CN111969073A - Semi-flexible solar module and manufacturing method thereof - Google Patents

Abstract

The invention discloses a semi-flexible solar module and a manufacturing method thereof, and in a first aspect, the invention provides a photovoltaic module scheme, a front layer of ultraviolet reflecting material; one or more impact cushioning layers; a crystalline silicon substrate, a multi-component compound thin film material, a polymer modified electrode type, and a solar cell layer of a sensitized nanocrystalline or organic compound solar cell; a support layer of semi-flexible material supporting the solar cell layer; a back layer; none of the layers is composed of glass. The solar module has certain flexibility and wider application than the traditional rigid solar module; and is lighter than conventional solar modules, has low transportation costs, and is easily bent, facilitating assembly to conform to the curvature of the installation site.

Description

Semi-flexible solar module and method of making the same

technical field

The present invention relates to solar modules, and more particularly, to semi-flexible solar modules using crystalline solar cells and methods of manufacturing the same.

Background technique

Solar cells or photovoltaic cells are electrical devices that convert light energy directly into electricity. Generally, multiple solar cells are integrated in a solar module, called a solar panel. Typically, solar modules include metal frames, crystalline solar cells, and glass cover sheets. Since crystalline solar cells are fragile, metal frames and glass cover sheets are used to protect the crystalline solar cells and generally keep the solar module in a preset shape.

More recently, flexible solar modules have been developed using thin-film solar cells, which are not as fragile as crystalline solar cells and can be rolled up. Thin-film solar modules tend to be smaller and more portable. But thin-film solar cells are less efficient at converting light into electricity than crystalline and other solar cells.

Therefore, we need a wide range of semi-flexible solar modules that can use crystalline and other solar cells.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the above problems existing in the prior art, and provide a semi-flexible solar module that can use crystalline silicon substrate, multi-component compound thin film material, polymer modified electrode type, sensitized nanocrystalline or organic compound solar cell. The invention also relates to electrical connection means for semi-flexible solar modules and surface patterns for semi-flexible solar modules. Due to its flexibility, the solar module has a wider range of uses than a rigid solar module. This semi-flexible solar module is also lighter than conventional solar modules. The semi-flexible component is easy to bend to conform to the curvature of the installation site; its light weight makes it less expensive to transport and easy to assemble; the surface of the component allows self-cleaning thanks to its non-stick material and its texture that minimizes surface tension ; This assembly can be fixed with adhesive or screws.

In order to realize the above-mentioned technical purpose and achieve the above-mentioned technical effect, the present invention is realized through the following technical solutions:

Semi-flexible solar modules including:

a front layer of UV reflective material;

one or more impact buffer layers;

A crystalline silicon substrate, a multi-component compound thin film material, a polymer modified electrode type, a solar cell layer of a sensitized nanocrystalline or organic compound solar cell;

a support layer of semi-flexible material that supports the solar cell layer;

a rear layer;

None of the layers consist of glass.

Preferably, the support layer is configured as a transparent support layer, and the transparent support layer is located between the front layer and the solar cell layer.

Preferably, the impact buffer layer is provided as an adhesive layer; one or more impact buffer layers thereof also serve as an adhesive layer.

Preferably, a second impact buffer layer is disposed between the solar cell layer and the support layer.

Preferably, one or more adhesive layers are further arranged between the front layer, the solar cell layer, the support layer and the back layer.

Preferably, a bus bar is provided on the solar cell layer, and a bypass diode is provided on the bus bar.

Preferably, a plurality of the bypass diodes are provided, and the plurality of bypass diodes are respectively arranged on different bus bars on the solar cell layer.

Preferably, the thickness of the solar module does not exceed 7mm.

Semi-flexible solar modules including:

Front layer formed by fluoroplastic film;

Multiple impact buffer layers formed from polymer encapsulation materials;

The solar cell layer formed by crystalline silicon substrate, multi-component compound thin film material, polymer modified electrode type, sensitized nanocrystalline or organic compound solar cell;

A support layer formed of thermoplastic polyester material;

and a back layer consisting of a photovoltaic backsheet.

