phosphide (InP).

such with mirrors and / or lenses of various kinds, for example with parabolic mirrors and / or lenses, constructed concentrator systems reduce the problem of high semiconductor material costs, especially the high silicon costs or the high gallium arsenide costs, by the concentration factor of the concentrator (factor larger as 1 up to a factor of 1,000); however, such concentrator systems are associated with a much higher mechanical effort, because this type of light concentration requires a relatively complex mechanical tracking.

At least in Central and Northern Europe, such concentrators have due to the cloudy climate there has not yet been enforced because Concentrators mainly use direct radiation. Although the proportion of diffuse radiation in the total radiation can be up to fifty percent, the diffuse remains Radiation at least in tracking concentrators mostly unused.

With regard to the design of photovoltaic concentrators, a distinction is primarily made between static systems and tracked systems. Static concentrators will be like conventional flat or Planar collectors permanently mounted, but have a design-related concentration ratio, which decreases with increasing acceptance angle of the radiation.

in this connection is understood as the maximum angle of incidence at the acceptance angle, in which the radiation can be absorbed.

tracked Photovoltaic systems reach concentration factors of over 100, but this is a very elaborate Mechanics and control required; this is especially true for biaxial tracked systems, so that the development of such tracked photovoltaic systems mainly limited to large systems.

By the high wind load is with tracked photovoltaic systems a stable support required so that tracked Concentrators typically require a large area and hardly possible integration in buildings is.

Even though even diffused light creates a certain brightness in the concentrator, can also be highly concentrated tracking Photovoltaic systems barely use this diffuse radiation and are suitable thus mainly for sunny climates, for example in southern Europe.

in principle can tracked systems with higher Acceptance angle can be designed to obliquely incident To use light or stray light. However, then it decreases the concentration ratio and thus the utilization of the direct radiation. This increases the relative overhead for tracking and fixation.

Based on the fact that for small to medium-sized photovoltaic systems, especially in cloudy climates, the problem is that static concentrators reach too low concentration ratios, but tracking concentrators require a very high cost for tracking and fixation, is in the document DE 202 20 390 U1 proposed a semistatic photovoltaic concentrator, wherein the base member is a static, fixed mounted mirror, whereas the absorber is movable with the solar cells parallel to the focal plane, whereby the focus is achieved on the absorber surface.

From the publication WO 89/05520 A1 an arrangement is known in which in a solar cell module a plurality of double-sided effective solar cells are provided, which are arranged over an array of a plurality of mutually parallel trough-shaped and semi-circular in cross-section mirrors; These mirrors redirect the part of the solar radiation incident on the underside of the solar cells next to the solar cells.

In the publication EP 0 059 464 A1 discloses a solar concentrator with a concave mirror concentrating the solar radiation on an absorber surface located between the mirror and the sun. The mirror is formed by a solid block of transparent material whose bottom is convexly curved and mirrored. In or on the top of the block, the absorber surface is arranged.

From the publication DE 195 08 071 A1 an arrangement is known in which in a solar cell according to the principle of thermovoltaics by the concentration of the sun's rays in the focal point or in the focal line of a specular cavity a higher energy yield than in a flat arrangement of the cells is achieved.

Other concentrator systems of the prior art are in the documents US 4,115,149 . US 4 173 968 . US 4,191,164 . US 4,388,481 . US 5 062 899 . US 5,344,496 . WO 78/00019 A1 . WO 83/01292 A1 . WO 90/10182 A1 . WO 96/24014 A1 . WO 97/00408 A2 and WO 2004/109195 A2 disclosed.

The The concentrator systems discussed above is their efficiency loss at temperature increase during operation as well as the increase in resistance the solar cells in Teilabschattung together. The resistance increases by heat and / or by Teilabschattung draw one Reduction of electricity generation, because the solar elements are connected in series.

In summary can be found that the known concentrator systems are mechanically complex and require a high level of maintenance, whereas the planar systems available today are too expensive due to the high silicon cost.

Besides There are also systems made of polysilicon photovoltaic modules and / or are constructed of thin-film photovoltaic modules. Such a Although construction is cheaper than a structure made of silicon photovoltaic modules, However, it regularly has a lower efficiency.

Illustration of the present invention: Task, solution, benefits

Based on the disadvantages and inadequacies set out above, as well as in appreciation of the state of the art outlined, the object of the present invention is to further develop a device of the type mentioned at the outset as well as a method of the aforementioned type that a significant cost reduction by using a concentrator system without moving parts can be achieved.

These The object is achieved by a device with the specified in claim 1 Characteristics and by a method with the specified in claim 9 Characteristics solved. Advantageous embodiments and expedient Further developments of the present invention are in the subclaims characterized.

The The present invention is basically based on utilization the defocusing of light radiation; this means at concave, especially spherical or parabolic domed, mirrors the arrangement of the photovoltaic Absorbers or solar cells below the focal point. alternative or in addition to this, the photovoltaic Absorber or solar cells between the focus of the mirror and be arranged at the apex of the mirror.

• – http://de.wikipedia.org/wiki/Kaustik_(Optik) ,
• – das von Carl Ernst Heinrich Grimsehl, Walter Schallreuter und Rudolf Seeliger verfasste ”Lehrbuch der Physik”, Band 3: Optik, Verlag Teubner, 14. Auflage (1962) ,
• – das von Henrik Wann Jensen verfasste Buch ”Realistic Image Synthesis Using Photon Mapping”, Verlag A. K. Peters, Wellesley (Juli 2001) oder
• – das Manuskript zum von Johannes Koffer, Institut für Angewandte Physik der Johannes-Kepler-Universität Linz, am 31. März 2005 gehaltenen Vortrag ”Lichtfokussierung durch Mikrokugeln” ).

