Photovoltaic power generation system

Abstract

A solar power generation system according to one embodiment comprises a solar panel that is provided above agricultural land. The solar power generation system comprises: a high-temperature damage determination unit that determines whether or not high-temperature damage will occur in crops cultivated in the agricultural land from the temperature at the agricultural land; a panel adjuster that operates a solar panel and adjusts the size of the shade on the agricultural land; a brightness detection unit that detects whether or not it is nighttime; and a control unit that controls the adjustment of the size of the shade by the panel adjuster. When the high-temperature damage determination unit has determined that the high-temperature damage will occur and the brightness detection unit has determined that it is not nighttime, the control unit controls the panel adjuster to operate the solar panel so as to increase the area of the shade formed on the agricultural land. When the high-temperature damage determination unit has determined that the high-temperature damage will occur and the brightness detection unit has determined that it is nighttime, the control unit controls the panel adjuster to tilt the solar panel so as to promote radiative cooling of the agricultural land.

Description

[Technical field]

[0001] The present disclosure relates to a solar power generation system. [Background technology]

[0002] Patent Document 1 describes a solar power generation system including a first solar panel unit having an actuator unit, a second solar panel unit not having an actuator unit, and a control unit. A detection signal from a water temperature sensor and a detection signal from an air temperature sensor are input to the control unit. The control unit detects the water temperature based on the detection signal from the water temperature sensor, and detects the air temperature based on the detection signal from the air temperature sensor. The control unit controls the actuator unit according to the detected water temperature and air temperature, and the controlled actuator unit swings the solar panel to control the amount of solar radiation on farmland.

[0003] Patent Document 2 describes solar panels installed on farmland. The solar panels are installed at a predetermined angle to the farmland so that they receive sunlight most efficiently. Crops are grown in areas of the farmland where the solar panels block sunlight. Sunlight is reflected by the ground and the bottom surface of the solar panel, and the light reflected by the bottom surface of the solar panel is irradiated onto the crops.

[0004] Patent Document 3 describes a photovoltaic power generation facility in which multiple arrays are installed above farmland. The arrays include modules with set light receiving angles. The photovoltaic power generation facility controls shading of the farmland. The arrays are elongated rectangular shapes. The narrow width of the arrays makes it possible to avoid shading a portion of the farmland for a long period of time and to generate shadows evenly over the farmland.

[0005] Patent Document 4 describes multiple solar power generation devices installed in rice fields. The solar power generation devices include solar panels, a stand supporting the solar panels, a linear actuator, a rotary actuator, a light sensor, and a controller. The linear actuator and rotary actuator tilt the solar panel so that the light receiving surface of the solar panel faces the position of the sun detected by the light sensor. The solar panel is provided with multiple solar modules and multiple openings. By allowing sunlight to pass below the solar panel through the multiple openings, it is possible to reduce areas that are shaded for long periods of time. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-67272 A [Patent Document 2] JP 2014-18082 A [Patent Document 3] JP 2011-129852 A [Patent Document 4] JP 2018-98999 A Summary of the Invention [Problem to be solved by the invention]

[0007] Each of the above-mentioned photovoltaic power generation systems can allow crops to receive sufficient sunlight and reduce the amount of shade on farmland. However, in farmland, especially in the summer, rising temperatures can cause high-temperature damage to crops. When high-temperature damage occurs, the crops may wither and the yield of the crops may decrease.

[0008] The present disclosure aims to provide a solar power generation system that can increase agricultural crop yields. [Means for solving the problem]

[0009] The solar power generation system according to the present disclosure is a solar power generation system including solar panels installed above farmland. The solar power generation system includes a high temperature damage determination unit that determines whether or not high temperature damage will occur to crops grown on the farmland based on the temperature of the farmland, a panel adjuster that operates the solar panel to adjust the size of the shadow on the farmland, a brightness detection unit that detects whether or not it is nighttime, and a control unit that controls the adjustment of the size of the shadow by the panel adjuster. When the high temperature damage determination unit determines that high temperature damage will occur and the brightness detection unit determines that it is not nighttime, the control unit controls the panel adjuster to operate the solar panel so as to increase the area of ​​the shadow formed on the farmland. When the high temperature damage determination unit determines that high temperature damage will occur and the brightness detection unit determines that it is nighttime, the control unit controls the panel adjuster to tilt the solar panel so as to promote radiative cooling in the farmland.

[0010] This solar power generation system includes a high temperature damage determination unit that determines whether or not high temperature damage will occur to crops grown on the farmland based on the temperature of the farmland, and a brightness detection unit that detects whether or not the farmland is at night. The solar power generation system includes a control unit that controls the adjustment of the size of the shadow by the panel regulator. When it is determined that high temperature damage will occur and the brightness detection unit determines that the farmland is not at night, the control unit operates the solar panel to increase the area of ​​the shadow formed on the farmland. Therefore, when it is determined that high temperature damage will occur and the farmland is not at night, the area of ​​the shade on the farmland increases, so that high temperature damage to the crops on the farmland can be suppressed. When it is determined that high temperature damage will occur and the brightness detection unit determines that the farmland is at night, the control unit tilts the solar panel to promote radiative cooling in the farmland. By promoting radiative cooling in the farmland, it is possible to suppress the accumulation of high temperature air in the farmland at night, so that the occurrence of high temperature damage at night can be suppressed. Therefore, it is possible to suppress the occurrence of high temperature damage not only during the day but also at night, so that it is possible to increase the yield of agricultural crops while collecting electricity with the solar panel.

