Solar Module

Abstract

A solar module comprising a plurality of solar cell strings arranged side by side, each having a positive electrode and a negative electrode at opposite ends of the solar cell string, the solar cell strings including: a first group of adjacent solar cell strings, each oriented such that the positive electrodes of the solar cell strings are disposed toward a first end of the solar module; and a second group of adjacent solar cell strings, each oriented such that the positive electrodes of the solar cell strings are disposed toward a second end of the solar module opposite the first end, the positive electrodes of the solar cell strings of the second group being electrically connected to the negative electrodes of the solar cell strings of the first group.

Description

[Technical field]

[0001] The present disclosure relates to solar modules, and in particular, but not exclusively, to solar modules of the type comprising multiple strings of solar cells arranged side-by-side. [Background technology]

[0002] A solar module for providing electrical energy from sunlight comprises an array of photovoltaic cells (also referred to herein as solar cells), each including a semiconductor substrate. The cells are traditionally connected such that current is routed through a grid of finger electrodes on the cell surface to a series of wider vertical busbar electrodes printed on the front and back of the cell. From the busbar electrodes, the current flows along a series of copper ribbons, each of which is soldered to a respective busbar electrode, to a junction box. In some configurations, the busbars are replaced by a series of copper ribbons / wires arranged on the grid of fingers.

[0003] In particular, multiple solar cells can be electrically connected in series and in rows to define solar cell strings. A solar module can include multiple such strings arranged side-by-side to form a row of solar cells. The solar cell strings can be electrically connected to each other and to a junction box by bus bars connected at the ends of the solar cell strings. Summary of the Invention

[0004] According to a first aspect, there is provided a solar module comprising a plurality of solar cell strings arranged side by side, each solar cell string having a positive electrode and a negative electrode at opposite ends of the solar cell string, the plurality of solar cell strings including: a first group of adjacent solar cell strings, each oriented such that a positive terminal of the solar cell string is disposed toward a first end of the solar module; A solar module is provided that includes: a second group of adjacent solar cell strings, each oriented such that the positive electrodes of the solar cell strings are disposed toward a second end of the solar module opposite the first end, and the positive electrodes of the solar cell strings of the second group are electrically connected to the negative electrodes of the solar cell strings of the first group.

[0005] The bus bars must be insulated from one another due to the potential risk of short circuits where the bus bars overlap, which increases the complexity of manufacturing and assembling the solar module. The disclosed configurations can allow solar cell strings to be connected to one another and to external circuits or components without the need to overlap the bus bars that provide connections for the solar cell strings. This can avoid the need to provide electrical insulation between the bus bars and / or reduce the likelihood of short circuits occurring.

[0006] The term "edge" is not intended to be limited to the longitudinal edge of a solar module (i.e., represented by the short side of a rectangular solar module), i.e., the "edge" can be any opposing area of ​​the solar module, including, for example, the opposing long side of a rectangular solar module.

[0007] For the avoidance of doubt, the term "adjacent" as used herein means two solar cell strings adjacent to each other with no solar cell string located between them. Two adjacent solar cell strings may be in contact with each other (i.e. directly adjacent) or may be spaced apart from each other.

[0008] It should also be understood that the term "connected" as used herein is intended to mean electrically connected and does not require direct (e.g., physical) contact between the connected components (i.e., the term does not require that a negative electrode of a first group be in direct contact with a positive electrode of a second group). For example, the two terminals may be physically spaced apart, and one or more wires (or other conductive elements) may be connected to both of the two terminals to electrically connect the terminals together.

[0009] The following are optional features, which can be applied alone or in any combination with any aspect.

[0010] Each solar cell string of the first group may be connected in series with at least one solar cell string of the second group.

[0011] Each solar cell string in the first group may be connected in parallel with the remaining other solar cell strings in the first group. Each solar cell string in the second group may be connected in parallel with the remaining other solar cell strings in the second group. The first group solar cell strings may be connected in series with the solar cell strings in the second group.

[0012] Each solar cell string may be connected in series with only one other solar cell string to define a solar cell string pair, and each solar cell string pair may include a first group of solar cell strings and a second group of solar cell strings. Each solar cell string pair may be connected in parallel with the remaining other solar cell string pairs.

[0013] The solar module may include one or more intermediate conductive elements electrically connecting the positive poles of the solar strings of the second group to the negative poles of the solar strings of the first group. Each intermediate conductive element may be attached to or integral with the solar string it connects. The one or more intermediate conductive elements may be integral with a busbar of the solar string. At least one (e.g., each) intermediate conductive element may be in the form of an interconnect busbar. At least one (e.g., each) intermediate conductive element may be in the form of a wire.

