Photovoltaic string optimization arrangement method for improving land unit area efficiency index

Abstract

The invention provides a photovoltaic string optimization arrangement method for improving a land unit area efficiency index, and belongs to the technical field of photovoltaic string optimization arrangement. The technical problem to be solved is to provide the photovoltaic string optimization arrangement method for improving the land unit area efficiency index. According to the technical scheme, a plurality of arrangement schemes are formulated by adjusting the azimuth angle or the installation inclination angle of each photovoltaic string, the land unit area efficiency index of each scheme is calculated, and all the schemes are sorted from small to large according to the unit area installation capacity; comparing the unit area installation capacity of each scheme, and if the schemes with the same unit area installation capacity exist, deleting the scheme with the small unit area power generation amount, and leaving the scheme with the maximum unit area power generation amount; comparing the generating capacity per unit area of each scheme, and deleting the scheme that the installation capacity per unit area is large and the generating capacity per unit area is small; the method is applied to photovoltaic string arrangement.

Description

Technical Field

[0001] The invention provides a photovoltaic string optimization arrangement method for improving the land unit area efficiency index, belonging to the technical field of photovoltaic string optimization arrangement. Background Art

[0002] The land resources used to develop photovoltaic projects are limited and precious. When arranging photovoltaic modules, if we blindly pursue the peak sunshine hours of photovoltaic modules throughout the year, since the power generation of photovoltaic modules installed in the same land area may not be much, it will lead to ineffective use of land resources and cause waste of land resources.

[0003] At present, the research on the layout of photovoltaic modules is mostly focused on how to improve the benefits of the project and how to increase the peak sunshine hours of photovoltaic modules throughout the year, but ignores the impact of the layout plan on the efficiency indicators per unit area of ​​land, including the installation capacity per unit area of ​​land, the power generation per unit area of ​​land and other factors. In addition, the layout plan currently adopted does not take into account the project benefit requirements, nor does it aim to improve the efficiency indicators per unit area of ​​land, which will still cause waste of photovoltaic land. Summary of the invention

[0004] In order to overcome the deficiencies in the prior art, the present invention aims to solve the technical problem of providing a photovoltaic string optimization arrangement method for improving the efficiency index per unit area of ​​land.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a photovoltaic string optimization layout method for improving the land unit area efficiency index, including the following layout steps:

[0006] Step 1: Develop multiple layout plans by adjusting the azimuth or installation inclination of each photovoltaic string, and calculate the land unit area efficiency indicators of each plan, including: land unit area installation capacity PS p (x) Power generation per unit area of ​​land PS s (x), levelized cost of electricity LCOE, incremental cost of electricity ΔLCOE;

[0007] Step 2: Install each solution according to the unit area capacity PS p (x) Sort from small to large;

[0008] Step 3: Compare the installation capacity per unit area PS of each solution p (x), if there are schemes with the same installed capacity per unit area, the scheme with the smallest power generation per unit area is deleted, leaving the scheme with the largest power generation per unit area;

[0009] Step 4: Compare the power generation per unit area of ​​each scheme, and first remove the scheme with large installed capacity per unit area but small power generation per unit area;

[0010] Step 5: If there is a current plan, compare the power generation per unit area and the installed capacity per unit area of ​​the current plan with those of the remaining plans. If there is a plan with an installed capacity per unit area less than or equal to the current plan and a power generation per unit area greater than the current plan, then select the plan with the largest power generation per unit area as the current plan.

[0011] Delete the schemes whose power generation per unit area and installed capacity per unit area are both smaller than the current scheme;

[0012] Step 6: Rearrange the schemes from small to large according to the installed capacity per unit area, and get schemes 1 to x, a total of x schemes. At this time, scheme 1 is the current scheme, and define the power generation per unit area and installed capacity per unit area of ​​scheme 1 as PS s (1) and PS p (1);

[0013] Step 7: Calculate the incremental electricity cost ΔLCOE1(x) between each solution:

[0014] Calculate the incremental electricity cost of plan x and plan x-1 respectively, starting from plan 2 to plan x;

[0015] Step 8: Calculate the incremental electricity cost ΔLCOE2(x) of each solution and the current solution:

[0016] Calculate the incremental electricity cost of plan x and plan 1 respectively, starting from plan 2 to plan x;

[0017] Step 9: Start the comparison from the solution x with the largest installed capacity, and determine whether to select this solution based on the incremental electricity cost ΔLCOE1(x) and ΔLCOE2(x). The judgment rule is:

[0018] If ΔLCOE1(x) and ΔLCOE2(x) are both less than the comprehensive electricity price of photovoltaic grid-connected transactions, this solution is selected;

[0019] If ΔLCOE1(x) or ΔLCOE2(x) is greater than the comprehensive electricity price of photovoltaic grid-connected transactions, delete the scheme and then analyze the next previous scheme x-1;

[0020] Step 10: Determine the best solution:

[0021] Start the analysis from the solution with large installed capacity. As long as ΔLCOE1(x) and ΔLCOE2(x) are both less than the comprehensive electricity price of photovoltaic grid-connected transactions, it is determined as the best solution and no further step is taken.

