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Title:
SOLAR BATTERY ASSEMBLY
Document Type and Number:
WIPO Patent Application WO/2011/023139
Kind Code:
A1
Abstract:
A solar battery assembly is provided. The solar battery assembly comprises a light-transmitting upper covering plate, a carrier (4), and a plurality of solar cells (3) disposed between the light-transmitting upper covering plate and the carrier (4). The solar cells (3) are connected in series, in parallel, or in a series-parallel connection via positive connection points (41) and negative connection points (42). Direct connections of positive lead-out electrodes (32) and negative lead-out electrodes (33) to the carrier (4) simplify the manufacturing process. The electrical connections are stable. Further, as the assembly can have an adjustable voltage, the maintenance is improved.

Inventors:
LUO HUI (CN)
Application Number:
PCT/CN2010/076446
Publication Date:
March 03, 2011
Filing Date:
August 29, 2010
Export Citation:
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Assignee:
BYD CO LTD (CN)
LUO HUI (CN)
International Classes:
H01L31/048; H01L31/02; H01L31/05
Foreign References:
CN201514948U2010-06-23
CN1625812A2005-06-08
CN1628390A2005-06-15
CN1373906A2002-10-09
CN2487114Y2002-04-17
CN2487113Y2002-04-17
US6703555B22004-03-09
Other References:
See also references of EP 2474045A4
Attorney, Agent or Firm:
TSINGYIHUA INTELLECTUAL PROPERTY LLC (Trade BuildingZhaolanyuan, Tsinghua University, Haidian, Beijing 4, CN)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. A solar battery assembly, comprising:

a light transmitting upper cover plate;

a carrier disposed beneath the light transmitting upper cover plate;

a plurality of solar cells disposed between the light transmitting upper cover plate and the carrier, each of which is connected to the carrier respectively to form a positive connection point and a negative connection point respectively, wherein

the plurality of solar cells are connected in series, in parallel or in parallel and series via the positive connection points and the negative connection points, wherein

the light transmitting upper cover plate, the carrier and the plurality of solar cells are adhered together.

2. The solar battery assembly according to claim 1, wherein each solar cell comprises a positive extraction electrode and a negative extraction electrode for extracting currents which are electrically connected to the carrier to form the positive connection point and the negative connection point respectively.

3. The solar battery assembly according to claim 1, wherein the positive connection points and the negative connection points are electrically connected via an electric circuit which is configured on the upper surface and/or the lower surface of the carrier.

4. The solar battery assembly according to claim 3, wherein the light transmitting cover plate is a glass plate.

5. The solar battery assembly according to claim3, wherein the carrier is a back sheet made of TPT composite membrane, TPE composite membrane, BBF composite membrane or PI composite membrane. 6. The solar battery assembly according to claim 5, wherein the carrier is a printed circuit board with the electric circuit being formed on a surface thereof.

7. The solar battery assembly according to claim 5, wherein the carrier is a glass plate or a steel plate with the electric circuit being formed on a surface thereof.

8. The solar battery assembly according to claim 7, wherein the electric circuit is formed by sintering the printed metal slurry on the surface of the carrier. 9. The solar battery assembly according to claim2, wherein a circuit connected by wires is configured on a lower surface of the carrier.

10. The solar battery assembly according to claim 2, wherein the positive connection points and the negative connection points are electrically conducted with the lower surface of the carrier, and the positive and the negative extraction electrodes are so configured as to form an exterior circuit.

11. The solar battery assembly according to claim 10, wherein a via-hole is formed at each of the connection points, through which the extraction electrodes are connected with the carrier.

12. The solar battery assembly according to claim 2, further comprising a lower cover plate disposed on a lower surface of the carrier.

13. The solar battery assembly according to claim 12, wherein each solar cell is connected in anti-parallel with a bypass diode which is arranged on the lower surface of the carrier or the lower cover plate.

