JP2014220268A - Condensed photovoltaic power generator and condenser lens member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condensed photovoltaic power generator and condenser lens member, capable of preventing degradation in condensation performance and photoelectric conversion efficiency by preventing deformation and positional deviation of a condenser lens caused by temperature changes.SOLUTION: The condensed photovoltaic power generator includes at least a solar battery and a condenser lens member disposed on the light-receiving surface side of the solar battery. The condenser lens member includes a substrate and a plurality of condenser lens arranged on one surface of the substrate at predetermined intervals.

Description

  The present invention relates to a concentrating solar power generation device and a condensing lens member that can prevent deformation and displacement of the condensing lens due to temperature changes, and prevent degradation of condensing performance and photoelectric conversion efficiency.

  In recent years, environmental problems such as global warming caused by an increase in carbon dioxide have become serious, and countermeasures are being promoted worldwide. In particular, solar power generation using solar energy is attracting attention as a clean energy source with a small environmental load in place of current thermal power generation, etc., and the function of converting light energy into electrical energy, that is, photoelectric conversion efficiency Development of high-power solar power generation equipment is underway.

  Photovoltaic power generators are broadly divided into a “non-condensing type” that irradiates solar cells directly with solar light and a “condensed type” that irradiates solar cells with sunlight condensed using a condensing lens member. Is done. Here, in the solar power generation device, since the solar cell has high photoelectric conversion efficiency but is expensive, it is important to reduce the power generation cost by suppressing the amount of use of the solar cell. Therefore, the “condensing type” is suitable in that power can be manufactured inexpensively and efficiently. For example, Patent Document 1 discloses an example of a concentrating solar power generation device having a group of Fresnel lenses arranged without a gap as a condensing lens member.

Here, a general concentrating solar power generation device will be described. FIG. 7 is a schematic perspective view showing an example of a general concentrating solar power generation device, and FIG. 8 is a cross-sectional view taken along the line CC of FIG. As illustrated in FIGS. 7 and 8, the concentrating solar power generation device 100 includes a condensing lens member 101 having a condensing lens 111 such as a Fresnel lens on a base material 112, and a solar cell 103. . For convenience, illustration of the solar cell is omitted in FIG.
Further, as illustrated in FIG. 7, the condensing lens member 101 has a plurality of condensing lenses 111 arranged without gaps in order to increase the amount of condensing.

  FIG. 9 is an explanatory diagram illustrating a light collecting function in the concentrating solar power generation device. As illustrated in FIG. 9, sunlight X incident perpendicularly to the condenser lens 111 is condensed by the condenser lens 111 and forms a focal point F. The solar cell 103 is disposed such that the surface on the condenser lens side (hereinafter referred to as a light receiving surface) is positioned on the focal point F, and the collected light is irradiated onto the solar cell 103. Thus, light energy is converted into electric energy to generate electricity. At this time, since it is sufficient that the solar cell is disposed at a place where the sunlight is irradiated, the use area of the solar cell can be reduced, and the solar cell can be obtained by condensing the light by the condenser lens. Since the amount of light received at can be increased, the photoelectric conversion efficiency is increased and a large amount of electric power can be generated.

Such a concentrating solar power generation apparatus is required to stably collect sunlight during the day in order to exhibit high photoelectric conversion efficiency. However, since concentrating solar power generation devices are mainly used outdoors, when the temperature difference between hours and seasons is large under the outdoor usage environment, the condensing lens expands and contracts as the temperature changes. There is a problem of producing.
In particular, the closer to the surface of the condenser lens that is not in contact with the substrate surface, the more easily the expansion and contraction in the thickness direction and the width direction occurs, and the shape change rate increases. This is because the material of the condensing lens has a larger linear expansion coefficient than the base material, so that deformation of the condensing lens is somewhat suppressed by applying stress to the base material on the surface in contact with the base material, This is because the surface that is not in contact with the substrate surface does not have a force to suppress the deformation of the condenser lens.
The higher the temperature is in the usage environment of the concentrating solar power generation device, the greater the coefficient of thermal expansion of the condensing lens, and the greater the stress applied to the inside due to thermal expansion. For this reason, in a condensing lens arranged without a gap, the stress generated by one condensing lens also reaches the other condensing lens in contact with the other condensing lens. It will deviate significantly from the arrangement position. At the same time, the focal position of the condenser lens also deviates from the light receiving surface of the solar cell.
As a result, there has been a problem that the amount of light received by the solar cell changes throughout the day and year, and the photoelectric conversion efficiency increases and decreases, resulting in an unstable power generation amount as the concentrating solar power generation device.

JP 2010-276845 A

  The present invention has been made in view of the above-described problems, and is a condensing type capable of preventing the condensing lens from being deformed and displaced due to a temperature change, and preventing a decrease in condensing performance and photoelectric conversion efficiency. A main object is to provide a solar power generation device and a condensing lens member.

  In order to solve the above-described problems, the present invention is a concentrating solar power generation device including at least a solar cell and a condensing lens member disposed on a light receiving surface side of the solar cell, wherein the concentrating solar power generation device is provided. A lens member has a base material and a plurality of condensing lenses arranged at a predetermined interval on one surface of the base material.

According to the present invention, by providing a condenser lens member in which the condenser lenses are arranged at a predetermined interval on the base material, even if each condenser lens causes expansion or the like with a temperature change, The stress caused by the shape change can be prevented from acting on other condensing lenses adjacent to each other, and the displacement of the arrangement position of the condensing lenses can be suppressed.
As a result, positional deviation between the focal position of the condensing lens and the light receiving surface of the solar cell can also be suppressed, so that a constant amount of condensing can be ensured regardless of temperature changes in the usage environment. It can be set as the concentrating solar power generation device which is highly efficient and can obtain the stable electric power generation amount.

  In the said invention, the said predetermined space | interval is the space | interval which the surface located in the opposite side to the said base material of the said adjacent condensing lens does not contact in the highest temperature in the use temperature range determined by use environment. Preferably there is. At the maximum temperature in the operating temperature range determined by the usage environment of the concentrating solar power generation device of the present invention, the adjacent condensing lens has a particularly large shape change, that is, opposite to the surface in contact with the substrate. By setting the distance between the surfaces of the condenser lenses located on the side so that they do not contact each other, the deviation of the arrangement position of the condenser lens due to the temperature change and the positional deviation between the focal position of the condenser lens and the light receiving surface of the solar cell This is because the power generation can be minimized and a stable power generation amount can be obtained.