In the case of spherical mirrors, this effect is very substantially assisted by the spherical aberration and the resulting caustics (for the phenomenon of caustics, see for example

• - http://de.wikipedia.org/wiki/Kaustik_(Optik) .
• - that from Carl Ernst Heinrich Grimsehl, Walter Schallreuter and Rudolf Seeliger wrote "Textbook of Physics", Volume 3: Optics, Verlag Teubner, 14th Edition (1962) .
• - that from Henrik Wann Jensen authored "Realistic Image Synthesis Using Photon Mapping", published by AK Peters, Wellesley (July 2001) or
• - the manuscript of Johannes Koffer, Institute of Applied Physics, Johannes-Kepler-University Linz, lecture "Light focusing by microspheres" held on March 31, 2005 ).

The The shape of a parabolic mirror is at small opening angles well approximated by a spherical mirror shape. A parabolic mirror has no caustic in the true sense on, but also creates a burning surface, if the to be illuminated object, so the solar cell, below the focal point is attached.

in the In contrast, in the present invention, the Kaustikeffekt a spherical mirror or the mixed form of a spherical-parabolic Mirror used for concentrators in photovoltaics.

Of the spherical or spherical parabolic mirrors Here, in a preferred manner, the shape of a groove or a Have spherical cap, wherein the migratory as a result of Kaustikeffekts Focus of the spherical or spherical-parabolic mirror is used for the benefit of the present invention.

The Exploitation of the caustics of a spherical or spherical parabolic Mirror is based on the properties of the concentrating element, namely the spherical or spherical-parabolic Mirror with his "wandering" focus, not however, on the properties of the absorber element and / or the absorber material; on this way is an application of the operation of the caustics one spherical concentrator in photovoltaic technology possible.

Becomes So in a spherical or spherical-parabolic Concentrator mirror whose Kaustik exploited, so is not only a reduction in silicon costs while maintaining the same energy yield possible, but also concentrating the incident Light without tracking the concentrator (so no additional costs for any mirror tracking arise).

• – ohne Nachführung: Toleranzwinkel von etwa ± zehn Grad oder größer;
• – mit unterstützender (konzentrierender) Optik direkt vor dem photovoltaischem Material: Toleranzwinkel von etwa ± fünfzehn Grad oder größer.

The caustics of the spherical concentrator mirror in this case enables amplification factors up to the order of the geometry factors (where the geometry factor is the ratio of the opening area of the concentrating mirror and thus the maximum light incidence to the area of the photovoltaic absorber used in the mirror):

• - without tracking: tolerance angle of about ± ten degrees or greater;
• - with supporting (concentrating) optics directly in front of the photovoltaic material: tolerance angle of about ± fifteen degrees or greater.

According to the Principle of the present invention will be the operation of the spherical or spherical-parabolic concentrator in diffused light improved by increasing its acceptance or tolerance angle, regardless of the type of absorber, but dependent of shape and arrangement in the concentrator, because this will increase the acceptance or tolerance angle influenced. Here, under the acceptance or tolerance angle the maximum angle of incidence understood in the which can be absorbed by the radiation.

On the basis of the invention essential fact that the Kaustik the spherical or spherical-parabolic concentrator mirror allows amplification of the incident light rays, the acceptance or tolerance of the direction of light, especially in diffuse (solar) light can be particularly large, which is particularly in tracking systems is advantageous because then regardless of the specific season-dependent position in the sun always very good results can be achieved.

at one with a spherical or spherical-parabolic Mirror system constructed concentrator system due to its Nachführfreiheit a high acceptance angle of the concentrating element obliquely incident light radiation. By location and shape of the absorber and by introducing optional additional optical Elements, such as lenses (systems), prisms or the like, the acceptance or tolerance angle can be influenced or increased become.

the essentially linear relationship between tolerance angle and Efficiency in diffused light is removable, as the efficiency increased as the acceptance or tolerance angle increases. This high efficiency in diffused light makes the spherical Concentrator very attractive.

These Property distinguishes the spherical or spherical-parabolic Concentrator in a very essential way of parabolic concentrators, the only a very low acceptance or tolerance angle and therefore have a relatively low efficiency in diffused light. Increasing the efficiency with increasing acceptance or tolerance angle is the applicable in the thermovoltaic property a spherical or spherical-parabolic Concentrator, regardless of the absorber element.

in the Result requires the optional tracking freedom of Photovoltaic device has a high acceptance or tolerance angle, in turn, a good processing of diffused light or stray light causes; This effect is also independent of the absorber element or from the absorber agent.

• – in oder unterhalb der, insbesondere durch die Kaustik bewirkten, Brennebene oder Brennfläche des Spiegelkörpers oder
• – zwischen der Brennebene oder Brennfläche des Spiegelkörpers und dem Scheitelpunkt des Spiegelkörpers oder
• – bei Vorsehen mindestens eines dem photovoltaischen Absorbermittel in Richtung des einfallenden Lichts und/oder in Richtung von reflektiertem Licht vorgelagerten lichtbrechenden, insbesondere optisch transparenten, Elements, zum Beispiel mindestens eines Prismas oder mindestens einer Linse, wie etwa mindestens einer Sammellinse, optionalerweise auch in Kombination mit mindestens einer Zerstreuungslinse, zwischen der Brennebene oder Brennfläche des Spiegelkörpers und dem Mittelpunkt des Spiegelkörpers angeordnet, insbesondere in Bezug auf den Spiegelkörper statisch montiert, ist, ist für die erfindungsgemäße Photovoltaik-Konzentratorvorrichtung kein mechanisch-technologisch aufwändiges Herstellungsverfahren erforderlich; vielmehr ist der mechanische Aufwand zur Herstellung, insbesondere zur mechanischen Aufhängung, der einzelnen Module vergleichbar mit dem oder geringer als der mechanische Aufwand zur Herstellung heutzutage erhältlicher planerer Systeme.

