Near-Horizon Ecological Photovoltaic System

Abstract

This invention discloses a near-horizontal ecological photovoltaic system, relating to the field of agricultural-photovoltaic complementary technology, aiming to solve the problems of insufficient space for photovoltaic installation in zero-carbon factories and industrial parks, as well as the large fluctuations in power generation of traditional photovoltaic systems. The system includes a south-facing tilted photovoltaic array A, with photovoltaic arrays B arranged at intervals of 3–15 meters on the surrounding ground. The photovoltaic panels are vertically installed and receive sunlight from both sides. The installed capacity ratio k of photovoltaic arrays B and A is precisely matched to the local geographical latitude φ, eliminating the need for energy storage and tracking supports, and achieving stable and balanced power generation throughout the day solely through array combination. This system can be integrated with agricultural, pastoral, and fishery sites, is suitable for latitude regions of 18°–50° across China, and can control power generation fluctuations within ±3%–±15%, improving local power consumption, reducing costs, and meeting the needs of zero-carbon construction.

Description

Technical Field

[0001] This invention relates to the field of agricultural-solar complementary technology, specifically to the innovative application of the applicant's prior patent "Swing-resistant and stable power generation agricultural-solar complementary system (CN120658176B)"—a near-horizontal ecological (agriculture, animal husbandry, and fishery) photovoltaic system. Background Technology

[0002] In the current practice of building zero-carbon factories and zero-carbon industrial parks, the applicant has found that the available space within factories and parks is extremely limited, and the area suitable for installing photovoltaic panels is even scarcer; conversely, the electricity consumption of enterprises within factories and parks is very high. This presents a contradiction: there is no land available for installing a large number of photovoltaic panels in the construction of zero-carbon factories and zero-carbon industrial parks.

[0003] The applicant's prior patents, such as "Strip Photovoltaic Power Generation Method (CN118589959B)" and "Swing-resistant and Stable Power Generation Agricultural Photovoltaic Complementary System (CN120658176B)," can all be erected above farmland, enabling the combined use of photovoltaics and farmland and effectively expanding the space for photovoltaic installation. This allows for installation in farmland surrounding zero-carbon factories and zero-carbon industrial parks, solving the problem of insufficient land for their construction.

[0004] However, traditional photovoltaic systems generally adopt a single south-facing tilt angle (south is a general azimuth description; it generally refers to due south, south-east, south-west, etc.) installation method, and the power generation curve shows a clear single peak shape at noon. The power is low in the morning and evening and the peak is high at noon. The intraday peak-valley difference is large and the fluctuation is violent, which is not conducive to stable power supply.

[0005] Existing technologies have introduced multi-directional and multi-angle photovoltaic (PV) arrangement schemes, such as mixed installations facing east, west, and south, in an attempt to smooth the power generation curve. Related technologies are disclosed in Chinese patents CN106100522B and CN114050772A, among others.

[0006] However, the existing solutions mentioned above have obvious drawbacks: they do not establish a precise capacity matching model that is strongly correlated with the local geographical latitude, resulting in unstable smoothing of the power generation curve in different latitude regions and poor adaptability; they do not optimize multiple sets of complementary structures such as east-west, southeast-northwest and southeast-northwest directions for vertical bifacial modules, and most of them require the use of tracking brackets or energy storage devices to achieve smoothing of the total power generation curve, which increases system costs and reduces system power generation efficiency; and they cannot achieve a daily total power generation curve that is close to a horizontal straight line without relying on tracking brackets.

[0007] Therefore, the industry urgently needs a technical solution that is simple in structure, adaptable to the construction of zero-carbon factories and zero-carbon parks, adaptable to all latitudes across the country, and can achieve near-horizontal power generation output simply by combining photovoltaic arrays themselves. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an ecological photovoltaic system with a flat-topped, broad-peaked daily power generation curve. Because its flat-topped, broad-peaked curve is approximately a horizontal straight line, this invention is figuratively named the near-horizontal ecological photovoltaic system.

