JPWO2009066720A1 - Solar cell module and solar power generation unit - Google Patents

Abstract

The solar cell module 1 of one embodiment of the present invention is separated from the solar cell element 30 that photoelectrically converts the irradiated sunlight Ls, the receiver substrate 20 on which the solar cell element 30 is placed, and the solar cell element 30. The primary optical system member 100 that transmits the sunlight Ls and irradiates the solar cell element 30 with the sunlight Ls, and is adjacent to the solar cell element 30 between the solar cell element 30 and the primary optical system member 100. The secondary optical system member 50 is arranged. A wall plate 200 placed on the receiver substrate 20 and inclined to the receiver substrate 20 at a first inclination angle θ1 of 45 degrees or more and connected to the primary optical system member 100, and formed on the surface of the wall plate 200 And a reflection surface 201 that reflects sunlight Ls transmitted from the primary optical system member 100.

Description

  The present invention includes a solar cell element that photoelectrically converts irradiated sunlight, and a primary optical system member that is arranged separately from the solar cell element and transmits sunlight to irradiate the solar cell element with sunlight. The present invention relates to a solar cell module and a photovoltaic power generation unit configured by arranging a plurality of such solar cell modules.

  As a solar power generation device, a non-condensing fixed plate type structure in which a solar cell module configured by laying solar cell elements without gaps is installed on a roof or the like is generally used. On the other hand, a technique for reducing the amount of high-priced solar cell elements among members (parts) constituting the solar power generation apparatus has been proposed.

  In other words, sunlight is collected using an optical lens, a reflecting mirror, and the like, and the solar cell element having a small area is irradiated to increase the generated power per area of the solar cell element. It has been proposed to reduce the cost of solar power generation equipment.

  The photoelectric conversion efficiency of a solar cell element improves as the concentration factor increases as element characteristics. However, if the position of the solar cell element is fixed, sunlight often enters as oblique light, and sunlight cannot be used effectively. Therefore, a tracking and concentrating solar power generation device with a high condensing magnification configured to track the sun and always receive sunlight in front has been proposed.

  FIG. 7: is sectional drawing which shows the structure of the solar cell module as the prior art example 1 applied to a tracking concentrating solar power generation device.

  The solar cell module 501 according to Conventional Example 1 receives sunlight Ls (sunlight Lsv) and collects the condensing lens 142 and sunlight Ls (sunlight Lsd) collected by the condensing lens 142. And a solar cell element 530 for photoelectric conversion. Moreover, the solar cell element 530 is placed on the receiver substrate 520. The condensing lens 142 is configured to have a focal position FP on the back side of the solar cell element 530.

  The conventional tracking concentrating solar power generation apparatus employs the solar cell module 501 having a high condensing magnification by the action of the condensing lens 142.

  In the tracking concentrating solar power generation device with high condensing magnification to which the solar cell module 501 according to Conventional Example 1 is applied, the working distance Dw from the condensing lens 142 to the surface of the solar cell element 530 is large. And the shape of the housing | casing (not shown) which fixes the correlation position of the solar cell element 530 becomes large.

  Therefore, the volume and weight of the solar cell module 501 are increased, resulting in a higher module material cost. Further, as the module weight increases, there is a problem that a high tracking drive capability is required, and the overall cost including the manufacturing cost and the operating cost increases. That is, reducing the weight of the solar cell module has been an important issue.

  In order to solve the problem of Conventional Example 1, a secondary optical system member is generally provided between the condenser lens and the solar cell element.

  Specifically, a structure using a convex lens as a secondary optical system member immediately above the surface of the solar cell element has been proposed (see, for example, Patent Document 1). In addition to a convex lens, a biconvex lens, a plano-convex lens, or a rhombus lens may be used.

  Further, there has been proposed a structure in which another similar Fresnel lens is overlapped with the Fresnel lens of the primary optical system member (see, for example, Patent Document 2).

  However, when a biconvex lens or plano-convex lens is used as the secondary optical system member, the problem of chromatic aberration is worsened, or the amount of incident light on the solar cell element is reduced due to reflection / transmission loss at the secondary optical system member. The problem that it falls is caused.

  In the method disclosed in Patent Document 1, since all the light incident on the solar cell element is transmitted through the secondary optical system member, there is a reflection / transmission loss due to the secondary optical system member. There is a problem that the amount of incident light is substantially reduced.

  Further, in the method disclosed in Patent Document 2, since all the light incident on the solar cell element is transmitted through the secondary optical system member, there is a problem similar to the method disclosed in Patent Document 1. .

  Further, the light collected by the primary optical system member (condensing lens) is taken into the secondary optical system member made of a light-transmitting material disposed immediately above the solar cell element, and totally reflected by the side surface. A structure to be collected on the surface of the battery element is disclosed (for example, see Patent Document 3 and Patent Document 4). For example, the technique described in Patent Document 3 will be described below as Conventional Example 2.

  FIG. 8 is an explanatory diagram showing a configuration of a solar cell module as Conventional Example 2 applied to a tracking concentrating solar power generation device.

  The solar cell module 600 according to Conventional Example 2 further includes a Fresnel lens 601 as a primary optical system member, a module holding unit 602 that functions as a casing of the solar cell module 600, and sunlight Ls collected by the Fresnel lens 601. A reflecting mirror 603 composed of a funnel-shaped aluminum alloy plate that converges, a secondary optical system member 610 that irradiates the solar cell element 620 while guiding the sunlight Ls focused by the reflecting mirror 603 while reflecting it from the side surface, the sun A circuit board 630 on which the battery element 620 is placed is provided.

  That is, the reflecting mirror 603 and the secondary optical system member 610 are provided in addition to the primary optical system member 601 and the module holding unit 602. Accordingly, the same problem as in the conventional example 1 occurs, and the configuration of the optical system is complicated, so that the manufacturing process becomes complicated and the cost in the manufacturing process increases.

