CA3205662A1 - Photovoltaic solar module - Google Patents

Abstract

A photovoltaic solar module includes: an outer glass layer positioned to receive sunlight thereon when the photovoltaic solar module is in use; a plurality of photovoltaic cells disposed beneath the glass layer, the photovoltaic cells being configured to receive sunlight through the glass layer; and a reflective layer disposed between the glass layer and the plurality of photovoltaic cells. The reflective layer includes at least one reflector. The at least one reflector is at least partially aligned with at least one photovoltaic cell of the plurality of photovoltaic cells to limit exposure to sunlight of the at least one photovoltaic cell when the photovoltaic cell is directly facing incoming sun rays, and to maintain exposure to sunlight when sun rays impinge on the outer glass layers at indirect angles of incidence.

Description

PHOTOVOLTAIC SOLAR MODULE
TECHNICAL FIELD
[0001] The present technology relates to the field of solar energy. In particular, the present disclosure relates to photovoltaic solar modules.
BACKGROUND

[0002] In the field of solar energy systems, the ability to harness solar power as a cost-effective source of electrical energy remains a challenge.

[0003] Solar power is typically captured by an interconnected array assembly of photovoltaic (PV) cells comprised by solar modules for electric power production.

[0004] In a typical photovoltaic system, solar modules may comprise local power optimizing devices configured to determine the most favorable operating condition of each solar module comprised within strings of interconnected solar modules, and each string of solar modules of the system may be connected to a grid-tied converter or inverter which may take the power from the PV modules at their maximum power points. Combining power optimizing components at the module (local) and system (global) levels provides high efficiency yields of power from photovoltaic systems, and this combination, which adds a significant cost, is typically used to extract the maximum power possible from each PV module within the system and from the system as a whole.

[0005] In some specific applications, power optimizing components at the module level are required to control the power output of each module, reducing the output power when the voltage exceeds a predetermined load threshold established, for example, by a load capacity of fuses or buried cables, and in these cases, capping the output of the modules restricts their peak performance.

[0006] Although combining power optimizing components at the local and global levels in a photovoltaic system provides functional optimization of system efficiency, there is a need for more economically viable ways to control the current output of photovoltaic modules in a system array.

[0007] Another way of controlling a waveform produced by a PV
module is to use modules that are sized for the application and for the grid requirements, where the maximum power output from each module at optimum conditions cannot exceed the load capacity. This significantly reduces the daily output of the system as compared to systems with local power optimizers, since output will be under capacity in all but optimum conditions. Therefore, there is a need for solar modules with consistent power output in varying conditions throughout the day, while eliminating the cost of local power optimizing components.
SUMMARY

[0008] It is an object of the present technology to ameliorate at least some of the inconveniences present in the prior art.

[0009] In accordance with aspects of the present technology, there is a provided a photovoltaic solar module configured to provide a consistent power output under varying illumination angles. Specifically, according to some embodiments, the PV solar module includes reflector strips which reflect away a portion of incident sunlight at normal incidence (thereby limiting efficiency at normal incidence) while also aiding in increasing efficiency of the module at some off-normal angles. In this way, the module can be configured to have good performance over a large range of angles (increasing a total amount of power produced) while the peak power can be configured to match other system requirements, such as matching the peak power of previously existing installations in order to refurbish solar power installations.

[00010] In accordance with an aspect of the present technology, there is provided a photovoltaic solar module, comprising an outer glass layer positioned to receive sunlight thereon when the photovoltaic solar module is in use; a plurality of photovoltaic cells disposed beneath the glass layer, the photovoltaic cells being configured to receive sunlight through the glass layer; and a reflective layer disposed between the glass layer and the plurality of photovoltaic cells, the reflective layer comprising at least one of reflector, the at least one reflector being at least partially aligned with at least one photovoltaic cell of the plurality of photovoltaic cells to limit exposure to sunlight of the at least one photovoltaic cell.

[00011] In some embodiments, the at least one reflector includes a plurality of reflectors, and the reflectors of the plurality of reflectors define a plurality of gaps therebetween.

[00012] In some embodiments, the reflective layer of the photovoltaic solar module is an optic film mesh.

[00013] In some embodiments, the at least one reflector comprises a facetted pattern with mirrored portions.

[00014] In some embodiments, for at least one photovoltaic cell of the plurality of photovoltaic cells: a portion thereof is covered by the at least one reflector; and a size of the portion covered by the at least one of the reflector is determined based on a desired modified power output of the photovoltaic solar module.

[00015] In some embodiments, the photovoltaic cells of the plurality of photovoltaic cells are arranged in a rectangular array.

[00016] In some embodiments, the photovoltaic cells of the plurality of photovoltaic cells are bifacial solar cells.

[00017] In some embodiments, the photovoltaic solar module further comprises a backing sheet disposed beneath the plurality of photovoltaic cells.

[00018] In some embodiments, when the photovoltaic solar module is in use: the at least one reflector reflects sun rays incident thereon toward the glass layer; when the sun rays reflected by the at least one reflector are at an off-normal angle of incidence to the glass layer, the glass layer reflects light by total internal reflection towards a corresponding photovoltaic cell; and when the sun rays reflected by the at least one reflector are at a normal angle of incidence to the glass layer, the glass layer transmits a majority of the sun rays therethrough outwardly of the photovoltaic solar module.

[00019] According to another aspect of the present technology, there is provided a method of refurbishing a solar module installation, the solar module installation including a plurality of used photovoltaic solar modules, the method including determining a nominal peak power output associated with each of the used photovoltaic solar modules; determining a peak power output associated with each one of a plurality of new photovoltaic solar modules; selecting at least one new photovoltaic module of the plurality of new photovoltaic modules, a peak power output difference between the nominal peak power output of each of the used photovoltaic solar modules and the peak power output of the at least one new photovoltaic solar module being below a threshold, the at least one new photovoltaic solar module having at least one reflector covering a portion of at least one photovoltaic cell of a plurality of photovoltaic cells thereof; and replacing at least one of the used photovoltaic solar modules with the at least one new photovoltaic solar module.

