Mobile albedo measurement bench

Abstract

With the increasing adoption of bifacial photovoltaic modules, the albedo, i.e., the reflectance coefficient of a surface, has become a very important characteristic in the design of solar power plants using such photovoltaic modules. The invention consists of a mobile and portable albedo measuring device that facilitates carrying out an on-site evaluation of the various ground vegetation covers and their respective solar radiation reflection coefficients, which is a fundamental step in assessing the power generation potential calculated during the design phase of a photovoltaic power plant using bifacial modules. The device of the utility model consists of a support element 2 that holds one end of an arm 3 and a pair of pyranometers 1 installed at the other end of the arm, the pyranometers being fixed to the arm by a leveling tray 6 that ensures the parallelism of the pyranometers to the analysis surface.

Description

[Technical field]

[0001] The present invention relates to albedo measurement. More specifically, the present invention relates to a mobile and portable bench for measuring the albedo of a surface. [Background technology]

[0002] Measuring albedo is a fundamental process in the field of photovoltaics in bifacial modules. Albedo is the percentage of incident solar radiation reflected by the Earth's surface, i.e. the ability of a surface to reflect sunlight. For bifacial photovoltaic modules, albedo is particularly important because these devices have the ability to capture sunlight from both the front and back sides while also utilizing light reflected by the ground or other nearby surfaces.

[0003] Importance of albedo measurements for photovoltaics using bifacial modules:

[0004] Energy efficiency: Accurate albedo measurements are essential for accurate estimation of the energy generated by a bifacial module, as reflected light contributes significantly to the overall system performance.

[0005] Layout optimization: By knowing the albedo of the area where bifacial modules will be installed, designers can optimize the layout of the solar power plant to position them in such a way as to maximize the use of this reflected radiation.

[0006] Project feasibility: Accurate albedo determination is also important during the project planning stage, as it allows assessing the economic and technical feasibility of installing a bifacial module at a given location.

[0007] Decision-making: Because albedo is a property that can vary over time, reliable albedo data allows solar power plant operators to make informed decisions about monitoring and maintaining the system to ensure its long-term efficiency.

[0008] Currently available commercial albedo measurement stations suffer from several significant drawbacks.

[0009] Complexity of Assembly: Existing stations are constructed of materials and equipment that are complex to assemble, which adds to the difficulty of installation.

[0010] High Cost: The high cost of these commercially available stations means that access to this technology is limited to large corporations and institutions with deep budgets.

[0011] Background technology WO 2021-162544, entitled "Geometrically and spectrally resolved albedometers for bifacial modules," discloses geometrically and spectrally resolved albedometers for photovoltaic modules, a method for determining reflected light characteristics, a method for optimizing the reflected light performance of solar cells, and a computer program for geometrically and spectrally resolving light.

[0012] WO 2023-158302, entitled "Casing for irradiance sensors," relates to a sensor for measuring light, in particular a sensor for measuring solar irradiance on a flat surface, more particularly a sensor designed to measure the flux density of solar radiation, such as from above a hemisphere within a limited wavelength range, a housing for the sensor, a sensor comprising the housing and a photovoltaic module, or a system comprising the sensor.

[0013] China Patent Application Publication No. 208155849, entitled "Portable multifunctional albedo observation device", discloses a portable multifunctional albedo observation device comprising an A-frame. A crossbar is connected to the A-frame, and comprises a sleeve tube, a joint tube, a large-diameter hollow rod and a small-diameter hollow rod. The large-diameter hollow rod and the small-diameter hollow rod are connected by a connecting tube to form a telescopic rod. The sleeve tube covers the A-frame. A fixing device is provided at the rear end of the crossbar for connecting a radiometer. The albedo observation device also includes a black light screen. The lower part of the black light screen is connected to a black telescopic support rod. The black light screen can be used to measure the sky light scattering albedo. The device is portable, has a high degree of integration and high operational efficiency, can be suitably moved in a wide range of natural areas to obtain albedo data, and can measure the albedo parameters of sky light scattering, providing effective parameters for verifying the albedo model. The device is painted black, and light pollution is reduced as much as possible. Summary of the Invention

[0014] This utility model discloses a mobile albedo measurement bench conforming to the standard ASTM E1918, in which a pyranometer measuring the incidence of solar radiation is mounted on a leveling tray, which is attached to the arm of the device. The leveling tray is adjustable to ensure that the pyranometer is perfectly parallel to the surface to be analyzed. This results in more accurate and reliable albedo measurements compared to the current technology. Other advantageous effects achieved by this utility model are higher mobility, lower cost, and better usability on uneven surfaces and in remote locations.