As the photovoltaic absorber according to the invention

• - In or below, caused in particular by the Kaustik, focal plane or focal surface of the mirror body or
• - Between the focal plane or focal surface of the mirror body and the vertex of the mirror body or
• - Providing at least one of the photovoltaic absorber means in the direction of the incident light and / or in the direction of reflected light upstream refractive, in particular optically transparent, element, for example at least one prism or at least one lens, such as at least one converging lens, optionally also in combination is arranged with at least one diverging lens, disposed between the focal plane or focal surface of the mirror body and the center of the mirror body, in particular mounted statically with respect to the mirror body, no mechanically-technologically complex manufacturing process is required for the photovoltaic concentrator according to the invention; Rather, the mechanical complexity for the production, in particular for mechanical suspension, of the individual modules is comparable to or less than the mechanical complexity for the production of planar systems available today.

Also this arrangement in a spherical or spherical-parabolic Concentrator is independent of the absorber element and / or from the absorber material and can therefore be used in photovoltaic technology be applied.

As a result the use of the caustic and the resulting burning surface at least one easily preparable spherical or approximately parabolic mirror surface has the present invention in a preferred embodiment neither complicated Lens systems still polished surfaces on. hereby becomes a mechanically stable modular construction without moving parts allows, so that a maintenance-free of the entire system given is.

According to one advantageous development of the present invention can be achieved by a trough-shaped embodiment of the spherical or parabolic mirror surface a significant reduction the shading can be achieved. Here, the active side of the Solar cells with advantage to face the mirror surface, so be directed to the inside of the mirror.

As a result, can be a direct shading within the invention Photovoltaic concentrator device can be reduced, so that the efficiency the arrangement according to the present invention can be increased.

by virtue of the preferably planar surface of the concentrator system According to the present invention, the mirror firmly on a building, preferably on the roof of a building Building, to be mounted. Due to the static mounting can the concentrator system according to the present Invention even replace a part of the roof, which in turn one represents significant cost advantage.

In expedient manner corresponds to the height of the concentrator in about half the radius of the spherical Mirror. This means, for example, at a radius of the spherical Mirror of eight centimeters an approximate height of the concentrator of four centimeters, what the height corresponds to today's planar systems.

There the achievable performance of solar cells with increasing temperature decreases, it is expedient in the concentrator device according to the present invention for to ensure sufficient cooling of the absorber, for Example by means of at least one integrated in the optical body Heat removal system, through which a significant increase the efficiency of the photovoltaic process or process can be.

For this can be at least one cooling system, for example at least a heat sink integrated in the optical system, and / or at least one active cooling is provided, in which the photovoltaic absorber by a flowing over Coolant is cooled.

All in all the present invention is characterized by a concentrator effect in a body or hollow body of optically transparent Material, which is a mechanically simple to produce and easily assembled system without mechanical Tracking is.

The present photovoltaic concentrator device has a focus on a focal plane and / or below a focal plane Focal plane or surface, wherein at least in the case of use a spherical mirroring of the optical body In addition, the effect of Kaustik comes into play. A appropriate position or positioning of the photovoltaic modules between the focus of the mirror body and the vertex of the mirror body and the shape of the photovoltaic modules determine the size of the gain and the acceptance angle.

According to one advantageous development of the present invention can the photovoltaic absorbers or photovoltaic modules on more than one side, especially on both or all Sides (surfaces), the absorber or module holder arranged be. In this way, directly incident light that otherwise shielded by the photovoltaic absorber or photovoltaic modules would be recorded in addition.

In Appropriately, by means of at least one the absorber material or absorber agent in the direction of the incident Light upstream or upstream or superset refractive, in particular optically transparent, element, for example by means at least one lens or by means of at least one prism, the increased by the Kaustik conditional acceptance angle become.

through The present invention is a multiplication of the radiation density and thus a minimization of the area in the photovoltaic absorber achievable, whereby a cost reduction of the photovoltaic modules compared goes hand in hand with conventional systems.

The The present invention further relates to a photovoltaic field, a photovoltaic panel or a photovoltaic panel comprising several Devices according to the above Art, the modular to the field, to the panel or to the plate composed can be and expediently one have common optically transparent cover.

The The present invention finally relates to the use at least one device according to the above specified type and / or at least one photovoltaic array, at least a photovoltaic panel or at least one photovoltaic panel according to the type of concentration set forth above of incident light, in particular of sunlight, on at least a photovoltaic absorber, in particular at least one Solar cell, for example on at least one solar panel or on at least one solar cell latch.

hereby is compared to existing photovoltaic systems, in particular to existing photovoltaic modules, a significant cost reduction achievable, with no for the photovoltaic concentrator Tracking is required. By an advantageous completed and / or planar surface is the device according to the present invention and / or the Photovoltaic field, the photovoltaic panel or the photovoltaic panel according to the present invention for the roof mounting suitable.