[00020] In some embodiments, the portion of the at least one photovoltaic cell covered by the at least one reflector is at least 10%.

[00021] In some embodiments, the peak power output of the at least one new photovoltaic solar module is within 25% of the nominal peak power output of each of the used photovoltaic solar modules.

[00022] In some embodiments, the peak power output of the at least one new photovoltaic solar module is approximately equal to the nominal peak power output of each of the used photovoltaic solar modules.

[00023] In some embodiments, the modified average power output of the at least one new photovoltaic solar module is greater than an average power output of each of the used photovoltaic solar modules.

[00024] In some embodiments, a number of the photovoltaic cells the at least one new photovoltaic solar module is the same as a number of photovoltaic cells of each of the used photovoltaic solar modules.

[00025] As used herein, the terms "new" and "used" denote simply if a given article, such as a solar module, has previously been installed or used for its intended use. For example, a new solar module may have previously been operated for testing its properties in a laboratory setting but will not generally have been previously used in a solar module installation.

[00026] Embodiments of the present technology each have at least one of the above-mentioned objects and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present technology that have resulted from attempting to attain the above-mentioned object may not satisfy this object and/or may satisfy other objects not specifically recited herein.

[00027] Additional and/or alternative features, aspects and advantages of embodiments of the present technology will become apparent from the following 5 description, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS

[00028] Embodiments will now be described more fully with reference to the accompanying drawings in which:

[00029] Figure 1 is a top view of a photovoltaic solar module according to an embodiment of the present technology;

[00030] Figure 2 is an exploded view of the photovoltaic solar module of Figure 1;

[00031] Figure 3 is a top view of a photovoltaic solar module according to another embodiment;

[00032] Figure 4A is a top view of a photovoltaic solar module according to another embodiment;

[00033] Figure 4B is a close-up view of a section of the photovoltaic solar module of Figure 4A;

[00034] Figure 4C is a close-up view of a reflector strip of the photovoltaic solar module of Figure 4A;

[00035] Figure 5A is a cross sectional view of the reflector strip of Figure 4C
taken along line 5A in Figure 40, shown when sunlight impinges thereon at an angle normal to a surface of an outer glass layer of the photovoltaic solar module;

[00036] Figure 5B is a cross sectional view of the reflector strip of Figure 4C
taken along line 5A in Figure 40, shown when sunlight impinges thereon at an approximately 45 angle of incidence to the outer glass layer of the photovoltaic solar module;

[00037] Figure 6 is a cross sectional view of a section of a photovoltaic solar module according to another embodiment;

[00038] Figure 7 is a cross sectional view of a section of a photovoltaic solar module according to another embodiment;

[00039] Figure 8A is a close-up view of a section of a reflector strip of the photovoltaic solar module of Figure 4A according to another embodiment;

[00040] Figure 8B is a cross sectional view of the reflector strip of Figure 8A
taken along line 8B in Figure 8A;

[00041] Figure 80 is a cross sectional view of the reflector strip of Figure 8A
taken along line 8C;

[00042] Figure 8D is a cross sectional view the reflector strip of Figure 8A taken along line 8B in Figure 8A, shown when light impinges on the photovoltaic solar module 210 at an off-normal angle of incidence;

[00043] Figure 9 is a graph comparing the power curve of a conventional PV
solar module and the photovoltaic solar module of the present technology; and

[00044] Figure 10 shows a flow chart of an illustrative embodiment of a method of refurbishing a solar module installation according to an embodiment of the present technology.
DETAILED DESCRIPTION

[00045] With reference to Figures 1 and 2, a non-limiting example of a photovoltaic (PV) solar module 10 for harvesting sunlight in accordance with an embodiment of the present technology is illustrated. The PV solar module may alternatively be referred to as a PV solar panel. As will be described in greater detail below, the PV solar module 10, and other embodiments thereof (including the PV
solar modules 110, 210 described further below), provides localized power conditioning to ameliorate at least some of the inconveniences present in the prior art.

[00046] A person skilled in the art would understand that modifications to the embodiments described below are possible, and necessary for specific applications, and the description below is meant to provide mere examples of a PV solar module of the present technology.

[00047] As shown in Figure 1, the PV solar module 10 comprises an optically transparent outer glass layer 12, a photovoltaic layer 36 including an array of thirty-five photovoltaic cells 14 positioned beneath the outer glass layer 12, and a reflective layer 16 disposed between the glass layer 12 and the photovoltaic cells 14. In this embodiment, the photovoltaic cells 14 are crystalline silicon (c-Si) photovoltaic cells. It is contemplated that the photovoltaic cells could be made of any other suitable photovoltaic material. In this embodiment, the outer glass layer 12 is a rectangular sheet of glass, but it can alternatively be made of any transparent material such as polymers.

[00048] The reflective layer 16 is an optical film mesh comprising four reflector strips 18, attached together at their opposite ends by two connector strips 24. The reflector strips 18 are strips of optical film comprising a mirrored microstructure thereon (as seen in the close-up views of Figures 4C and 8A for similar reflector strips 218, 258 described in detail further below). The reflector strips 18 are aligned and parallel to one another, and one connector strip 24 is positioned at each end of the reflector strips 18. The reflector strips 18 of the reflective layer 16 are positioned to cover a portion of one of the photovoltaic cells 14 which will be referred to as an optically shaded cell 26.

[00049] The photovoltaic cells 14 are arranged in a rectangular array to form a photovoltaic layer 36. The connector strips 24 of the reflective layer 16 are positioned over the gaps 38 formed between the optically shaded cell 26 and two adjacent ones of the photovoltaic cells 14 (on opposite sides of the optically shaded cell 26) which will be referred to herein as the adjacent cells 28, 29 of the photovoltaic layer 36.