14. The solar battery assembly according to claim 1, wherein the light transmitting upper cover plate, the carrier and the plurality of solar cells are adhered via polyvinyl butyral resin or ethylene-vinyl acetate.

15. The solar battery assembly according to claim 1, further comprising a sealing member for sealing the light transmitting upper cover plate, the plurality of solar cells and the carrier overlapped together.

16. The solar battery assembly according to claim 15, wherein the sealing member is formed with a groove for accommodating edges of the light transmitting upper cover plate, the plurality of solar cells and the carrier overlapped together with sealant being filled therein.

Description:
SOLAR BATTERYASSEMBLY

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority and benefits of Chinese Patent Application No. 200910189696.6, filed with SIPO on August 31 st , 2009, and Chinese Patent Application No. 200920204200.3 filed with SIPO on August 31 st , 2009, the entire contents of which are incorporated herein by reference.

FIELD

The present disclosure relates to solar energy field, more particularly to a solar battery assembly with improved configuration.

DESCRIPTION OF THE RELATED ART

As there is limited traditional energy reservation such as oil which has been consumed continuously along with serious pollution to the environment, utilization of wind energy and solar energy becomes popular now. Specifically, there is abundant resource of solar energy which has little geological restriction, therefore, solar energy becomes a hot and important point of the research nowadays.

As a core component of the solar battery, the solar battery assembly may normally be formed as following: laminating a glass, a binding layer, a plurality of solar cells, a binding layer and a back sheet; hot-pressing the laminated layers as described hereinabove; and sealing the above laminated assembly. Presently, a single solar cell may have a voltage of about 0.5V, which tends to be low and difficult for practical demands. Normally, an outdoor tool may need with a voltage of at least above 12V. Thus, a plurality of solar cells are normally connected in series or in parallel to satisfy voltage demand. That is, a current-extraction electrode of a solar cell is welded with an electrode grid line on the surface of the next solar cell, therefore the solar cells are connected in series or in parallel to meet the requirements thereof. However, the solar cell normally has a narrow electrode grid line which may lead to difficulties in positioning during welding and manufacturing. Meanwhile, in order to ensure the stable connections between the solar cells, the longer current-extraction electrodes thereof have to be designed.

Further, conventionally, a welding strip, such as a tin strip or a copper strip with a tin coating etc, is used which may increase cost for producing the same. Further, to arrange the solar cells orderly and to avoid the effects caused by relative movements to the solar cells and electrodes, positive and negative electrodes of a solar cell are normally positioned on opposite positions, thus it becomes easier to weld electrodes of neighboring solar cells. However, high welding temperature on one side may lead to sealing-off or desoldering of the electrodes already welded on the opposite side, thus leading to higher welding requirements. Additionally, there is strict waterproof requirement of the solar battery assembly for increasing service lifespan and improving performance thereof. In addition, the solar cells contained therein are non-adjustable with invariable voltage and current. Especially, any failure of the single cells may result in the malfunction of the whole solar battery assembly, thus bringing huge waste and great difficulty for maintenance.

SUMMARY

In viewing thereof, the present disclosure is directed to solve at least one of the problems existing in the prior art. Accordingly, a solar battery assembly may be provided, which may easily overcome the difficulty in electrode welding and desoldering with reduced cost and easy maintenance. In addition, the solar battery assembly may form different circuit configuration as conditions may require in addition to stable performance thereof.

According to an embodiment of the present disclosure, a solar battery assembly may be provided, comprising: a light transmitting upper cover plate; a carrier disposed beneath the light transmitting upper cover plate; a plurality of solar cells disposed between the light transmitting upper cover plate and the carrier, each of which is connected to the carrier respectively to form a positive connection point and a negative connection point respectively. The plurality of solar cells may be connected in series, in parallel or in parallel and series via the positive connection points and the negative connection points. The light transmitting upper cover plate, the carrier and the plurality of solar cells may be adhered together.