[0014] At least one intermediate conductive element (e.g., an interconnect bus bar) may include a core surrounded by an outer layer. The core may include copper (e.g., may be a copper plate). The outer layer may include a soldering alloy (i.e., have a melting point suitable for soldering).

[0015] The solar module may include a single (i.e., only one) intermediate conductive element connecting each positive pole of the solar cell strings of the second group to each negative pole of the solar cell strings of the first group. That is, the single intermediate conductive element may connect all of the solar cell strings of the first group to all of the solar cell strings of the second group. In such an embodiment, the intermediate conductive element may include a number of legs, each connected to a corresponding solar cell string, and a cross link connecting the multiple legs. Each leg may be substantially parallel to the long axis of the solar cell string. The cross link may be substantially perpendicular to the legs.

[0016] The solar module may include a plurality of intermediate conductive elements, each of which may connect a positive pole of a solar cell string of a second group in the solar cell string pair to a negative pole of a solar cell string of a first group in the solar cell string pair. In other words, each intermediate conductive element may connect (only) two solar cell strings, one from the first group (via the negative pole of the first group) and one from the second group (via the positive pole of the second group).

[0017] Each intermediate conductive element may include a first leg connected to a negative pole of a first group of solar cell strings, a second leg connected to a positive pole of a second group of solar cell strings, and a cross link connecting the first leg and the second leg. The first leg and the second leg may be substantially parallel to a long axis of the solar cell strings. The cross link may be substantially perpendicular to the first leg and the second leg. In this regard, each intermediate conductive element may be U-shaped.

[0018] The intermediate conductive elements (e.g., U-shaped intermediate conductive elements) may be arranged concentrically. Each group of solar cell strings may include a first solar cell string (i.e., may be the innermost solar cell string) that is closest to the remaining other groups of solar cell strings. Each group of solar cell strings may include a second solar cell string that is spaced outwardly (i.e., away from the remaining other groups of solar cell strings) from the first solar cell string. A second intermediate conductive element connecting the second solar cell strings of the first and second groups may extend around the first (innermost) intermediate conductive element connecting the first solar cell strings. Thus, the legs and cross links of the second intermediate conductive element may be longer than the legs and cross links of the first intermediate conductive element.

[0019] Each group of solar cell strings may include a third solar cell string spaced outwardly of the second solar cell string. A third intermediate conductive element may connect the third solar cell strings of the first and second groups. The third intermediate conductive element may extend around the second intermediate conductive element. Thus, the legs and cross links of the third intermediate conductive element may be longer than the legs and cross links of the second intermediate conductive element.

[0020] The solar module may include one or more first conductive elements for connecting to the positive electrodes of the first group of solar cell strings. The solar module may include a single first conductive element for connecting to the positive electrodes of the first group of solar cells. The first conductive element may include a plurality of legs connected to the positive electrodes of the solar cell strings and cross links connecting the plurality of legs.

[0021] The solar module may include one or more second conductive elements for connecting to the negative terminals of the second group of solar cell strings. The solar module may include a single second conductive element for connecting to the negative terminals of the second group of solar cells. The second conductive element may include a plurality of legs connected to the negative terminals of the solar cell strings and a cross link connecting the plurality of legs.

[0022] A bypass diode (e.g., a power management device) may be connected between the first group of solar cell strings and the second group of solar cell strings. All of the solar cell strings may be connected to the bypass diode. The bypass diode may connect the first conductive element to the second conductive element.

[0023] The bypass diode may be connected in parallel with the solar cell string and may have a first terminal connected to a positive electrode of one of the first group of solar cell strings and the second group of solar cell strings, and a second terminal connected to a negative electrode of the other of the first group of solar cell strings and the second group of solar cell strings.

[0024] The bypass diodes may be housed in a junction box, which may be located at the rear side of the solar module, i.e., the side of the solar module that is intended to face away from the radiation source (e.g. the sun) during use.

[0025] The bypass diode may be configured to have a low resistance in one current flow direction and a high resistance in the opposite current flow direction. The bypass diode is connected such that during normal use (e.g., when the solar cells of the solar cell string are not malfunctioning or shaded), the diode presents a high resistance to the normal direction of current. Thus, current flows through the solar cell string and not through the diode. However, when a solar cell of the string malfunctions or is shaded, that cell presents a higher resistance to current compared to when that cell is not malfunctioning or shaded. When two or more solar cells in a string malfunction or are shaded, the resistances of these solar cells combine and add together. When the solar cell resistance of the string increases above the high resistance of the diode, the current flows through the diode and not through the solar cell string, thereby facilitating current flow through other solar cell strings of the module. In essence, when the path through the bypass diode is the path of least resistance (e.g., when one or more cells of the solar cell string are shaded or malfunctioning), the current flows through the bypass diode. When the bypass diodes are not the path of least resistance (e.g., when the cells of the solar string are not shaded and not malfunctioning), the current flows through the solar string. Due to the provision of solar strings in parallel, the path of least resistance depends at least in part on the shading pattern across the solar module. That is, if one solar string is heavily shaded (so as to present high resistance), but other solar strings (in parallel) remain substantially unshaded, the current can pass through those solar strings instead of through the bypass diodes.

