WO2019212981A1

WO2019212981A1 - Systems and methods for ultraviolet imaging of photovoltaic modules

Info

Publication number: WO2019212981A1
Application number: PCT/US2019/029687
Authority: WO
Inventors: William B. HOBBS
Original assignee: The Southern Company
Priority date: 2018-04-30
Filing date: 2019-04-29
Publication date: 2019-11-07

Abstract

Devices and methods relating to detection of defects in solar modules are disclosed. A photovoltaic module inspection system can comprise a digital imaging device, a lens transparent to ultraviolet (UV) light, and a filter configured to permit transmission of UV light.

Description

SYSTEMS AND METHODS FOR ULTRAVIOLET

IMAGING OF PHOTOVOLTAIC MODULES

FIELD OF INVENTION

[0001] This application claims the benefit of United States Provisional Patent Application No. 62/664,598, filed 30 April 2018, the entire contents and substance of which is incorporated herein by reference in its entirety as if fully set forth below.

FIELD OF INVENTION

[0002] The present disclosure relates to photovoltaic module inspection devices for module defect detection and module material differentiation. In some aspects, the disclosure relates to digital imaging devices configured to leverage UV light to image photovoltaic panels for module defect detection and module material differentiation.

BACKGROUND

[0003] With repeated exposure to harsh weather and outdoor conditions, defects such as cracks commonly develop inside module panels (also referred to herein as solar panels), but are not readily noticeable. Instead, special and burdensome quality testing systems must be implemented to discover and address the defects. However, left undetected, these defects can negatively affect the lifecycle and effectiveness of the solar panels over time.

[0004] A typical solar module is formed of multiple layers including at least, a top glass layer, a front-side encapsulant layer (e.g., EVA-based), a solar cells layer, a back-side encapsulant layer, and a backing sheet. When cracks are formed in the solar cells layer, trace amounts of oxygen can travel through the cell crack from back-side layers (e.g., the back-side encapsulant layer and/or the backing sheet) to the front-side encapsulant and can cause chemical changes in the front-side encapsulant layer. This degradation of the encapsulant layer can change the way it responds to light of various spectra (e.g., absorbing light, reflecting light, transmitting light, fluorescing) and can permit detection of these cracks with the use of some advanced testing techniques.

[0005] One such quality inspection technique is Ultraviolet Fluorescence (UVF) imaging. It involves illuminating a solar module with UV -light and little or no other light for detection of the fluorescence inside the panel. Accordingly, this testing must be conducted at night or with a cover or hood that blocks out sunlight. It also requires that the imaging device remain resident on a tripod or other similar accessory to reduce noise and increase accuracy during the lengthy imaging process.

[0006] Another quality testing technique is electroluminescence (EL) imaging. It involves applying electrical current to a solar module’s electrical connectors and then imaging the module in near-infrared light. Accordingly, it requires use of an external power source. It also generally requires labor-intensive and time-consuming disconnection of the electrically connected panels, often necessitating that solar power plants temporarily shut down its operations for the inspections.

SUMMARY

[0007] These and other problems can be addressed by embodiments of the technology disclosed herein. The disclosed technology can comprise a system for inspecting solar modules for defects and for module material differentiation. The system for inspecting solar panel modules can comprise an imaging device including a main body and an imaging sensor. At least a portion of the imaging sensor can be disposed within the main body. The main body can be formed with an aperture to permit the imaging sensor to detect UV light. The imaging device can include a lens assembly that includes a lens, and the lens assembly can be removably attached to the main body, such as by the back end of the lens assembly.

[0008] The imaging device can include a filter, and the filter can be configured to permit light energy having a wavelength characteristic of the UV spectrum to pass through the filter. The filter can be configured to block and/or filter out light energy having one or more non-UV wavelengths (e.g., light energy in the visible light spectrum, infrared (IR) light spectrum, etc.). The filter can be positioned in front of and cover the imaging device’s lens. By permitting UV wavelengths to pass and/or by blocking or filtering non-UV wavelengths, a fluorescent effect can be made visible by the filter. Thus, when the solar module is exposed to a UV light source, the imaging device can capture an image of any zones of fluorescence in the solar module based on the UV light passing through the lens of the imaging device.