[0009] This invention discloses a near-horizontal ecological photovoltaic system, comprising a photovoltaic array A installed at a south-facing tilt angle, characterized in that: On the ground near photovoltaic array A (in farmland, etc.), a set of photovoltaic arrays B is arranged at intervals S; the interval S is 3 to 15 meters, which is used to create distance and leave space for planting / breeding. The photovoltaic array B (with its axis F roughly) is oriented north-south, and its photovoltaic panels are installed vertically, with the front and back sides facing east and west respectively to receive sunlight, that is, one side is roughly facing east and the other side is roughly facing west. The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 70-100%; the ground surface between adjacent photovoltaic arrays B (with a width of 3-15 meters) is used for planting crops, planting grass, or raising aquatic products; The installed capacity ratio of photovoltaic array B to photovoltaic array A is B / A=k, and k satisfies the following with respect to the local geographical latitude φ (unit: degrees): k=(1.85-0.03φ)±12% (that is, k is allowed to have a redundancy range of ±12%), where 18°≤φ≤50°; When photovoltaic array A and photovoltaic array B are combined, the total daily power generation curve has a flat-topped, broad-peak shape, and the power fluctuation relative to its equivalent average line does not exceed ±15%, preferably not exceeding ±8%. Explanation: The equivalent average line is a horizontal straight line with equal power generation and constant power, converted from a fluctuating actual / typical daily power generation curve. It is a virtual horizontal straight line used to simplify analysis, planning, and transaction settlement.

[0010] Preferably, in the aforementioned near-horizontal ecological photovoltaic system, the photovoltaic array B is divided into two groups, B1 and B2; group B1 (with axis F) runs north-south, and group B2 (with axis F) runs southwest to northeast, with the photovoltaic panels installed vertically; the front and back sides of the photovoltaic panels in group B1 face east and west respectively to receive sunlight, while the front and back sides of the photovoltaic panels in group B2 face southeast and northwest respectively to receive sunlight (for example, the front faces 45° east of south and the back faces 45° west of north, with the front approximately 45° east of south and the back approximately 45° west of north); by adjusting the installed capacity ratios (B1 / A and B2 / A) of photovoltaic arrays A, B1, and B2, the total daily power generation curves of the three arrays have a flat-topped, broad-peak shape, with power fluctuations relative to their equivalent average lines not exceeding ±8%.

[0011] Preferably, the installed capacity ratio k of the near-horizon ecological photovoltaic system is 1.85-0.03φ, where φ is the local geographical latitude (unit: degrees), and 18°≤φ≤50°.

[0012] The preferred value for the installed capacity ratio k is 1.85–0.03φ.

[0013] Preferably, in the aforementioned near-horizon ecological photovoltaic system, photovoltaic arrays A, B1, and B2 share an inverter or are configured with independent inverters. By adjusting the installed capacity ratio of the three (B1 / A and B2 / A), the total daily power generation curve, excluding 1.5 hours after sunrise and 1.5 hours before sunset (based on local true solar time), tends to be stable, and the power fluctuation (relative to its own equivalent average line) does not exceed ±5%.

[0014] Preferably, in the aforementioned near-horizon ecological photovoltaic system, the photovoltaic array B is divided into n groups (axis F) of photovoltaic arrays with different orientations, where n≥3 (preferably n≤15). The photovoltaic panels in this photovoltaic array are installed vertically, and the orientations of the n groups of photovoltaic arrays with different orientations are distributed around the sun's orbital path. The orientations of one group increase by 5° to 15° clockwise from another group. The photovoltaic array A and the n sub-arrays in the photovoltaic array B share an inverter or are configured with independent inverters. The total daily power generation curve of the n groups of photovoltaic arrays with different orientations and the photovoltaic array A tends to be stable, and the power fluctuation (relative to its own equivalent average line) does not exceed ±3%.

[0015] The beneficial effects of this invention are as follows.

[0016] Firstly, it requires no energy storage or tracking support. It can achieve near-horizontal power generation simply through structural combination, making the total daily power generation curve more stable and balanced. This prevents insufficient photovoltaic power during the morning and evening when the sun is at an angle, and excessive photovoltaic power during the midday sun, thereby reducing energy storage investment and costs.