[00050] In this embodiment, the proportion of the surface area of the optically shaded cell 26 covered and shaded by the reflector strips 18 is approximately 33.3%
(i.e., approximately one-third). However, it is contemplated that, in alternative embodiments, the proportion of the surface area of the optically shaded cell covered and shaded by the reflector strips 18 of the reflective layer 16 could be different, namely based on a desired modified power output of the photovoltaic solar module 10 and of the optically shaded cell 26.

[00051] When the photovoltaic solar module 10 is in use, the outer glass layer 12 is positioned to receive sunlight thereon. Furthermore, the photovoltaic layer 16 disposed beneath the glass layer 12 is configured to receive sunlight through the glass layer 12. The reflective layer 16 is disposed between the glass layer 12 and optically shaded photovoltaic cell 26 of the photovoltaic layer 36, and the reflector strips 18 of the reflective layer 16 limit exposure to sunlight of portions of the optically shaded photovoltaic cell 26 below. Each reflector strip 18 of the reflective layer 16 is at least partially aligned with the optically shaded photovoltaic cell 26 of the photovoltaic layer 36. The reflector strips 18 are equally spaced apart defining a plurality of gaps 19 therebetween, the portions of the optically shaded photovoltaic cells 36 positioned below the gaps 19 receive sunlight directly via the outer glass layer 12.

[00052] As shown in Figure 2, when assembling the photovoltaic solar module 10, the photovoltaic layer 36 is attached to a backing sheet 20 via a bottom encapsulant 34 such as an ethylene vinyl acetate (EVA) film or any other suitable encapsulating adhesive. Furthermore, the reflective layer 16 is positioned over the photovoltaic layer 36, with the reflector strips 18 positioned over the optically shaded cell 26, and the connector strips 24 positioned over the gaps 38 between the optically shaded cell 26 and the two adjacent cells 28,29. A top encapsulant 32 such as an EVA
film or any other suitable encapsulating optically transparent adhesive bonds the outer glass layer 12 to the photovoltaic layer 36, sandwiching the reflective layer 16 in place between the outer glass layer 12 and the PV cells 14 of the photovoltaic layer 36.

[00053] As shown in Figure 2, the photovoltaic cells 14 are wired together by tabbing wires 22. In this embodiment, all photovoltaic cells 14 comprised by the module 10 are connected in series. If the optically shaded cell 26 is producing less current than the other photovoltaic cells 14, the total power produced by the module 10 would be approximately equal to the number of photovoltaic cells 14 multiplied by the power produced by the optically shaded cell 26, due to the current limiting nature of the series interconnection. In analogous embodiments, all photovoltaic cells 14 could be shaded by reflector strips 18, for instance for creating an aesthetically uniform and/or desired visual aspect. In such a case, the module output would be the same as if only a single cell was shaded due to the cells being connected in series, as discussed above. This may be desirable to produce a consistent aesthetic effect.
Alternatively, reflector strips 18 could be arranged over some subset of photovoltaic cells 14, creating a pattern or graphic when viewed from a distance.

[00054] In other embodiments, the photovoltaic cells 14 could be grouped in smaller subgroups, with the photovoltaic cells 14 within each subgroup connected in series, and those subgroups could be connected together in series within the solar module 10. In such embodiments, a bypass diode would be provided per subgroup to enable operation of other subgroups if any subgroup is producing too low a current and limiting overall operation of the module 10.

[00055] The backing sheet 20 can be made of polymer or a combination of polymers. For embodiments where the photovoltaic cells 14 are single sided photovoltaic cells, the backing sheet 20 need not be transparent. However, in bifacial modules (i.e., PV solar modules configured so that the photovoltaic cells receive light from both sides thereof) the backing sheet 20 would be made of a transparent polymer, glass or any suitable transparent material.

[00056] When the photovoltaic solar module 10 is assembled, the outer glass layer 12 and the backing sheet 20 are brought together sandwiching the encapsulants 32, 34, the photovoltaic layer 36 and the reflective layer 16 in relatively fixed positions between them, allowing some degree of movement to account for thermal expansion of the cells 14.

[00057] Figure 3 shows a photovoltaic solar module 110 for harvesting sunlight according to an alternative embodiment. The PV solar module 110 comprises an optically transparent outer glass layer 112, a photovoltaic layer 136 comprising an array of sixteen of the photovoltaic cells 14 positioned beneath the outer glass layer 112, and a reflective layer 116 disposed between the glass layer 112 and the photovoltaic cells 14. As mentioned above, the photovoltaic cells 14 can be crystalline silicon (c-Si) photovoltaic cells or cells of made any suitable photovoltaic material. In this embodiment, the outer glass layer 112 is a square sheet of glass, but it can alternatively be made of any transparent material such as polymers.

[00058] In this embodiment, the photovoltaic layer 136 is a square array of photovoltaic cells 14 comprising twelve optically shaded photovoltaic cells 126 and four photovoltaic cells 14 that are not optically shaded. The reflective layer 116 is made of optical film comprising four reflector strips 118a-118d. Each reflector strip 118a-118d covers a portion of four of the optically shaded photovoltaic cells 126 that are aligned to form a row. The proportion of the surface area of each optically shaded cell 126 covered and shaded by the reflector strips 116 is determined based on a desired 5 modified power output of the photovoltaic solar module 110 and of the optically shaded cells 126.

[00059] The reflector strips 118a-118d are strips of optical film comprising a mirrored microstructure thereon. The reflector strips 118a-118d are aligned and extend parallel to one another and are evenly spaced apart, defining a plurality of gaps 10 119 between adjacent ones of the reflector strips 118a-118d. Each reflector strip 118a-118d of the reflective layer 116 is at least partially aligned with each of the optically shaded photovoltaic cells 126. Portions of the optically shaded photovoltaic cells 126 aligned with the gaps 119 receive sunlight directly via the outer glass layer 112. In this embodiment, one of the rows of four photovoltaic cells 14 is optically shaded by two reflector strips 118b and 118c, another one of the rows of four photovoltaic cells 14 is optically shaded by one reflector strip 118a, and another one of the rows of four photovoltaic cells 14 is optically shaded by one reflector strip 118d, while one of the rows of photovoltaic cells 14 is not optically shaded by the reflective layer 116.

