JP2010109045A - Light-collecting solar cell module - Google Patents

Abstract

Provided is a low-cost solar cell module in which a condenser lens and a solar cell element can be easily aligned, the manufacturing process can be simplified.
In a concentrating solar cell module in which solar cells are arranged between a front surface protective material and a back surface protective material, incident light from the front surface protective material side is irradiated between the surface protective material and the solar cells. A concentrating solar cell module, wherein a condensing lens is installed so as to condense on a battery cell.
[Selection] Figure 3

Description

  The present invention relates to a solar cell module with improved reliability.

  In recent years, solar power generation devices that directly convert sunlight into electrical energy have attracted attention and are being developed from the viewpoint of effective use of resources and prevention of environmental pollution. In order to spread solar power generation, it is necessary to increase the efficiency and cost of the solar power generation apparatus, and various types of solar power generation apparatuses are currently being developed.

As a high-efficiency solar power generation device, a type of concentrating solar power generation that takes out the power by irradiating the solar cell module consisting of solar cell elements smaller than the light receiving area of the condensing lens with sunlight condensed by the condensing lens The device is known. In general, a concentrating solar power generation device is configured with a combination of a small-area solar cell made of an expensive semiconductor such as high-efficiency GaAs or InGaP and a large condensing lens disposed on the solar cell, further increasing the efficiency. In order to achieve this, a drive device that tracks the movement of the sun is provided. Therefore, there is a drawback that the manufacturing cost is high (for example, see Patent Document 1). Therefore, as a low-cost concentrating solar power generation apparatus, a method of fixing only the concentrating lens and moving only the solar cells (for example, see Patent Documents 2 and 3), or condensing the condensing lens and the solar cells. A method of moving the entire solar cell module (see, for example, Patent Document 4) has been proposed. However, in a conventional device aiming at a condensing magnification of 100 times or more, a distance is taken between the condensing lens and the solar cell. There is a limit to miniaturization and cost reduction because it is necessary and heat dissipation and a driving device are required.
JP 2004-153202 A Japanese Patent No. 3275684 JP-A-11-125765 JP 2006-343435 A

  This invention is made | formed in view of such a condition, and it aims at providing the highly efficient solar cell module which does not use a large sized apparatus and expensive material.

  It is another object of the present invention to provide a low-cost solar cell module that can easily align the condenser lens and the solar cell element, simplify the manufacturing process, and reduce the cost.

  The above object of the present invention is achieved by the following configurations.

  1. In the concentrating solar cell module in which solar cells are arranged between the surface protection member and the back surface protection member, incident light from the surface protection member side is collected between the surface protection member and the solar cell on the solar cell. A concentrating solar cell module, wherein a condensing lens is installed so as to emit light.

  2. 2. The above-described general formula 1 is satisfied, where x (mm) is the focal length of the condenser lens and y (mm) is the distance between the incident surface of the condenser lens and the solar battery cell. Concentrating solar cell module.

General formula 1 0.3 <y / x <1
3. 3. The concentrating solar cell module according to 1 or 2, wherein the condensing lens is a condensing lens sheet in which a plurality of lenses are formed.

  4). 4. The concentrating solar cell module according to any one of 1 to 3, wherein the condensing lens is a condensing lens sheet comprising a plurality of linear Fresnel lenses.

  5. 5. The concentrating solar cell module according to claim 1, wherein a focal length x of the condensing lens is 1 mm or more and 10 mm or less.

  6). 6. The concentrating solar cell module according to any one of 1 to 5, wherein a focal length x of the condensing lens is 1 mm or more and 5 mm or less, and a lens pitch is 10 μm or more and 100 μm or less.

  7). The concentrating solar cell module according to any one of 1 to 6, wherein the solar cell is a CIS type compound semiconductor solar cell.

  According to the present invention, a condensing lens having a short focal length is installed under the surface protection member with the same configuration as the non-condensing type conventional module, thereby condensing the solar cells at low cost. A highly efficient solar cell module can be obtained. Furthermore, by installing a solar cell in front of the focal length of the condensing lens and designing the condensing magnification to about 10 to 50 times, efficiency improvement by condensing can be obtained even when oblique light is incident, The amazing effect of increasing the amount of power generation per day was also obtained.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

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

  FIG. 1 is a schematic view showing a part of a cross section of a general non-condensing solar cell module, in which adjacent solar cells 1 are connected by wiring 3. The solar cells thus connected are sandwiched between the transparent surface protection member 41 on the light incident side and the back surface protection member 42 on the back surface side through the sealing material layer 2.