[0017] Secondly, it is precisely matched according to geographical latitude, and can be adapted to different latitude regions across the country, such as Hainan, Shandong, Inner Mongolia, and Xinjiang, making it highly versatile.

[0018] Thirdly, the vertical double-sided east-west array can significantly improve the power generation in the morning and evening, offsetting the peak power of the midday tilt array, thus achieving natural complementarity.

[0019] Fourth, it can be used in combination with farmland, grassland, sandy land, and open space in industrial parks. It is particularly suitable for agricultural photovoltaic complementarity, ecological protection, desertification control, zero-carbon factory construction, and zero-carbon industrial park support, solving the problem of no land available for installing photovoltaic arrays near zero-carbon factories and zero-carbon industrial parks.

[0020] Fifth, the daily power generation curve fluctuates little, power generation is stable and balanced, grid friendly, significantly improves the local consumption ratio, reduces curtailment rate and dispatch pressure, and is suitable for the power supply needs of zero-carbon factories and zero-carbon parks. Attached Figure Description

[0021] Figure 1 is a schematic diagram of the arrangement of numerous photovoltaic arrays A installed at a south-facing tilt angle.

[0022] Figure 2 is Figure 1 A schematic diagram of the installation of photovoltaic array A.

[0023] Figure 3 is a schematic diagram of the installation of a photovoltaic array B with photovoltaic panels installed vertically.

[0024] Figure 4 is a schematic diagram of the installation of a photovoltaic array B with the photovoltaic panels vertically suspended.

[0025] Figure 5 shows the installation diagrams of photovoltaic array A installed at a south-facing tilt angle and photovoltaic array B installed vertically.

[0026] Figure 6 shows the installation diagrams of photovoltaic array A installed at a south-facing tilt angle, photovoltaic array B1 installed vertically (photovoltaic panel front facing east and back facing west), and photovoltaic array B2 installed vertically (photovoltaic panel front facing southeast and back facing northwest).

[0027] Figure 7 The graph shows the daily power output curve (single-peak curve) of an 8kW photovoltaic array A installed in Haikou City (20°N latitude on April 22nd) with a southward tilt. The solid line is the daily power generation curve, and the dashed line is the equivalent average line of the daily power generation curve, used to compare the fluctuation range of the flat-top broad peak.

[0028] Figure 8 The graph shows the daily power generation curve (a double-peak, single-valley curve) of an 8kW photovoltaic array B vertically installed in Haikou City (20°N latitude, April 22). The solid line represents the daily power generation curve, and the dashed line represents the equivalent average line of the daily power generation curve, used to compare the fluctuation range of the flat-top, wide-peak curve.

[0029] Figure 9 The graph shows the total daily power generation curves (with wavy, flat-topped, broad-peaked curves) for an 8kW photovoltaic array A installed at a southward tilt angle and an 8kW photovoltaic array B installed vertically in Haikou City (20°N latitude, April 22). The solid line represents the daily power generation curve, and the dashed line represents the equivalent average line of the daily power generation curve, used to compare the fluctuation range of the flat-topped, broad-peaked curve.

[0030] Figure 10The graph shows the total daily power output of three photovoltaic arrays in Haikou City (20°N latitude, April 22): an 8kW photovoltaic array A installed at a south-facing tilt angle, an 8kW photovoltaic array B1 installed vertically (with the front of the photovoltaic panels facing east and the back facing west), and an 8kW photovoltaic array B2 installed vertically (with the front of the photovoltaic panels facing southeast and the back facing northwest). The graphs are wavy, flat-topped, and broad-peaked curves. The solid lines represent the daily power generation curves, and the dashed lines represent the equivalent average of the daily power generation curves, used to compare the fluctuation range of the flat-topped, broad-peaked curves.

[0031] Figure 11 This is a schematic diagram showing the arrangement of photovoltaic arrays B with n different axes F. Detailed Implementation

[0032] The invention will be further illustrated below with examples from typical latitude regions.

[0033] Example 1.