[0009] The disclosed technology can comprise a method for inspecting solar modules. The method for inspecting solar modules can comprise exposing the solar module to a UV light source, activating an imaging device as disclosed above to capture an image of the module under UV exposure, and imaging the solar module via the image device as the solar module is exposed to the UV light source to generate a UV image of the solar module.

[0010] The disclosed technology includes a photovoltaic (PV) module inspection system that comprises an imaging device, a lens assembly, and a filter. The imaging device can include an aperture and an imaging sensor that is at least partially aligned with the aperture. The lens assembly can include a lens that is positioned to fully cover the aperture of the imaging device. The filter can be positioned to fully cover the lens, and the filter can be configured to pass ultraviolet (UV) light and block one or more wavelengths of non-UV light.

[0011] In any of the embodiments disclosed herein, at least a portion of the imaging sensor can be disposed within the main body.

[0012] In any of the embodiments disclosed herein, the main body further can include a protrusion configured to at least partially encase the lens.

[0013] In any of the embodiments disclosed herein, the filter can be configured to block visible light having a wavelength between 400 nm and 700 nm.

[0014] In any of the embodiments disclosed herein, the filter can be configured to block infrared light having a wavelength between 700 nm and 1 mm.

[0015] In any of the embodiments disclosed herein, the imaging sensor can be configured to detect UV radiation from a natural light source.

[0016] In any of the embodiments disclosed herein, the imaging sensor can be configured to detect UV radiation from an artificial light source.

[0017] In any of the embodiments disclosed herein, the filter can be configured to pass only light energy in a predetermined wavelength range.

[0018] In any of the embodiments disclosed herein, the predetermined wavelength range can be between 250 nm and 400 nm.

[0019] In any of the embodiments disclosed herein, the predetermined wavelength range can be between 280 nm and 400 nm.

[0020] In any of the embodiments disclosed herein, the predetermined wavelength range can be between 280 nm and 320 nm.

[0021] In any of the embodiments disclosed herein, the predetermined wavelength range can be between 320 nm and 400 nm.

[0022] In any of the embodiments disclosed herein, the PV module inspection system can comprise a display configured to display an image of a PV module. A first area of the image of the PV module can have a first brightness level and a second area of the image of the PV module can have a second brightness level, and a crack or other damage of a portion of the PV module corresponding to the first area of the image of the PV module is indicated if the first brightness level is above a predetermined threshold of brightness difference as compared to the second brightness level.

[0023] The disclosed technology includes a method for inspecting a PV module, and the method comprises exposing the PV module to a light source and activating a digital imaging device that includes an imaging sensor configured to detect UV light, a lens transparent to UV light, and a filter configured to transmit UV light and block visible light and infrared light. The method can include capturing an image of the PV module via the digital imaging device and analyzing the image to identify differences in UV reflectance of one or more portions of the PV module modules depicted in the image.

[0024] In any of the embodiments disclosed herein, the image can comprise a first image portion corresponding to a first portion of the PV module with the first image portion having a first level of brightness, and the image can comprise a second image portion corresponding to a second portion of the PV module with the second image portion having a second level of brightness. Analyzing the image can comprise determining whether the difference between the second level of brightness and the first level of brightness is above a predetermined threshold.

[0025] In any of the embodiments disclosed herein, the method comprises determining that a crack is present in the PV module proximate the second portion of the PV module if the difference between the second level of brightness and the first level of brightness is above the predetermined threshold.

[0026] In any of the embodiments disclosed herein, the method comprises determining that a crack is not present in the PV module proximate the second portion of the PV module if the difference between the second level of brightness and the first level of brightness is not above the predetermined threshold.

[0027] In any of the embodiments disclosed herein, the UV light can have a wavelength of between 250 nm and 400 nm.

[0028] In any of the embodiments disclosed herein, the UV light can have a wavelength of between 280 nm and 400 nm.