  In the said invention, it is preferable that the said predetermined | prescribed space | interval is in the range of 10 micrometers-10000 micrometers. In the concentrating solar power generation device of the present invention, by having a condensing lens member that makes the arrangement interval of the condensing lens within the above range, the deviation of the arrangement position of the condensing lens due to temperature change, and the collection This is because the positional deviation between the focal position of the optical lens and the light receiving surface of the solar cell can be minimized, and a stable power generation amount can be obtained.

  Moreover, this invention provides a condensing lens member characterized by having a base material and the several condensing lens arrange | positioned by predetermined spacing on the one surface of the said base material.

  According to the present invention, the condensing lens is a condensing lens member arranged with a predetermined interval, so that even if each condensing lens expands with temperature change, the condensing lens It is possible to prevent the stress caused by the change in the shape of the lens from acting on another condensing lens adjacent to the lens, and to suppress the displacement of the arrangement position of the condensing lens. Thereby, the condensing lens member of the present invention can secure a stable amount of condensing light regardless of the temperature change in the use environment.

  In the said invention, the said predetermined space | interval is the space | interval which the surface located in the opposite side to the said base material of the said adjacent condensing lens does not contact in the highest temperature in the use temperature range determined by use environment. Preferably there is. At the maximum temperature in the operating temperature range determined by the usage environment of the condensing lens member, the condensing located on the side opposite to the surface in contact with the base material, that is, the portion of the adjacent condensing lens that has a particularly large shape change. This is because, by setting the distance at which the lens surfaces do not contact each other, the shift of the arrangement position of the condensing lens due to the temperature change can be minimized.

  In the said invention, it is preferable that the said predetermined | prescribed space | interval is in the range of 10 micrometers-10000 micrometers. This is because, by setting the arrangement interval of the condenser lenses within the above range, the deviation of the arrangement position of the condenser lenses accompanying the temperature change can be minimized.

  According to the present invention, by disposing the condensing lens at a predetermined interval, it is possible to prevent the condensing lens from being deformed and displaced due to a temperature change, and to prevent the condensing performance from being lowered. There is an effect that the amount of power generated by the photovoltaic power generation apparatus can be secured stably.

It is a schematic plan view which shows an example of the concentrating solar power generation device of this invention. It is the sectional view on the AA line of FIG. It is explanatory drawing for demonstrating the deformation | transformation of a condensing lens by a temperature change, and generation | occurrence | production of the arrangement | positioning shift of a condensing lens. It is a schematic plan view which shows an example of the condensing lens member of this invention. It is the BB sectional view taken on the line of FIG. It is process drawing which shows an example of the manufacturing method of the condensing lens member of this invention. It is a schematic perspective view which shows an example of a general concentrating solar power generation device. It is CC sectional view taken on the line of FIG. It is explanatory drawing explaining the condensing function in a concentrating solar power generation device.

  Hereinafter, the concentrating solar power generation device and the condensing lens member of the present invention will be described. In the following description, “collective lens” may be abbreviated as “lens”.

A. First, the concentrating solar power generation device of the present invention will be described. The concentrating solar power generation device of the present invention is a concentrating solar power generation device having at least a solar cell and a condensing lens member disposed on the light receiving surface side of the solar cell, The lens member has a base material and a plurality of condensing lenses arranged at a predetermined interval on one surface of the base material.

The concentrating solar power generation device of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view showing an example of the concentrating solar power generation device of the present invention, and FIG. 2 is a cross-sectional view taken along line AA in FIG.
As illustrated in FIG. 1 and FIG. 2, the concentrating solar power generation device 10 of the present invention has a solar cell 2 fixed by the bottom frame portion 6 and a stand on the light receiving surface side of the solar cell 2. 3 and a plurality of condensing lens members 1 arranged through 3, and fixed to the ground or the like by a column 4 and a pedestal 5. For convenience, illustration of the solar cell 2, the stand 3, the column 4, the pedestal 5, and the bottom frame portion 6 is omitted in FIG. 1.
As illustrated in FIG. 1, the condensing lens member 1 is configured such that a plurality of condensing lenses 11 are arranged on the base material 12 with a predetermined interval W therebetween.
Further, as illustrated in FIG. 2, in the concentrating solar power generation device 10, the concentrating solar power generation device 10 is arranged so that the focal point F of one condensing lens 11 is positioned on the light receiving surface of one solar cell 2. ing.

  The concentrating solar power generation device of the present invention is characterized in that condensing lenses are arranged on a substrate at a predetermined interval. The reason will be described below.

  As described above, in the conventional concentrating solar power generation apparatus, in order to increase the amount of condensing light per unit of the condensing lens member, a condensing lens arranged without a gap to increase the condensing area is used. In addition, by arranging a solar cell at the focal position of each condenser lens, the amount of received light is increased and the photoelectric conversion efficiency is improved. In addition, as a material for the condensing lens, silicon or the like is mainly used from the viewpoint of cost reduction or the like.