  In other words, the methods disclosed in Patent Document 3 and Patent Document 4 are effective in solving the problems of alignment error, chromatic aberration, and light intensity distribution, but for total reflection on the side surface of the secondary optical system member. It is necessary to increase the incident angle to the side surface. Therefore, it is necessary to increase the focal length of the primary optical system member and to install the secondary optical system member and the solar cell element away from the primary optical system member. As a result, the working distance Dw ( (This is omitted in FIG. 8), which increases the overall weight.

  The increase in the working distance Dw of the solar cell module and the increase in weight leads to an increase in the size of the tracking mechanism unit (tracking drive system) that drives the solar cell module mounted thereon, and the cost of the tracking concentrating solar power generation device Causing inconveniences such as lowering operating performance such as up, handling difficulty, maintenance difficulty.

  Further, in the methods disclosed in Patent Document 3 and Patent Document 4, the incident light is incident on the solar cell element due to the reflection loss at the incident end face and the exit end face of the secondary optical system member and the transmission loss of the secondary optical system member. There is the same problem as Patent Document 1 and Patent Document 2 in that the amount of light decreases.

  In particular, in the case shown as Conventional Example 2 in FIG. 8, a funnel-shaped reflecting mirror 603 that can be easily manufactured at low cost by pressing an aluminum alloy plate is provided to reduce the influence of tracking errors and the like. I am trying. However, since only the sunlight Ls condensed by the primary optical system member (Fresnel lens 601) can be used, sunlight Ls other than the sunlight Ls incident on the reflecting mirror 603 and not condensed on the Fresnel lens 601. It is impossible to focus the sunlight Ls, and the improvement effect is limited.

  Further, in the method using the secondary optical system member described above, the secondary optical system member directly receives sunlight concentrated at high density by the primary optical system member, so that the secondary optical system member is configured. There is a problem that high heat resistance is required for the material (raw material) to be produced, resulting in an increase in the cost of the apparatus.

  In addition, in the conventional solar cell module, particularly when the concentration ratio is high, the energy density of the collected light beam is increased, and the sunlight concentrated on the area other than the solar cell element due to a tracking error or the like is irradiated. Then, members (parts such as wiring) other than the solar cell element are burned out, and there is a possibility that the glass arranged as the optical member is broken. That is, there is a problem that it is not possible to obtain a tracking and concentrating solar power generation device having sufficient reliability. In addition, there is a problem that a sufficient heat dissipation measure for these has not been proposed yet.

A Fresnel lens is generally used as a condensing lens. However, the groove (tooth boundary) of the Fresnel lens is slightly deformed due to the influence of processing accuracy, temperature characteristics, and the like. Therefore, it is difficult to completely collect the sunlight Lsv incident from the vertical direction, and a part of the sunlight Lsv becomes scattered light Lss so that the solar cell element is not irradiated, resulting in a decrease in light collection efficiency. Has brought. Further, as is clear from the above-described conventional example, the sunlight Ls irradiated to the solar cell element is limited to the direct light Lsd, and the light collection efficiency is limited.
US Pat. No. 5,167,724 US Pat. No. 6,653,551 JP 2002-289897 A JP 2003-258291 A

  The present invention has been made in view of such a situation, and it is possible to reduce the weight with a simple structure to improve the operation performance, and to improve the positioning of the solar cell element and the primary optical system member, An object of the present invention is to provide a solar cell module in which the scattered light is reflected in addition to the direct light to increase the amount of sunlight irradiated to the solar cell element, thereby improving the light collection efficiency and thus the power generation efficiency.

  Another object of the present invention is to provide a solar power generation unit that efficiently irradiates the solar cell element with direct light and scattered light to improve the light collection efficiency and thus the power generation efficiency, and improve the operation performance by reducing the weight. The purpose.

  The solar cell module according to the present invention is a solar cell element that photoelectrically converts irradiated sunlight, a receiver substrate on which the solar cell element is placed, and a solar cell module that is arranged separately from the solar cell element and transmits sunlight. A solar cell module comprising a primary optical system member that irradiates solar cell elements with sunlight, and is placed on the receiver substrate and tilted at a first tilt angle of 45 degrees or more with respect to the receiver substrate. A wall plate portion connected to the primary optical system member, and a reflective surface that is formed on the surface of the wall plate portion and reflects sunlight transmitted from the primary optical system member. It is characterized by being formed of a selective reflection film having a reflection characteristic that acts on the wavelength region.

  With this configuration, it is possible to reduce the weight with a simple structure and improve the operation performance. Further, the positioning of the solar cell element and the primary optical system member is improved in accuracy, and the scattered light is reflected in addition to the direct light. It is possible to obtain a solar cell module in which the amount of sunlight irradiated to the battery element is increased to improve the light collection efficiency and thus the power generation efficiency. Furthermore, it is possible to reflect only the sunlight in the wavelength region that effectively acts on photoelectric conversion in the solar cell element to the solar cell element, and the sunlight in the unnecessary wavelength region can be prevented from condensing on the solar cell element. It is possible to improve power generation efficiency and heat resistance.

  In the solar cell module according to the present invention, the wall plate portion is configured to support the primary optical system member.

  With this configuration, it is possible to simplify the structure and secure the strength, so it is possible to simplify the manufacturing process, reduce the number of manufacturing steps, and arrange a plurality of solar cell modules in parallel to achieve a large capacity. The solar power generation unit can be easily configured.

  In the solar cell module according to the present invention, the wall plate portion is made of a non-metallic material.

  With this configuration, the weight can be reduced and the workability can be improved, so that the handling during the manufacturing process or operation can be facilitated.

  In the solar cell module according to the present invention, the primary optical system member includes a condenser lens.

  With this configuration, the light collection efficiency can be further improved.

  In the solar cell module according to the present invention, the selective reflection film transmits sunlight having a wavelength of more than 1200 nm and reflects sunlight having a wavelength of 1200 nm or less.

  With this configuration, it is possible to prevent a temperature rise in the solar cell element due to sunlight in a long wavelength region that does not contribute to photoelectric conversion, and it is possible to improve temperature characteristics and power generation efficiency.

  In the solar cell module according to the present invention, the selective reflection film may be configured to transmit sunlight having a wavelength of more than 1380 nm and reflect sunlight having a wavelength of 1380 nm or less.