[00060] When the photovoltaic solar module 110 is in use, the outer glass layer 112 is positioned to receive sunlight thereon. Furthermore, the photovoltaic layer 136 disposed beneath the glass layer 112 is configured to receive sunlight through the glass layer 112. The reflective layer 116 is disposed between the glass layer 112 and the photovoltaic layer 136, and the reflector strips 118a-118d of the reflective layer 116 limit exposure to sunlight of covered portions of each of the optically shaded photovoltaic cells 126 therebeneath.

[00061] Figure 4A is a top view of an alternative embodiment of a photovoltaic solar module 210 for harvesting sunlight. The PV solar module 210 comprises an optically transparent outer glass layer 212, a photovoltaic layer 236 comprising an array of photovoltaic half-cut cells 214 positioned beneath the outer glass layer 212, and a reflective layer 216 disposed between the glass layer 212 and the photovoltaic half-cut cells 214. The photovoltaic half-cut cells 214 can be crystalline silicon (c-Si) photovoltaic cells or cells made of any suitable photovoltaic material where each half-cut cell 214 is a variation on standard silicon solar cells that can help improve solar module performance by cutting a standard cell in half or by making a cell half the size of a standard photovoltaic cell. The outer glass layer 212 is a rectangular sheet of glass, but it can alternatively be made of any transparent material such as polymers.

[00062] The photovoltaic layer 236 is a rectangular array of PV half-cut cells 214 comprising 144 (one hundred and forty-four) PV half-cut cells 214. The photovoltaic layer 236 is divided into two sub arrays 239a, 239b, with each sub array comprising 72 (seventy-two) half-cut cells 214. In this embodiment, the PV half-cut cells 214 within each sub array 239a, 239b can be connected in series and the sub arrays 239a, 239b can be connected together in parallel. In other embodiments, smaller groups of cells 214 within each sub array 239a, 239b can be connected in series, and then all groups of series connected half-cut cells 214 can be connected together in parallel.

[00063] In this embodiment, the reflective layer 216 is made of an optical film comprising six reflector strips 218, with each reflector strip 218 covering a portion of a plurality of optically shaded PV half-cut cells 226 of the plurality of PV
half-cut cells 214. The size of the portion covered and shaded by the reflector strips 216 is determined based on a desired modified power output of the photovoltaic solar module 210 and of the optically shaded cells 226. The proportion of the surface area of each optically shaded half-cut cell 226 that is covered and shaded by the reflector strips 216 is approximately 33.3% (i.e., approximately one-third). The reflector strips 218 are strips of optical film comprising a mirrored microstructure thereon (as seen in the close-up views of Figures 4C and 8A). The reflective layer 216 comprises two separate optical film meshes 240a, 240b, one optical film mesh 240a, 240b for each sub array 239a, 239b. As shown in Figure 4B, each optical film mesh 240a, 240b includes three reflector strips 218, attached together by connector strips 224 positioned at the ends of the reflector strips 218 and within the body of optical film mesh 240a, 240b, holding the reflector strips 218 together in each optical film mesh 240a, 240b. The reflector strips 218 are equally spaced apart, aligned and parallel to one another, and define a plurality of gaps 219 therebetween. The reflector strips 218 of the reflective layer 216 are positioned to cover portions of given ones of the optically shaded cells 226.

[00064] Each reflector strip 218 of the reflective layer 216 is at least partially aligned with corresponding ones of the optically shaded PV cells 226. Portions of the optically shaded photovoltaic cells 226 positioned below the gaps 219 receive sunlight directly via the outer glass layer 212. As shown in Figure 4A, in this embodiment, a row of four photovoltaic cells 214 within each sub-array of half-cut cells 214 is optically shaded by three reflector strips 218 of each corresponding optical film mesh 240a, 240b.

[00065] When the photovoltaic solar module 210 is in use, the outer glass layer 212 is positioned to receive sunlight thereon. Furthermore, the photovoltaic layer 236 disposed beneath the glass layer 212 is configured to receive sunlight through the glass layer 212. The reflective layer 216 is disposed between the glass layer 112 and the photovoltaic layer 236, and the reflector strips 218 of the reflective layer 216 limit exposure to sunlight of covered portions of each of the optically shaded photovoltaic cells 226 therebeneath.

[00066] Figure 4B is a close-up view of a circled section 4B
of the photovoltaic solar module 210 (see Figure 4A), where the optical film meshes 240a, 240b can be seen in detail. The reflective layer 216 is positioned over the photovoltaic layer 236, by placing one optical film mesh 240a, 240b over a section of each photovoltaic sub-array 239a, 239b respectively, covering portions of four PV half-cut cells 214 within each PV sub-array 239a, 239b. The reflector strips 218 are positioned over the optically shaded PV half-cut cells 226, and the connector strips 224 are positioned over the gaps 238 between adjacent PV half-cut cells 214, the gaps 238 being dead zones of the PV solar module 210_

[00067] Figure 4C is a close-up view of a circled section 4C
in Figure 4B, showing a close-up view of a reflector strip 218 comprising a mirrored microstructure thereon. The mirrored microstructure can vary in shape and orientation, with some designs comprising longitudinal facetted microreflector patterns and some comprising transverse facetted microreflector patterns, as described and shown in the close-up views of Figures 4C and 8A. Any reflector strip 218, 250, 254, 258 design described herein can be used in any of the embodiments of the PV solar modules 10, 110, of the present technology or variations thereof.