However, in such a concentrating solar power generation device, when the condensing lens is thermally expanded and contracted due to a temperature change in the use environment, particularly when the condensing lens is expanded, the condensing lens arrangement position is There is a problem that the lens deviates from the original position and the focal point of the lens deviates from the light receiving surface of the solar cell.
FIG. 3 is an explanatory diagram for explaining the deformation of the condensing lens and the occurrence of misalignment of the condensing lens due to a temperature change. FIG. 3A illustrates a part of a condensing lens member in a conventional concentrating solar power generation device, and FIG. 3B illustrates a part of the condensing lens member in the concentrating solar power generation device of the present invention. It is a thing. T ₀ is the design temperature of the condenser lens, and T _max is abbreviated as the maximum temperature (hereinafter referred to as “maximum temperature”) in the usage temperature range determined by the usage environment of the concentrating solar power generation device. .). In addition, X in FIG. 3 represents sunlight.
As illustrated in FIG. 3 (a), the condensing lens member 101 in the conventional concentrating solar power generation apparatus, a predetermined design temperature T ₀ The formed condenser lenses 111a and 111b (hereinafter collectively Are sometimes arranged on the base material 112 without a gap so as to have the focal point F ₀ on the solar cell 103.
When a concentrating solar power generation apparatus including such a condensing lens member 101 is used in the field, the condensing lens 111 is deformed such as thermal expansion due to a temperature change in the use environment, and reaches the maximum temperature _Tmax. It becomes the most expanded shape. The condensing lenses 111a and 111b generate stresses S (a) and S (b) inside due to thermal expansion, but the stresses spill over each other at the contact portions of the condensing lenses 111a and 111b. The condensing lenses 111b and 111a that have received the stresses S (a) and S (b) are displaced from the design positions.
If the condensing lens 111 is displaced, the focal position of the lens is also shifted from the design time. In particular, the focal point F ′ of the lens at the maximum temperature T _max is greatly deviated from the focal point F ₀ at the time of design, that is, before the condenser lens 111 is deformed, and the focal point F ′ deviates from the light receiving surface of the solar cell 103. The solar cell 103 cannot receive a sufficient amount of sunlight.
For this reason, there is a problem that the amount of light received by the solar cell changes depending on the operating temperature, and the photoelectric conversion efficiency increases and decreases, resulting in an unstable power generation amount as the concentrating solar power generation device.

The displacement due to the deformation of the condensing lens and the shift of the lens focus tend to have a larger deviation width as the condensing lens is disposed closer to the end of the condensing lens member. For this reason, there is a difference in the amount of collected light between the central portion and the end of the condensing lens member, and as a result, the condensing amount of the entire condensing lens member may not be increased.
In addition, when a material with a large coefficient of thermal expansion, such as silicon, is used for the condensing lens, it is difficult to stabilize the power generation amount because the lens deformation and the focal position shift width due to temperature change are further increased. There is a case.
Furthermore, in the conventional concentrating solar power generation apparatus in which the condensing lens is arranged without a gap, it is assumed that if a crack or the like is generated in a part of the condensing lens, it is spread to other lenses. Since a condensing lens that has been damaged has reduced condensing performance, the amount of condensing light as a condensing lens member also decreases, and as a result, there is a problem in that the power generation amount of the concentrating solar power generation device is reduced.

On the other hand, in the present invention, as illustrated in FIG. 3B, the condenser lenses 11 a and 11 b (hereinafter collectively referred to as “the condenser lens 11”) are spaced at a predetermined interval W. By arranging, the above problem was solved.
That is, since the condensing lens 11 is arranged on the base material 12 with a predetermined interval W in advance, the use temperature changes greatly, and the condensing lens 11 expands most at the maximum temperature _Tmax . Even if it exists, the contact of the adjacent condensing lenses 11 can be prevented. That is, the stresses S (a) and S (b) generated when the condensing lenses 11a and 11b are expanded can be prevented from interacting with each other. It becomes possible to suppress.
As a result, the positional deviation between the focal point F ′ of the lens at the maximum temperature T _max and the focal point F ₀ of the lens at the time of design is suppressed, and the focal point F ′ is positioned on the light receiving surface of the solar cell 2. In other words, even when the size and shape of the condensing lens changes with the temperature change in the usage environment, the solar cell can secure a constant amount of condensing, and as a result, can maintain high photoelectric conversion efficiency, It can be set as the concentrating solar power generation device which can obtain the stable electric power generation amount.

Further, by arranging the condensing lenses at a predetermined interval, even if the condensing lens is arranged at a position close to the end of the condensing lens member, the deviation width between the arrangement position and the focal position of the lens is the center. As with the condensing lens located in the section, the condensing lens can be minimized, and a uniform condensing amount can be secured over the entire surface of the condensing lens member, so that the total condensing amount can be increased. It becomes possible.
Further, even if some condensing lenses are broken due to cracks or the like, the damaged condensing lens and the adjacent condensing lens are arranged with a predetermined interval. Propagation to other condenser lenses can be prevented.
As a result, the condensing solar power generation device of the present invention can maintain the power generation amount for a long period of time because it can prevent a significant decrease in the light condensing amount of the entire condensing lens member due to damage. It becomes possible to have.

The degree of dimensional change of the condensing lens due to thermal expansion varies depending on the thickness of the condensing lens at the time of designing, etc., but usually the thickness of the condensing lens increases toward the surface that is not in contact with the substrate. The dimensional change in the direction and the width direction becomes large. For this reason, adjacent condensing lenses first come into contact with each other at the end portion (C portion in FIG. 3), and stress spreads due to the contact between the end portions C, resulting in a positional shift of the condensing lens. Become.
From the above-mentioned tendency, in the present invention, the predetermined intervals are set to the surfaces of the condensing lenses adjacent to each other on the side opposite to the base material at the maximum temperature in the use temperature range determined by the use environment. It is preferable that the distance is such that no contact occurs.

  Here, the “maximum temperature in the operating temperature range determined by the operating environment” is a temperature range generally assumed in an environment where the concentrating solar power generation apparatus is used, that is, concentrating solar light. The temperature reached by the condensing lens is measured with the power generation device installed in the field, and the maximum temperature in that temperature range is said. Specifically, the operating temperature range is within a range of -20 ° C to 70 ° C.

In addition, “the interval at which the surfaces of the adjacent condensing lenses that are opposite to the base material do not contact each other” means that the condensing lens is usually the most expanded shape at the highest temperature in the operating temperature range. Therefore, it means an arrangement interval at which the stress generated in one lens due to expansion or the like does not reach the other lens at the end of the surface opposite to the surface in contact with the base material.
Calculate the temperature difference between the design temperature when designing the condensing lens and the maximum temperature in the operating temperature range, and calculate the distance of the condensing lens based on the temperature difference from the linear expansion coefficient of the material used for the condensing lens. The ratio at which the dimension changes is calculated, and is defined from the dimension change rate and the thickness of the condensing lens at that time.
The “condensing lens design temperature” is a temperature designed such that the side surface in the thickness direction of the condensing lens in the present invention is perpendicular to the surface in contact with the base material of the lens. The design temperature is appropriately set according to the size per unit of the condensing lens, the pitch width at the time of arrangement, and the like, for example, in the range of 20 ° C. to 40 ° C.