[0029] In any of the embodiments disclosed herein, the UV light can have a wavelength of between 280 nm and 320 nm.

[0030] In any of the embodiments disclosed herein, the UV light can have a wavelength of between 320 nm and 400 nm.

[0031] In any of the embodiments disclosed herein, the visible light can have a wavelength of between 400 nm and 700 nm.

[0032] The disclosed technology includes a PV module inspection system comprising a processor and memory storing instructions that, when executed by the processor, can cause the PV module inspection system to capture a UV image of a PV module via a digital imaging device that includes an imaging sensor configured to detect UV light, a lens transparent to UV light, and a filter configured to transmit UV light and block visible light and infrared light. The instructions, when executed by the processor, can also cause the PV module inspection system to determine, based on the UV image, a first brightness level for a first area of the PV module and a second brightness level for a second area of the PV module and, responsive to determining that a brightness difference between the first brightness level and the second brightness level is above a predetermined threshold, determine that the first area of the PV module comprises a crack or other damage.

[0033] In any of the embodiments disclosed herein, the predetermined threshold is a first predetermined threshold and the instructions, when executed by the processor, further cause the PV module inspection system to determine, based on the UV image, a third brightness level for a third area of the PV module and a fourth brightness level for a fourth area of the PV module and, responsive to determining that a brightness difference between the third brightness level and the fourth brightness level is above a second predetermined threshold, determine that one or more materials of the third area of the PV module are different than one or more materials of the fourth area of the PV module.

[0034] In any of the embodiments disclosed herein, an aerial vehicle can comprise the PV module inspection system.

[0035] In any of the embodiments disclosed herein, the aerial vehicle can be a manned aircraft.

[0036] In any of the embodiments disclosed herein, the aerial vehicle can be an unmanned aircraft.

[0037] Further features of the disclosed technology, and the advantages offered thereby, are explained in greater detail hereinafter with reference to specific examples of the disclosed technology that illustrated in the accompanying drawings, wherein like elements are indicated be like reference designators.

BRIEF DESCRIPTION OF THE FIGURES

[0038] Reference will now be made to the accompanying figures, which are not necessarily drawn to scale, and wherein:

[0039] FIG. 1 depicts an example of a photovoltaic module inspection system.

[0040] FIG. 2 depicts an example resulting image of a photovoltaic module inspection system’s differentiation of materials in adjacent solar panels.

[0041] FIG. 3 depicts an example resulting image of a photovoltaic module inspection system’s exposure of cracks in a solar panel. DETAILED DESCRIPTION

[0042] Although certain examples of the disclosure are explained in detail, it is to be understood that other applications are contemplated. Accordingly, it is not intended that the disclosure is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other applications and of being practiced or carried out in various ways.

[0043] It must also be noted that, as used in the specification and the appended claims, the singular forms“a,”“an” and“the” include plural referents unless the context clearly dictates otherwise.

[0044] Also, in describing certain examples, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

[0045] Ranges can be expressed herein as from“about” or“approximately” one particular value and/or to“about” or“approximately” another particular value. When such a range is expressed, the range can extend from the one particular value and/or to the other particular value.

[0046] By“comprising” or“containing” or“including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

[0047] It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a device or system does not preclude the presence of additional components or intervening components between those components expressly identified.

[0048] Disclosed herein are systems and methods for inspecting photovoltaic (PV) modules for defects not readily ascertainable upon visual inspection. For example, the disclosed technology can include an inspection system comprising a digital imaging device outfitted with a filter that is configured to pass UV light and block visible and IR light, a lens transparent to UV light, and a sensor sensitive to or capable of detecting UV light. When a PV module such as a solar panel is exposed to a UV light source, the digital imaging device can capture images exposing cracks and other defects in the solar panel. There are many distinct advantages of this inspection system, including that it does not require a power source, it does not require the PV modules to be shut down, it does not have to be conducted at night or otherwise under cover from non-UV light, and it produces faster imaging than EL and conventional UVF methods and systems. The disclosed inspection system also eliminates the need for a tripod or other bulky imaging device accessories as it enables a simple, handheld implementation.