  In absorption by the atmospheric layer, there is a valley-shaped spectrum in the vicinity of the wavelength region of 1380 nm. By setting the reflection wavelength threshold of the selective reflection film to 1380 nm, even if there is some variation in film thickness or refractive index, the influence of the reflection characteristic of the selective reflection film is reduced, and the stability of the reflection characteristic of the selective reflection film is improved. Improved.

  In addition, the solar cell module according to the present invention includes a secondary optical system member that is arranged in the vicinity of the solar cell element and focuses the sunlight transmitted through the primary optical system member.

  With this configuration, chromatic aberration and intensity unevenness can be averaged, and the deterioration of the characteristics of the solar cell element due to the high energy density of the concentrated sunlight can be prevented, and the reliability of photoelectric conversion can be improved. .

  The solar power generation unit according to the present invention is a solar power generation unit configured by arranging a plurality of solar cell modules, wherein the solar cell module is the solar cell module according to the present invention. To do.

  With this configuration, it is possible to obtain a photovoltaic power generation unit that efficiently irradiates the solar cell element with direct light and scattered light to improve the light collection efficiency and thus the power generation efficiency, and improve the operation performance by reducing the weight.

  The solar cell module according to the present invention is a solar cell element that photoelectrically converts irradiated sunlight, a receiver substrate on which the solar cell element is placed, and a solar cell module that is arranged separately from the solar cell element and transmits sunlight. A solar cell module including a primary optical system member that irradiates solar cell elements with sunlight, and is placed on a receiver substrate and tilted at a first inclination angle of 45 degrees or more with respect to the receiver substrate. A wall plate portion connected to the system member, and a reflection surface that is formed on the surface of the wall plate portion and reflects sunlight transmitted from the primary optical system member. It is formed of a selective reflection film having reflective characteristics that act.

  Therefore, according to the solar cell module of the present invention, it is possible to reduce the weight with a simple structure to improve the operation performance, and to improve the positioning of the solar cell element and the primary optical system member so that direct light can be obtained. In addition, the scattered light is reflected to increase the amount of sunlight irradiated to the solar cell element, improving the light collection efficiency, and further, only the sunlight in the wavelength region that effectively acts on photoelectric conversion in the solar cell element. It is possible to provide a solar cell module with improved power generation efficiency and heat resistance because sunlight in an unnecessary wavelength region is reflected on the solar cell element and can be prevented from condensing on the solar cell element. There is an effect that it becomes possible.

  Moreover, according to the photovoltaic power generation unit according to the present invention, a plurality of solar cell modules according to the present invention are arranged to form a photovoltaic power generation unit, so that direct solar light and scattered light are efficiently irradiated to the solar cell element. There is an effect that it is possible to provide a photovoltaic power generation unit that improves the light collection efficiency and, in turn, the power generation efficiency and improves the operation performance by reducing the weight.

It is a see-through | perspective side view which shows the outline of the whole structure of the solar cell module which concerns on Embodiment 1 of this invention transparently. It is a see-through | perspective side view which shows in perspective the outline of the mounting state of the solar cell element of the solar cell module shown in FIG. 1, and the structure of a secondary optical system member. It is a see-through | perspective side view which shows the outline of the whole structure of the solar cell module which concerns on Embodiment 2 of this invention transparently. It is a see-through | perspective side view which shows the outline of the whole structure of the solar cell module which concerns on Embodiment 3 of this invention transparently. It is a see-through | perspective side view which shows the outline of the whole structure of the solar cell module which concerns on Embodiment 4 of this invention transparently. It is a perspective view which shows the outline of the whole structure of the photovoltaic power generation unit which concerns on Embodiment 6 of this invention overhead. It is sectional drawing which shows the structure of the solar cell module as the prior art example 1 applied to a tracking concentrating solar power generation device. It is explanatory drawing which shows the structure of the solar cell module as the prior art example 2 applied to a tracking concentrating solar power generation device. It is a figure for demonstrating Embodiment 7 of this invention, and is the spectrum of the direct light currently disclosed by the American Standards Association.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell module 10 Plate 11 Radiation fin 20 Receiver board 30 Solar cell 30s Solar cell 35 Resin sealing frame 36 Resin sealing part 37 Translucent coating plate 50 Secondary optical system member 50s Convex curved surface 51 Secondary optical system holder DESCRIPTION OF SYMBOLS 100 Primary optical system member 101 Plate glass 102 Fresnel lens 103 Antireflection film 200 Wall board part 201 Reflective surface (selective reflection film)
300 Photovoltaic power generation unit 310 Long frame Ls Sunlight Lsv Sunlight Lsd Direct light (sunlight)
Lss scattered light (sunlight)
Lsi Sunlight Roth Horizontal rotation Rotv Vertical rotation θ1 First tilt angle θ2 Second tilt angle

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Embodiment 1>
Based on FIG. 1 and FIG. 2, the solar cell module which concerns on this Embodiment is demonstrated.

  FIG. 1 is a perspective side view schematically showing the overall configuration of the solar cell module according to Embodiment 1 of the present invention.

  Solar cell module 1 according to the present embodiment is separated from solar cell element 30 that photoelectrically converts irradiated sunlight Ls, receiver substrate 20 on which solar cell element 30 is placed, and solar cell element 30. A primary optical system member 100 that is disposed and transmits sunlight Ls and irradiates solar cell element 30 with sunlight Ls.

  The solar cell element 30 is, for example, a three-junction compound semiconductor tandem solar cell (element) having a layer structure of InGaP / InGaAs / Ge. The solar cell element 30 is mounted on a receiver substrate 20 made of an aluminum plate, and the receiver substrate 20 is attached to a plate 10 that includes the radiation fins 11 and serves as a hit sink.

  In the present embodiment, a secondary optical system member 50 disposed adjacent to the solar cell element 30 is provided between the solar cell element 30 and the primary optical system member 100. The surface of the secondary optical system member 50 facing the primary optical system member 100 has a shape having a gentle convex curved surface 50 s, and the sunlight Ls irradiated to the convex curved surface 50 s is focused on the solar cell element 30. It is supposed to be configured.