According to some embodiments of the present disclosure, the carrier may be a lower cover plate of the solar battery assembly, or it may be any layer interposed between the plurality of solar cells and a lower cover plate which are capable of forming connection joints with the positive and negative electrodes.

According to an embodiment of the present disclosure, each solar cell is connected to the carrier respectively to create a positive connection point and a negative connection point, and the plurality of solar cells are connected in series, in parallel or in parallel and series via positive connection points and negative connection points, therefore the connection is more flexible and the circuit is more stable. Particularly, the voltage and the current may be adjustable by simply modifying the circuit or designing regulating elements with the circuit. Meanwhile, the solar battery assembly may still function well by adjusting the circuit when one or more solar cells fail, so that the failure of whole solar battery assembly may be avoided. Accordingly, the solar battery assembly may be self-repairable. Further, the adjustment of the connection in series or in parallel do not need complex processes such as desoldering the solar cells, therefore the solar cells may not be damaged. In addition, the solar cells may be replaced easily.

By electrically connecting the positive and negative extraction electrode to the carrier to form the positive connection point and the negative connection point for further connecting the plurality of solar cells in series, in parallel, or in parallel and series via the circuits formed on the surface of the carrier or the exterior circuit, conventional long welding strips which is about 2 times the length of the solar cells for welding may be avoided, and shorter welding strips may be adopted for secure welding, and shortcomings such as pseudo soldering may be avoided with reduced cost. Meanwhile, positive and negative extraction electrodes of each solar cell are extracted from both ends of the solar cell, the fixing of the positive and negative extraction electrodes on the carrier, especially when the carrier is the lower cover plate of the solar battery assembly, achieves the fixing of each solar cell, preventing the movement of the solar cell, especially damages by vibration to the solar cell, and further enhancing the service lifespan of the solar cells. In addition, since the process standard of the solar cell is lowered, the positive and negative extraction electrodes are only required to be disposed on the front or back surface of the solar cell without special requirement to the fixing thereof, and the process complexity is lowered with reduced cost.

Additional aspects and advantages of the embodiments of the present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the present disclosure will become apparent and more readily appreciated from the following descriptions taken in conjunction with the drawings in which:

Fig. 1 is a schematic view of a solar battery assembly according to an embodiment of the present disclosure; Fig. 2 is a schematic view of a solar battery assembly according to another embodiment of the present disclosure;

Fig. 3 is a schematic view of a carrier formed with electrode connection joints of a solar battery assembly according to an embodiment of the present disclosure;

Fig. 4 is a schematic view of connections of solar cells with the carrier according to an embodiment of the present disclosure;

Fig. 5 is a schematic view of connections of solar cells with a carrier according to another embodiment of the present disclosure;

Fig. 6 is a partially enlarged view of connections of the solar cells having a bypass diode with the carrier according to an embodiment of the present disclosure; and

Fig. 7 is a schematic view of a solar battery assembly according to an embodiment of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

Reference will be made in detail to embodiments of the present disclosure. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions.

According to an embodiment of the present disclosure, a solar battery assembly is provided, each solar cell of which may be easily welded in series, in parallel or in parallel and series. Further, the solar battery assembly is also adjustable and repairable which can be manufactured with reduced complexity. The solar battery assembly may comprise a light transmitting upper cover plate; a carrier disposed beneath the light transmitting upper cover plate; a plurality of solar cells disposed between the light transmitting upper cover plate and the carrier, each of which is connected to the carrier respectively to form a positive connection point and a negative connection point respectively. The plurality of solar cells may be connected in series, in parallel or in parallel and series via the positive connection points and the negative connection points. The light transmitting upper cover plate, the carrier and the plurality of solar cells may be adhered together, for example via an adhesive or binding agent.