Brief description of the drawings

As already discussed above, there are various possibilities for embodying and developing the teaching of the present invention in an advantageous manner. For this purpose, reference is made on the one hand to the claims subordinate to claim 1, on the other hand further embodiments, features and advantages of the present invention will be described below with reference to 1A to 5C illustrated embodiments explained in more detail.

It shows:

1A a schematic cross-sectional view of a production example of a mirror body of a device according to the present invention;

1B a schematic cross-sectional view of an alternative manufacturing example of a mirror body of a device according to the present invention;

2A a schematic cross-sectional view of a component of an embodiment of a device according to the present invention;

2 B a schematic cross-sectional view of a first embodiment of a device according to the present invention and the related Kaustik;

2C a schematic cross-sectional view of a focal point in the spherical mirror with vertically incident light;

2D in a schematic cross-sectional view of a conventional Kaustik;

2E a schematic cross-sectional view of a focal point in the spherical mirror with obliquely incident light;

2F a schematic cross-sectional view of a focal point superposition with perpendicular and obliquely incident light;

2G in a schematic cross-sectional view of the conventional Kaustik 2D with slight deviation from spherical shape in the direction of parabolic shape in the outer edge regions of the mirror body;

2H in a schematic cross-sectional view of the conventional Kaustik 2D and from 2G arranged with photovoltaic absorber means such that no tracking is required;

2I in a schematic cross-sectional view of the conventional Kaustik 2D , out 2G and from 2H with the focal point moving according to the position of the sun;

2J a schematic cross-sectional view of a conventional focal point in the parabolic mirror with perpendicular incident light;

2K a schematic cross-sectional view of a conventional focus in the parabolic mirror with obliquely incident light;

3A a schematic cross-sectional view of a component of an embodiment of a device according to the present invention;

3B in a schematic cross-sectional view one to 3A alternative component of an embodiment of a device according to the present invention;

3C a schematic cross-sectional view of a second embodiment of a device according to the present invention;

3D a schematic cross-sectional view of a third embodiment of an apparatus according to the present invention;

3E a schematic cross-sectional view of a fourth embodiment of a device according to the present invention;

4A a schematic cross-sectional view of an embodiment of a covered device according to the present invention;

4B in a schematic cross-sectional view of the device 4A with an optical element in the form of a lens displaced into the region between the focal plane or focal plane of the mirror body and the center of the mirror body;

4C in a schematic longitudinal section along the in 4A and in 4B respectively reproduced section line AA the device 4A and from 4B ;

5A in a schematic cross-sectional view of the basis of calculation for the device 5B ;

5B in a schematic-perspective cross-sectional view of the provided with a cover in the form of a cover plate device 3C ; and

5C in schematic perspective cross-sectional view of an embodiment of a concentrator array or panel according to the present invention.

Same or similar embodiments, elements or features are in 1A to 5C provided with identical reference numerals.

Best way to execute of the present invention

In order to avoid superfluous repetitions, the following explanations concerning the embodiments, features and advantages of the present invention (unless stated otherwise) refer to all in 1A to 5C illustrated exemplary embodiments of devices 100 . 100 ' . 100 '' . 100 ' according to the present invention; Here is the illustration in 1A to 5C not necessarily to scale and / or function, but is merely illustrative.

As 2A is removable, points the photovoltaic concentrator 100 . 100 ' . 100 '' . 100 ' a spherical or nearly parabolic concave mirror 10 For example, from polished aluminum surface or from mirrored plastic, such as mirrored Polysterolplatten on, wherein the cavity of this mirror coating 10 may be filled with a medium such as a gas, for example with air, or with a transparent liquid, for example with water, or with an optically transparent material.

When producing spherical or nearly parabolic concentrator mirrors 10 With mirrored Polysterolplatten or with other mirrored materials, a special mold can be used and then with this mold on pressure and / or over temperature the desired shape of the mirror 10 For example, the shape of a parabolic mirror may be provided by approaching through a spherical mirror (or vice versa).

This approach can also be used to the shape of the mirror 10 on one for the absorber 20 optically active surface 16 to reduce (cf. 3B ). The optically inactive surfaces 18 are formed perpendicular thereto (see. 3B ), whereby the possible packing density of a whole (photovoltaic) field or (photovoltaic) panel 200 (see. 5C ) can be significantly increased.

This approximately parabolic mirror shape is obtainable when, for example, a mirrored Polysterolplatte between two fixed breakpoints in the form of Befestigungsklötzen 12 (See embodiment according to 1A ) or mounting grooves 14 (See embodiment according to 1B ) is clamped. A realization with a bottom plate and with different mirrors is possible.

The clamping between the two stops 12 (see. 1A ) or 14 (see. 1B ) yields, to a very good approximation, a parabolic form of the equation y = a × x ² , which can then be converted into a spherical shape by pressure on the vertex. This pressure can be over the clamping of the mirror 10 be generated and maintained in the photovoltaic concentrator holder.

This is a possibility of simple, inexpensive and flexible production of spherical and parabolic mirrors 10 without the risk of mirror damage during production. The transparent clamping surface 40 also provides good protection of the mirror 10 which makes the concept suitable for outdoor applications.

The in relation to the mirror body 10 statically mounted (standard commercial) solar cells 20 are located below the focal point of the mirror 10 in his caused by the Kaustik Brennfläche. In 2 B is one of the possible arrangements of the photovoltaic absorber means, that is the solar cells 20 in the focal plane or surface of the mirror 10 shown.