[00068] Figures 5A and 5B show a cross sectional view of one of the reflector strips 218. Figure 5A shows the PV solar module 210 in use when sunlight impinges thereon at an angle normal to the surface 244 of the outer glass layer 212.
Sunlight will be normal to the surface 244 depending on the orientation of the module 210 with respect to the sun. On equinox at the equator one might expect the sun to rise at 6am and set at 6pm, and if the PV solar module 210 is positioned on a flat, level surface, direct (normal) incoming sunlight 246 will typically impinge thereon at noon.
An exemplary ray of direct sunlight 246 is shown in Figure 5A to demonstrate how the facetted and mirrored microstructure 242 reflects direct sunlight 246 impinging thereon back towards the exterior 248 of the PV solar module 210. As shown, a ray of direct sunlight 246 enters the body of the PV solar module 210 through the surface 244 of the outer glass layer 212 and is transmitted through the outer glass layer 212 and through the top encapsulant 232 towards the reflector strip 218 where it encounters the mirrored microstructure 242 designed to reflect light 246 back towards the surface 244 of the outer glass layer 212 where light 246 is reflected by total internal reflection back towards the mirrored microstructure 242 where a second reflection occurs redirecting light outwards to the exterior 248 of the PV solar module 210. The reflector strips 218 create a shading effect, rejecting direct sunlight 246 impinging thereon, therefore creating loss in power generation during times of the day when the module 210 is directly facing the sun. This effect, however, is desired for maintaining a broadened power curve of the module throughout the day, and this will be explained in further detail below. As shown in Figure 5A direct sunlight 247 impinging on the surface 244 of the outer glass layer 212 above the gaps 219 is transmitted directly to the cell 226 through the outer glass layer 212 and the top encapsulant 232 and is absorbed by the PV half-cut cell 226 generating power. Furthermore, direct sunlight 247 impinging on the surface 244 of the outer glass layer 212 above any of the PV
half-cut cells 214 that are not shaded by the reflective layer 216 is absorbed by the cells 214 generating power for the system.

[00069] Figure 5B shows the photovoltaic solar module 210 in use when sunlight impinges thereon at an approximately 45 angle of incidence. Incoming sunlight will be at approximately a 45 angle of incidence depending on the orientation of the module 210 with respect to the sun, the geographic location and the time of year. On equinox at the equator one might expect the sun to rise at 6am and set at 6pm, and if the module 210 is positioned on a flat, level surface, incoming sunlight 245 will typically impinge thereon at an angle of approximately 45' at 9am (or 3pm). An exemplary ray of sunlight 245 at a 45 angle of incidence is shown in Figure 5B to demonstrate how the mirrored microstructure 242 reflects sunlight 245 impinging thereon towards an optically shaded PV half-cut cell 226 of the solar module 210. As shown, a ray of indirect sunlight 245 enters the body of the solar module 210 through the surface 244 of the outer glass layer 212 and is transmitted through the outer glass layer 212 and through the top encapsulant 232 towards a reflector strip 218 where it encounters the mirrored microstructure 242 designed to reflect light 245 back towards the surface 244 of the outer glass layer 212 where light 245 is reflected by total internal reflection back towards the optically shaded PV half-cut cell 226 to which the reflector strip 218 is associated. The reflector strips 218 reflect nearly all indirect sunlight 245 impinging thereon towards an associated optically shaded PV half-cut cell 226, via total internal reflection on the surface 244 of the outer glass layer 212, for absorption and power generation by the photovoltaic cells 226, maintaining the power generation capacity of the PV half-cut cells 226 expected at off-normal angles of incidence if the reflective layer 216 were not present. Indirect sunlight 249 also enters the module 210 through the surface 244 of the outer glass layer 212 and can be transmitted directly through the outer glass layer 212 and the top encapsulant 232 to all unshaded PV half-cut cells 214, or to optically shaded PV half-cut cells 226 through the gaps 219 in the optical film meshes 240a and 240b. In Figures 5A and 5B, the mirrored microstructure comprises a zigzag pattern of mirror coated surfaces angled at 30 for reflecting light.