Specifically, the arrangement interval of the condenser lenses in the present invention is preferably in the range of 10 μm to 1000 μm, more preferably in the range of 20 μm to 500 μm, and particularly preferably in the range of 50 μm to 250 μm.
When the arrangement interval of the condenser lenses is larger than the above range, the number of condenser lenses arranged per condenser lens member is reduced. That is, since the amount of light collected per one condensing lens member is reduced, the amount of received light and the photoelectric conversion efficiency of the solar cell are also reduced, and a sufficient amount of power generation may not be obtained. On the other hand, when the arrangement interval is smaller than the above range, when the condensing lens is deformed due to expansion or the like, the adjacent condensing lenses come into contact with each other to exert force, thereby causing a deviation in the arrangement position. The focus of the lens may deviate from the light receiving surface of the solar cell. Further, the closer to the end of the condensing lens member, the greater the degree of positional deviation, so there may be a difference in the amount of condensing depending on the position of the condensing lens.

  The concentrating solar power generation device of the present invention has at least a condensing lens member and a solar cell. Each configuration will be described below.

1. Condensing lens member The condensing lens member in this invention is arrange | positioned at the light-receiving surface side of the said solar cell, the base material, and the several condensing lens arrange | positioned at one surface of the said base material by the predetermined space | interval It is what has.
Hereinafter, the condensing lens member in the present invention will be described separately for the condensing lens and the base material.

(1) Condensing lens The condensing lens in this invention should just be what can condense more sunlight, and can be suitably selected from what was conventionally used as a condensing lens. Examples of the condensing lens include a plano-convex lens, a Fresnel lens, and a Cassegrain type lens. Among them, the condensing lens in the present invention is preferably a Fresnel lens from the viewpoint of having a high condensing performance with a thin film. .
As illustrated in FIGS. 1 and 2, the Fresnel lens is a lens in which a normal lens is divided into concentric regions to reduce the thickness, and the surface thereof has a saw-like uneven cross section. is there.

The material of the condensing lens is not particularly limited as long as it can form a desired lens shape, but is preferably a material that does not easily expand or contract under the environmental temperature to be used. A resin material of × 10 ⁻³ / ° C. or lower is preferable, and a resin material having a linear expansion coefficient of 5 × 10 ⁻⁴ / ° C. or lower is particularly preferable. By setting the linear expansion coefficient to a predetermined numerical value or less, expansion and contraction due to temperature change are unlikely to occur, and the degree of lens shape change can be suppressed. As a result, the arrangement interval between adjacent condenser lenses can be set small, and more condenser lenses can be arranged on the base material, so that the condenser performance per condenser lens member is improved. Is possible. The thermal linear expansion coefficient is a value measured in a tensile mode using a thermomechanical analyzer (TMA / SS6100 manufactured by SII Nanotechnology Co., Ltd.).

  The resin material having the above-described linear expansion coefficient may be an ionizing radiation curable resin or a thermosetting resin, and among them, an ionizing radiation curable resin is preferable. Examples of the ionizing radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, a visible light curable resin, a near infrared curable resin, and the like. In the present invention, among others, an ultraviolet curable resin and an electron beam are used. A curable resin is preferably used, and specific examples include acrylic resins, urethane acrylate resins, inorganic-organic hybrid resins, and the like. Of these, urethane acrylate resins are excellent in curability and advantageous in terms of hardness.

The resin material for the condenser lens may contain a photopolymerization initiator. The photopolymerization initiator is appropriately selected according to the resin material of the condenser lens to be used. For example, acetophenones, benzophenones, Michler benzoylbenzoate, α-amyloxime ester, tetramethylchu Examples include ram monosulfide and thioxanthone.
Moreover, the resin material of the condensing lens may contain n-butylamine, triethylamine, poly-n-butylphosphine, or the like as a photosensitizer.

  In addition to the resin material described above, an antioxidant may be included as a material for the condenser lens in order to improve weather resistance. Although it does not specifically limit as antioxidant, Antioxidants, such as a phenol type, an amine type, a quinone type, an organic sulfur type, and a phosphate ester type, are mentioned. In addition, the said antioxidant can improve the weather resistance of a condensing lens by adding the quantity of about 1 weight% with respect to 100 weight% of total solid content of the material of a condensing lens.

  Moreover, the condensing lens may have another material other than the above-mentioned material as needed. Examples thereof include a photoinitiator, a crosslinking agent, a light stabilizer, a diffusing agent, glass beads, and a phosphor.

The surface shape of the condensing lens is not particularly limited. For example, when the condensing lens is a Fresnel lens, the concave and convex shape on the lens surface is a shape suitable for condensing sunlight. It can set suitably as follows.
In addition, the shape of the condenser lens as viewed from above is not particularly limited, and examples thereof include a polygon such as a quadrangle, a pentagon, and a hexagon.
Furthermore, the condensing lens usually has a flat surface on the light source side and the uneven surface of the lens on the solar cell side, but the surface on the light source side is a curved surface shape such as a half dome shape or a dome shape. It may be that having an uneven surface of the lens on the light source side.

  The size per condensing lens is not particularly limited as long as it is a size capable of condensing, and can be, for example, about 5 cm square.

The thickness of the condensing lens is appropriately set according to the design temperature at the time of manufacturing the condensing lens, the pitch width when the condensing lens is arranged, and the like. For example, the temperature difference between the design temperature of the condensing lens and the maximum temperature in the operating temperature range determined by the use environment of the concentrating solar power generation apparatus including the condensing lens, and the condensing lens used. It is preferable to calculate the dimensional change rate in the thickness direction and the width direction of the condensing lens from the linear expansion coefficient of the material, and to define the thickness of the condensing lens in consideration of the focal length of the lens at the time of expansion. .
For example, the thickness of the condensing lens is preferably in the range of 10 μm to 500 μm, and more preferably in the range of 50 μm to 200 μm. If the thickness of the condenser lens is larger than the above range, it may be easily affected by thermal expansion / contraction due to temperature change. It may be difficult to form the film.
In addition, the thickness of a condensing lens means the height from the surface which contacts a base material to the highest vertex among the uneven surfaces in a condensing lens.