[0022] If the analysis shows that both ΔLCOE1(2) and ΔLCOE2(2) do not meet the condition of being less than the comprehensive electricity price of photovoltaic grid-connected transactions, then Scheme 1 is judged to be the best scheme.

[0023] The installation capacity per unit area of ​​land PS is calculated in step 1. p (x) Power generation per unit area of ​​land PS s The specific method of (x) is:

[0024] The installation capacity per unit area PS p The calculation formula for (x) is:

[0025]

[0026] Among them: PS p Indicates the installed capacity per unit area; P dc represents the installed capacity of the photovoltaic power generation system; S represents the total area of ​​the photovoltaic power generation system;

[0027] The power generation per unit area PS s The calculation formula for (x) is:

[0028]

[0029] Among them: PS s It indicates the power generation per unit area; It indicates the online power of photovoltaic power generation system during the evaluation period.

[0030] The specific method for calculating the levelized cost of electricity LCOE and the incremental cost of electricity ΔLCOE in step 1 is:

[0031] The calculation formula of the levelized cost of electricity LCOE is:

[0032]

[0033] Where: n represents the number of years the system has been in operation; N represents the evaluation period of the photovoltaic power generation system; I 0 Represents the static initial investment of the photovoltaic system; I t V stands for value-added tax deduction; R Represents the residual value of the photovoltaic system; M n represents the operating cost in the nth year; Y n Indicates the annual online power consumption;

[0034] The incremental cost per kilowatt-hour ΔLCOE is specifically the cost required for each additional kilowatt-hour of electricity generated by changing the installation inclination and azimuth of the photovoltaic string. The calculation formula is:

[0035]

[0036] Where: ΔI 0 Indicates the increase in static initial investment of photovoltaic system; ΔI t Indicates the increase in VAT deduction; ΔV R Indicates the increase in the residual value of the photovoltaic system; ΔM n Indicates the increase in operating costs; ΔY n Indicates the annual increase in grid-connected electricity.

[0037] The specific method for calculating the incremental electricity cost ΔLCOE1(x) between the various schemes in step 7 is:

[0038] The calculation formula of the incremental electricity cost ΔLCOE1(x) is:

[0039]

[0040] The specific method for calculating the incremental electricity cost ΔLCOE2(x) of each scheme and the current scheme in step eight is:

[0041] The calculation formula of the incremental electricity cost ΔLCOE2(x) is:

[0042]

[0043] Compared with the prior art, the present invention has the following beneficial effects: for limited photovoltaic land, the present invention proposes the concept and calculation method of incremental electricity cost, and calculates and analyzes the unit area installation capacity PS of each solution. p (x), power generation per unit area PS s (x), the incremental kilowatt-hour cost between each scheme ΔLCOE1(x) and the incremental kilowatt-hour cost between each scheme and the current scheme ΔLCOE2(x). The resulting photovoltaic layout scheme comprehensively considers the requirements of investment returns and achieves the goal of increasing the installed capacity per unit area of ​​land PS p (x) and power generation per unit area PS s (x) Purpose. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention will be further described below in conjunction with the accompanying drawings:

[0045] Figure 1 A flowchart of the steps of the optimization arrangement method of the present invention;

[0046] Figure 2 A topographical diagram of a certain west slope plot in an embodiment of the present invention;

[0047] Figure 3 This is a rendering of the final optimized layout of a west slope plot in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] like Figure 1 As shown, the present invention optimizes the layout of photovoltaic strings based on the consideration of the land unit area efficiency index and aims to improve the land unit area efficiency index. The land unit area efficiency index to be calculated mainly includes: land unit area installation capacity, land unit area power generation, levelized kilowatt-hour cost, and incremental kilowatt-hour cost. The specific calculation method is:

[0049] (1) The calculation formula for the installed capacity per unit area of ​​land is:

[0050]

[0051] Where: PS p Indicates the installed capacity per unit area (Wp / m 2 );P dc represents the installed capacity of the photovoltaic power generation system (Wp); S represents the total area of ​​the photovoltaic power generation system (m 2 ).

