Ground scene adaptation method for power generation synergy of double-sided photovoltaic module

Abstract

The invention discloses a ground scene adaptation method for power generation synergy of a double-sided photovoltaic module. The ground scene adaptation method comprises the following steps: performing ground scene investigation on the double-sided photovoltaic module; calculating the reflectivity of different types of ground scenes according to the obtained canopy reflection spectrum curves of the suitable dominant plants in different ground scenes; obtaining the module back irradiance of the double-sided photovoltaic module above different types of ground scenes; constructing a nonlinear function model between the component back irradiance and the ground scene reflectivity; and based on the scene vegetation configuration mode and coverage constraint, screening suitable plant species to configure ground scene vegetation. According to the invention, under the requirement of building a double-sided photovoltaic module power station with an under-panel ecological benefit or an under-panel economic benefit, high-reflectivity plants with good ecological benefit or economic benefit are configured below the module and between array lines, so that photovoltaic new energy power generation and an under-surface ecological and economic win-win situation is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of double-sided photovoltaic modules, and in particular relates to a ground scene adaptation method for increasing the efficiency of power generation of double-sided photovoltaic modules. Background Art

[0002] Compared with single-sided photovoltaic modules, bifacial photovoltaic modules have a low temperature coefficient, low photo-induced attenuation, and good weak light response. The power generation efficiency of bifacial photovoltaic modules is affected by the comprehensive power generation efficiency of the front and back of the modules, and the ground scene where the photovoltaic modules are located directly affects the power generation performance of the back of the bifacial photovoltaic modules, mainly including the impact of the ground scene reflectivity on the output power of the bifacial modules. At the same time, external factors such as ground scene changes, temperature changes, and back irradiance differences are one of the main reasons for the mismatch of bifacial modules and the reduction of power generation performance.

[0003] Unlike highly homogenized artificial ground scenes, in fragile natural ecosystems such as desertification and rocky desertification, the ground scenes are highly heterogeneous, and the vegetation is mostly sparse or patchy. The reflectivity of the back of the module is affected by the ground exposure rate, rocks, plant species, plant phenology, and non-photosynthetic vegetation composition. The canopy reflectivity of different plants can differ by more than 2 times, and there are also obvious differences in different phenological periods of plants. The reflectivity differences caused by complex ground scenes lead to uneven irradiance on the back of bifacial photovoltaic modules in space. We will vigorously promote new energy projects for ecological restoration, and use deserts, Gobi, rocky desertification, and barren slopes and beaches to explore new models of organic integration of energy and ecological restoration and characteristic industrial development. However, engineering facilities such as cement hardening and gravel paving on the underlying surface of photovoltaic modules will destroy the original ecological functions and lead to the loss of biodiversity and species habitats.

[0004] Therefore, it is urgent to develop photovoltaic projects that are friendly to ecological and environmental functions. Innovating ground scene control technology that is compatible with bifacial photovoltaic modules and has ecosystem functional diversity is an effective way to solve the mismatch of back-side power generation of bifacial photovoltaic modules and improve the back-side power generation efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a ground scene adaptation method for improving the power generation efficiency of double-sided photovoltaic modules in response to the above-mentioned deficiencies in the prior art, so as to solve the problems of rapid increase in the operating temperature of double-sided photovoltaic modules, strong heterogeneity of back radiation, and compromise between power generation performance and ecological friendliness due to the high heterogeneity of the ground environment in fragile ecosystems.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A ground scene adaptation method for increasing the power generation efficiency of a double-sided photovoltaic module comprises the following steps:

[0008] S1. Conduct a ground scene survey on bifacial PV modules;

[0009] S2. Calculate the reflectance of different types of ground scenes based on the canopy reflectance spectral curves of suitable dominant plants in the obtained different ground scenes;

[0010] S3. Obtain the irradiance on the back side of the bifacial PV module above different types of ground scenes;

[0011] S4. Construct a non - linear function model between the irradiance on the back side of the module and the ground scene reflectance;

[0012] S5. According to the non - linear function model between the irradiance on the back side of the module and the ground scene reflectance, and based on the constraints of the scene vegetation configuration pattern and coverage, screen suitable plant species to configure the ground scene vegetation.