According to another embodiment of the present disclosure, each solar cell comprises a positive extraction electrode and a negative extraction electrode for extracting current, the positive and negative extraction electrodes are electrically connected to the carrier respectively to form the positive connection point and the negative connection point. With the solar battery assembly according to the embodiment of the present disclosure, the positive and negative extraction electrodes may be connected directly to the carrier, therefore the production thereof may be simplified and the connection thereof may become more stable. Also the voltage of the solar battery assembly may be adjustable which can also be repaired with easy maintenance.

According to an embodiment of the present disclosure, each solar cell comprises a positive extraction electrode and a negative extraction electrode for extracting currents which are electrically connected to the carrier to form the positive connection point and negative connection point respectively. Thus, the plurality of solar cells may be connected in series, in parallel or in series and parallel by the electric connection of the positive and the negative extraction electrodes to the carrier. Conventional long welding strips which may be twice the length of the solar cell may not be needed with short welding strips being used instead to enhance stability of the connection. Further, the process of welding the positive and negative extraction electrodes to the carrier is simplified, some problem such as poor or pseudo soldering may be avoided with reduced cost. Meanwhile, the positive and the negative extraction electrodes are led out from both ends of one solar cell, and each solar cell may be fixed by fixing the positive and the negative extraction electrodes of each solar cell on the carrier respectively, especially when the carrier is a lower cover plate, thus avoiding the movement of the solar cells and especially the damage to the solar cells caused by the movement, enhancing applicability and lifespan of the solar cells. Furthermore, the processing standard is lowered as the positive and negative extraction electrodes are designed to be provided on the front surface or the back surface without further location requirement, and even relative movement may be allowed. Therefore, the processing difficulty and cost thereof may be decreased or reduced accordingly.

According to some embodiments of the present disclosure, the positive connection points and the negative connection points are electrically connected to each other via an electric circuit which is configured on the upper surface and/or the lower surface of the carrier. Therefore, different connections, such as connection in series, in parallel or in parallel and series, may be achieved easily. According to some embodiment of the present disclosure, an external circuit may be arranged, and the positive and the negative connection points may penetrate through the carrier to be connected by the external circuit, thus achieving the connection in series, in parallel or in parallel and series and adjustment of the solar cells via the external circuit which is not formed on the surface of the carrier. For example, the solar cells may be connected with each other in series by connecting the neighboring positive and negative connection points of the adjacent solar cells. Alternatively, the circuit may be connected via normal wires, or formed by sintering the metal slurry on the carrier. Normal components, such as bypass diodes, that are required by the solar battery assembly may be arranged in the circuit. According to some embodiments of the present disclosure, regulating elements, such as resistances, or switching diodes etc, may be arranged in the circuits accordingly.

The light transmitting upper cover plate may be an upper cover plate commonly used in the art, such as a glass plate.

According to an embodiment of the present disclosure, the carrier may be a lower cover plate directly. According to another embodiment of the present disclosure, the carrier may be any layer disposed between the solar cells and the lower cover plate to be connected with the positive and negative extraction electrodes for forming the positive and negative connection points.

According to some embodiments of the present disclosure, the carrier may be a regular back sheet made of TPT composite membrane, TPE composite membrane, BBF composite membrane, PI composite membrane or the like. According to a preferred embodiment of the present disclosure, a printed circuit board (PCB) board may be used instead. That is, an integrated circuit board formed by a chemical etching conductive film such as a copper foil may be used as the lower cover plate of the solar battery assembly. As necessary circuits are formed in the PCB, the electrode connection points may be electrically connected directly. According to a preferred embodiment of the present disclosure, other components, such as bypass diodes, may be arranged on the upper surface or the lower surface of the PCB board. According to some embodiments of the present disclosure, a hard lower cover plate with aesthetic attractive appearance and a strength which may be attached well with the upper cover plate made of glass may be adopted, such as a glass plate, or a steel plate, so that the layout of the circuits on the surface thereof may be easily formed.