  The secondary optical system member 50 is positioned and fixed with respect to the solar cell element 30 by the secondary optical system holder 51. Details of the secondary optical system member 50 will be described with reference to FIG.

  The primary optical system member 100 is a plate glass 101 that functions as a basic structure, a Fresnel lens 102 that functions as a condensing lens for the solar cell element 30 and is disposed on the solar cell element 30 side with respect to the plate glass 101, and the outside of the plate glass 101. The antireflection film 103 is disposed on the surface and prevents reflection of sunlight Ls on the external surface. Since the primary optical system member 100 includes the condensing lens, it is possible to further improve the condensing efficiency.

  The solar cell module 1 according to the present embodiment includes a wall plate 200 as a means for mechanically connecting the primary optical system member 100 and the solar cell element 30 and fixing the correlation position. In addition, a reflection surface 201 is formed on the wall plate portion 200.

  That is, the solar cell module 1 is mounted on the receiver substrate 20 and inclined with a first inclination angle θ1 of 45 degrees or more with respect to the receiver substrate 20 and connected to the primary optical system member 100, And a reflecting surface 201 that is formed on the surface of the wall plate 200 and reflects sunlight Ls that has passed through the primary optical system member 100 and is incident thereon. Since the sunlight Ls is reflected by the reflecting surface 201 having the first inclination angle θ1 of 45 degrees or more, the amount of irradiation light that is reliably focused to the solar cell element 30 side by multiple reflection and is irradiated to the solar cell element 30. Will be increased.

  In addition, since the wall plate part 200 is provided between the primary optical system member 100 and the solar cell element 30, a housing that protects the space between the primary optical system member 100 and the solar cell element 30 is not required and is lightweight. Can be achieved. That is, the space constituted by the primary optical system member 100 and the wall plate portion 200 is a structure and can be effectively used as a space for concentrating and focusing sunlight as it is. Cost and weight can be reduced.

  Moreover, since sunlight Ls is reflected in the solar cell element 30 direction by the reflective surface 201, the position of the solar cell element 30 (receiver board | substrate 20) with respect to the focus position FP (refer FIG. 7) of the Fresnel lens 102 is highly accurate. It is not necessary to control, and it is possible to reduce the distance (working distance Dw) between the solar cell element 30 and the primary optical system member 100, and further, it is possible to reduce the weight and thickness.

  Therefore, the weight can be reduced with a simple structure to improve the operation performance, and the positioning of the solar cell element 30 and the primary optical system member 100 is highly accurate, and the scattered light Lss is reflected in addition to the direct light Lsd. Thus, the amount of sunlight Ls applied to the solar cell element 30 can be increased, and the light collection efficiency and thus the power generation efficiency can be improved.

  That is, in the present embodiment, by providing the wall plate portion 200 and the reflection surface 201, it is possible to irradiate the solar cell element 30 also with respect to the scattered light Lss. Therefore, it is possible to obtain the solar cell module 1 in which the power generation efficiency and the operation performance are improved by suppressing the influence of the accuracy and temperature characteristics of the Fresnel lens 102. In addition, by improving the operation performance accompanying the weight reduction of the solar cell module 1, for example, it becomes possible to reduce the ratio of the driving load in the tracking drive to the generated power.

  As described above, the sunlight Ls (Lsv) incident perpendicularly to the light receiving surface of the primary optical system member 100 is condensed by the primary optical system member 100 and directed to the secondary optical system member 50 (solar cell element 30). The direct light Lsd that is directly irradiated and the scattered light Lss that is not condensed by the Fresnel lens 102 because it is incident on the interdental boundary region of the Fresnel lens 102 are roughly divided. Further, the sunlight Ls (Lsi) incident on the light receiving surface of the primary optical system member 100 from an oblique direction is not collected by the Fresnel lens 102 and thus becomes scattered light Lss.

  The direct light Lsd is condensed toward the secondary optical system member 50 and irradiated to the solar cell element 30. On the other hand, the scattered light Lss is not condensed toward the secondary optical system member 50. However, the scattered light Lss is reflected (multiple reflected) in the direction of the solar cell element 30 by the reflecting surface 201 formed on the surface of the wall plate part 200 and focused on the secondary optical system member 50. Since the wall plate part 200 is inclined at a first inclination angle θ1 of 45 degrees or more with respect to the receiver substrate 20 (light receiving surface of the solar cell element 30), the scattered light Lss is transmitted to the secondary optical system member 50. It becomes possible to focus on the accuracy and irradiate the solar cell element 30.

  That is, in the present embodiment, the direct optical light Lsd collected by the primary optical system member 100 and the scattered light Lss focused by the reflecting surface 201 are irradiated to the secondary optical system member 50 (solar cell element 30). Thus, the light collection efficiency and the power generation efficiency can be improved.

  The first inclination angle θ1 is appropriately determined within the range of 45 degrees or more and less than 90 degrees in consideration of the distance between the solar cell element 30 and the primary optical system member 100, the characteristics of the reflection surface 201, and the like. It is possible.

  The wall plate portion 200 is desirably configured to have a strength to support the primary optical system member 100. With this configuration, the structure can be simplified and the strength can be ensured. Therefore, the manufacturing process can be simplified, the number of manufacturing steps can be reduced, and a plurality of solar cell modules 1 can be arranged side by side. A solar power generation unit with a capacity can be easily configured.

  The wall plate 200 is preferably formed of a non-metallic material such as a flame retardant thermoplastic polyester resin. With this configuration, it is possible to reduce the weight of the solar cell module 1 and to improve the workability. Therefore, it is possible to facilitate the handling during the manufacturing process or operation, and to realize cost reduction. .

  The reflective surface 201 is configured by laminating a high reflectivity film having a high reflectivity by laminating a plurality of polymer material films (translucent films) having different refractive indexes on the wall plate portion 200. . That is, the reflective surface 201 can be formed by a high reflectivity film formed by stacking two types of polymer materials that are non-metallic films.