[0013] Furthermore, in S1, the ground scene survey on the bifacial PV module includes:

[0014] The ground scene survey area is the PV sub - array area. Survey sample points are arranged in a "meter" shape or a "field" shape in the PV sub - array area. There are 5 - 9 survey sample points per 1MW sub - array. Each survey sample point includes two sub - sample points, namely between the rows of the array and under the module. The size of the sub - sample point is 1m - 2m×1m - 2m.

[0015] Furthermore, the survey objects in the ground scene survey area include vegetation, rocks, and soil within the sub - sample points;

[0016] The survey indicators include plant species, vegetation productivity, plant life form, rock exposure rate, and soil exposure rate.

[0017] Furthermore, in S2, calculating the reflectance of different types of ground scenes includes:

[0018] Survey in descending order of the coverage of each plant species, collect the canopy spectral data of the species within the survey sub - sample points, and record their coverage percentage values C1, C2,... C i i, where i is the number of species; or collect the canopy spectral data of crops, economic plants, Chinese medicinal materials, forage grasses, and ecological restoration plants planted in the PV field area. Randomly measure 8 - 12 healthy plants for each plant species, monitor each plant 6 - 8 times, and take the average of the monitoring values as the original reflectance Q plant of the plant species; measure the reflectance Q s of the bare - land area in the same scene.

[0019] Furthermore, S3 includes: arranging irradiance probes on the back side of the bifacial PV module. The installation inclination angle of the irradiance probe is the same as the inclination angle of the bifacial PV module, and use the irradiance probe to collect and obtain the irradiance on the back side of the bifacial PV module above different types of ground scenes.

[0020] Furthermore, a nonlinear function model between the back irradiance of the component and the reflectivity of the ground scene is constructed in S4, including:

[0021] Q rear =α·Q1+β·Q2+γ·ρ·Q3

[0022] Among them, Q rear is the irradiance on the back of the component; Q1 is the horizontal direct irradiance; Q2 is the horizontal scattered irradiance; Q3 is the ground reflected irradiance; α is cosθ / sinζ, θ is the angle between the direct light and the normal of the back of the component, ζ is the solar altitude angle; β is the visual factor of the back of the component receiving sky scattering; γ is the visual factor of the back of the component receiving ground reflection; ρ is the ground scene reflectivity.

[0023] Furthermore, in S5, according to the nonlinear function model between the back irradiance of the component and the reflectivity of the ground scene, and based on the scene vegetation configuration mode and coverage constraints, suitable plant species are selected to configure the ground scene vegetation type, including:

[0024] Substituting ρ into Q rear =α·Q1+β·Q2+γ·ρ·Q3, and the Q under different plant ground scenes is obtained. rear value;

[0025] When the vegetation coverage is 100%, ρ is constrained by a single plant configuration mode, ρ = Q plant ;

[0026] When the ground scene is bare land, that is, the vegetation coverage is 0, ρ = Q s ;

[0027] When ρ is constrained by a mixed planting configuration of multiple plants, the reflectance of the vegetation canopy is constrained by the reflectance of different plant species, the reflectance of the bare land part and its coverage, that is:

[0028] ρ=C1·ρ1+C2·ρ2+…C i ·ρ i +C s Q s

[0029] Among them, C1, C2, ...C i is the coverage of species 1, 2, …i, ρ1, ρ2, …ρ i is the reflectance Q of species 1, 2, ...i plant1 ,Q plant2 ,…Q planti ,C s is the coverage of bare land, Q s is the bare earth reflectivity;

[0030] When restoring vegetation or planting plants under the component, solve according to the plant configuration mode and plant coverage. When other parameters are fixed, Q rear It is proportional to the reflectivity of the plant. When high-reflectivity plants are selected for planting, ρ is the largest, and the back of the component obtains the highest vegetation canopy reflected irradiance.