When a back sheet, a glass plate or a steel plate is used, according to one embodiment of the present disclosure, metal slurry may be printed onto the upper surface of the carrier facing toward the solar battery assembly, and then sintered to form the required circuits, that is, the electric circuit may be formed by sintering the printed metal slurry on the upper surface of the carrier. Therefore, the connection points may be connected easily, the process thereof may be simplified with reduced cost. Particularly, because the circuit is provided inside the solar battery assembly, it is rarely influenced by external environment, and the performance and the lifespan of the solar battery is enhanced accordingly. Also, it is much easier to connect a bypass diode with each solar cell so that the solar cell may be protected accordingly.

According to another embodiment of the present disclosure, the metal slurry may also be printed onto the lower surface of the carrier and then sintered to form the desired circuits. According to a preferred embodiment of the present disclosure, a circuit connected by wires may be configured on the lower surface of the carrier, which is easy to be formed outside the solar battery assembly and easy to be operated. According to another embodiment of the present disclosure, only connection points which are connected with the lower surface of the carrier are disposed on the carrier. For example, a via- hole may be formed at each of the connection points, through which the positive and negative extraction electrodes are connected with the carrier which may further be connected via an external circuit disposed outside the solar battery assembly. The current extracting electrodes may be attached to the carrier via adhesive or binding agent. Due to the structure described hereinabove, the extraction electrodes and the solar cells are fixed more tightly, so that the solar battery assembly may be more stable and the lifespan may be extended accordingly.

According to some embodiments of the present disclosure, the carrier may be the one for carrying the connection points rather than the lower cover plate of the solar battery assembly. That is to say, a further lower cover plate may be attached to the lower surface of the carrier. Preferably, due to the configuration of the circuits on the carrier rather than the lower cover plate, the lower cover plate functions only for encapsulation purpose. There are no special limits on the material of the carrier. When only the electrode connection points are formed on the carrier, the extraction electrodes may penetrate through the connection points and connect with the circuit on or outside the lower cover plate. The circuit on the lower cover plate may refer to the circuit on the carrier without a special limit herein. And the solar cells are fixed by the structure as described above so that the movements of the solar cells are avoided. There is no special limit to the material and structure of the carrier, so that the sealing of the solar battery assembly may be realized more easily. The solar cell is not directly connected with the lower cover plate especially, not directly connected with the electrical component configured on the lower cover plate. Therefore, the components are protected effectively and the lifespan of the solar battery assembly may be extended. There is no special limit to the kind of the lower cover plate. According to some embodiments of the present disclosure, it may be a glass plate or a steel plate etc. According to some embodiments of the present disclosure, at least one bypass diodes may be connected in anti-parallel with the solar cells for preventing hot spot effect. The diodes may be disposed between the solar cells and the carrier or between the carrier and the lower cover plate. That is to say, according to one embodiment of the present disclosure, a diode may be fixed inside the solar battery assembly for each solar cell. According to another embodiment of the present disclosure, each solar cell may be connected with a bypass diode in parallel and the diode may be fixed between the solar cells to avoid reverse breakdown. According to a preferred embodiment of the present disclosure, the diodes may be arranged on the lower surface of the carrier or the lower cover plate, and a bypass diode may be connected in parallel with an array of solar cells as shown in Fig. 7. The at least one bypass diode may be connected with the carrier or the lower cover plate via welding or attaching thereto via conductive adhesives. The bypass diodes may be connected in anti-parallel with the solar cells. That is, the positive electrode of the bypass diode is connected with the negative extraction electrode of the solar cell, and the negative electrode of the bypass diode is connected with the positive extraction electrode of the solar cell respectively.

According to some embodiments of the present disclosure, components for adjusting the circuits may be arranged in the circuit to adjust the voltage of the solar battery assembly so that the failure of a single solar cell may not affect the whole assembly. And other electrical components may be adopted, such as resistances, or switch triodes, to improve the stability and performance of the circuit. Preferably, in order to extend the lifespan of the components, a sealing agent or a sealing cover may be adopted to coat or cover the components to protect the circuit or the components respectively.