  The high reflectivity film is made of, for example, a polyester resin (2-vinyltetrahydrofuran) as the first polymer material, and a polymer material composed of 2,3-naphthalenedicarboxylic acid and ethylene glycol as the second polymer material. It can be formed by stacking.

  For example, the refractive index of the polyester resin (2-vinyltetrahydrofuran) is about 1.55, and the thickness of the single layer film is about 145 nm. In addition, the refractive index of the polymer material made of 2,3-naphthalenedicarboxylic acid and ethylene glycol was about 1.88, and the thickness of the single layer film was about 120 nm. A reflective surface 201 was formed by pasting the high reflectivity film formed by alternately stacking, for example, 50 to 500 layers of these two types of polymer material films (translucent films) on the wall plate portion 200.

  In addition, each of the single layers is light-transmitting and includes a first polymer material (polyester resin (2-vinyltetrahydrofuran)) and a second polymer material (2,3-naphthalenedicarboxylic acid and ethylene glycol). As described later, it becomes possible to realize different optical characteristics for a specific wavelength region.

  That is, the reflective surface 201 (high reflectivity film) could be a selective reflection film (reflective surface 201) having reflection characteristics that act on a specific wavelength region.

  Therefore, only sunlight Ls in a wavelength region that effectively acts on photoelectric conversion in the solar cell element 30 is reflected to the solar cell element 30, and sunlight Ls in an unnecessary wavelength region that does not contribute to photoelectric conversion is directed to the solar cell element 30. It is possible to prevent the condensing of light and improve the power generation efficiency and heat resistance.

  The selective reflection film (high reflectivity film) formed by the combination of the first polymer material and the second polymer material described above transmits sunlight Ls having a wavelength of over 1200 nm and sunlight Ls having a wavelength of 1200 nm or less. Can be reflected.

  Therefore, it is possible to prevent a temperature rise in the solar cell element 30 due to sunlight Ls in a long wavelength region (wavelength of over 1200 nm) that does not contribute to photoelectric conversion, and it is possible to improve temperature characteristics and power generation efficiency.

  The selective reflection film (high reflectance film) formed by the combination of the first polymer material and the second polymer material described above has a reflectance of 90% or more with respect to sunlight Ls having a wavelength of 1200 nm or less. It was possible to do. Therefore, it is possible to reliably and easily realize the reflection of the sunlight Ls at the selected specific wavelength.

  The condition for setting the reflectance of the selective reflection film to 90% or more is influenced by the refractive index of the polymer material to be selected, but is not limited to the combination of the two types of polymer materials described above, and for example, three types of high It can also be realized by a combination of molecular materials.

  The high reflectivity film (selective reflection film) constituting the reflection surface 201 can be formed, for example, by sticking a sheet (or film) to the wall plate portion 200 in a tile shape. That is, it is desirable that the high reflectance film (selective reflection film) is attached to the wall plate portion 200. With this configuration, it is possible to easily form a large-area reflecting surface 201 with good uniformity.

  As the high reflectance film, for example, an inorganic resist, a fluorine coating material, or the like can be applied in addition to the above-described combination of polymer materials. Moreover, according to the low-cost white film, selective reflection is difficult, but there is an effect of multiple reflection, and it can be applied as a high reflectance film.

  Further, it is desirable to coat a transparent silicone film on the high reflectance film. For example, when a high-reflectance film is attached to the wall plate 200 in a tile shape, it is desirable to form a silicone film at least locally with respect to the joint formed between the tiles. That is, the silicone film acts as a filler for the joints between the tiles, and the reflection characteristics can be further improved. The transparent silicone film is desirably formed before the secondary optical system member 50, the secondary optical system holder 51, and the like are disposed.

  The coating formation of the silicone film can be performed, for example, by spraying a silicone resin by spraying or the like. By forming the coating in a spray form, it is possible to reliably reduce the film thickness and make it uniform.

  The silicone film can also function as a sealant between the members. For example, it is possible to temporarily fix the positions of the respective members by spraying the transparent silicone resin in a state where the receiver substrate 20 and the wall plate portion 200 are positioned, and the optical positional deviation at the time of installation is reduced. Can be suppressed.

  Further, the selective reflection film (reflection surface 201) can be disposed in the entire light receiving surface area of the wall plate portion 200. Alternatively, a low-cost total reflection film (a reflection film having no selective characteristics with respect to the wavelength) is disposed in the light receiving surface region having a low light energy density, and a selective reflection film is disposed in the light receiving surface region having a high light energy density. Thus, the cost can be reduced.

  As described above, the solar cell element 30 is a three-junction compound semiconductor tandem solar cell (solar cell element) using InGaP / InGaAs / Ge. However, a solar cell element using other materials can also be used. is there. For example, the present invention can be similarly applied to solar cell elements made of other inorganic materials such as Si, GaAs, CuInGaSe, and CdTe.

  Moreover, as a structure of a solar cell element, it applies to structures of various forms such as a single-junction cell, a monolithic multi-junction cell, and a mechanical stack type in which various solar cell elements having different wavelength sensitivity regions are connected. It is possible.

  FIG. 2 is a perspective side view schematically showing the mounting state of the solar cell element of the solar cell module shown in FIG. 1 and the outline of the configuration of the secondary optical system member.

  The solar cell element 30 is bonded (connected) to the receiver substrate 20, is further resin-sealed with a resin sealing frame 35 and a resin sealing portion 36, and is bonded to the surface of the resin sealing portion 36. It is protected by a cover plate 37. The resin sealing frame 35 is formed using, for example, white silicone resin, the resin sealing portion 36 is formed using, for example, transparent silicone resin, and the translucent covering plate 37 is formed using, for example, glass.

  The secondary optical system holder 51 that holds the secondary optical system member 50 is bonded and fixed to, for example, a resin sealing frame 35. Further, the secondary optical system member 50 is brought into close contact with the translucent covering plate 37 so as not to cause a loss in the optical path. In addition, by arranging the secondary optical system member 50 and the secondary optical system holder 51 on the inner side with respect to the resin sealing frame 35, the sunlight Ls is not directly irradiated to the receiver substrate 20. The translucent cover plate 37 and the secondary optical system member 50 can be integrally formed.

