PORTABLE SHINGLED SOLAR MODULES
1. A portable solar module comprising:
- a plurality of strips, each strip including at least one bus bar formed on a top surface thereof;
electrically conductive adhesive electrically connecting each strip when applied to the strip and the strips are arranged to overlap one another to connect the strips in series;
at least one string of overlapped strips, wherein the portable solar module has an output of less than about 200 Watts (W) and an output voltage greater than about 5 Volts (V).
The present disclosure describes a portable solar module including a plurality of strips, each strip including at least one bus bar formed on a top surface thereof. The solar module further includes electrically conductive adhesive electrically connecting each strip when applied to the strip where the strips are arranged to overlap one another to connect the strips in series, and at least one string of overlapped strips, wherein the portable solar module has an output of less than about 130 W and less than about 30V.
- 1. A portable solar module comprising:
a plurality of strips, each strip including at least one bus bar formed on a top surface thereof; electrically conductive adhesive electrically connecting each strip when applied to the strip and the strips are arranged to overlap one another to connect the strips in series; at least one string of overlapped strips, wherein the portable solar module has an output of less than about 200 Watts (W) and an output voltage greater than about 5 Volts (V).
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- 13-18. -18. (canceled)
The present disclosure relates to solar modules, and more particularly, to solar cells incorporated into shingled array module (“SAM”), and methods of manufacturing a solar module of bonded solar cells in a shingled array.
Over the past few years, the use of fossil fuels as an energy source has been trending downward. Many factors have contributed to this trend. For example, it has long been recognized that the use of fossil fuel-based energy options, such as oil, coal, and natural gas, produces gases and pollution that may not be easily removed from the atmosphere. Additionally, as more fossil fuel-based energy is consumed, more pollution is discharged into the atmosphere causing harmful effects on life close by. Despite these effects, fossil-fuel based energy options are still being depleted at a rapid pace and, as a result, the costs of some of these fossil fuel resources, such as oil, have risen. Further, as many of the fossil fuel reserves are located in politically unstable areas, the supply and costs of fossil fuels have been unpredictable.
Due in part to the many challenges presented by these traditional energy sources, the demand for alternative, clean energy sources has increased dramatically. To further encourage solar energy and other clean energy usage, some governments have provided incentives, in the form of monetary rebates or tax relief, to consumers willing to switch from traditional energy sources to clean energy sources. In other instances, consumers have found that the long-term savings benefits of changing to clean energy sources have outweighed the relatively high upfront cost of implementing clean energy sources.
One form of clean energy, solar energy, has risen in popularity over the past few years. Advancements in semiconductor technology have allowed the designs of solar modules and solar panels to be more efficient and capable of greater output. Further, the materials for manufacturing solar modules and solar panels have become relatively inexpensive, which has contributed to the decrease in costs of solar energy. As solar energy has increasingly become an affordable clean energy option for individual consumers, solar module and panel manufacturers have made available products with aesthetic and utilitarian appeal for implementation on residential structures. As a result of these benefits, solar energy has gained widespread global popularity.
The present disclosure is directed to a solar module including a plurality of strips, each strip including at least one bus bar formed on a top surface thereof, electrically conductive adhesive electrically connecting each strip when applied to the strip and the strips are arranged to overlap one another to connect the strips in series, and at least one string of overlapped strips, wherein the portable solar module has an output of less than about 200 Watts (W) and an output voltage of not less than about 5 Volts (V). The portable solar module may have an output of not less than about 100 W and 12 V, not less than about 5 W and 5 V, or not less than about 2 W.
The portable solar module may include at least two strings separated by a hinge, and each string may include 18 strips. The hinge separates at least two halves of the portable solar module, and each half includes at least three strings of 18 strips. The strings on one half of the portable solar module are connected in parallel with each other and the halves of the portable modules may be connected in series with one another. The output of the portable solar module may be at least 100 W and 12V.
In a further embodiment, the strings on one half of the portable solar module are connected in parallel with one another, and the strings in each half of the portable solar module are connected either in series or parallel.