In principle, the photovoltaic absorber agent 20 essentially parallel (cf. 3C ) or substantially perpendicular (cf. 3D ) to the focal plane or focal surface of the mirror body 10 be arranged.

• – insbesondere beliebig zur Brennebene oder Brennfläche des Spiegelkörpers 10 gewinkelte und/oder
• – insbesondere beliebig zueinander gewinkelte Anordnung der photovoltaischen Absorbermittel 20 ist möglich (vgl. Ausführungsbeispiel gemäß 3E). Hierbei bestimmen die geometrische Lage bzw. Positionierung der Photovoltaikmodule 20 sowie die Ausbildung der Photovoltaikmodule 20 die Konzentratorverstärkung und den Akzeptanzwinkel.

Also any,

• - In particular arbitrary to the focal plane or focal plane of the mirror body 10 angled and / or
• - In particular arbitrarily mutually angled arrangement of the photovoltaic absorber means 20 is possible (cf. 3E ). This is determined by the geometric position or positioning of the photovoltaic modules 20 as well as the training of the photovoltaic modules 20 the concentrator gain and the acceptance angle.

From the exemplary presentation of the 3D and the 3E further states that the photovoltaic modules 20 also in the direction of the incoming light (in 3D and in 3E So up) can be arranged. In this way, directly incident light, otherwise through the photovoltaic modules 20 shielded would be additionally recorded with. This also applies to other arrangements of the photovoltaic absorber 20 , as for example 2H ,

In 2 B the dashed line forms the so-called envelope (= envelope or envelope) of the caustic, whereby the envelope is understood as the curve which touches each curve of the family of curves in a single point. The focal surface is the extension of the dot-dash line.

As 2E . 2F and 2I is removable, the tip of the caustic envelope or caustic envelope moves with the angle of incidence of the radiation, resulting in a spherical mirror arrangement in a very large compared to a parabolic mirror acceptance angle. This acceptance angle is then due to the geometric arrangement and shape of the photovoltaic modules 20 certainly.

In the embodiment according to 3D is illustrated by means of a the absorber material or absorber means 20 upstream or upstream or upstream refractive, optically transparent element in the beam direction 22 (= in 3D an example of a lens) of the conditional by the Kaustik acceptance angle can be further increased. This takes into account that the focal point or focal surface of the spherical mirror 10 with the obliquely incident light (cf. 2E and 2F ) wanders (cf. 2I ). By bringing on such an element 22 can therefore visually increases the effect of Kaustik and thus a larger acceptance angle can be obtained.

By means of an appropriately trained tracking, for example in angular steps of about five degrees to about ten degrees, the acceptance angle can be much larger. Here, in a preferred manner, the photovoltaic module 20 inside the mirror calotte 10 according to the focal point migration (cf. 2I ), but not the entire mirror.

This is an essential difference in the Kaustik ausnützenden, the wandering focal point (see. 2I ) following a spherical mirror to a parabolic mirror according to the present invention and is due to the symmetry of the spherical mirror and the effect of Kaustik.

According to 2D . 2G and 2H the tip of the caustic is basically on the circle with radius R / 2. At oblique incidence of light, the tip of the caustic moves on this circle (cf. 2E . 2F . 2I ).

Will now according to 2H the photoabsorbers 20 mounted on a body with radius R / 2 and with a radius greater than R / 2, the caustic tip moves on obliquely incident light on this circular body, and in turn no tracking is required (see. 2H ). As a photoabsorber 20 Thin-film photomodules are best suited for this, because such thin-film photomodules can be applied to bodies of any shape.

The reinforcement over the caustic does not depend solely on the geometry and / or the shape of the photovoltaic modules 20 but also from the design of the mirror 10 , Is according to 2G in the outer marginal areas of the mirror 10 from the exact spherical shape of the mirror 10 towards a slightly parabolic shape of the mirror 10 Deviated, this slight deviation does affect the concentration at the top of the envelope.

This In other words, that still has a caustic effect Mixed forms in the design of the mirror essential to the invention Interest can be.

Alternatively or in addition to this can also from a parabolic shape of the mirror 10 by pressure over at least one (pressure) plate in a spherical shape of the mirror 10 be transferred. In this way, there is no clearly defined spherical mirror, but expediently a mixed form of parabolic mirror and spherical mirror. Should be a clearly spherical mirror 10 provided, the (pressure) plate has a spherical design, or the plastic mirror is thermoformed.

Based 2J (= Focal point in the parabolic mirror with vertical incident light) and 2K (= Focal point in the parabolic mirror with oblique, namely about fifteen degrees of incident light), the differences between the use of a spherical mirror 10 and the use of a parabolic mirror.

While in the parabolic mirror symmetry or perfection is achieved (only) with perpendicularly incident light, in the case of the spherical mirror 10 Symmetry (also) achieved with obliquely incident light, so that when obliquely incident light at the spherical mirror 10 no disintegration of the focal point, but only a shift, that is, "wandering" of the focal point takes place (see. 2I ).

The present invention is based on the use of this resulting from Kaustik migratory, but stable focus or this resulting from the Kaustik migratory, but stable focal surface, the wandering focal point or the migrating focal surface has the advantage that the spherical mirror 10 basically does not need to be tracked.

The representation in 3A is as well as the alternative representation in 3B removable, that the concentrator system 100 . 100 ' . 100 '' . 100 ' a cover formed for the purpose of translucence or optical transparency, for example, of (acrylic) glass 40 in the form of a cover plate, with the concave mirror 10 connected, in particular screwed, and may for example have an optical refractive index n of about 1.5 or higher.