[0031] The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules provided by the present invention has the following beneficial effects:

[0032] 1. The method of the present invention improves the ground reflected irradiance below the module and between the array rows through investigation and monitoring, plant screening, species configuration, etc., and constructs a relationship model between the irradiance on the back of the module and parameters such as the reflectivity of the plant canopy, the reflectivity of the vegetation community, and the vegetation coverage. By artificially intervening in the underlying vegetation, the irradiance on the back of the module is increased, thereby improving the power generation efficiency of the bifacial photovoltaic module.

[0033] 2. The method of the present invention breaks through the traditional method of improving the ground reflectivity of bifacial photovoltaic modules, which is limited to white paint, cement, sand, land and other surface treatment methods with weak ecological or economic functions. Under the requirement of building a bifacial photovoltaic module power station with under-panel ecological benefits or under-panel economic benefits, high-reflectivity plants with good ecological or economic benefits are arranged under the modules and between the array rows, so as to achieve a win-win situation between photovoltaic new energy power generation and the underlying surface ecology and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a flow chart of the ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules.

[0035] Figure 2 It is a schematic diagram of a double-sided photovoltaic module of the present invention. DETAILED DESCRIPTION

[0036] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0037] Example 1

[0038] A method for adapting a double-sided photovoltaic module power generation enhancement to a ground scenario in this embodiment is a method for adjusting the adaptation of double-sided photovoltaic module power generation to the ground scenario based on technologies such as optimizing the irradiance uniformity on the back of the photovoltaic module, monitoring the reflectivity of the plant canopy, screening and configuring suitable plants, etc., which can solve the problems that the working temperature of the double-sided module rises rapidly, the irradiance heterogeneity on the back is strong, and the power generation performance and ecological friendliness cannot have both due to the high heterogeneity of the ground environment in the fragile ecosystem. Refer to Figure 1 and Figure 2 , and specifically includes the following steps:

[0039] Step S1: Conduct a ground scenario survey on the double-sided photovoltaic module, determine the ground scenario survey area, survey object, and survey indicators of the double-sided photovoltaic module, and divide different types of ground scenarios, which are specifically as follows:

[0040] The ground scenario survey area is in the photovoltaic sub-array area. In the photovoltaic sub-array area, survey sample points are arranged in a "meter" shape or a "field" shape. There are 5 - 9 survey sample points per 1MW sub-array. Each sample point includes 2 sub-sample points, namely between the rows of the array and under the module. The size of the sub-sample point is 1m - 2m × 1m - 2m.

[0041] Among them, the survey objects include surface conditions such as vegetation, rocks, and soil within the sub-sample points.

[0042] The survey indicators include plant species, vegetation productivity, plant life form, rock exposure rate, and soil exposure rate.

[0043] Step S2: Calculate the reflectivity of different types of ground scenarios according to the obtained canopy reflectance spectral curves of suitable dominant plants in different ground scenarios, which specifically includes the following content:

[0044] Survey in descending order of plant species coverage, collect the canopy spectral data of species within the survey sub-sample points, and record their coverage percentage values C1, C2,... C i , where i is the number of species; or collect the canopy spectral data of crops, economic plants, Chinese medicinal materials, forages, and ecological restoration plants planted in the photovoltaic field area. For each plant, randomly measure 8 - 12 healthy plants, monitor each plant 6 - 8 times, and take the average of the monitoring values as the original reflectivity Q plant of this plant species; measure the reflectivity Q s of the bare land area in the same scenario.

[0045] Between 10:00 am and 2:00 pm on a sunny day, monitor the canopy spectral data of plants with a coverage of 80% or more within the survey sample points, or the canopy spectral data of plant species such as crops, economic plants, Chinese medicinal materials, forages, and ecological restoration plants suitable for planting in the photovoltaic field area. For each plant, randomly measure 8 - 12 healthy plants, monitor each plant 6 - 8 times, and take the average of the monitoring values as the original reflectivity Qplant , and generate the canopy reflectance spectral curves of dominant plants in different ground scenes.