The beneficial effects of the present invention are:

1. The present invention provides a semi-flexible solar module that can use crystalline silicon substrate, multi-component compound thin film material, polymer modified electrode type, sensitized nanocrystalline or organic compound solar cell;

2. The present invention also relates to an electrical connection device for a semi-flexible solar module and a surface pattern for a semi-flexible solar module;

3. The solar module of the present invention has a wider range of uses than the traditional rigid solar module due to its certain flexibility; it is lighter in weight and lower in transportation cost than the traditional solar module, and is easy to bend and assemble to conform to the curvature of the installation location;

4. The present invention uses non-stick material and its texture to minimize the surface tension, so that the surface of its components allows self-cleaning; in addition, the components can also be fixed with adhesives or screws.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly and implement it according to the content of the description, the following describes the preferred embodiments of the present invention in detail with the accompanying drawings. Specific embodiments of the present invention are given in detail by the following examples and the accompanying drawings.

Description of drawings

The accompanying drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

Figure 1 shows an example of a semi-flexible solar module;

Figure 2 shows another example of a semi-flexible solar module;

Figure 3 shows yet another example of a semi-flexible solar module;

Figure 4 is still another example of a semi-flexible solar module;

Figure 5 shows an example of the busbars and bypass diodes in the semi-flexible solar module with junction box of Figure 1;

Figure 6 shows an example of a series connector for the semi-flexible solar module of Figure 1;

Figure 7 illustrates an example of a parallel connector for the semi-flexible solar module of Figure 1;

Figure 8 shows an example of a junction box for use with the connector of Figure 5;

Figure 9 shows a close-up of the bypass diode in the laminated solar module;

Figure 10 is a top view showing the surface pattern applied to the front layer of the semi-flexible solar module of Figure 1;

Figure 11 is a side view showing the surface pattern applied to the front layer of the semi-flexible solar module of Figure 1;

12 is a flow diagram of a method of applying a pattern to the surface of a solar module.

Detailed ways

Below in conjunction with accompanying drawing, the present invention is further described:

FIG. 1 illustrates an example of a semi-flexible solar module 100 . In this example, solar assembly 100 includes front layer 105 , impact buffer layer 110 , solar cell layer 115 , support layer 120 , and back layer 125 .

FIG. 2 shows another example of a semi-flexible solar module 200 . The example of FIG. 2 is similar to that of FIG. 1 except that an additional shock buffer layer 110 is provided between the solar cell layer 115 and the support layer 120 .

FIG. 3 shows a further example of a semi-flexible solar module 300 . In the present embodiment, the support layer 120 and the solar cell layer 115 in FIG. 2 have been switched in position, with the support layer 120 now overlying the solar cell layer 115 and between the two shock buffer layers 110 . Placing the support layer 120 on top of the solar cell layer 115 is to strengthen the buffer layer against severe external shocks, but it will slightly reduce the transmission of light.

The front layer 105 is transparent in order to provide some protection to the solar module. In particular, the front layer 105 may provide ultraviolet (UV) protection to reduce or prevent degradation of the underlying layers due to sunlight exposure. The front layer 105 may be made of at least one material selected from ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene, polyvinyl fluoride film, and ethylene propylene copolymer. The thickness of the previous layer may be less than 0.2 mm. Depending on the material chosen, the purpose of the previous layer is to provide:

a has good adhesion to the lower layer (can be treated by surface treatment);

b Good dielectric strength, helping to make the front layer 105 an effective insulator;

c good mechanical strength (tear strength) and dimensional stability;

d moisture protection;

e Low surface energy, so the front layer 105 will remain clean and can be easily cleaned.

The impact buffer layer 110 is intended to absorb impact energy, such as hail, snow, solid debris from wind, etc., to prevent damage to the solar cells within the solar cell layer 115 . The shock buffer layer 110 may generally be disposed adjacent to the solar cell layer 115 . In some cases, shock buffer layers 110 may be provided on both sides of the solar cell layer 115 to provide greater protection. In some cases, the impact buffer layer 110 may also serve as an adhesive between the front layer 105 and the solar cell layer 115 and/or between the solar cell layer 105 and the support layer 120 and/or other layers in the stack. The impact buffer layer 110 may be at least one material selected from ethylene vinyl acetate (EVA), silicone sealants, epoxy resins, polyolefins, butyl rubber-based adhesives, or vinyl phenolic resins.