[00070] It is possible to design functional reflective layers comprising alternative patterned microstructures within their reflective strips which may serve the same function of rejecting direct incoming sunlight and reflecting indirect sunlight towards the surface of the outer glass layer where it is reflected by total internal reflection towards photovoltaic cells, and these designs can be used in any variation of a PV
solar module 10, 110, 210. For instance, Figure 6 shows a reflector strip 250 (in place of the reflector strip 218) according to an alternative embodiment of the PV
solar module 210. As can be seen, the reflector strip 250 comprises a mirrored microstructure 252 having a zigzag pattern of mirror coated surfaces angled at 45 for reflecting light. Exemplary rays are shown in Figure 6, where direct light 247 impinging on the surface 244 of the outer glass layer 212 is transmitted directly to the cells 214, 226, or direct light 246 is reflected by the mirrored microstructure 252 towards the exterior 248 of the module 10, 110, 210 via two reflections on facets of the mirrored microstructure 252. In this embodiment, indirect light 249 can be transmitted directly to the optically shaded PV cells 226 through the gaps 219 within the reflective layer 216, or indirect light 245 may be reflected by the mirrored microstructure 252 towards the surface 244 of the outer glass layer 212 where light is reflected by total internal reflection back towards the photovoltaic cell 226.
5 [00071] Figure 7 shows an alternative embodiment of the photovoltaic solar module 210 in which the PV solar module 210 comprises alternative reflector strips 254 (instead of the reflector strips 218 or 250), each having a mirrored microstructure 256. The mirrored microstructure 256 comprises a half-cylindrical pattern of curved mirror coated surfaces angled for reflecting light. Exemplary rays are shown in Figure 10 7, where direct light 247 impinging on the surface 244 of the outer glass layer 212 is transmitted directly to the cells 214, or direct light 246 is reflected by the mirrored microstructure 256 towards the exterior 248 of the module. In this embodiment, indirect light 249 can be transmitted directly to the PV cells 226 through the gaps 219 within the reflective layer 216, or indirect light 245 may be reflected by the mirrored 15 microstructure 256 towards the surface 244 of the outer glass layer 212 where light is reflected by total internal reflection back towards the photovoltaic cell 226.
[00072] The reflector strips 218, 250, 256 shown in Figures 40-7 have longitudinal microstructure patterns thereon, where the microstructures are made of symmetrically facetted mirror coated optical elements extending longitudinally along the length of the reflector strips 218, 250, 256. However, improved efficiency can be achieved in embodiments where the reflector strips comprise a transverse microstructure pattern as shown in the embodiment of Figures 8A-8D. Notably, Figure 8A is a close-up view of a section of the PV solar module 210 according to an alternative embodiment in which the PV solar module 210 comprises alternative reflector strips 258 (instead of the reflector strips 218, 250 or 256). The section 8A is analogous to circled section 40 of the embodiment detailed in Figure 4B. Each reflector strip 258 comprises a transverse microstructure pattern 260 that could be used in any PV solar module 10, 110, 210 of the present technology or variations thereof.
[00073] The reflector strip 258 comprises the transverse mirrored microstructure 260 thereon extending transversally along the length of the reflector strip 258. The mirrored microstructure 260 is a mirror coated pattern of symmetrical, facetted, mirror coated optical elements for reflecting incoming sunlight 245, 246, 247, 249.
[00074] Figure 8B is a cross sectional view of one of the reflector strips 258 when light impinges on the PV solar module 210 at a normal angle of incidence. The section shown in Figure 8B is marked by dotted line 8B in Figure 8A. In Figure 8B, the PV
solar module 210 is in use when sunlight impinges thereon at an angle normal to the surface 244 of the outer glass layer 212. Sunlight will be normal to the surface 244 of the PV solar module 210 depending on the orientation of the module 210 with respect to the sun. On equinox at the equator one might expect the sun to rise at 6am and set at 6pm, and if the module 210 is positioned on a flat, level surface, direct (normal) incoming sunlight 246 will typically impinge thereon at noon. An exemplary ray of direct sunlight 246 is shown in Figure 8B to demonstrate how the facetted and mirrored microstructure 260 reflects direct sunlight 246 impinging thereon back towards the exterior 248 of the solar module 210.
[00075] Figure 8C is a cross sectional view taken along dotted line 8C in Figure 8A. In Figure 8C, the PV solar module 210 is in use when sunlight impinges thereon at an angle normal to the surface 244 of the outer glass layer 212. Sunlight will be normal to the surface 244 of the solar module 210 depending on the orientation of the module 210 with respect to the sun. On equinox at the equator one might expect the sun to rise at 6am and set at 6pm, and if the module 210 is positioned on a flat, level surface, direct (normal) incoming sunlight 246 will typically impinge thereon at noon.
An exemplary ray of direct sunlight 246 is shown in Figure 8C to demonstrate how the facetted and mirrored microstructure 260 reflects direct sunlight 246 impinging thereon back towards the exterior 248 of the solar module 210.
[00076] As shown in Figures 8B and 8C, an exemplary ray of direct sunlight enters the body of the PV solar module 210 through the surface 244 of the outer glass layer 212 and is transmitted through the outer glass layer 212 and through the top encapsulant 232 towards the reflector strip 258 where it encounters the mirrored microstructure 260 designed to reflect light 246 back towards the surface 244 of the outer glass layer 212 where light 246 is reflected by total internal reflection back towards the mirrored microstructure 260 where a second reflection occurs redirecting light outwards to the exterior 248 of the module 210. The reflector strips 258 create a shading effect, rejecting direct sunlight 246 impinging thereon, therefore creating loss in power generation during times of the day when the module 210 is directly facing the sun. This effect, however, is desired for maintaining a broadened power curve of the module 210 throughout the day. As shown in Figure 8B, direct sunlight 247 impinging on the surface 244 of the outer glass layer 212 above the gaps 219 is transmitted directly to the cell 226 through the outer glass layer 212 and the top encapsulant 232 and is absorbed by the PV half-cut cell 226 generating power. Furthermore, direct sunlight 247 impinging on the surface 244 of the outer glass layer 212 above any of the PV half-cut cells 214 that are not shaded by the reflective layer 216 is absorbed by the cells 214 generating power for the system.
[00077] Figure 8D is a cross sectional view of a close-up of one of the reflector strips 258 when light impinges on the PV solar module 210 at an off-normal angle of incidence. The section shown in Figure 8D is marked by dotted line 8B in Figure 8A.
In Figure 8D, the PV solar module 210 is shown in use when sunlight impinges thereon at an approximately 45 angle of incidence. Incoming sunlight 245 will be at approximately a 45' angle of incidence depending on the orientation of the module 210 with respect to the sun, the geographic location and the time of year. On equinox at the equator one might expect the sun to rise at 6am and set at 6pm, and if the module 210 is positioned on a flat, level surface, incoming sunlight 245 will typically impinge thereon at an angle of approximately 45 at 9am (or 3pm). An exemplary ray of sunlight 245 at a 45 angle of incidence is shown in Figure 8D to demonstrate how the mirrored microstructure 260 reflects sunlight 245 impinging thereon towards an optically shaded PV half-cut cell 226 of the solar module 210. As shown, a ray of indirect sunlight 245 enters the body of the solar module 210 through the surface 244 of the outer glass layer 212 and is transmitted through the outer glass layer 212 and through the top encapsulant 232 towards a reflector strip 258 where it encounters the mirrored microstructure 260 designed to reflect light 245 back towards the surface 244 of the outer glass layer 212 where light 245 is reflected by total internal reflection back towards the optically shaded PV half-cut cell 226 to which the reflector strip 258 is associated. The reflector strips 258 reflect nearly all indirect sunlight 245 impinging thereon towards an associated optically shaded PV half-cut cell 226, via total internal reflection on the surface 244 of the outer glass layer 212, for absorption and power generation by the photovoltaic cells 226, maintaining the power generation capacity of the PV half-cut cells 226 expected at off-normal angles of incidence if the reflector strip 258 were not present. Indirect sunlight 249 also enters the module 210 through the surface 244 of the outer glass layer 212 and can be transmitted directly through the outer glass layer 212 and the top encapsulant 232 to all unshaded PV half-cut cells 214, or to optically shaded PV half-cut cells 226 through the gaps 219. In Figures 8A-8D, the mirrored microstructure 260 comprises a zigzag pattern of transverse mirror coated facetted surfaces angled at 30 for reflecting light.
[00078] The reflector strip 258 described in Figures 8A-8D can be used in reflective layers 16, 116, 216 of any of the above described embodiments, interchangeably with any of the above described longitudinal reflector strip designs 18, 118, 218, 250, 254.
[00079] The PV solar modules 10, 110, 210 of any of the embodiments of the present technology use a reflective layer 16, 116, 216 to reject direct incoming light 246 outwardly of the solar module 10, 110, 210, and to redirect indirect light impinging thereon towards an optically shaded PV cell 26, 126, 226 for absorption and power generation. The reflector strips 18, 118, 218, 250, 254, 258 create a shading effect, rejecting direct sunlight 246 impinging thereon, therefore creating drop in power generation during times of the day when the corresponding PV solar module 10, 110, 210 is directly facing the sun. This effect, however, is desired for levelling off the overall efficiency of the module throughout the day. On equinox, at the equator one might expect the sun to rise at 6am and set at 6pm, and if a solar module is positioned on a flat, level surface, direct (normal) incoming sunlight will typically impinge thereon at noon. A conventional photovoltaic solar module (without optical optimization) will have its peak power production at this time (noon), given that conventional PV
solar modules are most efficient when light impinges directly thereon. Figure 9 shows a comparative line graph of two 300-Watt solar modules, one being a conventional PV
solar module and the other being the PV solar module as described according to any of the embodiments presented herein. The conventional PV solar module displays peak power at noon, whereas the PV solar module 10, 110, 210 of the present technology displays a drop in power at noon, two peaks in power at approximately 11am and 1pm, and a flatter level of efficiency throughout the day due to a boost provided by the redirecting of indirect light that is provided by the reflector strips.