  As described above, the secondary optical system member 50 disposed in the vicinity of the solar cell element 30 focuses the sunlight Ls transmitted through the primary optical system member 100 and incident through the convex curved surface 50s, and the solar cell. The element 30 is irradiated. That is, the solar cell element is provided through the resin sealing portion 36 and the translucent cover plate 37 in which the sunlight Ls having good uniformity is disposed inside the resin sealing frame 35 and seals the solar cell element 30. 30 is irradiated.

  Therefore, the sunlight Ls incident on the secondary optical system member 50 is mixed with the sunlight Ls in each wavelength region, chromatic aberration / intensity unevenness is averaged, photoelectric conversion efficiency is improved, and photoelectric conversion reliability is improved. It becomes possible to improve the property.

  Moreover, the secondary optical system member 50 can suppress the influence on the solar cell element 30 by the sunlight Ls condensed at a high energy density. That is, there is a possibility that the cell temperature of the solar cell element 30 is significantly increased due to the high energy density of the concentrated sunlight Ls, and the photoelectric conversion efficiency of the solar cell element 30 and the generated power may be reduced. By disposing the system member 50, it is possible to relax the high energy density and prevent the characteristics of the solar cell element 30 from deteriorating.

  The external size (chip size) of the solar cell element 30 is about several mm to about 10 mm from the viewpoints of reduction of the solar cell element material to be used, ease of processing, and ease / simplification of the manufacturing process. It is desirable to do.

  The current generated by the solar cell element 30 is appropriately taken out of the solar cell element 30 by wiring formed on the receiver substrate 20. Since the wiring formed on the receiver substrate 20 needs to ensure highly reliable insulation, for example, the connection pattern formed of copper foil is covered with an insulating film such as an organic material and insulated. Has been.

  The receiver substrate 20 is provided with wiring formed in a desired pattern via a suitable insulating layer on a base base such as an aluminum plate or a copper plate. That is, the wiring provided on the receiver substrate 20 is connected to an electrode (not shown) of the solar cell element 30 and includes a connection pattern (not shown) for taking out to the outside.

  By providing appropriate wiring to the connection pattern for taking out the receiver substrate 20 to the outside, a plurality of solar cell elements 30 can be connected in series / parallel, and a plurality of solar cell modules 1 are provided. A photovoltaic power generation unit 300 (see FIG. 6) can be formed.

  As described above, the secondary optical system member 50 is preferably made of glass, for example. By comprising glass, heat resistance and weather resistance can be improved, and focusing on sunlight Ls can be executed effectively. The secondary optical system holder 51 can be made of, for example, a synthetic resin or a metal member having the same quality as that of the wall plate 200 in consideration of mechanical strength, heat dissipation, and the like.

<Embodiment 2>
A solar cell module according to the present embodiment will be described based on FIG.

  FIG. 3 is a perspective side view schematically showing the overall configuration of the solar cell module according to Embodiment 2 of the present invention.

  Since the basic configuration and operational effects of the solar cell module 1 according to the present embodiment are the same as those of the solar cell module 1 according to the first embodiment, different items will be mainly described.

  In the present embodiment, the secondary optical system member 50 applied in the first embodiment is removed. Therefore, the wall plate part 200 irradiates the solar cell element 30 with sunlight Ls without passing through the secondary optical system member 50.

  Further, the inclination angle of the wall plate portion 200 is set to two stages. That is, the side closer to the solar cell element 30 (receiver substrate 20) with respect to the first tilt angle θ1 closer to the primary optical system member 100 (region corresponding to the secondary optical system member 50 of the first embodiment). The second inclination angle θ2 is further increased. Therefore, it is possible to reliably improve the reflectivity of sunlight Ls toward the solar cell element 30 on the side closer to the solar cell element 30 and to increase the amount of light applied to the solar cell element 30.

  Further, the reflection surface 201 is also formed on the region of the wall plate portion 200 that has the second inclination angle θ2. Therefore, it becomes possible to focus the sunlight Ls on the region where the second inclination angle θ2 is set, and to irradiate the solar cell element 30. Similarly to the first embodiment, the scattered light Lss is added to the direct light Lsd. Since the solar cell element 30 can be reflected and irradiated, the light collection efficiency can be improved and the power generation efficiency of the solar cell module 1 can be improved.

  Further, the wall surface 200 is formed with a reflective surface 201 (high reflectivity film), but unlike the first embodiment, the reflective surface 201 is not formed in a region close to the primary optical system member 100. It is said that. That is, it is possible to reduce the formation cost for the reflective surface 201 by omitting the formation of the reflective surface 201 in a region far from the solar cell element 30 and in which the effect of reflection of the scattered light Lss on the reflective surface 201 is small. It becomes.

  The resin sealing frame 35, the resin sealing portion 36, and the translucent covering portion 37 are the same as those in the first embodiment.

<Embodiment 3>
The solar cell module according to the present embodiment will be described based on FIG.

  FIG. 4 is a perspective side view schematically showing the overall configuration of the solar cell module according to Embodiment 3 of the present invention.

  Since the basic configuration and operational effects of the solar cell module 1 according to the present embodiment are the same as those of the solar cell module 1 according to the first and second embodiments, different points will be mainly described.

  In the present embodiment, the secondary optical system member 50 applied in the first embodiment is removed. Therefore, the wall plate part 200 irradiates the solar cell element 30s with sunlight Ls (scattered light Lss) without passing through the secondary optical system member 50.

  Further, the primary optical system member 100 is composed of a plate glass 101 and an antireflection film 103, and the Fresnel lens 102 is omitted. Therefore, the primary optical system member 100 does not perform so-called condensing.

  Therefore, the sunlight Ls irradiated to the solar cell element 30s can suppress the energy density as compared with the first embodiment and the second embodiment. Therefore, it is possible to apply a solar cell element 30s formed of a silicon-based material (for example, crystalline silicon) having a low photoelectric conversion efficiency at a high temperature as compared with a compound semiconductor.