[0034] See Figure 5 In Haikou City, Hainan Province (latitude φ≈20°), select a vegetable plot and install photovoltaic array A at a south-facing tilt angle (20°). The optimal tilt angle for photovoltaic installation is the angle (angle with the horizontal plane) that allows the modules to receive the most solar radiation and generate the most power throughout the year. The optimal tilt angle is roughly equivalent to the local latitude; for example, Haikou is at 20° North latitude, so the optimal tilt angle is 20°.

[0035] In the vegetable gardens and other farmland near the photovoltaic array A, a set of photovoltaic arrays B with an axis F oriented north-south is arranged at intervals (S=8 meters).

[0036] The photovoltaic panels in the photovoltaic array B are installed vertically at a 90° tilt angle, with their front and back sides facing east and west respectively to receive sunlight.

[0037] The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 95-100%; the ground surface between adjacent photovoltaic arrays B is used for planting crops, grass, or aquaculture.

[0038] The installed capacity ratio of photovoltaic array B to photovoltaic array A is B / A=k, where k is 1.85 - 0.03 × 20 = 1.25. Of course, based on this preferred value, a redundancy of ±12% can be relaxed, and k can be selected as 1.1 to 1.4 (the same applies to other embodiments).

[0039] The photovoltaic array A described above represents the optimal south-facing tilt angle installation. To the right is a vertically arranged photovoltaic array B, with its axis F oriented north-south and receiving sunlight from both east and west sides. The sun travels from east to south to west, enabling continuous complementary power generation throughout the day. In this way, the combination of photovoltaic arrays A and B results in a more stable and balanced daily power generation curve, exhibiting a flat-top, broad-peak shape. Power fluctuations relative to their equivalent average line will not exceed ±15%, similar to... Figure 9 As shown, there won't be a shortage of photovoltaic power when the sun shines at an angle in the morning and evening, but an abundance of photovoltaic power when the sun shines directly at noon.

[0040] Example 2.

[0041] See Figure 6 In Haikou City, Hainan Province (latitude φ≈20°), select a vegetable field and install 10 photovoltaic arrays A at the optimal tilt angle (20°).

[0042] On the ground surface such as in the vegetable garden near the photovoltaic array A, a set of photovoltaic arrays B1 with the axis F running north-south is arranged at intervals (S=8 meters).

[0043] The photovoltaic panels in the photovoltaic array B1 are installed vertically at a 90° tilt angle, with their front and back sides facing east and west respectively to receive sunlight.

[0044] The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 95-100%; the ground surface between adjacent photovoltaic arrays B1 is used for planting crops, grass, or aquaculture.

[0045] In addition, a photovoltaic array B2 with axis F oriented from northeast to southwest is added. The photovoltaic panels in photovoltaic array B2 are installed vertically at a 90° tilt angle, with their front and back sides facing southeast and northwest respectively to receive sunlight. The sum of the installed capacity of photovoltaic array B2 and photovoltaic array B1, and the ratio of the installed capacity of photovoltaic array A, is k=1.25. Through reasonable allocation, the total daily power generation curve of the three arrays has a flat-topped, broad-peak shape, and the power fluctuation relative to their equivalent average line does not exceed ±8%, preferably not exceeding ±5%.

[0046] The photovoltaic array A described above represents the optimal south-facing tilt angle installation method; to the right are vertically arranged photovoltaic arrays B1 and B2; the sun travels from east to south to west, enabling continuous complementary power generation throughout the day. In this way, the combination of photovoltaic array A with photovoltaic arrays B1 and B2 results in a more stable and balanced daily power generation curve, as shown in the image. Figure 10 As shown, there won't be a shortage of photovoltaic power when the sun shines at an angle in the morning and evening, or an abundance of photovoltaic power when the sun shines directly at noon.

[0047] Example 3.

[0048] See Figure 5 In Jinan City, Shandong Province (latitude φ≈36.5°), a vegetable field was selected, and 10 photovoltaic arrays A were installed at the optimal tilt angle (36.5°).

[0049] On the ground surface such as farmland near the photovoltaic array A, a set of photovoltaic arrays B with the axis F running north-south is arranged at intervals (S=8 meters).