In these embodiments, there is no special limit to the materials of the positive and negative extraction electrodes. The solar cells may be any kind normally adopted in the art, such as multi-crystal silicon solar cells, single-crystal silicon solar cells or thin-film solar cells.

In these embodiments, the positive and the negative extraction electrode may be led out respectively from ends of each solar cell. The positive extraction electrode may be attached to the back surface grid lines of the solar cell; the negative extraction electrode may be attached to the front surface grid lines of the solar cell. The method of attachment may be any kind known in the art, for example, tin soldering, conductive adhesive agent attaching, and so on. There is no special limit to the position of the electrode grid line, the front and back surface electrode grid lines may be designed at opposing positions on the front and the back surface. Instead, the front surface and the back surface grid lines may not be configured at opposing positions on the front and back surface so that processing difficulty may be decreased.

According to a preferred embodiment of the present disclosure, no circuit may be configured outside the solar battery assembly to reduce external influence on the circuit such as the performance and lifespan thereof. In addition, the bypass diode for bypass protection may be connected more easily with simplified manufacturing processes. Furthermore, it is easy to realize large scale production.

According to some embodiments of the present disclosure, the adhesive or binding agent may be polyvinyl butyral resin or ethylene-vinyl acetate. The binding agent may be filled between the upper cover plate and the solar cells, and the carrier or the lower cover plate. According to a preferred embodiment of the present disclosure, the binding agent may be polyvinyl butyral resin(PVB) which has excellent light transmittance, weatherability and UV resistance in addition to an expansion coefficient closer to the solar cell after adhesion. Accordingly, in one embodiment, at room temperature or a lower temperature, PVB films may be formed between the laminated light transmitting upper cover plate, the plurality of solar cells, and the carrier or the lower cover plate at first. Then, after vacuumizing and hot pressing the laminated layers, the PVB film may be melted and filled in the space of the solar battery assembly to form an integrated body. In other embodiments, liquid PVB may be filled in the solar battery assembly to shape and encapsulate the solar battery assembly accordingly. The process is simple and the connection thus formed is stable. Moreover, the strength and stability of the welding points are enhanced due to the sealing agent. Further, the lifespan of the components may be extended because of the encapsulation thereof.

According to some embodiments of the present disclosure, the solar battery assembly may further comprise a sealing member for sealing the laminated light transmitting cover plate, the plurality of solar cells and the carrier, in order to be water-proof, and dust-proof, and avoid external influence on the performance and the lifespan of the solar battery assembly. Preferably, the sealing member may be formed with a groove for accommodating edges of the light transmitting upper cover plate, the plurality of solar cells and the carrier overlapped together with a sealant filled therein, so as to seal more tightly to be water-proofing and dust-proofing. In addition, the solar battery assembly thus configured is especially adapted to electricity consuming devices such as vehicles etc. satisfying stricter requirement thereof and avoiding looseness of the sealing members which may influence the performance and the lifespan of the solar battery assembly because of vibration thereof. The sealing agent may be any known in the art, such as silica gel, or epoxy resin etc. The shape of the solar battery assembly may be of any shape known in the art.

In the following, the present invention will be described in more detail in conjunction with the accompanying drawings.