[0049] FIG. 1 illustrates an example photovoltaic (PV) module inspection system 100. As shown, the PV module inspection system 100 includes an imaging device 102 including a main body 104 and an imaging sensor 106. At least a portion of the imaging sensor 106 can be operably housed inside the main body 104. The main body 104 can be formed with an aperture to permit the sensor 106 to detect UV light. The imaging device 102 can further comprise a lens assembly 108, and the lens assembly 108 can include a lens, a front end, and a back end. The back end of the lens assembly 108 can be removably attached to the main body 104. The front end of the lens assembly 108 can be removably attached to a filter 110. The filter 110 can be positioned in front of the lens 108 such that the filter 110 does not physically engage or contact the lens of the lens assembly 108. The imaging device 102 can be a modified consumer digital camera (i.e., the imaging sensor 106 can be a consumer digital camera including at least some of the modifications described herein).

[0050] The main body 104 can further include a protrusion configured to at least partially encase the lens 108, which may protect the lens 108. The protrusion can have any suitable shape to effectively encase the lens 108. For example, the protrusion can have a shape that is cylindrical or have a cross-section that is substantially, square, or triangular, combinations thereof, or any other suitable shape or combination of shapes. The main body 104 can be an injection molded assembly of parts of any suitable material. For example, the main body 104 can be an injection molded assembly of plastic parts.

[0051] The lens of the lens assemblyl08 can be positioned to fully cover the aperture of the main body 104. The lens 108 can be configured to pass only light energy in a predetermined wavelength range. The predetermined wavelength range can be characteristic of some or all of the UV spectrum. For example, the lens 108 can be configured to pass light energy having a wavelength between 250 nm and 400 nm. As another example, the lens 108 can be configured to pass light energy having a wavelength between 280 nm and 400 nm. As yet another example, the lens 108 can be configured to pass light energy having a wavelength between 280 nm and 320 nm. As yet another example, the lens 108 can be configured to pass light energy having a wavelength s between 320 nm and 400 nm.

[0052] The lens 108 can be formed of any suitable material permitting transmission of light energy in the UV spectrum. For example, a material selected from the group consisting of quartz glass, silica glass, soda lime glass, poly-methyl-meth-acrylate (e.g., Plexiglass®), polyethylene, acrylic, any other suitable material, and combinations thereof. The lens 108 can be transparent. The lens 108 can be formed of transparent soda-lime-silica glass. The lens 108 can further comprise a polarizer. The lens 108 can have any shape suitable for engaging the main body 104 and/or the filter 110. The PV module inspection system 100 can include multiple lenses 108, and each of these lenses can be independently removably attached to main body 104.

[0053] The filter 110 can be positioned in front of the lens 108. The filter 110 can be mounted to the lens 108. The filter 110 can be positioned between the main body 104 and the lens 108. The filter 110 can be positioned in front of the sensor 106. Regardless of position relative other components of the PV module inspection system 100, the filter 110 can be positioned such that all light passing between the solar module(s) 112 and the sensor 106 must necessarily pass through the filter 110. The filter 110 can be configured to pass UV light in a specific wavelength range. The filter 110 can be configured to pass only light energy in a predetermined wavelength range. The predetermined wavelength range can be characteristic of some or all of the UV spectrum. For example, the filter 110 can be configured to pass light energy having a wavelength between 250 nm and 400 nm. As another example, the filter 110 can be configured to pass light energy having a wavelength between 280 nm and 400 nm. As yet another example, the filter 110 can be configured to pass light energy having a wavelength between 280 nm and 320 nm. As yet another example, the filter 110 can be configured to pass light energy having a wavelength between 320 nm and 400 nm. The filter 110 can block visible light and infrared light. The filter 110 can pass UV light while blocking visible light and infrared light. The filter 110 can be a commercially available, low-pass filter. Example low- pass filters include B+W 72mm #403 UV-pass filter and 365nm UV Pass Filter Short Pass Filter ZWB1 Square 50*50mm.