  FIG. 2 is a conceptual diagram of a general concentrating solar cell. The solar cell 1 is installed on the substrate 6 in the vicinity of the focal length of the condensing lens 51, and the condensing lens and the solar cell are arranged so that the light condensed 100 to 500 times hits the solar cell of a small area. The installation position is controlled. In this case, if the incident angle of sunlight changes, the solar cell will not be exposed to light, so the condenser lens or the solar cell is moved mechanically using a tracking device, and the light is always applied to the solar cell. It is controlled to hit.

  Therefore, a general concentrating solar cell has a structure in which one or both of the condensing lens and the solar cell move, and the manufacturing process is complicated, and advanced control by a tracking device is required.

  FIG. 3 shows a cross-sectional view of the concentrating solar cell module of the present invention. The present invention is characterized in that the condensing lens is installed on the back surface of the surface protection member 41, and is a solar cell module in which the condensing lens and solar cells are integrated.

  The concentrating solar cell module of the present invention is preferably about the same thickness as a conventional non-concentrating solar cell module, and the module thickness z shown in FIG. 3 is preferably 1 mm or more and 100 mm or less, Furthermore, it is preferable that they are 1 mm or more and 30 mm or less.

  As the condensing lens used in the present invention, a general lens such as a convex lens or a Fresnel lens can be used. However, a cylindrical lens that condenses light in a slit shape on a linear array of solar cells is preferable. It is preferable that the lens is a lens sheet formed continuously. FIG. 3 shows an example using the condensing lens sheet 52.

  Moreover, in order that the thickness of the concentrating solar cell module of the present invention is approximately the same as the conventional non-condensing solar cell module, the focal length of the condensing lens used in the present invention is preferably short, The focal length x is preferably 10 mm or less, and more preferably 1 mm or more and 5 mm or less.

  FIG. 4 is a conceptual diagram showing the focal length x, the distance y between the incident surface of the condenser lens and the solar battery cell, and the incident angle of incident light. 4A shows an incident state when incident light is incident on the solar cell module at an incident angle of 0 degrees, and FIG. 4B shows an incident state when incident light is incident obliquely at an incident angle θ.

  In the present invention, the focal length x and the distance y between the incident surface of the condenser lens and the solar battery cell are preferably in the range of 0.3 <y / x <1, and further 0.45 < More preferably, it is in the range of y / x <0.95.

  In the present invention, the light collection magnification can be adjusted by installing the solar cells at the above positions, and the preferred light collection magnification is 2 to 50 times. Furthermore, by placing the solar cell in front of the focal length of the condensing lens and making the surface area of the solar cell equivalent to that of the condensing lens, oblique incident light hits the solar cell with high illuminance, Photoconversion efficiency can be made higher than that of a non-condensing solar cell module of solar cells having the same area.

  In the concentrating solar cell module of the present invention, the distance y between the incident surface of the condensing lens and the solar cell can be adjusted by the sealing material layer between the condensing lens and the solar cell.

  As the sealing material, ethylene-vinyl acetate (EVA) and polyvinyl butyral (PVB), silicone resin, urethane resin, acrylic resin, fluorine resin, ionomer resin, ethylene-acrylic acid, which are generally used as transparent sealing materials A copolymer, an ethylene-methacrylic acid copolymer, a polyethylene resin, a polypropylene resin, an acid-modified polyolefin resin, an epoxy resin, a polyester resin, and the like are preferable, and EVA having particularly high translucency and adhesiveness is preferable. Furthermore, in order to adjust the distance y between the incident surface of the condenser lens and the solar battery cell, a sealing film in which two or more different resins are laminated can be used. In the present invention, two EVA films are used. It is preferable to adjust the distance y between the incident surface of the condensing lens and the solar battery cell to a predetermined distance by sandwiching a polyester resin film therebetween.

  A condensing lens preferable in the present invention is a lens sheet in which short-focus linear Fresnel lenses are continuously formed, and it is preferable to produce a condensing lens sheet having such a structure at low cost.

  The condensing lens sheet can be produced by forming fine irregularities of the Fresnel lens structure on the surface of the transparent resin film.

  The Fresnel lens having a focal length of 10 mm or less used in the present invention is preferably formed by producing a lens pitch as a mold, pressing a UV curable resin against the mold, and then peeling off after curing. That is, it is preferable to form a lens sheet having a focal length of 1 mm or more and 5 mm or less by transferring a lens pitch of 10 μm or more and 100 μm or less to a UV curable resin using a roll-shaped mold.