  The transmittance (visible light transmittance) in the visible light region of the condenser lens is preferably 80% or more, and more preferably 90% or more. This is because if the visible light transmittance of the condensing lens is smaller than the above range, the amount of sunlight collected decreases, so the amount of received light in the solar cell also decreases, and as a result, the amount of power generation decreases. The visible light transmittance is a value measured according to JIS K7361-1.

(2) Substrate The substrate in the present invention may be any substrate that has transparency and has a strength capable of arranging a plurality of condensing lenses. As such a substrate, a glass substrate, an acrylic resin, a polymethyl methacrylate resin, a polycarbonate resin, an epoxy resin, an epoxy acrylate resin, a urethane acrylate resin, a polyester resin, a phenol resin, or the like is used. Can do. Among them, a glass substrate is preferable in the present invention. This is because the glass base material has a higher light transmittance and surface hardness than other base material materials, and has a small linear expansion coefficient and is not easily affected by temperature changes.
The substrate may be a single layer or a laminate.

  Moreover, when the said base material is a resin base material, in order to improve a weather resistance, you may contain a ultraviolet absorber. The ultraviolet absorber may be either inorganic or organic. Examples of inorganic ultraviolet absorbers include titanium oxide, cerium oxide, and zinc oxide. Moreover, as an organic type ultraviolet absorber, a benzotriazole type, a triazine type, a benzophenone type, a salicylate type, an acrylonitrile type etc. can be used, for example, Of these, a triazine type is preferable. This is because the ultraviolet absorbing ability is high, and it is difficult to deteriorate even with high energy such as ultraviolet rays.

  The transmittance of the substrate in the visible light region (visible light transmittance) is preferably 80% or more, and more preferably 90% or more. This is because if the visible light transmittance of the substrate is smaller than the above range, the amount of sunlight collected by the condensing lens member is reduced, so that the amount of received light in the solar cell is also reduced, and as a result, the amount of power generation is reduced. . The transmittance is a value measured according to JIS K7361-1.

The thickness of the substrate is not particularly limited, and can be appropriately designed according to the required strength, but is preferably about 3 mm to 5 mm, for example.
In addition, the shape of the base material is not particularly limited, but has a size that allows a plurality of condenser lenses to be arranged at predetermined intervals, and is a shape that can efficiently collect sunlight. If it is.

  The base material may have a hard coat layer on the surface on the light receiving side. The hard coat layer can prevent the condensing lens member from being damaged or cracked due to external impact. As a material for the hard coat layer, a generally used hard coat layer material can be used. Examples thereof include a curable resin composition for a hard coat layer containing reactive irregular silica fine particles having a reactive functional group on the surface and a binder component having a reactive functional group.

  The thickness of the hard coat layer is not particularly limited, but is preferably about 5 μm to 20 μm, for example.

  In addition, a primer layer may be provided on the surface in contact with the condenser lens. The primer layer can improve the adhesion between the substrate and the condenser lens. As a material of the primer layer, a commonly used primer layer material can be used, and examples thereof include an epoxy acrylate resin composition and a urethane acrylate resin composition. The primer layer may contain a silane coupling agent in order to improve adhesion.

  The thickness of the primer layer is not particularly limited, but is preferably about 0.1 μm to 10 μm, for example.

(3) Condensing lens member In the condensing lens member in this invention, it is preferable that the difference of the linear expansion coefficient of a condensing lens and a base material is small. When the condensing lens member and the base material expand and contract as the temperature changes in the usage environment, a difference occurs in the dimensional change rate of each member. For this reason, even when the condensing lenses are arranged at a predetermined interval, there may be a problem that the arrangement position of the condensing lens is shifted as the shape of the base material changes.
The difference in absolute value of the linear expansion coefficient between the condenser lens and the substrate is preferably in the range of 1 × 10 ⁻⁵ / ° C. to 30 × 10 ⁻⁵ / ° C., and more preferably 1 × 10 ⁻⁵ / It is preferable to be within the range of 10 ° C. to 10 × 10 ⁻⁵ / ° C.

As described above, the condensing lens member in the present invention has a plurality of condensing lenses arranged at a predetermined interval. However, on the substrate located between the two condensing lenses, You may have the layer (intervening layer) which consists of resin materials. The intervening layer connects two adjacent condenser lenses.
The thickness of the intervening layer on the substrate located between the condensing lenses is preferably large enough not to affect the condensing lens even if the intervening layer expands and contracts due to heat, for example, 100 μm. The following is preferable.
When the thickness of the intervening layer exceeds the above range, the stress due to expansion and contraction that occurs in the intervening layer due to a temperature change increases, and the stress acts on the condensing lens to be connected, thereby shifting the arrangement of the condensing lens. May occur.

The condensing lens member in this invention will not be specifically limited if it has the condensing lens and base material which were mentioned above, A required structure can be selected suitably and can be added. For example, the condensing lens member in the present invention may have a frame part for fixing the condensing lens and the substrate.
The size of the frame portion is not particularly limited, and can be appropriately designed according to the size of the condensing lens member.
About the height of a frame part, it is preferable to design higher than a condensing lens, for example, it is preferable to design high about 1 micrometer-1 cm. When the condensing lens member of the present invention is laid flat and transported, the condensing lens can be prevented from being damaged. In addition, the height of a frame part means the height from the surface of a base material.

The material of the frame part is not particularly limited. For example, the frame part may be formed by applying a thermosetting resin or ionizing radiation curable resin to a place where the frame part is to be formed, and curing the resin. More specifically, the ionizing radiation curable resin is cured by applying an ionizing radiation curable resin to the entire surface on which the condenser lens is formed, and exposing only the portion where the frame portion is to be formed using a mask. Thereafter, the frame portion can be formed by developing.
As another method, on the surface on which the condensing lens is formed, an ionizing radiation curable resin is applied only to a portion where the frame portion is to be formed by a screen printing method, and then exposed to the ionizing radiation curable resin. The frame portion can also be formed by curing the resin.

  The frame part may be transparent or colored by some method. Moreover, it is preferable that the linear thermal expansion coefficient of a flame | frame part is a numerical range between the linear expansion coefficient of a condensing lens, and the linear expansion coefficient of the material of the part in which a condensing lens member is installed. It is because it can suppress that the location where sunlight condenses by the stress which arises inside a flame | frame part by temperature change fluctuates.