The solar cell layer 115 is composed of crystalline silicon substrate, multi-component compound thin film material, polymer modified electrode type, sensitized nanocrystalline or organic compound solar cell. These cells may be of conventional size, such as 156 mm x 156 mm, or may be other sizes or types of cells mounted on the solar cell layer 115 . In a solar panel, the cells can be connected in series with solder tape or something similar, each solar cell can be soldered together manually or automatically, or conductive glue can be used to glue the solar cells to the solder tape.

The support layer 120 is configured to have sufficient load-bearing properties to enable the support layer 120 to support the solar cell layer 115 so that the solar cell layer 115 does not crack. Accordingly, the support layer 120 may be rigid or semi-flexible and made of at least one material selected from the group of materials: polyethylene terephthalate (PET), polyurethane, polyetherimide, polyethylene - Vinyl fluoride, ethylene-vinyl acetate, polyester, fiberglass sheets, insulating coated plastic or stainless steel sheets, carbon fiber reinforced thermoplastics and glass fiber reinforced thermoplastics. In some examples, if the support layer is placed over the solar cell, the support layer needs to be transparent and not more than 0.8 mm thick. In some cases, the thickness needs to be about 0.5 mm. If the support layer is placed under the solar cell layer, the thickness of the material may be between 0.5 mm and 2 mm.

In some cases, support layer 120 may be transparent and may be placed on top of solar cell layer 115 . It is intended that placing the support layer 120 over the solar cell layer 115 will provide further protection for the solar cell layer 115 from impacts and the like. As shown in FIGS. 2 and 3 , in some cases, support layer 120 may be disposed above solar cell layer 115 , and shock buffer layer 110 may be disposed above and below support layer 120 and below solar cell layer 115 , in order to provide a softer layer for impact protection while also including impact protection from the support layer 120 .

The back layer 125 is to provide different physical or chemical properties to protect from various environmental factors. These properties include, for example: mechanical strength, UV resistance, dielectric strength, thermal stability, hydrolytic stability and moisture resistance. The backing layer 125 may be rigid or semi-flexible and may be selected from polyester polyester sheet, kynar film, plastomer, aluminum coated sheet, stainless steel coated sheet, fiberglass, carbon fiber reinforced thermoplastic, glass fiber reinforced thermoplastic. The thickness of the back layer 120 may be less than 6 mm. What needs to be known is that crystalline solar cells are fragile when the film is rolled up. This semi-flexible solar panel can bend at least 30 degrees over a 1-meter range, with a curve radius greater than 800 mm.

In some cases, the backing layer 120 may include multiple sub-layers, for example, a sub-layer of polyurethane thermoplastic material as a middle sub-layer or an upper sub-layer, and in addition to this sub-layer, at least a second material layer is required for the backing layer 120. The second layer material can be, polyvinyl fluoride (polyvinyl formal), or polyvinylidene fluoride, thermoplastic fluoropolymer material (with high water resistance and intrinsic strength, low penetration of moisture, steam, petroleum and can be used for a wide range of temperature range, for example, -70°C to 110°C).

In each of the above examples, one or more adhesive layers 130 may be provided between the layers to maintain adhesion when the layer of material itself cannot be used to establish adhesion between the layers. In some cases, the adhesive layer 130 may also act as the impact buffer layer 110 .

FIG. 4 shows another example of a solar module 400 . FIG. 4 shows the specific materials of the above-mentioned layers in the solar module 400 .

In this particular embodiment, the front layer 405 is a fluorine-based plastic. This plastic has UV protection and other properties such as high light transmittance (greater than or equal to 92%), high dielectric strength, which helps make the layer an effective insulator, good mechanical strength and moisture permeability. Properties that may be required by these preceding layers. The front layer 405 may be bonded to the support layer 420 with a first adhesive layer 407 of ethylene-ethylene-vinyl acetate. In some cases, the first adhesive layer 407 may include two or more sub-layers of ethylene-vinyl acetate material. In this embodiment, the first adhesive layer 407 may also function as the impact buffer layer 410 .

The support layer 420 is a polyethylene terephthalate material. In this case, the support layer 420 may also serve as the shock buffer layer 410 . The second adhesive layer 413 adheres the support layer 420 to the solar cell layer 415 . The third adhesive layer 423 adheres the solar cell layer 415 to the backside layer 425 . The second and third adhesive layers 413 , 423 may act as a further impact buffer layer 410 for the solar cell layer 415 .