[0046] Step S3, obtaining the irradiance on the back side of the bifacial photovoltaic modules above different types of ground scenes;

[0047] Specifically, an irradiation probe is arranged on the back side of the bifacial photovoltaic module. The installation inclination angle of the irradiation probe is consistent with the inclination angle of the bifacial photovoltaic module. The irradiation probe is used to collect and obtain the irradiance on the back side of the bifacial photovoltaic module above different types of ground scenes.

[0048] Step S4: construct a nonlinear function model between the back irradiance of the component and the reflectivity of the ground scene. The expression of the nonlinear function model is:

[0049] Q rear =α·Q1+β·Q2+γ·ρ·Q3

[0050] Among them, Q rear is the irradiance on the back of the component; Q1 is the horizontal direct irradiance; Q2 is the horizontal scattered irradiance; Q3 is the ground reflected irradiance; α is cosθ / sinζ, θ is the angle between the direct light and the normal of the back of the component, ζ is the solar altitude angle; β is the visual factor of the back of the component receiving sky scattering; γ is the visual factor of the back of the component receiving ground reflection; ρ is the ground scene reflectivity.

[0051] Step S5: According to the nonlinear function model between the back irradiance of the component and the reflectivity of the ground scene, and based on the scene vegetation configuration mode and coverage constraints, suitable plant species are selected to configure the ground scene vegetation, which specifically includes the following contents:

[0052] Substituting ρ into Q rear =α·Q1+β·Q2+γ·ρ·Q3, and the Q under different plant ground scenes is obtained. rear value;

[0053] When the vegetation coverage is 100%, ρ is constrained by a single plant configuration mode, ρ = Q plant ;

[0054] When the ground scene is bare land, that is, the vegetation coverage is 0, ρ = Q s ;

[0055] When ρ is constrained by a mixed planting configuration of multiple plants, the reflectance of the vegetation canopy is constrained by the reflectance of different plant species, the reflectance of the bare land part and its coverage, that is:

[0056] ρ=C1·ρ1+C2·ρ2+…C i ·ρ i +C s Q s

[0057] Among them, C1, C2, ...C i is the coverage of species 1, 2, …i, ρ1, ρ2, …ρ i is the reflectance Q of species 1, 2, ...i plant1 ,Q plant2 ,…Q planti ,C s is the coverage of bare land, Q s is the bare earth reflectivity.

[0058] When restoring vegetation or planting plants under the component, solve according to the plant configuration mode and plant coverage. When other parameters are fixed, Q rear It is proportional to the reflectivity of the plant. When high-reflectivity plants are selected for planting, ρ is the largest, and the back of the component obtains the highest vegetation canopy reflected irradiance.

[0059] The high-reflectivity plants screened by the present invention are configured with a ground vegetation pattern under the constraints of economic benefits and ecological restoration benefits to achieve multiple functions such as back-side power generation gain, economic efficiency improvement, and ecological friendliness; the ground scene control technology of the present invention, which is compatible with double-sided photovoltaic modules and has ecosystem functional diversity, is an effective way to solve the back-side power generation mismatch of double-sided photovoltaic modules and improve the back-side power generation efficiency.

[0060] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A ground scene adaptation method for increasing the power generation efficiency of a double-sided photovoltaic module, characterized in that: It includes the following steps: S1. Conduct a ground scene survey on the bifacial PV module; S2. Calculate the reflectance of different types of ground scenes according to the canopy reflectance spectral curves of suitable dominant plants in different ground scenes obtained; S3. Obtain the irradiance on the back side of the bifacial PV module above different types of ground scenes; S4. Construct a non-linear function model between the irradiance on the back side of the module and the ground scene reflectance; S5. According to the non-linear function model between the irradiance on the back side of the module and the ground scene reflectance, and based on the constraints of the scene vegetation configuration mode and coverage, screen suitable plant species to configure the ground scene vegetation.