[0054] The filter 110 can have any suitable shape for effectively covering at least one end of the lens assembly 108. As nonlimiting examples, the filter 110 can have a cross-sectional shape that is substantially circular, ovular, square, rectangular, triangular, combinations thereof, or any other suitable shape. The filter 110 can have any suitable size for effectively covering at least one side of lens 108. As nonlimiting examples, the filter 110 can be between 3 cm to 8 cm wide, between 4 cm to 7 cm wide, between 3 cm to 6 cm wide, or 5 cm wide. The filter 110 can have any suitable thickness for effectively passing UV light and/or blocking visible light and infrared light. For example, the filter 110 can be 1 mm thick, 2 mm thick, or 3 mm thick.

[0055] The sensor assembly 106 can include at least one sensor configured to capture images. The sensor assembly 106 can include at least one sensor positioned to detect UV radiation. The sensor assembly 106 can detect UV radiation from natural light sources such as sunlight, and/or artificial light sources such as light-emitting diodes (LEDs), xenon bulbs, fluorescent lamps (e.g., “blacklights”), halogen lamps, metal halide lamps combinations thereof, and the like.

[0056] As shown in FIG. 2, the solar module inspection system 100 can be configured to image and differentiate between materials of one or more solar modules 112 that are not readily ascertainable in the visible spectrum. In accordance with the disclosed technology, such an image can be provided by a consumer imaging device (e.g., a consumer digital camera) that has been modified to include an imaging sensor 106 assembly sensitive to or capable of detecting UV light, a lens 108 transparent to UV light, and a filter 110 configured to transmit UV light and block visible light and infrared light. As shown in FIG. 2, the resulting UV image can indicate that the solar panel is comprised of different materials, which is not distinguishable in the visible image that is indicative of a visible inspection of the solar module(s) 112.

[0057] As shown in FIG. 3, the solar module inspection system 100 can be configured to image and identify cracks or other defects within one or more solar modules 112, not readily ascertainable in the visible spectrum. In accordance with the disclosed technology, the imaging sensor 106 can be sensitive to or otherwise capable of detecting UV light, the lens 108 can be transparent to UV light, and the filter 110 can pass UV light and block visible light and infrared light. Because cracks in a solar cell (or other damage) can affect the transmissivity and reflectivity of the encapsulant over the solar cell (as compared to an uncracked or undamaged solar cell), the resulting UV image, such as the example image shown in FIG. 3, can identify cracked or damaged solar cells by indicating discoloration in any areas where there are cracked or damaged solar cells (as compared to uncracked or undamaged solar cells). This change in the cracked or otherwise damaged solar cell’s UV reflectivity can affect the solar cell’s reflectance, such that the resulting UV image can depict the cracked or otherwise damaged solar cell as being“lighter” or“darker” compared to an uncracked or undamaged solar cell, depending on the material of the solar cell. That is, a cracked or otherwise damaged solar cell can reflect more or less UV over cracked areas than uncracked solar cells, depending on the type of material.

[0058] The imaging device 102 can further comprise a user controller to activate the sensor assembly 106 and capture an image. The user controller can communicate with a processor for converting the captured image data into a viewable format. The user controller can be in any suitable form. For example, the user controller can be a button. The imaging device 102 can further comprise a memory device for storing captured images. The memory device can be in one or more suitable forms (e.g., volatile or non-volatile memory, random access memory (RAM), read only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, flash memory, a redundant array of independent disks (RAID), and the like), for storing files such as image files. The imaging device 102 can further comprise a display for displaying one or more captured images. The display can be in any suitable form, such as an LCD screen, and LED screen, or an OLED screen. The imaging device 102 can further comprise input and/or output ports for engaging with chargers, external memory, audio inputs/outputs, and the like.