A further embodiment of the present disclosure is directed to a method of manufacturing a portable solar module including singulating a solar cell to form a plurality of strips, each strip including at least a portion of bus bar, cutting the strips to form a plurality of solar squares, each square including at least a portion of the bus bar on at least one side of the solar square, and applying electrically conductive adhesive (ECA) to the plurality of solar squares. The method further includes overlapping a desired number of solar squares such that the ECA bonds the busbar of one cell to a second surface of an adjacent solar square to form a row of solar squares, arranging the rows of solar squares in a desired pattern, and electrically connecting the rows of solar squares to achieve a desired output power and voltage.
The method may further include electrically connecting the rows of solar squares in series or in parallel. And the desired number of squares is 10 and the output of the portable solar module is about 2 W.
Various aspects of the present disclosure are described hereinbelow with reference to the drawings, which are incorporated in and constitute a part of this specification, wherein:
Further details and aspects of exemplary embodiments of the present disclosure are described in more detail below with reference to the appended figures.
The present disclosure is directed to shingled solar modules and particularly portable solar modules. While there have been a variety of applications teaching the methods of formation and structure of a shingled array module (SAM), these have been directed at SAMs for use in industrial and solar power plant applications. Generally, these SAMs have an output of about 300 Watts. SAMs have the benefit of an increased output and efficiency as compared to traditional solar modules. These increases in output and efficiency are based largely on the increased total surface area available for absorption of sunlight as compared to traditional solar modules. While these SAMs are indeed of great benefit and superior to traditional solar modules, they are awkwardly sized and poorly fit for use in more portable applications such as on recreational vehicles, yachts, or even personal solar charging devices.
The general process for forming a SAM is described with respect to
As illustrated in
A back side 146 of the solar cell 100 likewise includes metallization, as illustrated in
The particular locations of the front and back side bus bars are strategically selected. In particular, the front side bus bars may be formed at locations that are away from one or both of the edges of the solar cell 100, which thereby reduces side leakage and improves shunt resistance. As a result, high yield and improved low irradiation performance are achieved. Furthermore, by grouping two of the front side bus bars together so that they are adjacent each other, three sets of probes may be employed, rather than the typical five or six sets of probes, to contact bus bars during flash testing. The fewer number of probes used also reduces the shadow impact of the probes during the testing to thereby improve the accuracy and consistency of cell efficiency test.
The back side bus bars 148, 150, 152, 154, 156 are unevenly spaced apart across the solar cell 100. Specifically, the back side bus bars 148, 150, 152, 154, 156 are formed at locations on the back side 146 of the solar cell 100 such that upon cleaving the solar cell 100 into a plurality of strips made up of each of the discrete sections 106, 108, 110, 112, 114, the front side bus bar 116, 118, 120, 122, 124 of the strip is on an edge opposite from an edge on which a back side bus bar 148, 150, 152, 154, 156 is formed. For example, turning to
Having produced or been provided a solar cell 100, the process of building a SAM can begin. With reference to
The solar cell is cut at step 304. Specifically, scribe lines are formed into the back surface of the solar cell so that when the solar cell is broken, the split occurs in the gap on the front surface of the solar cell between the discrete cells. Each scribe line has a depth of between about 10% and about 90% of wafer thickness. In an embodiment, the scribe lines extend across the solar cell from edge to edge. In another embodiment, one or both of the scribe lines extends from one edge to just short of an opposite edge of the solar cell. The scribe lines may be formed using a laser, a dicing saw and the like. In an embodiment, as illustrated in