  The wall plate portion 200 is configured with a single inclination angle (first inclination angle θ1: not shown), but setting corresponding to the condensing lens is not required, so that the inclination angle can be freely designed. The degree gets bigger. Further, the reflecting surface 201 is formed on the entire surface of the wall plate portion 200. The inclination angle of the wall plate part 200 can be set in two stages as in the second embodiment. Further, the reflective surface 201 can be formed in a limited manner as in the second embodiment.

<Embodiment 4>
Based on FIG. 5, the solar cell module according to the present embodiment will be described.

  FIG. 5 is a perspective side view schematically showing the overall configuration of the solar cell module according to Embodiment 4 of the present invention.

  Since the basic configuration and operational effects of the solar cell module 1 according to the present embodiment are the same as those of the solar cell module 1 according to the first embodiment, different items will be mainly described.

  In the present embodiment, the primary optical system member 100 applied in the first embodiment is configured by only the Fresnel lens 102 formed from a glass plate.

  A secondary-side reflective film 50r is formed on the surface of the secondary optical system member 50 that faces the wall plate portion 200 (secondary optical system holder 51). The secondary reflective film 50r is preferably configured to have the same characteristics as the selective reflective film of the first embodiment, for example. With this configuration, a temperature increase due to sunlight Ls focused on the secondary optical system member 50 can be suppressed, and the temperature characteristics of the solar cell element 30 can be improved.

  Note that the secondary-side reflective film 50r according to the present embodiment can also be applied to the first embodiment. In this case, the operational effects of the first embodiment can be further improved.

<Embodiment 5>
Since the basic configuration and operational effects of the solar cell module according to the present embodiment are the same as those of the solar cell module 1 according to Embodiment 1, the drawings are omitted, and different matters are mainly described.

  In Embodiment 1, a non-metallic film, that is, a polymer material film is applied as the reflective surface 201 as a multilayer structure. However, in this embodiment, a reflective film having a two-layer structure is used instead of the multilayer polymer material film. Although it is possible to form a film by combining various metal materials and non-metal materials, in this embodiment, for example, aluminum and silicon oxide are used.

  For example, an aluminum film is formed by applying a vacuum deposition method to the wall plate portion 200 made of a thermoplastic polyester resin. The degree of vacuum during vapor deposition is 1 × 10 −6 Torr, and the film thickness is about 3 μm. Further, a silicon oxide film (SiOx) of about 0.2 μm is deposited on the formed aluminum film to protect the aluminum film.

  Therefore, since the manufacturing apparatus and the manufacturing method used in the existing solar cell manufacturing process can be applied as they are, it is possible to easily and accurately form the reflective surface 201 (a highly reflective reflective film). .

  Moreover, the shape of the wall board part 200 can be made into two steps like Embodiment 2. FIG.

<Embodiment 6>
Based on FIG. 6, the photovoltaic power generation unit according to the present embodiment will be described.

  FIG. 6 is a perspective view showing an overview of the overall configuration of the photovoltaic power generation unit according to Embodiment 6 of the present invention.

  The photovoltaic power generation unit 300 according to the present embodiment is configured by arranging a plurality of the solar cell modules 1 described in the first to fourth embodiments. Accordingly, the direct-light Lsd and the scattered light Lss are efficiently radiated to the solar cell element 30 in a large area to improve the power generation efficiency, improve the operation performance by reducing the weight, and make the solar power generation unit 300 with large generated power. Is possible.

  A plurality of solar cell modules 1 are arranged along a long frame 310 in series or in parallel according to applications such as necessary generated power and possible installation area, and are configured as a solar power generation unit 300. In addition, the solar cell module 1 can also be made into the independent form by arrange | positioning in the separate flame | frame different from the elongate frame 310. FIG.

  The solar power generation unit 300 is supported by the support column 320 and is automatically driven in the direction of tracking the sun by the rotation Roth in the horizontal direction and the rotation Rotv in the vertical direction by the tracking mechanism (not shown). The primary optical system member 100 (incident surface) disposed on the surface is directed to be perpendicular to the sunlight Ls. That is, it is configured as a so-called tracking concentrating solar power generation device.

  The tracking mechanism (tracking drive system) tilts the primary optical system member 100 (incident surface) to the azimuth axis for directing the primary optical system member 100 (incident surface) to the azimuth of the sun and the altitude of the sun. Therefore, it is possible to track the sun with high accuracy because it is constituted by two separate tracking drive devices for the tilt axis for the purpose.

  As a power system of the tracking drive system, a motor and a speed reducer are used to rotate a gear at a predetermined rotational speed to drive in a predetermined direction, and a hydraulic pump and a hydraulic cylinder are used to adjust the cylinder to a predetermined length. By doing so, there is a method of driving in a predetermined direction, and either method may be used.

  A method of calculating the sun's trajectory in advance with a clock mounted inside the tracking drive system that controls the operation of the tracking drive system, and controlling the solar cell module to face the sun, from a photodiode to the tracking drive system, etc. A method of attaching a solar sensor to monitor and control the sun direction as needed is known as a solar tracking method, and any method may be used.

  In the first to fourth embodiments, it has been described that the solar cell module 1 can eliminate the need for a housing. However, as shown in the present embodiment, a housing ( For example, the above-described long frame 310) can be arranged.

<Embodiment 7>
Since the basic configuration and operational effects of the solar cell module according to the present embodiment are the same as those of the solar cell module according to Embodiment 5, the drawings are omitted, and different matters will be mainly described based on FIG. .

FIG. 9 is a diagram for explaining the seventh embodiment of the present invention, and American Society for Testing and Materials (ASTM) Terrestrial Reference Spectra for FIG.
This is a spectrum of direct light disclosed by Photovoltaic Performance Evaluation.