  The condensing lens sheet is preferably disposed so as to be in contact with the back surface of the front surface side protection member as shown in FIG. 3, or the lens shape is preferably processed on the back surface side of the front surface protection member.

  The solar cell 1 used in the present invention has a semiconductor junction such as a PN junction or a PIN junction inside, a silicon semiconductor material such as single crystal silicon, polycrystalline silicon, or amorphous silicon, or a compound semiconductor material such as GaAs or CuInSe. A general solar cell material such as an organic material such as a dye-sensitized system can be used. In the solar cell module configuration of the present invention, a crystal material such as single crystal silicon, polycrystalline silicon, GaAs, or CuInSe is used. The solar cell used is preferably used.

  In the present invention, it is particularly preferable to use a CIS type solar battery cell using a thin film of a compound semiconductor material made of Cu—In—Ga—Se in terms of high efficiency by light collection and productivity. That is, as shown in FIG. 5, in a solar cell module in which the CIS type solar cell 1 formed on the substrate 6 is sealed between the front surface protection member 41 and the back surface protection member 42, the Fresnel lens structure 1 unit width a is 1 A concentrating solar cell module can be easily formed by stacking and concentrating the condensing lens sheet 52 formed with the same width as the individual solar cell width b on the substrate on which the solar cells are formed.

The surface electrode 11 is preferably a transparent conductive film, and particularly a transparent conductive film containing a light-transmitting conductive oxide such as SnO ₂ , ITO, IWO, ZnO or the like. The back electrode 12 is formed of a conductive material such as silver, aluminum, copper, nickel, molybdenum, tin, gold, or an alloy thereof, and molybdenum or a molybdenum compound is particularly preferable. Note that the electrode may have a single layer structure containing a conductive material or a multilayer structure.

  The surface protective member 41 on the light incident side is usually a glass substrate such as silicate glass. As for the thickness of a glass substrate, 0.1-10 mm is common, and 0.3-5 mm is preferable. The glass substrate may generally be chemically or thermally strengthened. A resin material can also be used to reduce the weight of the solar cell module.

  The resin material used as the light incident side transparent protective member is not particularly limited as long as the light receiving surface side of the solar cell is translucent. For example, polycarbonate, acrylic resin, polyethylene terephthalate, polybutylene terephthalate, Polyvinyl chloride, polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinylidene chloride, polyphenylene sulfide, polyamide, polyurethane, polymethacrylate, polyacrylonitrile, ABS, phenol resin, melamine resin, formaldehyde resin, urea resin, unsaturated polyester resin, It may be composed of an epoxy resin, natural rubber or a derivative thereof, or may be composed of two or more kinds of the above resins, or may be composed of two or more kinds of resin plates bonded together.

  The back surface protection member 42 can be made of the same material as the light incident side transparent surface protection member 41. However, in order to further reduce the mass of the entire module, a relatively soft film-like polyethylene terephthalate (PET) is used. It can be composed of a material such as a film, a resin film such as a fluororesin film, a resin film on which a metal oxide vapor deposition film such as silica or alumina is formed, a metal film such as an aluminum foil, or a laminated film thereof. it can.

  In addition, the back surface side protection member 42 is provided with a function of suppressing heating of the solar battery cell due to light collection by providing a concavo-convex structure, attaching a film made of a metal having high thermal conductivity, or a radiation fin. You can also

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, the aspect of this invention is not limited to this.

Example 1
<Production of solar cell module>
As shown in FIG. 1 or FIG. 3, a light incident side transparent protective member 41 made of a glass plate (thickness 3 mm) or a surface protective member in which a condensing lens sheet is previously bonded to a glass plate, and two pieces of aluminum foil Four solar cells 1 are connected in series with the back side protection member 42 having a thickness of 1 mm sandwiched between PET films, and solar cell module No. 1-4 were produced. As the solar cell, a single crystal silicon wafer having a size of 10 cm square and a thickness of 150 μm was used, and an aluminum electrode was attached to the front and back surfaces. At this time, a sealing material using a PET film sandwiched between 0.5 mm thick EVA films was used so that the distance y between the incident surface of the condensing lens and the solar battery cell would be the value shown in Table 1. It was adjusted. Sealing was performed by thermocompression bonding with a vacuum laminator at a temperature of 150 ° C. under vacuum.