Next, the scribed solar cell 100 is split at step 306. In an embodiment in which the solar cell may be singulated, the solar cell is placed on a vacuum chuck including a plurality of fixtures which are aligned adjacent each other to form a base. The vacuum chuck is selected so that the number of fixtures matches the number of discrete sections of the solar cell to be singulated into strips. Each fixture has apertures or slits, which provide openings communicating with a vacuum. The vacuum, when desired, may be applied to provide suction for mechanically temporarily coupling the solar cell to the top of the base. To singulate the solar cell, the solar cell is placed on the base such that the each discrete section is positioned on top of a corresponding one of the fixtures. The vacuum is powered on and suction is provided to maintain the solar cell in position on the base. Next, all of the fixtures move relative to each other. In an embodiment, multiple ones of the fixtures move a certain distance away from neighboring fixtures thereby causing the discrete sections of the solar cell to likewise move from each other and form resulting strips. In another embodiment, multiple ones of the fixtures are rotated or twisted relative to their longitudinal axes thereby causing the discrete sections of the solar cell to likewise move and form resulting strips. The rotation or twisting of the fixtures may be effected in a predetermined sequence, in an embodiment, so that no strip is twisted in two directions at once. In still another embodiment, mechanical pressure is applied to the back surface of the solar cell to substantially simultaneously break the solar cell into the strips. It will be appreciated that in other embodiments, other processes by which the solar cell is singulated alternatively may be implemented. Upon completion of singulation in step 306, the solar cell 100 is separated into its sections or strips 106-114 as shown in
After the solar cell is singulated, the strips are sorted in step 308. In particular, as shown in
With continued reference to
In an embodiment as illustrated in
As is known in the art any solar cell, or portion thereof, regardless of the size is approximately 0.6 volts. Thus both the cell depicted in
In order to charge typical lead acid batteries a charge voltage of about 14-16 volts is necessary. In order to achieve the desired voltage it is necessary that the input to a charge controller (i.e., the output of the solar module) be approximately 18-19V, and will be stepped down in the charge controller to the desired 14-16V charge voltage. As will be appreciated there are additional degradations of the output of the solar module over time, thus a convenient design criteria is to design the solar module to output 20V and 100 W of power.
In the context of a fixed flat solar module 202 to output 20V, 33 strips 106-114 must be connected in series as described above. Then three strings 170 of strips 106-114 can be connected in parallel to output the desired 100 W. If an output current of 130 W is desired then four strings 170 must be connected in parallel. For the folded portable module 200 design, a different configuration is necessary. First because of the one or more hinges, the total length of the string 170 can only be about half (or ⅓, ¼, ⅕, ⅙th) of the length of the solar module once unfolded. In the context of a ½ folded solar module 200, each string 170 will have approximately 18 strips. While this is somewhat more than half the needs of a fixed flat solar module 202, the additional strips are necessary to account for losses created by the wiring of the two halves to one another. As a result a 100 W folded solar module will have three strings 170 of 18 strips 106-114. The strips 106-114 are connected in series to form the string 170 as described above. A string 170 of 18 strips will output approximately 10V. The strings 170 of the first half of the solar module 200 are connected in series with the strings 170 of the second half of the solar module, resulting in a string output total of approximately 20V. The two sets of three strings 170 are connected in parallel and output about 100 W. If four strings 170 are utilized the output is approximately 130 W. The portable SAMs 200 and 202 are particularly useful in recreational vehicle yachts for charging batteries.
A further embodiment of the present disclosure can be seen with respect to
Though depicted in
An alternative to cutting the solar cell into 20 strips is to cut the solar cell into 5 strips as in the other embodiments if the present disclosure, and then cut each strip 106-114 into four generally square pieces 306, as depicted in
Though described herein as having a specific number of strips and strings, each SAM may be formed of a variety of strips and strings without departing from the scope of the present disclosure depending on the application. Thus strings of 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100 or more strips and any number therein between to achieve a desired output voltage and power are contemplated within the scope of the present disclosure. Further SAMs having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 strings have the number of strips described above are contemplated within the scope of the present disclosure to achieve a desired output voltage and power. Similarly the formation of series connected squares can also vary from 2-100, and any number therein between, and can be formed in parallel rows in any number from 2-100 as desired by the designer for a specified or desired voltage and power rating.
While several embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Any combination of the above embodiments is also envisioned and is within the scope of the appended claims. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope of the claims appended hereto.