[0015] The present utility model will now be described with reference to a typical embodiment thereof and with reference to the accompanying drawings, in which: FIG. [Brief description of the drawings]

[0016] [Figure 1]1 is a schematic diagram of an albedo measuring device according to the present invention. [Diagram 2] FIG. 1 is a diagram of an albedo measuring device according to the present invention. [Diagram 3] FIG. 1 is a diagram of an albedo measuring device according to the present invention. [Figure 4A] FIG. 2 is a diagram of the lower plate of the leveling tray according to the present invention. [Figure 4B] FIG. 2 is a diagram of the upper plate of the leveling tray according to the present invention. [Diagram 5] FIG. 2 is a diagram of a set of screws, nuts, springs and washers according to the present invention. [Figure 6] FIG. 2 is a diagram of one of the sets of screws, nuts, springs and washers according to the present invention. [Figure 7] FIG. 2 is a diagram of the lower sheet of the assembled leveling tray according to the present invention. [Figure 8] FIG. 2 is a diagram of a leveling tray clip that fits onto the arm of the present invention. [Figure 9] FIG. 2 is a diagram of an assembled leveling tray according to the present invention. [Figure 10] FIG. 2 is a detailed view of the assembled leveling tray according to the present invention. [Figure 11] FIG. 2 is a bottom view of the assembled leveling tray of the present invention. [Figure 12] FIG. 2 is a top view of an assembled leveling tray according to the present invention. [Figure 13] FIG. 2 is a diagram of a leveling tray assembled with a pyranometer according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Specific aspects of the present disclosure are described below. As an effort to provide a concise description of these aspects, all features of an actual embodiment may not be described in the description report. It should be understood that in the development of any actual embodiment, as in any engineering or design project, numerous embodiment-specific decisions must be made to accomplish the developer's specific objectives, such as complying with system- and business-related constraints that may vary from embodiment to embodiment. It should also be understood that such development efforts may be complex and time-consuming, but are nevertheless routine design and manufacture by those of ordinary skill in the art having the benefit of this disclosure.

[0018] Current albedo meters typically incorporate a counterweight at the end of the support arm closest to the support to compensate for the weight of the pyranometer located at the other end of the arm. This prevents the weight of the pyranometer from unbalancing the device. However, the pyranometer can still be heavy enough to bend the arm, causing it to shift out of alignment with the ground. This requires that the arm be made of a dense material that is stiff enough to withstand this bending.

[0019] The use of denser and more rigid materials in the construction of the arms increases the weight of the albedo measuring device, reducing its portability and mobility, and also increases its manufacturing costs.

[0020] To overcome this problem, the present invention discloses a mobile albedo measurement bench conforming to the standard ASTM E1918, in which a pyranometer is mounted on the end of an arm by a leveling tray to keep the pyranometer parallel to the analyzed surface. Thus, the measurement bench of the present invention provides a more accurate and reliable measurement of the albedo of the analyzed surface.

[0021] 1 is a schematic diagram of an albedo measurement device 10 according to the present invention. The components of the device 10 are described below. Support element 2: constitutes the base of the structure and acts as a support for the other components. A conventional aluminium terrain tripod meeting the requirements of the ISO12858-2 standard may be used. The support element 2 must be adjustable in height to ensure the positioning of the pyranometer 1 at a height d2 of 50 centimetres above the analysis surface according to ASTM E1918. Preferably, the support element 2 should have fixing elements for the equipment. The fastening elements and bolts preferably use square nuts with dimensions equivalent to the width of the lower rail of the arm 3.

[0022] Arm 3: constitutes a rod for supporting the pyranometer 1, preferably consisting of an aluminum profile according to the present utility model. A commercially available aluminum profile of about 2.60 meters can be used to mount the photovoltaic module on the roof. To facilitate the transportation of the device, the arm can be split, for example, to constitute two 1.30 meter rods. To connect the rods in a simple manner on site, two aluminum profile joints should be used, one for the bottom rail and one for the side rail of the profile. Preferably, the arm 3 is painted black to reduce light reflection from itself and thus its influence on the albedo measurement. The arm 3 or its split rod must be rigidly fixed to the support element 2 to prevent movements due to wind action and must be mounted such that the distance d1 between the pyranometer 1 and the support element 2 is about 2 meters, as required by ASTM E1918, to minimize shadowing on the analysis surface. Furthermore, the arm should extend beyond the support element 2 in the opposite direction to the pyranometer 1 for the mounting of the counterweight 4.

[0023] Counterweight 4: Due to the bending moment caused by the weight of the pyranometer 1 at the end of the arm 3, preferably a structure acting as a counterweight is installed at the opposite end of the arm 3 to stabilize the device 10. The counterweight can be a metal structure with a central hole similar in profile to the arm 3, or a canvas bag filled with enough gravel to ensure stability of the albedo measurement device 10.

[0024] Leveling tray 6: a structure for leveling the pyranometer 1 to prevent bending due to its weight. It is preferably made up of two aluminum plates, at least 5 mm thick, designed to reduce their shadow on the analysis surface. To do this, the sheets can be cut so that their dimensions are less than those of the pyranometer 1 to avoid further shadow casting. One of the plates must have holes corresponding to the screws used to attach the pyranometer 1, since to it the pyranometer 1 will be directly attached. The other plate is attached to the arm 3 by any means deemed appropriate, for example with screws or clips for the photovoltaic module. The plates of the leveling tray 6 are fastened to each other by three or more screws. Further details are given below.