[0052] (2) The formula for calculating the power generation per unit area of ​​land is:

[0053]

[0054] Where: PS s Indicates the power generation per unit area (kWh / m 2 ); It indicates the online power consumption of photovoltaic power generation system during the evaluation period (kWh).

[0055] (3) The formula for calculating the levelized cost of electricity is:

[0056]

[0057] Where: LCOE represents the levelized cost of electricity (yuan / kWh); n represents the number of years the system has been in operation; N represents the evaluation period of the photovoltaic power generation system; I 0 represents the static initial investment of the photovoltaic system (yuan); I t V represents the value-added tax deduction (yuan); R Represents the residual value of the photovoltaic system (yuan); M n represents the operating cost in the nth year (yuan); Y n Indicates annual online electricity consumption.

[0058] (4) Incremental cost per kilowatt-hour refers to the cost of generating additional kilowatt-hours of electricity by changing certain boundary conditions through optimized design of a photovoltaic power generation project. In the present invention, it refers to the cost of generating additional kilowatt-hours of electricity by changing the installation inclination and azimuth of the strings. The calculation formula is:

[0059]

[0060] Where: ΔLCOE represents the incremental electricity cost (yuan / kWh); ΔI 0 Indicates the increase in static initial investment of photovoltaic system (yuan); ΔI t Indicates the increase in VAT deduction (yuan); ΔV R Indicates the increase in residual value of the photovoltaic system (yuan); ΔM n Indicates the increase in operating costs (yuan); ΔY n Indicates the annual increase in grid-connected electricity.

[0061] The photovoltaic string optimization arrangement method provided by the present invention comprises the following specific steps:

[0062] Step 1: The present invention changes the installation inclination and azimuth of the components. The number of strings on the same plot varies greatly. Therefore, multiple layout schemes can be obtained by adjusting the azimuth and installation inclination. The unit area installation capacity PS of each scheme is calculated according to formula (1) and formula (2). p (x) and power generation per unit area PS s (x).

[0063] Step 2: Install each solution according to the unit area capacity PS p (x) Sort from small to large.

[0064] Step 3: Compare the installation capacity per unit area PS of each solution p (x), if there is installed capacity per unit area PS p (x) Same solution, but removing the power generation per unit area PS s (x) Small solution, leaving the power generation per unit area PS s (x) The largest solution.

[0065] Step 4: Compare the power generation per unit area of ​​each plan. If the installed capacity per unit area is large but the power generation per unit area is small, the plan will be discarded first.

[0066] Step 5: If there is a current solution, compare the power generation per unit area and the installed capacity per unit area of ​​the current solution with the remaining solutions. If there is a solution with an installed capacity per unit area less than or equal to the current solution and a power generation per unit area greater than the current solution, select the solution with the largest power generation per unit area as the current solution.

[0067] Delete the plans whose power generation per unit area and installed capacity per unit area are both smaller than the current plan.

[0068] Step 6: Rearrange the order from small to large according to the installed capacity per unit area. At this time, we get Scheme 1 to Scheme x, a total of x schemes, Scheme 1 is the current scheme, and its power generation per unit area and installed capacity per unit area are PSs (1) and PS p (1).

[0069] Step 7: Calculate the incremental LCOE between each scheme according to formula (5), that is, the incremental LCOE between scheme x and scheme x-1, starting from scheme 2 to scheme x:

[0070]

[0071] Step 8: Calculate the incremental LCOE of each scheme and the current scheme according to formula (6), that is, the incremental LCOE of scheme x and scheme 1, starting from scheme 2 to scheme x:

[0072]

[0073] Step 9: Start the comparison from the scheme with the largest installed capacity (i.e., scheme x), and analyze the incremental electricity costs ΔLCOE1(x) and ΔLCOE2(x). If ΔLCOE1(x) and ΔLCOE2(x) are both less than the comprehensive photovoltaic grid-connected electricity price, then select this scheme; if ΔLCOE1(x) or ΔLCOE2(x) is greater than the comprehensive photovoltaic grid-connected electricity price, then discard this scheme and then analyze the previous scheme x-1.

[0074] Step 10: Determine the best solution. Start the analysis from the solution with the largest installed capacity. As long as ΔLCOE1(x) and ΔLCOE2(x) are both less than the comprehensive electricity price of photovoltaic grid-connected transactions, it is determined to be the best solution and no further steps are required. If the analysis shows that ΔLCOE1(2) and ΔLCOE2(2) do not meet the condition of being less than the comprehensive electricity price of photovoltaic grid-connected transactions, then Solution 1 is the best solution.