[0050] The photovoltaic panels in the photovoltaic array B are installed vertically at a 90° tilt angle, with their front and back sides facing east and west respectively to receive sunlight.

[0051] The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 95-100%; the ground surface between adjacent photovoltaic arrays B is used for planting crops, grass, or aquaculture.

[0052] The installed capacity ratio of photovoltaic array B to photovoltaic array A is B / A=k, where k is 1.85 - 0.03 × 36.5 = 0.755. Of course, a redundancy of ±12% can be relaxed based on this preferred value.

[0053] The photovoltaic array A described above represents the optimal south-facing tilt angle installation. To the right is a vertically arranged photovoltaic array B, oriented north-south and receiving sunlight from both east and west sides. The sun travels from east to south to west, enabling continuous complementary power generation throughout the day. In this way, the combination of photovoltaic arrays A and B will result in a more stable total power generation curve during the peak daily power generation period. With a flat-topped, wide-peak shape, the power fluctuation relative to its own equivalent average line will be ≤±8%, thus tending to be stable and balanced, so that there is not enough photovoltaic power when the sun shines at an angle in the morning and evening, and there is too much photovoltaic power to use when the sun shines directly at noon.

[0054] Example 4.

[0055] See Figure 5 In Hohhot, Inner Mongolia (latitude φ≈40.5°), a piece of Gobi desert (suitable for planting drought-resistant crops) was selected, and 10 photovoltaic arrays A were installed at the optimal tilt angle (40.5°).

[0056] On the Gobi Desert near the photovoltaic array A, a set of photovoltaic arrays B with their axes F oriented north-south are arranged at intervals (S=8 meters).

[0057] The photovoltaic panels in the photovoltaic array B are installed vertically at a 90° tilt angle, with their front and back sides facing east and west respectively to receive sunlight.

[0058] The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 95-100%; the ground surface between adjacent photovoltaic arrays B is used for planting crops, grass, or aquaculture.

[0059] The installed capacity ratio of photovoltaic array B to photovoltaic array A is B / A=k, where k is 1.85 - 0.03 × 40.5 = 0.635. Alternatively, based on this preferred value, a redundancy of ±12% can be relaxed, and k can be selected as 0.5588 to 0.7112.

[0060] The photovoltaic array A described above represents the optimal south-facing tilt angle installation. To the right is a vertically arranged photovoltaic array B, oriented north-south and receiving sunlight from both east and west sides. The sun travels from east to south to west, enabling continuous complementary power generation throughout the day. In this way, the combination of photovoltaic arrays A and B will result in a more stable total power generation curve during the peak daily power generation period. With a flat-topped, wide-peak shape, the power fluctuation relative to its own equivalent average line will be ≤±8%, thus tending to be stable and balanced, so that there is not enough photovoltaic power when the sun shines at an angle in the morning and evening, and there is too much photovoltaic power to use when the sun shines directly at noon.

[0061] Example 5.

[0062] See Figure 5 In Urumqi, Xinjiang (latitude φ≈43°), 10 photovoltaic arrays A were installed on the Gobi Desert (where drought-resistant crops can be grown) at the optimal tilt angle (43°).

[0063] On the Gobi Desert (where drought-resistant crops can be grown) near the photovoltaic array A, a set of photovoltaic arrays B with their axes F oriented north-south are arranged at intervals (S=8 meters).

[0064] The photovoltaic panels in the photovoltaic array B are installed vertically at a 90° tilt angle, with their front and back sides facing east and west respectively to receive sunlight.

[0065] The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 95-100%; the ground surface between adjacent photovoltaic arrays B is used for planting crops, grass, or aquaculture.

[0066] The installed capacity ratio of photovoltaic array B to photovoltaic array A is B / A=k, where k is 1.85 - 0.03 × 43 = 0.56. Alternatively, based on this preferred value, a redundancy of ±12% can be relaxed, and k can be selected as 0.4928 to 0.6272.