[00080] In some cases, it may be advantageous to use the photovoltaic solar modules 10, 110, 210, according to the present technology, to refurbish photovoltaic solar module installations. As referred to herein, a solar module installation is a collection of photovoltaic solar modules operatively connected together to form an electricity generating system.
[00081] For example, some solar module installations may benefit from replacing one or more used photovoltaic solar modules within a system which have stopped working or have degraded over time. In such a case, the solar module installation could both benefit from replacing the functionality of the less efficient used module, as well as from the broadened power curve of the solar modules 10, 110, 210. It is also possible to replace some solar modules within the solar installation, even if not suffering from diminished performance, with the higher output PV solar modules 10, 110, 210. This may depend on the particular installation having sufficient load capacity for boosting the overall power output of the system.
[00082] A method 300 of refurbishing a solar module installation with the photovoltaic solar modules 10, 110, 210 according to the present technology will now be described with reference to Figure 10. Notably, the solar module installation is formed from a plurality of used photovoltaic solar modules, some of which may have degraded over time, or stopped working. In the present non-limiting example, it is assumed that the solar module installation has enough carrying capacity to handle a boost in peak power and broadening of the peak power output, although this is generally determined on a case-by-case basis.
[00083] The method 300 begins, at step 310, with determining a nominal peak power output associated with one or more of the used photovoltaic solar modules of the photovoltaic solar module installation. As originally installed, the used photovoltaic solar modules likely all functioned with a same or similar peak power, for which the solar module installation was configured. In some cases, the method 300 could also include determining the actual peak power output for each solar module, for example in order to choose which used solar module has the most diminished power output or to choose which used solar module is to be replaced. In some cases, only a predetermined used solar module may be tested.