[0075] In the specific operation of the present invention, when the power generation and initial investment of the alternative schemes are not fixed and have a large difference, the power generation difference and initial investment difference between the two alternative schemes should be compared to analyze whether the incremental initial investment spent on obtaining the incremental power generation is worthwhile. It is not advisable to blindly pursue the minimum cost per kilowatt-hour or the maximum peak sunshine hours. Land resources are limited and precious. In the case of investment income operation, the installed capacity per unit area of ​​land PS should be increased. p (x) and power generation per unit area PS s (x).

[0076] The method proposed in the present invention calculates and analyzes the unit area installation capacity PS of each solution. p (x), power generation per unit area PS s(x), the incremental cost per kWh between each scheme ΔLCOE1(x) and the incremental cost per kWh between each scheme and the current scheme ΔLCOE2(x). The optimal scheme takes into account the requirements of investment return and achieves the goal of increasing the installed capacity per unit area of ​​land PS. p (x) and power generation per unit area PS s (x) Purpose.

[0077] like Figure 2 As shown, in an embodiment of the present invention, the layout method adopted by the present invention is applied to a certain west slope landform, and the layout analysis of photovoltaic components and strings is performed in the area:

[0078] Assume that the center coordinates of the plot are N: 35.0138°; E: 110.9973°, west slope (low in the southwest corner and high in the northeast corner), and the plot area is 66078m 2 The average slope angle of the terrain is 26 degrees; the layout uses N-type TOPCon bifacial 585Wp modules with a module size of 2278mm×1134mm×35mm. 26 photovoltaic modules are used as a string in a vertical 2×13 layout.

[0079] When performing layout analysis, multiple layout schemes are obtained by adjusting the installation inclination angle and string azimuth of the photovoltaic modules. The unit area installation capacity PS of each scheme is calculated according to formula (1): p , calculate the power generation per unit area PS of each scheme according to formula (2) s , and according to the unit area installation capacity PS p Sorted from small to large, the results are shown in Table 1 below.

[0080] The first two numbers of the scheme name in the table represent the installation inclination angle, and the last two numbers represent the azimuth angle. For example, 2540 means the installation inclination angle is 25° and the azimuth angle is 40°.

[0081]

[0082] Table 1 Arrangement results ranking table

[0083] From the data in the table, we can see that the installed capacity per unit area PS of Schemes 3, 5, 9, 11, 12, 14, 17, and 18 is p Larger, power generation per unit area PS s Instead, these programs should be deleted first.

[0084] There are no current plans for this project.

[0085] The remaining solutions are installed according to the unit area capacity PS p Reorder from smallest to largest.

[0086] According to formula (5), starting from Scheme 2, the incremental LCOE between each scheme ΔLCOE1(x) is calculated, that is, the incremental LCOE between Scheme x and Scheme x-1.

[0087] According to formula (6), starting from scheme 2, the incremental electricity cost ΔLCOE2(x) of each scheme compared with the current scheme is calculated.

[0088] The calculation results are shown in Table 2 below:

[0089]

[0090] Table 2 Statistics of reordering schemes and calculation results of ΔLCOE1 and ΔLCOE2

[0091] The comprehensive electricity price for photovoltaic grid-connected transactions is assumed to be 0.18 yuan / kWh.

[0092] From the installation capacity per unit area PS p The largest scheme, namely scheme 11, is compared. Schemes 11, 10, 9, and 8 all fail to meet the condition that both ΔLCOE1(x) and ΔLCOE2(x) are less than the comprehensive electricity price of photovoltaic grid-connected transactions.