As shown in Fig. 1, 3, 4 and 7, the glass plate 1, the PVB film 2, a plurality of solar cells 3 and a PVB film 2, a carrier 4 being a glass plate formed with printed and sintered metal slurry circuit may be overlapped and thermally sealed. A sealing member 5 formed with a groove, may be fixed around the laminated glass plate 1, the solar cells 3 and the carrier 4. A layer of adhesive 6 may be disposed inside the groove of the sealing member 5. Thus, the solar battery assembly is formed accordingly. Then, a positive electrode 10 and a negative electrode 11 of the solar battery assembly are led out for extracting current. A bypass diode 8 is connected in anti-parallel with the positive electrode 10 and the negative electrode 11 respectively. A positive extraction electrode 32 and a negative extraction electrode 33 may be led out from both ends of the solar cell 3 respectively. The positive extraction electrode 32, one end of which is welded to the grid lines on the back surface of the solar cell, may penetrate through the PVB film 2 and be welded to the carrier 4 with the other end thereof to form the positive connection point 41. The negative extraction electrode 33, one end of which is welded to the grid lines 31 on the front surface of the solar cell 3, may penetrate through the PVB film 2 and be further welded to the carrier 4 with the other end thereof to form the positive connection point 42. A plurality of positive connection points 41 and a plurality of negative connection points 42 are electrically connected via the circuit on the surface of the carrier 4 so that the plurality of solar cells are connected in serie, in parallel or in parallel and series respectively. The positive and negative electrodes of one solar cell 3 may be located at the corresponding opposite positions of the back surface and the front surface of the solar cell respectively.

As shown in Figs. 2, 3, 5 and 7, the glass plate 1, the PVB film 2, the plurality of solar cells 3 the PVB film 2, and the carrier 4 for insulation and fixing formed with via-holes and the PCB board 7 having circuits formed thereon may be overlapped and heat sealed. A sealing member 5, which is formed with a groove, may be fixed around and seals the overlapped glass plate 1, the plurality of solar cells 3 and the carrier 4. The layer of the adhesive 6 may be disposed inside the groove of the sealing member 5. Accordingly, the solar battery assembly may be formed. Then the positive electrode 10 and the negative electrode 11 of the solar battery assembly may be led out accordingly. The bypass diode 8 is connected in anti-parallel with the positive electrode 10 and the negative electrode 11. The two ends of the solar cell 3 respectively lead out a positive extraction electrode 31 and a negative extraction electrode 32. The positive extraction electrode 31, one end of which is welded to the grid lines on the back surface of the solar cell, penetrates through the PVB film 2 and is welded to the carrier 4 via the other end thereof to form the positive connection point 41. The negative extraction electrode 32, one end of which is welded to the grid lines 31 on the front surface of the solar cell 3, penetrates through the PVB film 2 and further is welded to the carrier 4 via the other end thereof to form the positive connection point 42. A plurality of the positive connection points 41 and a plurality of the negative connection points 42 are electrically connected via the circuit on the surface of the carrier 4 so that the plurality of solar cells are connected in series, in parallel or in parallel and series. The positive and the negative electrode of one solar cell may be located at the back surface and the front surface of the solar cell respectively rather than at the corresponding opposite positions, i.e. the positions thereof may not be corresponding to each other which may bring benefit to the welding of the extraction electrodes with the electrode grid lines of the solar cell without causing problems such as sealing-off and/or poor soldering.

Fig. 6 shows a partial schematic view of connections between the solar cell 3 having a parallel connected bypass diode 8 and the carrier 4. The two ends of the solar cell 3 are respectively led out a positive extraction electrode 31 and a negative extraction electrode 32 respectively which are further welded with the carrier 4 to form the positive connection points 41 and the negative connection points 42 on the lower surface of the carrier 4 respectively. A bypass diode 8 is connected in parallel corresponding to one solar cell 3 on the lower surface of the carrier 4. The positive electrode 81 of the bypass diode 8 is connected with the negative connection point 42 of the carrier via a wire-welding electrode 9, and the positive electrode 82 of the bypass diode 8 may be connected with the negative connection point 41 of the carrier via another wire-welding electrode 9, so that the bypass diode 8 is connected in anti-parallel with the solar cell 3 accordingly.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that changes, alternatives, and modifications can be made in the embodiments without departing from spirit and principles of the present disclosure. Such changes, alternatives, and modifications all fall into the scope of the claims and their equivalents.