  The solar cell element 30 used in the present embodiment is, for example, a three-junction compound semiconductor tandem solar cell (solar cell element) having an InGaP / InGaAs / Ge layer structure. The Ge cell serving as the bottom cell of the solar cell element 30 has a spectral sensitivity of up to 1900 nm in the long wavelength region, and is significantly larger than the photocurrent (Iph) of the InGaP cell serving as the top cell and the InGaAs cell serving as the middle cell. Photocurrent (Iph) substantially similar to that of the InGaP top cell and InGaAs middle cell can be obtained by absorption in the spectral sensitivity range up to 1300 nm in the long wavelength region. Since the top cell, middle cell, and bottom cell are connected in series, the photocurrent of the three-junction compound semiconductor tandem solar cell depends on the minimum photocurrent among the three cells. That is, if incident light having a wavelength region up to 1300 nm is collected, sufficient tandem solar cell current matching can be achieved. Therefore, except for light in the wavelength region of 1300 nm or longer, it is possible to prevent the sunlight in the unnecessary wavelength region from condensing on the solar cell element and improve the power generation efficiency and heat resistance. It becomes.

However, when producing a selective reflection film, it is affected by fluctuations in reflection characteristics due to the refractive index of the film material, an error in film thickness, and the like. As shown in FIG. 9, the wavelength region is 1380 nm due to absorption by the atmospheric layer.
There is a valley-shaped spectrum in the vicinity. If the reflection wavelength threshold of the selective reflection film is 1380 nm, even if there is a slight variation in the film thickness or refractive index, the reflection characteristics of the selective reflection film are less affected, and selective reflection. The stability of the reflective properties of the film is improved.

  In the solar cell module according to the present invention, the selective reflection film can be composed of a laminated film of at least two layers formed by vacuum deposition, but a non-vacuum preparation method is desirable from the viewpoint of cost.

  In this embodiment, the wall board part 200 used as the support board of a selective reflection film is comprised from the material of a flame-retardant thermoplastic polyester resin.

  The reflective surface 201 is configured by laminating a high reflectivity film having a high reflectivity by laminating a plurality of polymer material films (translucent films) having different refractive indexes on the wall plate portion 200. . That is, the reflective surface 201 can be formed by a high reflectance film formed by stacking two types of polymer materials that are non-metallic films.

  The high reflectivity film is made of, for example, a polyester resin (2-vinyltetrahydrofuran) as the first polymer material, and a polymer material composed of 2,3-naphthalenedicarboxylic acid and ethylene glycol as the second polymer material. It can be formed by stacking.

  For example, the refractive index of the polyester resin (2-vinyltetrahydrofuran) is about 1.55, and the thickness of the single layer film is about 223 nm. In addition, the refractive index of the polymer material composed of 2,3-naphthalenedicarboxylic acid and ethylene glycol was about 1.88, and the thickness of the single layer film was about 184 nm. The reflective surface 201 was formed by pasting the high reflectance film formed by alternately stacking the two kinds of polymer material films (translucent films), for example, 20 to 200 layers on the wall plate portion 200.

  The condition for setting the reflectance of the selective reflection film to 90% or more is influenced by the refractive index of the polymer material to be selected, but is not limited to the combination of the two types of polymer materials described above. It can also be realized by a combination of polymer materials.

  In addition, the high reflectance film | membrane which comprises the reflective surface 201 can be formed by sticking the sheet | seat (or film) on the wall board part 200 in tile shape, for example. That is, it is desirable that the high reflectance film (selective reflection film) is attached to the wall plate portion 200. With this configuration, the large-area reflecting surface 201 can be easily formed with good uniformity.

  As the high reflectance film, for example, an inorganic resist, a fluorine coating material, or the like can be applied in addition to the above-described combination of polymer materials. Moreover, according to the low-cost white film, selective reflection is difficult, but there is an effect of multiple reflection, and it can be applied as a high reflectance film.

  The final protective coating of the silicone film is performed by spraying a silicone resin by spraying or the like to form a V-shaped light collecting structure (wall plate portion 200 and selective reflection surface 201).

  The solar cell module of the present invention is excellent in light collection efficiency, power generation efficiency, heat resistance, and economical efficiency, and can be suitably used for solar power generation. Moreover, the solar power generation unit equipped with the solar cell module of the present invention can be expected from excellent power generation efficiency and economy, and is also advantageous from the viewpoint of operation performance due to weight reduction.

Claims (8)

A solar cell element that photoelectrically converts irradiated sunlight, a receiver substrate on which the solar cell element is placed, and a solar cell element that is arranged separately from the solar cell element to transmit sunlight and irradiate the solar cell element with sunlight A solar cell module comprising a primary optical system member,
A wall plate portion mounted on the receiver substrate and inclined to the receiver substrate at a first inclination angle of 45 degrees or more and coupled to the primary optical system member;
A reflective surface that is formed on the surface of the wall plate portion and reflects sunlight transmitted from the primary optical system member;
The solar cell module, wherein the reflection surface is formed of a selective reflection film having a reflection characteristic that acts on a specific wavelength region. The solar cell module according to claim 1, wherein
The said wall board part is set as the structure which supports the said primary optical system member. The solar cell module characterized by these. The solar cell module according to claim 1 or 2, wherein
The said wall board part is formed with the nonmetallic material. The solar cell module characterized by the above-mentioned. The solar cell module according to any one of claims 1 to 3,
The solar cell module, wherein the primary optical system member includes a condenser lens. It is a solar cell module as described in any one of Claim 1 thru | or 4, Comprising:
The selective reflection film transmits sunlight having a wavelength of more than 1200 nm and reflects sunlight having a wavelength of 1200 nm or less. It is a solar cell module as described in any one of Claim 1 thru | or 4, Comprising:
The selective reflection film transmits sunlight having a wavelength of more than 1380 nm and reflects sunlight having a wavelength of 1380 nm or less. The solar cell module according to any one of claims 1 to 6,
A solar cell module comprising: a secondary optical system member that is arranged in the vicinity of the solar cell element and focuses sunlight transmitted through the primary optical system member. A photovoltaic power generation unit configured by arranging a plurality of solar cell modules,
The solar cell module is a solar cell module according to any one of claims 1 to 7, wherein the solar cell module is a solar power generation unit.

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