[0025] Pyranometer 1: Two vertically aligned pyranometers are used, the first oriented upwards to receive incident solar radiation and the second oriented downwards to receive solar radiation reflected from the analysis surface. Pyranometer 1 may be any current technology irradiance measurement device deemed suitable.

[0026] Cable 5: Optional element that allows communication between pyranometer 1 and a data acquisition device remote from device 10. Cable 5 can be omitted if pyranometer 1 is capable of storing collected data in an internal memory for subsequent download, or if pyranometer 1 is capable of transmitting data wirelessly.

[0027] Data Acquisition Device (not shown): for acquiring the data collected by the pyranometer. Commercially available data loggers are available and can be configured to acquire data from the pyranometer 1 with a time resolution of 1 second. The data in the data acquisition device must then be analyzed and processed to ensure that all measurement points are within the determination of ASTM E1918 and to reliably obtain the albedo value (reflected irradiance divided by incident irradiance).

[0028] 2 and 3 show an apparatus 10 according to the present disclosure in use during a demonstration test.

[0029] Figures 4A and 4B show the details of the leveling tray 6 according to the present invention. The upper plate 61 is designed in a substantially rectangular shape, one of its ends being substantially circular to fit the shape of the pyranometer 1 and provide better support, and has a corresponding hole for mounting the pyranometer 1. This end may be of any other shape and have any other type of hole deemed suitable for better supporting the pyranometer 1. The opposite end is rectangular and has holes 63a for fixing by preferably three sets of screws, washers and nuts 65 (Figure 5). Preferably, the screws are spring wound to help level the pyranometer 1 with the ground. For example, when the nuts are loosened for leveling adjustment, the upper plate 61 moves with the loosened nuts. The spring ensures that the upper plate 61 is always in the position that the nuts were set for leveling adjustment. Figures 5 and 6 show the set 65 in more detail.

[0030] The lower plate 62 has a hole 63b corresponding to the hole 63a to receive the assembly 65. The lower plate 62 also has a hole 64 to receive a fastener for the arm 3. Preferably, the fastener is a clip 66 that fits onto the arm 3.

[0031] Figure 7 shows the lower plate 62 assembled with the screw and nut set 65 and the clip 66. Figure 8 shows details of the clip 66 for connection to the arm 3. The lower plate 62 slides towards the arm 3, engaging and securing the clip 66 onto the arm 3.

[0032] The assembled leveling tray 6 is shown in Figures 9 and 10. Figure 11 shows a bottom view of the assembled leveling tray 6, where the screws, nuts and washers of the assembly 65 and those used to attach the clips 66 are visible. Figure 12 is a top view of the assembled leveling tray 6, where the upper portion of the assembly 65 is visible.

[0033] In FIG. 13 the levelling tray 6 is shown assembled with the pyranometer 1 mounted thereon.

[0034] Each nut and bolt set 65 can be adjusted individually by tightening or loosening each nut of each set 65. This ensures that the pyranometer 1 is perfectly parallel to the surface to be analysed. Adjustment of the levelling tray 6 can also compensate for irregularities in the surface on which the support element 2 rests, allowing the device 10 to be used in rough areas. A levelling device, for example a levelling bubble from the pyranometer 1 itself, can be used to ensure that the pyranometer 1 is parallel to the surface.

[0035] As the levelling tray 6 ensures parallelism of the pyranometer 1, the arm 3 can be constructed from lighter and thinner materials, reducing the overall weight and cost of the apparatus 10 and increasing its portability and mobility. In this regard, the levelling tray 6 is preferably constructed so that it does not collapse under the weight of the pyranometer 1. Preferably, the plates 61 and 62 are 5 mm or greater in thickness.

[0036] In accordance with the present disclosure, the apparatus 10 as described is lightweight, portable, mobile, and low cost, advantageous characteristics that allow the apparatus 10 to be transported in small vehicles and handled by personnel without difficulty.

[0037] The device 10 of the present invention is ideal for use in remote areas, where it is highly desirable for the data acquisition device to be battery powered.

[0038] While aspects of the present disclosure are susceptible to various modifications and alternative forms, specific aspects have been shown by way of example in the drawings and have been described in detail herein. It is to be understood, however, that the present invention is not limited to the particular forms disclosed. Rather, the present invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the following claims.

Claims

1. An albedo measuring device (10), comprising: The present invention comprises a support element (2), an arm (3) supported on the support element (2), and a pyranometer (1), The apparatus (10) further comprises a leveling tray (6) attached to one end of the arm (3); The pyranometer (1), is mounted on the leveling tray (6), the apparatus (10).

2. 2. The apparatus (10) of claim 1, wherein the leveling tray (6) comprises an upper plate (61), a lower plate (62), three sets of screws, washers and nuts (65), and clips (66).

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