To better exploit diffused and / or oblique incident light, the planar cover 40 (see. 1A . 1B . 3A . 3B . 5B ) be provided with at least one thin coating, in particular with at least one thin film and / or with at least one thin layer of different production methods for light deflection. This results in an equivalent or comparable effect as refractive effects of optically different you the media.

• – an der Oberseite und/oder an der Unterseite der Abdeckung 40 oder
• – an der Oberseite eines massiven, optisch transparenten Körpers 50 angeordnet sein.

By this optional technical measure, the angular range of the obliquely incident light can be increased. The thin films and / or thin layers can

• - at the top and / or bottom of the cover 40 or
• - at the top of a massive, optically transparent body 50 be arranged.

To the efficiency of photovoltaic or solar cells 20 is a hollow, with gas, for example, with air flowing through or by liquid, for example, water, heat sink passed through 30 provided on the one exemplary dimensioning of fifteen millimeters having solar cells 20 are mounted (see. 3C ).

Commercially are solar cells as plates in the format of about 150 millimeters up about 150 millimeters available; also solar cell bars with a dimension of about 15 millimeters to about 150 millimeters are commercially available and in the present invention used.

This cooling system, which is operated with gas, for example with air, and / or with liquid, for example with water, is basically optional, because at 3C Although achievable concentrator factor can be used with a cooling housing, but also without liquid.

This arrangement in the photovoltaic concentrator 100 . 100 ' . 100 '' . 100 ' allows the solar cells 20 even when not vertical (cf. 2C ), but diagonally (cf. 2E ) incident light without tracking the concentrator 100 . 100 ' . 100 '' . 100 ' illuminate. Furthermore, the caustic effect also causes scattered light and / or diffuse light a concentration of light in the focal surface and thus an optimal photovoltaic behavior not only in direct or oblique incidence of light, but also in diffused light and / or in scattered light. It should be remembered that obliquely incident light and diffused light are closest to northern European light conditions.

As with the device 100 . 100 ' . 100 '' . 100 ' According to the present invention, concentration ratios between a factor greater than 1 and higher factors are readily realizable (the actual concentration factor depends inter alia on the arrangement of the solar cells 20 in the burning surface), the silicon cost in the present invention is reduced by this factor over planar modules, thereby causing a significant cost reduction. In the embodiment according to 3C is a geometry factor of about 1: 3 reproduced.

In 4A . 4B and 4C is the cross section of one with a cover 40 in the form of a cover plate made of acrylic glass provided photovoltaic concentrator module 100 ' represented according to the present invention. The photoelement plates make it possible to have different widths for the photovoltaic absorber 20 provided.

• – in oder unterhalb der, insbesondere durch die Kaustik K bewirkten, Brennebene oder Brennfläche F des Spiegelkörpers 10 und/oder
• – zwischen der Brennebene oder Brennfläche F des Spiegelkörpers 10 und dem Scheitelpunkt des Spiegelkörpers 10 angeordnet, nämlich in Bezug auf den Spiegelkörper 10 statisch montiert sein.

In the present invention, the photovoltaic absorber agent 20 in principle

• - In or below, in particular caused by the Kaustik K, focal plane or focal plane F of the mirror body 10 and or
• Between the focal plane or focal plane F of the mirror body 10 and the vertex of the mirror body 10 arranged, namely with respect to the mirror body 10 be statically mounted.

According to the 4A . 4B and 4C illustrated embodiment of the device 100 ' is the photovoltaic module designed as an exemplary dimensioning of about two centimeters to about ten centimeters photovoltaic absorber means 20 in the direction of the incident light L (and in the direction of reflected light) a refractive, optically transparent element 22 in the form of a (collecting) lens made of acrylic glass upstream (in 4C is accordingly a lens mounting post 32 between the condenser lens 22 and the acrylic cover plate 40 arranged).

In this case, an upstream optical element 22 is the photovoltaic absorber agent 20 between the focal plane or focal surface F of the mirror body 10 and the center M of the mirror body 10 arranged, namely with respect to the mirror body 10 statically mounted. According to 4A and 4B the radius of the lens is measured 22 to R / 2, where R is the radius of the designed as Polysterol Spiegelkalotte mirror body 10 is. The at least one (collecting) lens 22 Optionally, it can also be combined with at least one upstream and / or downstream diverging lens. In certain applications, it is also useful to the absorber 20 defocused, that is slightly offset to the dome center M to arrange.

In 5B is the cross section of a photovoltaic concentrator module 100 represented according to the present invention. This module-shaped device 100 has a concave trough-shaped or trough-shaped, in cross-section spherical or approximately parabolic curved mirror 10 as well as a cover plate 40 on, at the mirror 10 facing bottom underside of the rectangular cross-section heat sink 30 is attached, in its lower part, in turn, the solar cells 20 are arranged laterally bar-shaped.

Alternatively or additionally, an attachment of the heat sink 30 also at the bottom of the mirror 10 be made in the vertex.

The cooling element arranged below the focal point, for example 30 may be formed of aluminum and have an exemplary dimension of fifteen millimeters to twenty millimeters to two millimeters.

Such, based 5B illustrated arrangement 100 is mechanically simple and inexpensive to implement, requires no (or only a very simple internal) tracking and has a closed, flat surface in the form of the cover plate 40 , as is not uncommon in conventional planar systems.