[00084] To determine the nominal peak power, data or documentation provided from the supplier with the used solar modules or the installation could be consulted, for example. For the case of determining the actual peak power output, measurement is generally done by measuring the output of each used photovoltaic solar module at 5 optimum conditions, although the specific measurement method may vary. Peak power of each used photovoltaic solar module can be measured in the field, for instance, by cleaning the modules and measuring the output throughout the day to determine the power curve and peak power of each used PV solar module within the installation. Peak power can also be determined by flash testing, where artificial light 10 is provided to simulate sunlight and measure the output of the used PV solar module in optimal conditions including optimal temperature.
[00085] The method 300 continues, at step 312, with determining a peak power output associated with one or more new photovoltaic solar modules 10, 110, 210. In some cases, a plurality of new solar modules 10, 110, 210 could be supplied, and the 15 peak power output could be tested for each one. In some non-limiting examples, there could be only one new solar module 10, 110, 210 supplied and/or available. The peak power of new photovoltaic modules is generally determined using flash testing, although details may vary. Depending on the particular embodiment of the method 300, steps 310 and 312 could be performed in either order or simultaneously.
It is also 20 contemplated that the determining the peak power output at step 312 of the new solar modules could be performed by retrieving technical data corresponding to the one or more new solar modules, for example from the supplier or documentation supplied with the new solar modules.
[00086] The method 300 continues, at step 314, with selecting one or more new photovoltaic modules 10, 110, 210 to be used to replace one or more of the used solar modules. A particular one of the new photovoltaic modules 10, 110, 210 is chosen to minimize a peak power output difference between the nominal peak power output of used photovoltaic solar modules and the peak power output of chosen new photovoltaic solar module. The new photovoltaic solar module 10, 110, 210 is specifically chosen such that the peak power difference is below a threshold, such that the peak power of the new photovoltaic solar module 10, 110, 210 is as closely matched as possible to the nominal peak power of the used photovoltaic solar module, for which the solar module installation is configured, to be replaced. In some non-limiting embodiments, the threshold is about 10%. In some cases, the peak power output difference between the peak power output of the used photovoltaic solar modules and the peak power output of each of the new photovoltaic solar modules could be determined by data comparison.
[00087] The method 300 continues, at step 316, with replacing one or more of the used photovoltaic solar modules with one or more new photovoltaic solar modules 10, 110, 210. Specifics of removing the used solar modules and connecting the new solar modules 10, 110, 210 will depend on the particular solar module installation and will not be further described herein. In some implementations of the method 300, all of the used photovoltaic solar modules could be replaced, such that mechanical and/or electrical infrastructure in place is utilized while providing all new PV
solar modules 10, 110, 210.
[00088] Refurbishing the solar module installation according to the method 300 of Figure 10, wherein a combination of used photovoltaic solar modules and the photovoltaic solar modules 10, 110, 210 of the present technology are wired together, could generally result in solar module installation of generally enhanced efficiency with a broadened power curve. As is mentioned briefly above, the PV solar module 10, 110, 210 of the present technology experiences a drop in efficiency (power produced compared to the light energy incident on the module) when sunlight impinges on the PV solar modules at a normal angle to the surface, while providing a broadening of the overall power curve as shown in Figure 9.
[00089] According to non-limiting embodiments of the present technology, replacing one or more used solar modules with the solar modules 10, 110, 210, the solar module installation generally has a greater average power output over a given day than was previously possible with the collection of used solar modules, either in as degraded by use and exposure, or by their nominal technical specifications.
[00090] Although embodiments have been described above with reference to the accompanying drawings, those of skill in the art will appreciate that variations and modifications may be made without departing from the scope thereof as defined by the appended claims.

[00091] Modifications and improvements to the above-described implementations of the present technology may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present technology is therefore intended to be limited solely by the scope of the appended claims.

Claims (15)

What is claimed is:

1. A photovoltaic solar module, comprising:
an outer glass layer positioned to receive sunlight thereon when the photovoltaic solar module is in use;
a plurality of photovoltaic cells disposed beneath the glass layer, the photovoltaic cells being configured to receive sunlight through the glass layer; and a reflective layer disposed between the glass layer and the plurality of photovoltaic cells, the reflective layer comprising at least one reflector, the at least one reflector being at least partially aligned with at least one photovoltaic cell of the plurality of photovoltaic cells to lirnit exposure to sunlight of the at least one photovoltaic cell.

2. The photovoltaic solar module of claim 1, wherein the at least one reflector includes a plurality of reflectors, and the reflectors of the plurality of reflectors define a plurality of gaps therebetween.

3. The photovoltaic solar module of claim 2, wherein the reflective layer is an optic film mesh.

4. The photovoltaic solar module of claim 1, wherein the at least one reflector comprises a facetted pattern with mirrored portions.

5. The photovoltaic solar module of claim 1, wherein, for at least one photovoltaic cell of the plurality of photovoltaic cells:
a portion thereof is covered by the at least one reflector; and a size of the portion covered by the at least one reflector is determined based on a desired modified power output of the photovoltaic solar module.

6. The photovoltaic solar module of claim 5, wherein the portion of the at least one photovoltaic cell covered by the at least one reflector is at least 10%.

7. The photovoltaic solar module of any one of claims 1 to 6, wherein the photovoltaic cells of the plurality of photovoltaic cells are arranged in a rectangular array.

8. The photovoltaic solar module of any one of claims 1 to 7, further comprising a backing sheet disposed beneath the plurality of photovoltaic cells.

9. The photovoltaic solar module of claim 1, wherein, when the photovoltaic solar module is in use:
the at least one reflector reflects sun rays incident thereon toward the glass layer;
when the sun rays are incident on the at least one reflector at an angle of incidence above a critical angle, the glass layer reflects light by total internal reflection towards a corresponding photovoltaic cell; and when the sun rays reflected by the at least one reflector are at a normal angle of incidence to the glass layer, the glass layer transmits a majority of the sun rays therethrough outwardly of the photovoltaic solar module.

10. A method of refurbishing a solar module installation, the solar module installation comprising a plurality of used photovoltaic solar modules, the method comprising:
determining a nominal peak power output associated with each of the used photovoltaic solar modules;
determining a peak power output associated with each one of a plurality of new photovoltaic solar modules;
selecting at least one new photovoltaic module of the plurality of new photovoltaic modules, a peak power output difference between the nominal peak power output of each of the used photovoltaic solar modules and the peak power output of the at least one new photovoltaic solar module being below a threshold, the at least one new photovoltaic solar module having at least one reflector covering a portion of at least one photovoltaic cell of a plurality of photovoltaic cells thereof; and replacing at least one of the used photovoltaic solar modules with the at least one new photovoltaic solar module.

11. The method of claim 10, wherein the portion of the at least one photovoltaic cell covered by the at least one reflector is at least 10%.

12. The method of claim 10, wherein:
the peak power output of the at least one new photovoltaic solar module is within 25% of the nominal peak power output of each of the used photovoltaic solar modules.

13. The method of claim 12, wherein the peak power output of the at least one new photovoltaic solar module is approximately equal to the nominal peak power output of each of the used photovoltaic solar modules.

14. The method of any one of claims 10 to 13, wherein the modified average power output of the at least one new photovoltaic solar module is greater than an average nominal power output of each of the used photovoltaic solar modules.

15. The method of any one of claims 10 to 14, wherein a number of the photovoltaic cells the at least one new photovoltaic solar module is the same as a number of photovoltaic cells of each of the used photovoltaic solar modules.