<Evaluation of solar cell module>
The solar cell module produced above was irradiated with pseudo-sunlight at 25 ° C. and an irradiation intensity of 1000 mW / cm ² by a solar simulator whose spectrum was adjusted to AM 1.5, and the open voltage [V] of the solar cell and 1 cm ^2. The nominal maximum output operating current [A] and the nominal maximum output operating voltage [V] are measured, and the nominal maximum output [W] (JIS C8911-1998) is obtained from these products, and this is used as the output of each module. . Furthermore, the output of the module 1 produced without using the condenser lens was calculated as 100, and the output of another level was calculated.

  It can be seen that the concentrating solar cell module of the present invention exhibits an excellent output level while being approximately the same thickness as a conventional solar cell module.

(Example 2)
<Production of solar cell module>
As shown in FIG. 5, after forming the back electrode 12 which consists of Mo on the soda glass substrate 6, the Cu-Ga / In precursor film | membrane was formed, and the CIS type semiconductor layer was formed by the selenization method. Thereafter, a Zn (O, S, OH) _x , ZnO: B transparent conductive film layer was formed as the surface electrode 11, and CIS type solar cells in which 50 unit cells having a width of 2 mm were connected in series by patterning were produced. As shown in FIG. 5, this CIS type solar battery cell is sandwiched between a 3 mm thick glass plate 41 with a condensing lens sheet 52 having a 2 mm wide Fresnel lens structure and an aluminum foil sandwiched between two PET films. The solar cell module No. is sealed between the back side protective member 42 having a thickness of 1 mm. 5-11 were produced. At this time, as a sealing material, a PET film sandwiched between 0.5 mm thick EVA films was used, and the distance y between the incident surface of the condensing lens and the solar battery cell was a value shown in Table 2. It was adjusted. Sealing was performed by thermocompression bonding with a vacuum laminator at a temperature of 150 ° C. under vacuum.

<Evaluation of solar cell module>
The solar cell module produced above was irradiated with pseudo-sunlight at 25 ° C. and an irradiation intensity of 1000 mW / cm ² by a solar simulator whose spectrum was adjusted to AM 1.5, and the open voltage [V] of the solar cell and 1 cm ^2. The nominal maximum output operating current [A] and the nominal maximum output operating voltage [V] are measured, and the nominal maximum output [W] (JIS C8911-1998) is obtained from these products, and this is used as the output of each module. .

  Furthermore, the incident angle at which the solar simulator module is irradiated with light from the solar simulator is changed as shown in Table 2, and the same measurement is performed. The output of the module 5 produced without using the condenser lens is output at 0 degree. Other levels of output were calculated as 100.

  The results are listed in Table 2.

  It can be seen that the CIS-type concentrating solar cell module of the present invention exhibits a high output level over a wide range of incident angles of light as compared with the conventional solar cell module.

It is a part of a general non-condensing solar cell module cross section. It is a conceptual diagram of a general concentrating solar cell. The concentrating solar cell module sectional drawing of this invention is shown. It is a conceptual diagram which shows the focal distance x, the incident surface of a condensing lens, the distance y of a photovoltaic cell, and the incident angle of incident light. The CIS type concentrating solar cell module of the present invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solar cell 2 Sealing material layer 3 Wiring 6 Base material 11 Front surface electrode 12 Back surface electrode 41 Surface protection member 42 Back surface protection member 51 Condensing lens 52 Condensing lens sheet

Claims (7)

In the concentrating solar cell module in which solar cells are arranged between the surface protection member and the back surface protection member, incident light from the surface protection member side is collected between the surface protection member and the solar cell on the solar cell. A concentrating solar cell module, wherein a condensing lens is installed so as to emit light. The following general formula 1 is satisfied, where x (mm) is the focal length of the condenser lens and y (mm) is the distance between the incident surface of the condenser lens and the solar battery cell. Concentrating solar cell module.
General formula 1 0.3 <y / x <1 3. The concentrating solar cell module according to claim 1, wherein the condensing lens is a condensing lens sheet on which a plurality of lenses are formed. The concentrating solar cell module according to claim 1, wherein the condensing lens is a condensing lens sheet including a plurality of linear Fresnel lenses. The concentrating solar cell module according to any one of claims 1 to 4, wherein a focal length x of the condensing lens is 1 mm or more and 10 mm or less. 6. The concentrating solar cell module according to claim 1, wherein a focal length x of the condensing lens is 1 mm to 5 mm and a lens pitch is 10 μm to 100 μm. The concentrating solar cell module according to claim 1, wherein the solar cell is a CIS type compound semiconductor solar cell.

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