Because of the effect of the mirror 10 and the associated caustics of the entire concentrator body 50 it is clear in its interior, that is 1A to 5C also illustrated the system substantially more independent of the problem of partial shading, which adversely affects the operation of conventional planar systems.

A based 5C illustrated photovoltaic concentrator array or panel 200 According to the present invention, a plurality of (in 5C three examples) of the 5B shown modular photovoltaic devices 100 under a closed planar surface 40 on.

Of the Modular construction of the present invention makes it possible not only, the carrier body directly in a carrier frame but also allows the use of solar cells other materials than silicon. This distinguishes the present Photovoltaic concentrator very much of conventional concentrator setups and is also a prerequisite for a "service friendliness" of System.

The constructed photovoltaic field or photovoltaic panel 200 (see. 5C ) has an exemplary area of about one square meter and may, for example, comprise twenty individual modules, each having an exemplary dimension of about one hundred millimeters to about five hundred millimeters.

Due to its planar surface, such a photovoltaic panel or panel can 200 (see. 5C ) are mounted firmly on a building, for example integrated into the roof of a building.

With the present invention, solar current gain factors between about 3 (<-> higher acceptance angle) and about 6 can be achieved. Typical radii of the spherical mirrors 10 can be between about six centimeters and about ten centimeters, which corresponds to a typical height of the concentrator between about four centimeters and about six centimeters.

at a solar power amplification factor of about four can with The present invention provides a silicon savings of about 75 percent be achieved; at higher amplification factors the cost reduction improves.

All in all includes the present invention in monocrystalline photovoltaic modules a savings potential of about 25 percent to about 35 percent (where an increase in efficiency of the concentrator by improvement the working point of the photovoltaic module not yet is taken into account).

• – in einer Kostenreduktion für das photovoltaische Material,
• – durch die Kaustik in einem Konzentratoraufbau ohne Notwendigkeit der Nachführung des konzentrierenden Elements,
• – in einem flachen Aufbau des Konzentrators (exemplarische Bauhöhe: etwa fünf Zentimeter) und
• – in einer planaren Oberfläche resultiert.

In summary, it can be stated that the spherical shape of the mirror calotte 10 as a concentrator for the photovoltaic modules

• In a cost reduction for the photovoltaic material,
• By the caustic in a concentrator structure without the need for tracking the concentrating element,
• - in a flat construction of the concentrator (exemplary height: about five centimeters) and
• - results in a planar surface.

100

Device for concentrating incident light, in particular sunlight (= embodiment according to 2 B . 3C . 5B )

100 '

Device for concentrating incident light, in particular sunlight (= embodiment according to 3D )

100 ''

Device for concentrating incident light, in particular sunlight (= embodiment according to 3E )

100 '

Device for concentrating incident light, in particular sunlight (= embodiment according to 4A . 4B . 4C )

200

photovoltaic field or photovoltaic panel

10

concave mirror or mirrors, in particular mirror bodies or mirroring

12

Breakpoint, in particular mounting block (= embodiment according to 1A )

14

Breakpoint, in particular Befestigungsnut (= embodiment according to 1B )

16

optically active surface, in particular the concave mirror or mirror 10 (= Embodiment according to 3B )

18

optically inactive surface, in particular of the concave mirror or mirror 10 (= Embodiment according to 3B )

20

photovoltaic Absorber, in particular photovoltaic element or solar cell, for Example solar cell plate or solar cell latch

22

photorefractive Element, in particular optically transparent refractive body, for Example lens or prism

30

cooling device or coolant

32

Spacer or mounting post, in particular between refractive element 22 and cover 40

40

Cover, in particular (Ab-) cover plate or clamping surface or (top) surface, for Example planar and / or transparent (Ab-) cover plate or clamping surface or level closed surface, such as acrylic sheet or plexiglass plate or polyester plate or polysterol plate or polystyrene sheet

50

hollow body or body

F

Focal point or focal plane or focal plane (= embodiment according to 4A )

K

Kaustik (= embodiment according to 4A )

L

Light or incidence of light (= embodiment according to 4A )

M

Center point (= embodiment according to 4A )

R

Radius (= embodiment according to 4A )

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 20220390 U1 [0001, 0017]
• WO 89/05520 A1 [0018]
• EP 0059464 A1 [0019]
• - DE 19508071 A1 [0020]
• US 4115149 [0021]
• US 4173968 [0021]
• US 4191164 [0021]
• US 4388481 [0021]
• US 5062899 [0021]
• US 5344496 [0021]
• WO 78/00019 A1 [0021]
• WO 83/01292 A1 [0021]
• WO 90/10182 A1 [0021]
• WO 96/24014 A1 [0021]
• WO 97/00408 A2 [0021]
• WO 2004/109195 A2 [0021]

Cited non-patent literature

• - http://en.wikipedia.org/wiki/Kaustik_(Optik) [0028]
• - Carl Ernst Heinrich Grimsehl, Walter Schallreuter and Rudolf Seeliger wrote "Lehrbuch der Physik", Volume 3: Optics, Verlag Teubner, 14th Edition (1962) [0028]
• - Henrik Wann Jensen authored book "Realistic Image Synthesis Using Photon Mapping", published by AK Peters, Wellesley (July 2001) [0028]
• - Johannes Koffer, Institute of Applied Physics, Johannes-Kepler-University Linz, lecture "Light focusing by microspheres" held on March 31, 2005 [0028]

Claims (10)