  The condensing lens member in the present invention may have, for example, an antireflection layer, an adhesion auxiliary layer, and the like in addition to the above-described portions.

In the condensing lens member, the number of condensing lenses per base material is not particularly limited, and an arbitrary number is appropriately selected according to the shape of the concentrating solar power generation device of the present invention. Can be set.
Note that the pitch width of the condensing lens in the condensing lens member may be set as appropriate according to the arrangement interval or the like as long as a desired condensing amount is obtained.

2. Solar cell In the solar cell of the present invention, a condensing lens member is disposed on the light receiving surface side. Specifically, the solar cell is disposed at a position where the condenser lens is focused.

  The solar cell is not particularly limited, and a conventionally known solar cell can be used. Specifically, a monocrystalline or polycrystalline silicon solar cell, an amorphous silicon solar cell, a compound semiconductor solar cell, an organic semiconductor solar cell including an organic photoelectric conversion layer, or the like can be used. Furthermore, a multi-junction solar cell in which a plurality of the above-described solar cells are joined can also be used. Among these, a multi-junction solar cell is preferable in that high conversion efficiency can be obtained.

3. Concentrating Solar Power Generation Device In the concentrating solar power generation device of the present invention, the arrangement interval between the condensing lens member and the solar cell is appropriately set according to the focal length of the condensing lens.

The concentrating solar power generation device includes at least the condensing lens member and the solar cell described above, and may include other members.
For example, it has a stand part for fixing a plurality of condensing lens members, a bottom frame part for fixing a plurality of solar cells, a column supporting the bottom frame unit, and a pedestal for fixing the column. Type solar power generation device can be installed at a desired position.
Moreover, you may have the system etc. for carrying out a tracking drive according to a motion of the sun so that it may face directly with the sun as other members.

4). Manufacturing method of concentrating solar power generation device As a manufacturing method of the concentrating solar power generation device of the present invention, a condensing lens member can be arranged so as to overlap with a solar cell in plan view. There is no particular limitation as long as the focal point can be positioned on the light receiving surface of the solar cell.
For example, a condensing lens member in which a plurality of condensing lenses are arranged on a substrate in advance at a predetermined interval is fixed by a frame portion, and a solar cell is also arranged on the bottom frame portion in accordance with the arrangement of the condensing lenses. The frame part and the bottom frame part are arranged so as to overlap in plan view through the stand part, and the height of the stand part is adjusted so that the focal point of one condenser lens is positioned on the light receiving surface of one solar cell. Then, the concentrating solar power generation device can be manufactured by a method of fixing to the pedestal via the support.
In addition, since the manufacturing method of a condensing lens member is demonstrated in the term of "B. Condensing lens member" mentioned later, description here is abbreviate | omitted.

B. Next, the condensing lens member of the present invention will be described. The condensing lens member of the present invention has a base material and a plurality of condensing lenses arranged at a predetermined interval on one surface of the base material.

The condenser lens member of the present invention will be described with reference to the drawings. 4 is a schematic plan view showing an example of the condensing lens member of the present invention, and FIG. 5 is a cross-sectional view taken along the line BB of FIG.
As illustrated in FIGS. 4 and 5, the condensing lens member 1 of the present invention is configured such that a plurality of condensing lenses 11 are arranged on a base material 12 with a predetermined interval W therebetween.

  Among the above, the interval W is the maximum temperature in the use temperature range determined by the use environment of the collective lens member 1, and the surface of the adjacent collective lenses (11 a and 11 b in FIG. 4) and the base material 12. It is preferable that it is the space | interval which the surfaces located on the opposite side of the surface which touches do not contact. The specific value of the interval W is preferably in the range of 10 μm to 10000 μm.

  According to the present invention, by using a condensing lens member arranged with a predetermined interval between the condensing lenses, even if each condensing lens expands and contacts with a temperature change, It is possible to prevent the stress caused by the shape change of the condensing lens from acting on other condensing lenses adjacent to each other, and it is possible to suppress the displacement of the arrangement position of the condensing lens. Thereby, the condensing lens member of the present invention can secure a stable amount of condensing light regardless of the temperature change in the use environment.

The condensing lens member of this invention has a condensing lens and a base material at least.
Hereinafter, each part of the condensing lens member of the present invention will be described.

1. Condensing lens A plurality of condensing lenses in the present invention are arranged at a predetermined interval on one surface of the substrate.
Among these, at the highest temperature in the operating temperature range determined by the usage environment of the condensing lens member, the interval between the condensing lenses adjacent to each other having a particularly large shape change rate, that is, the substrate is in contact with each other. It is preferable that the distance between the surfaces located on the opposite sides of the surfaces is not in contact. This is because the displacement of the arrangement position of the condenser lens can be minimized. Specifically, when the interval is within the range of 10 μm to 10000 μm, the above-described effects can be more exhibited.
About the condensing lens in this invention, since it can be made to be the same as that of what was demonstrated by the term of the "A. concentrating solar power generation device" mentioned above, description here is abbreviate | omitted.

2. Base Material The base material in the present invention can be the same as that described in the above-mentioned section “A. Concentrating Solar Power Generation Device”, and thus description thereof is omitted here.

3. Condensing lens member The condensing lens member of the present invention is not particularly limited as long as it has the plurality of condensing lenses described above on the base material, and other necessary members can be appropriately selected and added. it can. Since the other members in the condensing lens member of the present invention can be the same as those described in the section of “A. Concentrating solar power generation device” described above, description thereof is omitted here.

4). The manufacturing method of a condensing lens member The manufacturing method of the condensing lens member of this invention will not be specifically limited if it is a method which can arrange | position a condensing lens on a base material with a predetermined space | interval accurately.
For example, a single-sided master original plate forming step for forming a master original plate that is a transfer shape of a target condenser lens, a single-sided replica original plate forming step for forming a plurality of single-sided replica original plates using the single-sided master original plate, A tiling process in which a plurality of single-sided replica masters are arranged on a base with predetermined intervals to form one multi-sided master master, and a condensing lens master is formed using the multi-sided master master. An optical lens original plate forming step and a condensing lens member forming step of collectively forming a condensing lens member in which a plurality of condensing lenses are arranged on a substrate at a predetermined interval using the condensing lens original plate. The method can be used.
By the above-described method, the condensing lens member of the present invention in which the condensing lenses are arranged on the substrate at a predetermined interval can be formed in a lump, and manufacturing can be facilitated.