The backside layer 425 is formed of a tetrafluoroethane plastic film material having a thickness of approximately 0.645 mm. This layer has high tensile strength, dimensional stability and low water vapor permeability. In this example, the thickness of the fluorine-based plastic layer is 0.1 mm, the thickness of the adhesive layer is 0.5 mm, the thickness of the thermoplastic support layer is 0.4 mm, the thickness of the solar cell layer is 0.20 mm, and the thickness of the back layer is 0.4 mm.

Typically, the examples of semi-flexible solar modules described herein are fabricated without the use of glass in order to allow a degree of flexibility for the solar module. In addition, the solar module generally does not require an aluminum frame, which is approximately 40% to 50% of the weight of a conventional module. For example, the weight load of a conventional solar module is about 11 kg/square meter, while the weight load of the semi-flexible solar modules provided herein is about 4 to 5 kg/square meter. In some specific cases, the weight is approximately 4.6 kg/m². The solar module is intended to include solar modules integrated from high-efficiency, low-cost crystalline silicon cells of a lightweight, rigid or semi-flexible substrate structure. In some cases, the semi-flexible structure allows about 30 degrees of component bending. The total thickness of the components should be between 8mm and less. In some special cases, the thickness of the solar module may be 3 mm.

FIG. 5 illustrates the solar cell layer 115 in further detail. As shown in Figure 5, the solar cell layer 115 will include a plurality of solar cells and bus bars extending across both sides of the solar cells to interconnect the solar cells and allow the solar cells to produce and pass electrical current through the solar cells. The bus bars can be assembled into the solar cell layer 115 by conventional methods, such as by conventional manual or automated welding techniques. In other cases, the busbars may be bonded to the solar cell layer 115 by a conductive adhesive. In some cases of this example, the bus bars will be covered by, for example, the impact buffer layer 110 and the front layer 105 during the lamination process. Among them, the junction box 450 , the battery string 455 , and the battery slice 460 .

FIG. 7 shows the low state button connector 550 in the parallel connection state. Similar to FIG. 6 , FIG. 7 includes male studs 555 and female sockets 560 on the solar module configured to connect to corresponding connectors 565 and 570 in a parallel manner via press connections. To ensure that there are no holes, the connectors must be filled. In some cases, the filler may be silicone or a similar material. Busbars can be covered with insulating tape to prevent short circuits from contact with other conductive materials.

FIG. 8 shows a junction box 600 provided on the solar cell layer 105 to the bus bar 605 . The bus bar 605 may be connected to the junction box terminal 610 by soldering or the like. If the module power does not exceed (including) 100w, the junction box contains a bypass diode; if the module power exceeds 100w, the junction box does not contain a bypass diode, but the bypass diode is integrated into the module.

Figure 9 shows the provision of one or more diodes on the bus bar. These bypass diodes are used to protect the solar cells from the risk of hot spots when one or more solar cells are shaded or damaged in some way. Usually each string of solar cells has a bypass diode. In conventional solar modules, bypass diodes are provided in the junction box. However, in some instances, the bypass diodes are placed directly on the busbars and wrapped in the stack of layers of the solar module.

Traditional bypass diodes for solar panels can act as a protection mechanism, allowing electricity to continue to be produced within the panel even if one or more strings of cells are inoperative, eg, shaded, damaged, or the like. Typically, all strings of cells are connected in series, and each cell produces current proportional to the amount of sunlight it receives. If any one cell starts to operate at a low capacity, for example, the cell is shaded, contaminated, damaged, or other similar reasons, the overall string current may be limited to what the weakest cell can supply. In this case, the solar panels cannot operate at full capacity.

A typical battery may have a forward voltage of about 0.5 v when at optimum loading. If the cell is shaded, the cell may not draw as much current as other cells in its vicinity, then the cell may be forced into reverse operating mode where it is subject to negative voltage. Underperforming cells can become heating elements, creating hot spots on solar modules that can damage them. To prevent these problems, arrange the series cells of pv components into strings and connect a bypass diode in parallel with each string.

The purpose of the connector is to use a low-profile and compact form for integration into solar modules. In some cases, the connector thickness is about 0.7 mm, making the lamination process of flexible components easier and smoother than traditional processes. The diodes on the busbar are soldered between the two strings. By integrating diodes, it is feasible to use more diodes per solar module, which allows the remaining substrings to continue to operate in partially shaded conditions.