For concentrating incident light, in particular sunlight, provided device ( 100 ; 100 '; 100 ''; 100 ' ), comprising at least one statically mounted channel or trough-shaped mirror body ( 10 ), by means of which the incident light on at least one photovoltaic absorber ( 20 ), in particular to at least one solar cell, for example to at least one solar cell plate or at least one solar cell latch, is deflectable, characterized in that the photovoltaic absorber means ( 20 ) - in or below the / r, in particular caused by the Kaustik wandering, focal point or focal plane or focal surface of the mirror body ( 10 ) or - between the focal point or focal plane or focal plane of the mirror body ( 10 ) and the vertex of the mirror body ( 10 ) or - if at least one of the photovoltaic absorber means ( 20 ) in the direction of the incident light and / or in the direction of reflected light upstream refractive, in particular optically transparent, element ( 22 ), for example at least one prism or at least one lens, such as at least one converging lens, optionally also in combination with at least one diverging lens, between the focal point or focal plane or focal plane of the mirror body ( 10 ) and the center of the mirror body ( 10 ), in particular with respect to the mirror body ( 10 ) is statically mounted. Device according to claim 1, characterized by, in particular, by the caustic and / or by the curving focal point or focal plane or focal plane of the mirror body resulting from the caustic (s) ( 10 ), tracking freedom, in particular of the photovoltaic absorber ( 20 ), or - by at least one tracking device for, in particular according to the focus or focal plane or Brennflächenwanderung carried out, tracking the photovoltaic absorber means ( 20 ), in particular within the dome of the mirror body ( 10 ), for example in angular increments of about five degrees to about ten degrees. Device according to claim 1 or 2, characterized by at least one hollow body filled with gas, for example with air, or with liquid, for example with water, or by at least one solid, optically transparent body ( 50 ), wherein the mirror body ( 10 ) in the hollow body or in the body ( 50 ) can be integrated. Device according to at least one of claims 1 to 3, characterized in that - the mirror body ( 10 ) is at least spherically and / or at least approximately parabolic in cross-section, in particular in cross-section in its outer edge regions of a spherical shape in one, for example approximately or slightly, parabolic shape passes or vice versa, or - that - the mirror body ( 10 ) substantially or almost at least one of the photovoltaic absorber means ( 20 ) optically active surface ( 16 ) and - at least one optically inactive surface ( 18 ), in particular the mirror body ( 10 ), to the optically active surface ( 16 ) is formed substantially or approximately perpendicular, in particular to a high packing density of the mirror body ( 10 ) and / or the photovoltaic absorber agent ( 20 ). Device according to at least one of claims 1 to 4, characterized by at least one, in particular in the body or in the hollow body ( 50 ) integrated, cooling device ( 30 ), for example of aluminum, wherein the photovoltaic absorber ( 20 ) at the cooling device ( 30 ), in particular - substantially parallel or - substantially perpendicular or - at least an arbitrary angle to the focal point or focal plane or focal plane of the mirror body ( 10 ), can be arranged. Device according to at least one of claims 1 to 5, characterized by at least one mirror body ( 10 ) including the photovoltaic absorber agent ( 20 ) covering, optically transparent cover ( 40 ), in particular cover plate or clamping surface, for example made of acrylic or glass, wherein the cover ( 40 ) can be provided with at least one light-deflecting coating, in particular with at least one light-deflecting film and / or with at least one light-deflecting layer, wherein the light-deflecting coating - on the photovoltaic absorber means ( 20 ) facing side of the cover ( 40 ) and / or at the photovoltaic absorber means ( 20 ) facing away from the cover ( 40 ) or - at the top of the solid, optically transparent body ( 50 ) can be arranged. Device according to claim 5 and in particular according to claim 6, characterized in that the cooling device ( 30 ) - at the mirror body ( 10 ) facing the underside of the cover ( 40 ) and or - on the mirror body ( 10 ), in particular at the vertex of the mirror body ( 10 ), for example at the bottom of the mirror body ( 10 ) is arranged. Photovoltaic field or photovoltaic panel ( 200 ), comprising a plurality of devices ( 100 ; 100 '; 100 ''; 100 ' ) according to at least one of claims 1 to 7. Method for concentrating incident light, in particular sunlight, by means of the caustic effect of at least one statically mounted trough-shaped or trough-shaped mirror body ( 10 ), through which the incident light is directed to at least one relative to the mirror body ( 10 ) statically mounted photovoltaic absorber ( 20 ), in particular to at least one solar cell, for example to at least one solar cell plate or at least one solar cell latch, is deflected, characterized in that the photovoltaic absorber ( 20 ) - in or below the / r, in particular caused by the Kaustik wandering, focal point or focal plane or focal surface of the mirror body ( 10 ) or - between the focal point or focal plane or focal plane of the mirror body ( 10 ) and the vertex of the mirror body ( 10 ) or - if at least one of the photovoltaic absorber means ( 20 ) in the direction of the incident light and / or in the direction of reflected light upstream refractive, in particular optically transparent, element ( 22 ), for example at least one lens, such as at least one converging lens, or at least one prism, between the focal point or focal plane or focal plane of the mirror body ( 10 ) and the center of the mirror body ( 10 ) is located. Use of at least one device ( 100 ; 100 '; 100 ''; 100 ' ) according to at least one of claims 1 to 7 and / or at least one photovoltaic panel or photovoltaic panel ( 200 ) according to claim 8 for concentrating incident light, in particular sunlight, on at least one photovoltaic absorber means ( 20 ), in particular on at least one solar cell, for example on at least one solar cell plate or on at least one solar cell latch.