[0026] In this way, the bypass diode allows current to flow through the solar module, thereby allowing it to collect current generated by other interconnected solar modules even when the solar module itself is not generating current (e.g., due to shading or malfunctioning, the solar cell causes an increase in resistance).

[0027] The positive electrodes of the first group of solar cell strings may be substantially aligned with the negative electrodes of the second group of solar cell strings in a direction across the solar cell strings. The negative electrodes of the first group of solar cell strings may be substantially aligned with the positive electrodes of the second group of solar cell strings in a direction across the solar cell strings.

[0028] The solar module may include six solar cell strings. The first group may include three solar cell strings. The second group may include three solar cell strings. The first group and the second group may include the same number of solar cell strings.

[0029] Each solar cell string includes a plurality of solar cells. For example, each solar cell string may include 10 to 30 solar cells, such as 15 to 26 solar cells.

[0030] The solar cells of each solar cell string may partially overlap each other along the length of the solar cell string, i.e., the solar cells may be arranged in a shingle manner. The solar cells of each string may be connected in series.

[0031] Each solar cell may be rectangular with a length greater than its width. Each solar cell may be oriented such that the width of the solar cell is aligned with the length of the solar cell string.

[0032] Each solar cell may be a half-cut solar cell (i.e., formed of a square solar cell that has been split (i.e., cut) into two parts), and thus each solar cell may have a width that is twice the length of the solar cell.

[0033] Each solar cell may be a triple cut solar cell (i.e., formed of a square solar cell divided into three sections). Thus, each solar cell may have a width that is three times the length of the solar cell. Each solar cell may be otherwise formed of a solar cell divided into four or five sections (so as to have a width four or five times the length of the solar cell).

[0034] By cutting the solar cell (e.g., in halves, thirds, quarters, fifths), resistive losses can be reduced. Resistive losses have a quadratic relationship with the area of ​​each cell (and therefore the length of each cell for a given width). That is, resistive losses are proportional to the square of the area of ​​the cell, and therefore, by reducing the length, resistive losses can be reduced.

[0035] Cutting the solar cells into halves, thirds, quarters, fifths, etc. means that more cells can be placed into a module of a given size.

[0036] It will be understood that each solar cell may be configured to define any type of solar cell structure. For example, each solar cell may define a heterojunction (HJT) type solar cell. Alternatively, each solar cell may define a tandem junction solar cell. Similarly, any suitable means for electrically coupling the solar cells of the solar cell string to each other may be provided. In one example, the solar cells of each solar cell string may be connected to each other by a foil and wire arrangement, such as Smart Wire Connect Technology (SWCT®). That is, a foil may be provided on the front and back of each cell, and a wire may extend from the front of each cell (between the foil and the front surface) to the back of the adjacent cell (between the back surface and the foil). In another example, the solar cells may be connected by one or more conductive elements, such as ribbons (e.g., copper ribbons).

[0037] Those skilled in the art will understand that, unless mutually exclusive, a feature or parameter described in connection with any one of the above embodiments may be applied to any other embodiment. Further, unless mutually exclusive, any feature or parameter described herein may be applied to any embodiment and / or may be combined with any other feature or parameter described herein. [Brief description of the drawings]

[0038] Embodiments will now be described, by way of example only, with reference to the drawings in which:

[0039] [Figure 1] FIG. 1 is a schematic diagram of a solar module. [Diagram 2] FIG. 2 is a schematic diagram of a modified example of the solar module of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Aspects and embodiments of the present disclosure will now be discussed with reference to the accompanying drawings. Further aspects and embodiments will be apparent to those skilled in the art. In the figures, dimensions of elements may be exaggerated for clarity. Also, the relative dimensions of elements shown in the figures do not necessarily represent the actual relative thicknesses of the elements in all embodiments.

[0041] 1 shows a solar module 100 with six solar cell strings 101a, 101b arranged side-by-side in parallel and extending between opposing first and second ends 102, 103 of the solar module 100. In particular, there are three solar cell strings 101a and three solar cell strings 101b. Although it is not clear from the figure, each solar cell string 101a, 101b is formed of a number of solar cells connected in series. The solar cells may in particular be arranged so as to partially overlap in the longitudinal direction of the string (i.e. arranged in a shingle manner).