FIG. 6 is a process diagram showing an example of the method for producing the condensing lens member of the present invention described above, and illustrates the case where a Fresnel lens is provided as the condensing lens.
First, as shown in FIG. 6A, the surface of the metal substrate 21 is cut using a cutting tool 22 to form a single-sided master original plate 20 that is an inverted shape of a target condenser lens (Fresnel lens). (One-sided master master forming process).
Next, as shown in FIG. 6B, a resin material 31 is applied to the single-sided master master 20 and cured to produce a plurality of single-sided replica masters 30 (single-sided replica master forming step).
Subsequently, as shown in FIG. 6 (c), the obtained single-sided replica master 30 is tiled on the base 41 with a predetermined interval W, and one multi-sided master 40 is obtained. Create (tiling process).
Thereafter, as shown in FIG. 6 (d), an electroforming process 51 is performed on the surface of the multi-face master master 40 to create a condensing lens master 50. Finally, as shown in FIG. 6 (e). The transfer surface of the condensing lens original plate 50 is pressed against a resin material layer 61 made of a condensing lens forming resin material (hereinafter sometimes referred to as a lens forming material) applied on the substrate 12, By photocuring the resin material layer 61, it is possible to obtain the condensing lens member 1 in which a plurality of condensing lenses 11 are arranged on the base material 12 with a predetermined interval W therebetween. 6D is a condensing lens original plate forming step, and FIG. 6E is a condensing lens member forming step.

  Hereinafter, each step will be described.

(1) Single-sided master original plate forming step The master original plate forming step is a step of forming a master original plate that is a transfer shape of a condensing lens. In addition, the master original plate formed in this step has a condensing lens on one side.

  The material used for the single-sided master plate is preferably a metal having a hardness that does not cause breakage of the cutting tool during cutting, and examples thereof include aluminum, copper, and nickel.

  The method for forming the single-sided master plate is not particularly limited, but it is usually preferable to form a desired pattern by cutting the surface of the metal plate by a lathe cutting method. Specifically, a metal plate is attached to the front lathe and rotated, and the cutting tool is pressed against the metal plate. At this time, the tip angle of the cutting tool is set to the same angle as the tip angle of the convex portion of the target condenser lens, and a concave / convex pattern is formed on the surface of the metal plate, thereby forming the inverted shape of the target condenser lens. can do.

(2) Single-sided replica original plate forming step The single-sided replica original plate forming step is a step of forming a plurality of single-sided replica original plates using the single-sided master original plate formed in the above-described step.

  The material used for the single-sided replica master may be a metal material such as nickel, or a resin material such as an ionizing radiation curable resin or a thermosetting resin.

  The method for forming the single-sided replica original plate is not particularly limited, but can be selected according to the material to be used. For example, when forming a single-sided replica original plate with a resin material, it can be formed by applying a resin material to the transfer surface of the single-sided master original plate and curing it by light or heat. Further, when the one-sided replica original plate is formed of a metal material, it can be formed by electroforming the transfer surface of the one-sided master original plate.

(3) Tiling process The tiling process is a process in which a plurality of single-sided replica masters are arranged on a base with a predetermined interval to form one multi-sided master master. In this step, by arranging a single-sided replica original plate with a predetermined interval in advance, when forming a plurality of condensing lenses in a collective lens forming step described later, a predetermined interval is provided between the condensing lenses. Can be provided.

As a tiling method, any method can be used as long as a plurality of single-sided replica originals can be arranged on a base at a predetermined interval. As illustrated in FIG. 6C, pins 42 are provided on the base, A method in which the one-sided replica original plate 30 is arranged using this as a fulcrum is preferable. When placing on the base via an adhesive or the like, if the placement position of the single-sided replica original is displaced at one place, the other part is also displaced accordingly, and a plurality of single-sided replica originals are placed accurately. This is because there are cases where it cannot be done.
Although it does not specifically limit as a material of the said base, For example, the base material made from aluminum etc. can be used.

(4) Condensing lens original plate forming step The condensing lens original plate forming step is a step of forming a condensing lens original plate using a multi-faced master original plate. A method for forming the condensing lens original plate is not particularly limited, and for example, an electroforming method such as Ni can be used.

(5) Condensing lens member forming step In the condensing lens member forming step, a condensing lens member in which a plurality of condensing lenses are arranged on a substrate at a predetermined interval is collectively used using the above-described condensing lens original plate. It is a process of forming. The base material used for the condensing lens member and the lens forming material are the same as those described in the above-mentioned section “A. Condensing solar power generation device 1. Condensing lens member”.
Further, as a method for forming the condensing lens member, a method for applying a lens forming material to the transfer surface of the condensing lens original plate, disposing a base material on the application surface and curing it by light or heat, or the lens There is a method in which a base material on which one of the forming materials is applied is separately prepared, the applied surface is pressed against the transfer surface of the condensing lens original plate, and cured by light or heat.

  In this step, in order to improve the adhesion between the condensing lens and the base material, an adhesion auxiliary layer may be formed before applying the lens forming material on the base material.

(6) Manufacturing method of condensing lens member Although the condensing lens member of this invention can be formed through the above-mentioned process, it may have another process. For example, after the tiling step, a plating step may be performed in which one side of the resin-made multi-face master master plate is subjected to plating treatment to be conductive.

5. Uses As a use of the condensing lens member of the present invention, it can be suitably used for general solar power generation devices including those equipped with a secondary condenser.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

[Example 1]
First, a white plate float glass (manufactured by AGC Fabricec Co., Ltd.) having a thickness of 3.2 mm and a size of 1010 mm × 510 mm was prepared and used as a glass substrate. Next, an adhesion auxiliary layer forming material having the following composition was prepared, applied to one side of the glass substrate, and heated at 150 ° C. for 10 minutes. In addition, the thickness of the coating film of the adhesion auxiliary layer forming material after heating was 1.0 μm to 2.0 μm.