In some examples, a solar module can be configured to include a surface pattern 900 on the surface of the solar module as shown in FIG. 4 on the front layer 405 as shown in FIGS. 10 and 11 . The surface pattern 900 may be produced mechanically, for example, by subjecting the front layer 405 to a pressure treatment. The surface pattern 900 is designed to prevent surface wrinkles in the production process of the module, reduce the loss of sunlight reflection, and improve the output efficiency of the module. In some conventional solar modules, severe surface wrinkles can be observed. Examples of solar modules herein include a special pattern template applied to the surface of the front layer 405 during module processing, which is designed to provide consistent surface angular contact through a pre-set contoured mold. The preset outline may be one of the following patterns, including a debossed pattern, a triangular pattern, a rectangular pattern, a square pattern, and a linear cross-hatched pattern. By printing a cross-hatched pattern on the front layer 405 of the solar module, the surface wrinkles of the module can be reduced or eliminated while the solar module can maintain a light penetration efficiency of more than 90%. Surface stencils can be selected from high temperature stencil plastics, cross-wrapped PTFE fiber stencils, deformed fiberglass stencils, and coated metal stencils.

Figure 12 shows a method of applying the template to a solar module. At 1005, materials are placed to make solar modules. At 1010, a template is placed on the top layer of the solar module. At 1015, the solar panels are fed into the laminator. The lamination process may include achieving a vacuum and maintaining it for a period of time, the pressure is controlled not to be greater than 90 kPa, and the temperature is around 175 °C. At 1020, the solar modules are removed from the laminator to cool. The finished components are placed on a discharge conveyor, laminated and cooled. In some cases, in order to maintain the shape of the component surface pattern and prevent the component from warping during cooling, a thick flat plate or similar object may be placed on top of the pattern for a period of time.

The purpose of a localized surface treatment is to increase the surface energy, resulting in excellent bond strength when a junction box or other connector contacts the surface. Localized surfaces can be treated with techniques such as corona (in the case of o2/n2, n2, n2/co2, etc.), flame treatment, atmospheric plasma activation, atmospheric or low pressure plasma deposition.

In the foregoing description, for the purposes of explanation, corresponding details have been set forth in order to provide a thorough understanding of the examples. In other instances, well-known electrical structures and circuits are shown in block diagram form in order not to obscure the understanding. For example, no specific details are provided as to whether the examples described herein are implemented as software routines, hardware circuits, firmware, or a combination thereof.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. should be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (9)

1. a semi-flexible solar module, characterized in that, comprising: a front layer of UV reflective material; one or more impact buffer layers; A crystalline silicon substrate, a multi-component compound thin film material, a polymer modified electrode type, a solar cell layer of a sensitized nanocrystalline or organic compound solar cell; a support layer of semi-flexible material that supports the solar cell layer; a rear layer; None of the layers consist of glass. 2 . The semi-flexible solar module according to claim 1 , wherein the support layer is configured as a transparent support layer, and the transparent support layer is located between the front layer and the solar cell layer. 3 . 3 . The semi-flexible solar module according to claim 1 , wherein the impact buffer layer is configured as an adhesive layer; and one or more impact buffer layers thereof also serve as an adhesive layer. 4 . 4 . The semi-flexible solar module according to claim 1 , wherein a second impact buffer layer is arranged between the solar cell layer and the support layer. 5 . 5 . The semi-flexible solar module according to claim 1 , wherein one or more adhesive layers are further arranged between the front layer, the solar cell layer, the support layer and the back layer. 6 . 6 . The semi-flexible solar module according to claim 1 , wherein a bus bar is arranged on the solar cell layer, and a bypass diode is arranged on the bus bar. 7 . 7 . The semi-flexible solar module according to claim 6 , wherein a plurality of bypass diodes are provided, and the plurality of bypass diodes are respectively arranged on different bus bars on the solar cell layer. 8 . 8 . The semi-flexible solar module according to claim 1 , wherein the thickness of the solar module is no more than 7 mm. 9 . 9. A semi-flexible solar module, characterized in that, comprising: Front layer formed by fluoroplastic film; Multiple shock buffer layers formed from polymer encapsulation materials; The solar cell layer formed by crystalline silicon substrate, multi-component compound thin film material, polymer modified electrode type, sensitized nanocrystalline or organic compound solar cell; A support layer formed of thermoplastic polyester material; and a back layer consisting of a photovoltaic backsheet.

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