2. The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules according to claim 1 is characterized in that: In the S1, the ground scene survey on the bifacial PV module includes: The ground scene survey area is the PV sub-array area. Survey sample points are arranged in a "meter" shape or a "field" shape in the PV sub-array area. 5 - 9 survey sample points are arranged per 1MW sub-array. Each survey sample point includes two sub-sample points, namely between the rows of the array and below the module. The size of the sub-sample point is 1m - 2m × 1m - 2m.

3. The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules according to claim 2 is characterized by: The survey objects in the ground scene survey area include vegetation, rocks, and soil within the sub-sample points; The survey indicators include plant species, vegetation productivity, plant life form, rock exposure rate, and soil exposure rate.

4. The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules according to claim 1 is characterized by: In the S2, calculating the reflectance of different types of ground scenes includes: Investigate the canopy spectrum data of species in the survey sub-sample points from large to small, and record their coverage percentage values ​​C1, C2, ...C i , where i is the number of species; or collect canopy spectral data of crops, economic plants, Chinese medicinal materials, forage, and ecological restoration plants planted in the photovoltaic field, randomly measure 8-12 healthy plants of each plant, monitor each plant 6-8 times, and take the average of the monitored values ​​as the original reflectance Q of the plant species plant ; Measure the reflectivity Q of the bare ground area in the same scene s .

5. The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules according to claim 1 is characterized in that: The S3 includes: Arranging an irradiance probe on the back side of the bifacial PV module. The installation inclination angle of the irradiance probe is the same as the inclination angle of the bifacial PV module, and the irradiance probe is used to collect and obtain the irradiance on the back side of the bifacial PV module above different types of ground scenes.

6. The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules according to claim 4 is characterized in that: In the S4, constructing a non-linear function model between the irradiance on the back side of the module and the ground scene reflectance includes: Q rear =α·Q1+β·Q2+γ·ρ·Q3 Among them, Q rear is the irradiance on the back of the component; Q1 is the horizontal direct irradiance; Q2 is the horizontal scattered irradiance; Q3 is the ground reflected irradiance; α is cosθ / sinζ, θ is the angle between the direct light and the normal of the back of the component, ζ is the solar altitude angle; β is the visual factor of the back of the component receiving sky scattering; γ is the visual factor of the back of the component receiving ground reflection; ρ is the ground scene reflectivity.

7. The ground scene adaptation method for increasing the power generation efficiency of double-sided photovoltaic modules according to claim 6 is characterized in that: In the S5, according to the non-linear function model between the irradiance on the back side of the module and the ground scene reflectance, and based on the constraints of the scene vegetation configuration mode and coverage, screening suitable plant species to configure the ground scene vegetation type includes: Substituting ρ into Q rear =α·Q1+β·Q2+γ·ρ·Q3, and the Q under different plant ground scenes is obtained. rear value; When the vegetation coverage is 100%, ρ is constrained by a single plant configuration mode, ρ = Q plant ; When the ground scene is bare land, that is, the vegetation coverage is 0, ρ = Q s ; When ρ is constrained by a mixed planting configuration mode of multiple plants, the canopy reflectance of the vegetation is constrained by the reflectances of different plant species, the reflectance of the bare ground part, and their coverages, that is: p=C1·p1+C2·p2+…C i ·r i +C s ·Q s Among them, C1, C2, ...C i is the coverage of species 1, 2, …i, ρ1, ρ2, …ρ i is the reflectance Q of species 1, 2, ...i plant1 ,Q plant2 ,…Q planti ,C s is the coverage of bare land, Q s is the bare earth reflectivity; When restoring vegetation or planting plants under the component, solve according to the plant configuration mode and plant coverage. When other parameters are fixed, Q rear It is proportional to the reflectivity of the plant. When high-reflectivity plants are selected for planting, ρ is the largest, and the back of the component obtains the highest vegetation canopy reflected irradiance.

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