[0042] Each solar string 101a, 101b includes a positive pole and a negative pole (as depicted by the plus and minus signs in the figure) at the opposite ends of the solar strings 101a, 101b. The solar cell strings 101a, 101b are arranged in a first group 104 of solar cell strings 101a and a second group 105 of solar cell strings 101b. The solar cell strings 101a of the first group 104 may be different (e.g., different type, size, shape, etc.) from the solar cell strings 101b of the second group 105, or they may be the same. Each of the first group 104 and the second group 105 includes three solar cell strings 101a, 101b. As is clear from the figure, the positive poles of the solar strings 101a of the first group 104 are disposed towards the first end 102 of the solar module 100. Thus, the negative electrodes of the solar cell strings 101 a of the first group 104 are disposed towards the second end 103 of the solar module 100 .

[0043] The solar cell strings 101b of the second group 105 have an inverted orientation relative to the solar cell strings 101a of the first group 104. Thus, each solar cell string 101b of the second group 105 has a negative pole disposed toward the first end 102 of the solar module 100 and a positive pole disposed toward the second end 103 of the solar module 100.

[0044] The negative pole of the solar cell strings 101a in the first group 104 is electrically connected to the positive pole of the solar cell strings 101b in the second group 105. In particular, each solar cell string 101a in the first group 104 is connected in series with a single solar cell string 101b in the second group 105 to define a solar cell string pair. Each pair of solar cell strings 101a, 101b is connected by an intermediate conductive element in the form of an interconnect busbar 106a, 106b, 106c. There are three pairs of solar cell strings 101a, 101b and therefore three corresponding intermediate interconnect busbars 106a, 106b, 106c.

[0045] The first intermediate interconnect busbar 106a connects the innermost pair of solar cell strings 101a, 101b (i.e., those closest to the vertical centerline of the solar module 100 as shown in FIG. 1). The second intermediate interconnect busbar 106b connects the pair of solar cell strings 101a, 101b immediately outside the innermost pair of solar cell strings 101a, 101b. The third intermediate interconnect busbar 106c connects the outermost pair of solar cell strings 101a, 101b. In this manner, the intermediate busbars 106a, 106b, 106c are arranged concentrically so as not to overlap. Each intermediate interconnect busbar 106a, 106b, 106c includes a pair of legs 107 extending parallel to the solar cell strings 101a, 101b and cross links 108 connecting the legs 107. Thus, each of the intermediate interconnect bus bars 106a, 106b, 106c is substantially U-shaped. Also, for each of the intermediate interconnect bus bars 106a, 106b, 106c, the length of the associated cross link 108 may be greater than the length of each associated leg 107.

[0046] The solar module 100 further comprises a first conductive element in the form of a first interconnect busbar 109 including a number of legs 110 connected to the solar cell strings 101a of the first group 104 and cross links 111 extending transversely to connect the legs 110. The first interconnect busbar 109 may connect the positive poles of the solar cell strings 101a of the first group 104 to a positive connector 108 of the solar module 100. The positive connector 108 may connect the solar module 100 to one or more external components, such as additional solar modules (not shown).

[0047] A second conductive element in the form of a second interconnect busbar 112 is also provided, the second interconnect busbar 112 including a number of legs 113 connected to the solar cell strings 101b of the second group 105 and cross-link bridges 114 extending transversely to connect the legs 113. The second interconnect busbar 112 may connect the negative terminals of the solar cell strings 101b of the second group 105 to a negative terminal connector 115 of the solar module 100. This negative terminal connector 115 may also connect the solar module 100 to one or more external components, such as further solar modules (not shown). In this manner, each pair of connected solar cell strings 101a, 101b is connected in parallel with the remaining other pairs of solar cell strings 101a, 101b.

[0048] 1, due to the configuration of the solar cell strings 101a, 101b, the first interconnect busbar 109 and the second interconnect busbar 112 do not overlap. This avoids the need to insulate the first interconnect busbar 109, 112 from each other in the overlap area since there is no overlap area. This in turn reduces the cost and complexity of manufacturing the solar module 100 since insulation for the overlap area is not required.

[0049] The bypass diode 116 is connected between the first interconnect busbar 109 and the second interconnect busbar 112 so as to be connected in parallel with the solar cell strings 101a, 101b. The bypass diode 116 is configured to conduct when the solar cell strings 101a, 101b are reverse biased (e.g., due to shading or malfunction of a solar cell). The bypass diode 116 is connected to the first interconnect busbar 109 and the second interconnect busbar 112 via connectors 118 and 119, respectively.