<Material for forming adhesion auxiliary layer>
Polymerizable monomer: Isocyanuric acid triacrylate (manufactured by Toagosei Co., Ltd .: Aronix M315) 12.5 parts by weight Silane coupling agent: 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM503) ... 12.5 parts by weight-film-forming auxiliary: cellulose acetate butyrate (manufactured by Eastman Chemical Japan Co., Ltd .: CAB381-2) ... 3.6 parts by weight-photopolymerization initiator: 2,4,6-trimethylbenzoyl -Diphenyl-phosphinoxide (BASF: Lucillin TPO) 1.5 parts by weight. Solvent: Methyl ethyl ketone (Pure Chemical Co., Ltd.) 69.9 parts by weight

  Subsequently, a lens forming material having the following composition was prepared, and this was applied onto the dried adhesion auxiliary layer forming material to form a resin material layer, and then a Fresnel lens (49.9 mm × 49.9 mm). ) Of a condensing lens original plate (hereinafter, sometimes referred to as a mold) of 1000 mm × 500 mm, in which 200 inverted shapes (hereinafter, referred to as a condensing lens transfer portion) are arranged at intervals of 0.1 mm. The shape of the Fresnel lens was shaped by pressing.

<Lens forming material>
Urethane acrylate oligomer (Shin Nakamura Chemical Co., Ltd .: NK Oligo U-15HA) 50.0 parts by weight Polymerizable monomer: Tripropylene glycol diacrylate (Toagosei Co., Ltd .: Aronix M220) 0 parts by weight-photopolymerization initiator: 2,4,6-trimethylbenzoyl-diphenyl-phosphinoxide (manufactured by BASF: Lucillin TPO): 5.0 parts by weight

With the mold pressed, the resin material layer was cured by irradiating ultraviolet rays of 1250 ± 150 mJ / cm ² from the glass substrate side with a fusion D bulb, and then released from the mold. A condensing lens member was obtained in which 200 Fresnel lenses having a thickness of 50 μm were individually arranged at intervals of 0.1 mm on a glass substrate.

[Comparative Example 1]
An acrylic plate (Acrylite L manufactured by Mitsubishi Rayon Co., Ltd.) having a thickness of 3 mm and a size of 1010 mm × 510 mm is set on the mold shown in Example 1 and the mold temperature is heated to 170 ° C. and then added to the sheet. A condensing lens member in which one surface of the acrylic plate was molded into 200 Fresnel lenses was obtained by applying pressure so that the pressure was 90 kg / cm ² and performing hot pressing for 1 minute.

[Evaluation]
(Measurement of thermal deformation of condensing lens member under operating temperature)
The condensing lens members obtained in Example 1 and Comparative Example 1 are diagonal from the center position of the Fresnel lens A located on the outermost end face among the Fresnel lenses arranged in 10 × 20. The distance between the center positions of the Fresnel lens B located on the outermost end face was measured. The measurement was performed at room temperature (25 ° C.) and at a temperature heated to 70 ° C., which is assumed as the maximum temperature during use. Table 1 and Comparative Example 1 show the results of Example 1 for the relative coordinates of B when the coordinates of A are fixed to (0, 0), and the linear expansion coefficient of the base material at each temperature in Fresnel lenses A and B. Table 2 shows the results.

From Table 1 and Table 2, in Example 1, the temperature change of the center coordinate was greatly suppressed as compared with Comparative Example 1. This is because in Example 1, each Fresnel lens is arranged in close contact with the glass substrate independently at an interval of 0.1 mm, so that the change in coordinates is affected only by thermal deformation of the glass substrate. It is presumed to be due to this.
In Example 1, since the deviation of the focal position of the Fresnel lens due to the temperature change is very small, the deterioration of the light collecting performance can be suppressed even when the temperature is high, and the light collecting performance stable against the temperature change can be obtained. It was possible to hold.

[Example 2]
In order to correspond to the arrangement of each Fresnel lens of the condensing lens member of Example 1, multi-junction solar cells in which a plurality of 200 organic semiconductor solar cell elements were joined were arranged in the bottom frame portion. Next, the condenser lens member of Example 1 was fixed on the bottom frame portion via a stand so that the center of each Fresnel lens and the corresponding solar cell element overlapped in plan view. The height of the stand part was adjusted so that the focal point of the Fresnel lens was positioned on the light receiving surface of the corresponding solar cell element, and then the light was fixed to the pedestal via a column to obtain a concentrating solar power generation device.
Also in Example 2, the same results as in Example 1 were obtained for the deviation of the center coordinates of Fresnel lenses A and B when heated to room temperature (25 ° C.) and 70 ° C. Even when the temperature changed from room temperature to 70 ° C., the focal point of the Fresnel lens was located on the light receiving surface of the solar cell element as at room temperature, and a stable light collecting function was obtained regardless of the temperature change. .

DESCRIPTION OF SYMBOLS 1 ... Condensing lens member 2 ... Solar cell 10 ... Condensing type solar power generation device 11 ... Condensing lens 12 ... Base material

Claims (6)

Solar cells,
A concentrating solar power generation device having at least a condensing lens member disposed on a light receiving surface side of the solar cell,
The concentrating solar power generation device, wherein the condensing lens member includes a base material and a plurality of condensing lenses arranged at a predetermined interval on one surface of the base material.   The predetermined interval is an interval at which the surfaces of the condensing lenses adjacent to each other on the side opposite to the base do not contact each other at the maximum temperature in the operating temperature range determined by the usage environment. The concentrating solar power generation device according to claim 1.   3. The concentrating solar power generation device according to claim 1, wherein the predetermined interval is in a range of 10 μm to 10000 μm.   A condensing lens member, comprising: a base material; and a plurality of condensing lenses arranged at a predetermined interval on one surface of the base material.   The predetermined interval is an interval at which the surfaces of the condensing lenses adjacent to each other on the side opposite to the base do not contact each other at the maximum temperature in the operating temperature range determined by the usage environment. The condensing lens member according to claim 4.   6. The condensing lens member according to claim 4, wherein the predetermined interval is in a range of 10 [mu] m to 10000 [mu] m.