[0067] The photovoltaic array A described above represents the optimal south-facing tilt angle installation. To the right is a vertically arranged photovoltaic array B, oriented north-south and receiving sunlight from both east and west sides. The sun travels from east to south to west, enabling continuous complementary power generation throughout the day. In this way, the combination of photovoltaic arrays A and B will result in a more stable total power generation curve during the peak daily power generation period. With a flat-topped, wide-peak shape, the power fluctuation relative to its own equivalent average line will be ≤±8%, thus tending to be stable and balanced, so that there is not enough photovoltaic power when the sun shines at an angle in the morning and evening, and there is too much photovoltaic power to use when the sun shines directly at noon.

[0068] Example 6.

[0069] like Figure 11 As shown, photovoltaic array B is divided into n groups (axis F) of sub-arrays with different orientations, where n=3 (north-south orientation, northeast-southwest orientation, etc.). The photovoltaic panels in this sub-array are installed vertically at a 90° tilt angle. The orientations of the three groups of sub-arrays with different orientations are distributed around the sun's orbit (corresponding to east-west, southeast-northwest, etc., receiving sunlight). In this way, the total daily power generation curve of the n groups of sub-arrays with different orientations and photovoltaic array A will tend to be stable, exhibiting a flat-top, broad-peak shape, and the power fluctuation relative to its equivalent average line will not exceed ±3%.

[0070] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it; any equivalent substitutions or modifications made based on the proportioning formula, structural combination and near-horizontal power generation concept of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A near-horizontal ecological photovoltaic system, comprising a photovoltaic array A installed at a south-facing tilt angle, characterized in that: On the ground surface near the photovoltaic array A, a set of photovoltaic arrays B are arranged at intervals S, where the interval S is 3 to 15 meters. The photovoltaic array B is oriented north-south, with its photovoltaic panels installed vertically and facing east and west respectively to receive sunlight. The photovoltaic panels are bifacial photovoltaic panels with a bifaciality of 70-100%; the ground surface between adjacent photovoltaic arrays B is used for planting crops, grass, or aquaculture. The installed capacity ratio k of photovoltaic array B to photovoltaic array A satisfies the following condition with respect to the local geographical latitude φ: k = (1.85 - 0.03φ) ± 12%, where 18° ≤ φ ≤ 50°; When photovoltaic array A and photovoltaic array B are combined, the total daily power generation curve has a flat-topped, broad-peak shape, and the power fluctuation relative to its own equivalent average line does not exceed ±15%.

2. The near-horizon ecological photovoltaic system according to claim 1, characterized in that: The photovoltaic array B is divided into two groups, B1 and B2. Group B1 is oriented north-south, and group B2 is oriented southwest to northeast, with the photovoltaic panels installed vertically. The front and back sides of the photovoltaic panels in group B1 face east and west respectively to receive sunlight, while the front and back sides of the photovoltaic panels in group B2 face southeast and northwest respectively to receive sunlight. By adjusting the installed capacity ratio of photovoltaic array A, photovoltaic array B1, and photovoltaic array B2, the power fluctuation of the total daily power generation curve of the three arrays relative to their equivalent average line does not exceed ±8%.

3. The near-horizon ecological photovoltaic system according to claim 1, characterized in that: The preferred value for the installed capacity ratio k is 1.85- 0.03φ, where φ is the local geographical latitude, and 18°≤φ≤50°.

4. The near-horizon ecological photovoltaic system according to claim 2, characterized in that: The photovoltaic arrays A, B1, and B2 share an inverter or are configured with independent inverters. By reasonably configuring the installed capacity ratio of the three, the power fluctuation of the total daily power generation curve, excluding the 1.5 hours after sunrise and before sunset, relative to its own equivalent average line does not exceed ±5%.

5. The near-horizon ecological photovoltaic system according to claim 2, characterized in that: The photovoltaic array B is divided into n sub-arrays with different orientations, where n≥3. The photovoltaic panels in the sub-arrays are installed vertically, and the orientations of the n sub-arrays with different orientations are distributed around the sun's orbital path. The power fluctuation of the total daily power generation curve of the n sub-arrays with different orientations and the photovoltaic array A relative to their own equivalent average line does not exceed ±3%.

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