[0093] The ΔLCOE1(7) of Scheme 7 is less than 0.18 and ΔLCOE2(7) is less than 0.18, so the best solution is Scheme 7, that is, the layout of 25° inclination and 40° azimuth. The layout results of the best solution are as follows: Figure 3 shown.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing the layout of photovoltaic strings to improve the efficiency index per unit area of ​​land, characterized by: The following steps are included in the layout: Step 1: Develop multiple layout plans by adjusting the azimuth or installation inclination of each photovoltaic string, and calculate the land unit area efficiency indicators of each plan, including: land unit area installation capacity PS p (x) Power generation per unit area of ​​land PS s (x), levelized cost of electricity LCOE, incremental cost of electricity ΔLCOE; Step 2: Install each solution according to the unit area capacity PS p (x) Sort from small to large; Step 3: Compare the installation capacity per unit area PS of each solution p (x) If there are plans with the same installed capacity per unit area, the plan with the smallest power generation per unit area will be deleted, leaving the plan with the largest power generation per unit area; Step 4: Compare the power generation per unit area of ​​each scheme, and first remove the scheme with large installed capacity per unit area but small power generation per unit area; Step 5: If there is a current plan, compare the power generation per unit area and the installed capacity per unit area of ​​the current plan with those of the remaining plans. If there is a plan with an installed capacity per unit area less than or equal to the current plan and a power generation per unit area greater than the current plan, then select the plan with the largest power generation per unit area as the current plan. Delete the schemes whose power generation per unit area and installed capacity per unit area are both smaller than the current scheme; Step 6: Rearrange the schemes from small to large according to the installed capacity per unit area, and get schemes 1 to x, a total of x schemes. At this time, scheme 1 is the current scheme, and define the power generation per unit area and installed capacity per unit area of ​​scheme 1 as PS s (1) and PS p (1); Step 7: Calculate the incremental electricity cost ΔLCOE1(x) between each solution: Calculate the incremental electricity cost of plan x and plan x-1 respectively, starting from plan 2 to plan x; Step 8: Calculate the incremental electricity cost ΔLCOE2(x) of each solution and the current solution: Calculate the incremental electricity cost of plan x and plan 1 respectively, starting from plan 2 to plan x; Step 9: Start the comparison from the solution x with the largest installed capacity, and determine whether to select this solution based on the incremental electricity cost ΔLCOE1(x) and ΔLCOE2(x). The judgment rule is: If ΔLCOE1(x) and ΔLCOE2(x) are both less than the comprehensive electricity price of photovoltaic grid-connected transactions, this solution is selected; If ΔLCOE1(x) or ΔLCOE2(x) is greater than the comprehensive electricity price of photovoltaic grid-connected transactions, delete the scheme and then analyze the next previous scheme x-1; Step 10: Determine the best solution: Start the analysis from the solution with large installed capacity. As long as ΔLCOE1(x) and ΔLCOE2(x) are both less than the comprehensive electricity price of photovoltaic grid-connected transactions, it is determined as the best solution and no further step is taken. If the analysis shows that both ΔLCOE1(2) and ΔLCOE2(2) do not meet the condition of being less than the comprehensive electricity price of photovoltaic grid-connected transactions, then Scheme 1 is judged to be the best scheme.

2. A photovoltaic string optimization layout method for improving land unit area efficiency index according to claim 1, characterized in that: The installation capacity per unit area of ​​land PS is calculated in step 1. p (x) Power generation per unit area of ​​land PS s The specific method of (x) is: The installation capacity per unit area PS p The calculation formula for (x) is: Among them: PS p Indicates the installed capacity per unit area; P dc represents the installed capacity of the photovoltaic power generation system; S represents the total area of ​​the photovoltaic power generation system; The power generation per unit area PS s The calculation formula for (x) is: Among them: PS s It indicates the power generation per unit area; It indicates the online power of photovoltaic power generation system during the evaluation period.

3. A photovoltaic string optimization arrangement method for improving the land unit area efficiency index according to claim 2, characterized in that: The specific method for calculating the levelized cost of electricity LCOE and the incremental cost of electricity ΔLCOE in step 1 is as follows: The calculation formula of the levelized cost of electricity LCOE is: Where: n represents the number of years the system has been in operation; N represents the evaluation period of the photovoltaic power generation system; I0 represents the static initial investment of the photovoltaic system; I t V stands for value-added tax deduction; R Represents the residual value of the photovoltaic system; M n represents the operating cost in the nth year; Y n Indicates the annual online power consumption; The incremental cost per kilowatt-hour ΔLCOE is specifically the cost required for each additional kilowatt-hour of electricity generated by changing the installation inclination and azimuth of the photovoltaic string. The calculation formula is: Where: ΔI0 represents the increase in static initial investment of photovoltaic system; ΔI t Indicates the increase in VAT deduction; ΔV R Indicates the increase in the residual value of the photovoltaic system; ΔM n Indicates the increase in operating costs; ΔY n Indicates the annual increase in grid-connected electricity.

4. A photovoltaic string optimization arrangement method for improving the land unit area efficiency index according to claim 3, characterized in that: The specific method for calculating the incremental electricity cost ΔLCOE1(x) between the various schemes in step 7 is: The calculation formula of the incremental electricity cost ΔLCOE1(x) is: The specific method for calculating the incremental electricity cost ΔLCOE2(x) of each scheme and the current scheme in step eight is: The calculation formula of the incremental electricity cost ΔLCOE2(x) is:

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