[0059] The memory can include instructions that, when executed by the processor, cause the PV module inspection system 100 to capture or receive a UV image (i.e., an image taken using the disclosed technology) and automatically analyze the UV image to identify one or more PV modules 112 that are cracked or otherwise damaged. The PV module inspection system 100 can determine a brightness level for a plurality of areas or zones of the PV module 112 and can compare the plurality of areas or zones to one another. If a particular area or zone of the PV module 112 has a brightness level that is above a first predetermined threshold of brightness difference, the PV module inspection system 100 can determine that the particular area or zone has a crack or is otherwise damaged. For example, if a first portion of the PV module 112 (e.g., a comparatively small portion of the PV module 112) has a first brightness level and a second portion of the PV module 112 (e.g., a comparatively large portion of the PV module 112) has a second brightness level and the difference between the first brightness level and second brightness level is above a predetermined threshold, the PV module inspection system 100 can determine that the first portion of the PV module has a crack or is otherwise damaged.

[0060] Alternately or in addition, if a particular area or zone of the PV module 112 has a brightness level that is above a second predetermined threshold of brightness difference, the PV module inspection system 100 can determine that the particular area or zone comprises a material different than other areas or zones of the PV module 112. As nonlimiting examples, the predetermined threshold of brightness difference can be 1%, 3%, 5%, 10%, 15%, 20%, 25%, 35%, 50%, or any other useful threshold. The predetermined threshold of brightness difference may depend on the type of materials included in the PV module 112.

[0061] The imaging device 102 can be used in conjunction with a manned or unmanned aircraft, which may be particularly beneficial for inspecting large PV module systems. For example, the imaging device 102 may be mounted to an aerial vehicle (e.g., a manned aircraft, an unmanned aircraft such as a drone). The manned aircraft or unmanned aircraft may also include a UV light source. The UV light source also can be mounted to the manned aircraft or unmanned aircraft.

[0062] The disclosed technology includes a method for inspecting solar modules, and the method can include exposing a PV module to a UV light source and activating a digital imaging device that includes an imaging sensor assembly 106 sensitive to or otherwise capable of detecting ultraviolet light, a lens 108 transparent to UV light, and a filter 110 configured to transmit UV light and block visible light and infrared light. The method can include capturing an image of the PV module via the digital imaging device. The method can further comprise analyzing the resulting image or images to identify or characterize differences in UV reflectivity of one or more solar modules depicted in the image or images. As described herein, differences in reflectance can be used to identify locations of cracks or other damage or defects within the solar modules, which cannot be readily apparent in the visible spectrum. Alternately or in addition, differences in reflectance can be used to identify differences in the types of materials used in PV modules, e.g., adjacent modules made of different materials appear differently in the resulting images.

[0063] It will be appreciated from the foregoing that the present disclosure provides a substantial improvement in photovoltaic module inspections. In particular, the disclosure allows for the inspection of solar panels free from the burdens of the night inspections characteristic of UV fluorescence testing and of costly power consumption as is required with electroluminescence testing. To the contrary, the disclosed detection system can be used during the day with a wireless, handheld digital imaging device. The instant detection system provides for faster imaging and more accurate detection of cell defects.

Claims

CLAIMS What is claimed is:

1. A photovoltaic (PV) module inspection system comprising:

an imaging device comprising a main body comprising:

an aperture; and

an imaging sensor at least partially aligned with the aperture; a lens assembly comprising a lens positioned to fully cover the aperture; and a filter fully covering the lens, the filter configured to pass ultraviolet (UV) light and block one or more wavelengths of non-UV light.

2. The PV module inspection system of Claim 1, wherein at least a portion of the imaging sensor is disposed within the main body.

3. The PV module inspection system of Claim 1, wherein the main body further includes a protrusion configured to at least partially encase the lens.

4. The PV module inspection system of Claim 1, wherein the filter is configured to block visible light having a wavelength between 400 nm and 700 nm.

5. The PV module inspection system of Claim 1, wherein the filter is configured to block infrared light having a wavelength between 700 nm and 1 mm.

6. The PV module inspection system of Claim 1, wherein the imaging sensor is configured to detect UV radiation from a natural light source.