[0050] The solar module 100' illustrated in Figure 2 is a variation of the solar module described above, and therefore many of the features of this solar module 100' remain the same and the same reference numbers are used.

[0051] The solar module 100' of this variation differs only in that a single intermediate conductive element in the form of an intermediate interconnect busbar 106' is provided (as opposed to multiple intermediate interconnect busbars as shown in FIG. 1). The intermediate interconnect busbar 106' includes multiple legs 107' and a single cross-link 108' connecting all of the legs 107'. This variation can allow the solar module 100' to be more compact than the solar module of FIG. 1 (i.e., due to the need to space apart the U-shaped busbars 106a, 106b, and 106c of FIG. 1). This means that for a given solar module surface area, a higher percentage of the area of ​​the solar module 100' can contain power-generating solar cells compared to the solar module 100. In this way, the solar module 100' can generate more electricity than a comparably sized solar module 100, meaning that the solar module 100' has higher power and higher efficiency compared to the solar module 100. Additionally, because the multiple intermediate interconnect bus bars of solar module 100 are replaced by a single intermediate interconnect bus bar of solar module 100', the manufacturing cost and complexity is lower compared to that of solar module 100. Furthermore, solar module 100 and solar module 100' each require only a single bypass diode.

[0052] It will be understood that the present invention is not limited to the embodiments described above, and various modifications and improvements can be made without departing from the concepts described herein. Any feature can be used separately or in combination with any other feature, except where mutually exclusive, and the present disclosure extends to and includes all combinations and subcombinations of one or more features described herein.

Claims

1. A solar module comprising a plurality of solar cell strings arranged side by side, each solar cell string having a positive electrode and a negative electrode at opposite ends of the solar cell string, and the plurality of solar cell strings: a first group of adjacent solar cell strings, each oriented such that a positive terminal of the plurality of solar cell strings is disposed toward a first end of the solar module; a second group of adjacent solar cell strings, each oriented such that a positive electrode of the plurality of solar cell strings is disposed toward a second end of the solar module opposite the first end, wherein the positive electrode of the solar cell strings of the second group is electrically connected to the negative electrode of the solar cell strings of the first group; 2. A solar module, comprising:

2. The solar module according to claim 1 , wherein each solar cell string of the first group is connected in series with at least one solar cell string of the second group.

3. 3. The solar module of claim 2, wherein each solar cell string in the first group is connected in parallel with the remaining other solar cell strings in the first group, and each solar cell string in the second group is connected in parallel with the remaining other solar cell strings in the second group.

4. 2. The solar module of claim 1, wherein each solar cell string is connected in series with only one other solar cell string to define a solar cell string pair, and each solar cell string pair includes a solar cell string of the first group and a solar cell string of the second group.

5. The solar module according to claim 4 , wherein each pair of solar cell strings is connected in parallel with the remaining pairs of solar cell strings.

6. The solar module of claim 1 , comprising one or more intermediate conductive elements connecting the positive electrodes of the second group of solar cell strings to the negative electrodes of the first group of solar cell strings.

7. 2. The solar module of claim 1, comprising a single intermediate conductive element connecting each positive electrode of the second group of solar cell strings to each negative electrode of the first group of solar cell strings.

8. 5. The solar module of claim 4, comprising a plurality of intermediate conductive elements, each intermediate conductive element connecting the positive electrode of the solar cell string of the second group in the solar string pair to the negative electrode of the solar cell string of the first group in the solar string pair.

9. Each intermediate conductive element is 9. The solar module of claim 8, comprising: a first leg connected to the negative electrode of the solar cell string of the first group; a second leg connected to the positive electrode of the solar cell string of the second group; and a cross link connecting the first leg and the second leg.

10. The solar module of claim 8 , wherein the intermediate conductive elements are arranged concentrically.

11. a first conductive element connected to the positive electrodes of the first group of solar cell strings; The solar module according to claim 1 , further comprising: a second conductive element connected to the negative electrodes of the second group of solar cell strings.

12. The solar module according to claim 1 , further comprising a bypass diode connected in parallel with the solar cell string.

13. A first conductive element connected to the positive electrodes of the first group of solar cell strings; a second conductive element connected to the negative electrode of the second group of solar cell strings; The solar module of claim 12 , wherein the bypass diode is connected between the first conductive element and the second conductive element.

14. The solar module of claim 1 , wherein each solar cell string includes a plurality of solar cells that overlap in a longitudinal direction of the solar cell string.

15. 15. The solar module of claim 14, wherein each solar cell is rectangular and has a width greater than its length.

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