7. The PV module inspection system of Claim 1, wherein the imaging sensor is configured to detect UV radiation from an artificial light source.

8. The PV module inspection system of Claim 1, wherein the filter is configured to pass only light energy in a predetermined wavelength range.

9. The PV module inspection system of Claim 1, wherein the predetermined wavelength range is between 250 nm and 400 nm.

10. The PV module inspection system of Claim 1, wherein the predetermined wavelength range is between 280 nm and 400 nm.

11. The PV module inspection system of Claim 1, wherein the predetermined wavelength range is between 280 nm and 320 nm.

12. The PV module inspection system of Claim 1, wherein the predetermined wavelength range is between 320 nm and 400 nm.

13. The PV module inspection system of Claim 1 further comprising a display configured to display an image of a PV module,

wherein a first area of the image of the PV module has a first brightness level and a second area of the image of the PV module has a second brightness level,

wherein a crack or other damage of a portion of the PV module corresponding to the first area of the image of the PV module is indicated if the first brightness level is above a predetermined threshold of brightness difference as compared to the second brightness level.

14. A method for inspecting a photovoltaic (PV) module, the method comprising:

exposing the PV module to a light source;

activating a digital imaging device comprising:

an imaging sensor configured to detect ultraviolet (UV) light; a lens transparent to UV light; and

a filter configured to transmit UV light and block visible light and infrared light;

capturing an image of the PV module via the digital imaging device; and

analyzing the image to identify differences in UV reflectance of one or more portions of the PV module modules depicted in the image.

15. The method of claim 14, wherein the image comprises a first image portion

corresponding to a first portion of the PV module, the first image portion having a first level of brightness, wherein the image comprises a second image portion corresponding to a second portion of the PV module, the second image portion having a second level of brightness, wherein analyzing the image comprises: determining whether the difference between the second level of brightness and the first level of brightness is above a predetermined threshold

16. The method of claim 15, wherein, if the difference between the second level of brightness and the first level of brightness is above the predetermined threshold, the method further comprises determining that a crack is present in the PV module proximate the second portion of the PV module.

17. The method of claim 15, wherein, if the difference between the second level of brightness and the first level of brightness is not above the predetermined threshold, the method further comprises determining that a crack is not present in the PV module proximate the second portion of the PV module.

18. The method of claim 14, wherein the UV light has a wavelength of between 250 nm and 400 nm.

19. The method of claim 14, wherein the UV light has a wavelength of between 280 nm and 400 nm.

20. The method of claim 14, wherein the UV light has a wavelength of between 280 nm and 320 nm.

21. The method of claim 14, wherein the UV light has a wavelength of between 320 nm and 400 nm.

22. The method of claim 14, wherein the visible light has a wavelength of between 400 nm and 700 nm.

23. A photovoltaic (PV) module inspection system comprising:

a processor;

memory storing instructions that, when executed by the processor, cause the PV module inspection system to:

capture an ultraviolet (UV) image of a PV module via a digital imaging device comprising: an imaging sensor configured to detect UV light;

a lens transparent to UV light; and

determine, based on the UV image, a first brightness level for a first area of the PV module and a second brightness level for a second area of the PV module; responsive to determining that a brightness difference between the first brightness level and the second brightness level is above a predetermined threshold, determine that the first area of the PV module comprises a crack or other damage.

24. The PV module inspection system of Claim 23, wherein the predetermined threshold is a first predetermined threshold and the instructions, when executed by the processor, further cause the PV module inspection system to:

determine, based on the UV image, a third brightness level for a third area of the PV module and a fourth brightness level for a fourth area of the PV module;

responsive to determining that a brightness difference between the third brightness level and the fourth brightness level is above a second predetermined threshold, determine that one or more materials of the third area of the PV module are different than one or more materials of the fourth area of the PV module.

25. An aerial vehicle comprising the PV module inspection system of Claim 23.

26. The aerial vehicle of Claim 25, wherein the aerial vehicle is a manned aircraft.

27. The aerial vehicle of Claim 25, wherein the aerial vehicle is an unmanned aircraft.