[0011] The solar power generation system may include a water sprinkler nozzle that sprinkles water on farmland. When the high temperature damage determination unit determines that high temperature damage will occur, the control unit may control the water sprinkler nozzle to sprinkle water on the farmland from the water sprinkler nozzle. In this case, water is sprinkled on the farmland from the water sprinkler nozzle when it is determined that high temperature damage will occur, so that high temperature damage to agricultural crops can be suppressed even when the temperature is high.

[0012] The solar power generation system may include a pesticide fertilizer spraying nozzle that sprays pesticide fertilizer on farmland. When the high temperature damage determination unit determines that high temperature damage will occur, the control unit may control the pesticide fertilizer spraying nozzle to spray the pesticide fertilizer on farmland from the pesticide fertilizer spraying nozzle. In this case, the pesticide fertilizer is sprayed from the pesticide fertilizer spraying nozzle when it is determined that high temperature damage will occur, so that it is possible to prevent agricultural crops from withering due to high temperature damage.

[0013] The solar power generation system may include a wind gauge that measures wind volume and wind direction in the farmland. When the wind volume measured by the wind gauge is equal to or greater than a wind volume threshold, the control unit may control the panel regulator to tilt the solar panel so that the sunlight receiving surface of the solar panel is parallel to the wind direction measured by the wind gauge. In this case, when the wind volume is equal to or greater than the wind volume threshold, the solar panel is tilted so that the light receiving surface of the solar panel is parallel to the wind direction at that time. Therefore, when the wind is strong, the solar panel is tilted so that the light receiving surface of the solar panel is parallel to the wind direction, so that an increase in wind stress on the solar panel can be suppressed.

[0014] The photovoltaic power generation system may include a blower that blows air into the farmland. The control unit may control the blower to blow air into the farmland when the high temperature damage determination unit determines that high temperature damage will occur. In this case, air is blown into the farmland from the blower when it is determined that high temperature damage will occur, so that high temperature damage to crops in the farmland can be suppressed. Effect of the Invention

[0015] According to the present disclosure, crop yields can be increased. [Brief description of the drawings]

[0016] [Figure 1] FIG. 2 is a side view illustrating farmland to which the solar power generation system according to the embodiment is applied. [Diagram 2] 1 is a functional block diagram of a solar power generation system according to an embodiment. FIG. [Diagram 3] FIG. 13 is a diagram illustrating an example of a table of shadow information. [Figure 4] 13 is a diagram showing an example of a high temperature damage determination table used by a high temperature damage determination unit; FIG. [Diagram 5] 13(a), (b), and (c) are diagrams illustrating modified examples of the solar panel. [Figure 6] FIG. 2 is a diagram illustrating a nozzle unit of the solar power generation system according to the embodiment. [Figure 7] 4 is a flowchart illustrating an example of steps of a high temperature damage suppression method according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of a solar power generation system according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and duplicated descriptions are omitted as appropriate. The drawings are partially simplified or exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0018] Fig. 1 is a side view that shows a schematic diagram of a solar power generation system 1 according to an embodiment. As shown in Fig. 1, in the solar power generation system 1, solar panels P, each of which is composed of a plurality of solar modules, are arranged above farmland N, and each solar panel P generates solar power. The solar panel P has, for example, a rectangular shape. The solar panel P has a light-receiving surface P1 that receives sunlight L from the sun T. When the solar panel P receives sunlight L on the light-receiving surface P1, it generates power according to the amount of light received.

[0019] For example, multiple crops C of the same type are planted in farmland N, and the multiple crops C are cultivated in the farmland N. As an example, the crops C are rice, and the farmland N is a rice field. In the solar power generation system 1, the number of solar panels P is, for example, several hundred, and the multiple solar panels P are arranged vertically and horizontally in a plan view. Therefore, sunlight L from the sun T is irradiated onto the crops C in the farmland N, and a shadow S is formed on the farmland N. As an example, when the multiple solar panels P extend horizontally, the shading rate of the sunlight L on the farmland N is 40%. However, the shape and size of the shadow S changes as the sun T moves over time.

[0020] The solar power generation system 1 includes a support structure 2 that supports multiple solar panels P above farmland N. Each solar panel P is installed on the support structure 2 above the farmland N. The support structure 2 includes multiple pillars 2b extending upward from the farmland N, and beam members 2c that span the multiple pillars 2b at the top of the multiple pillars 2b. Multiple shafts 3 are attached to the beam members 2c, and a solar panel P is supported on each shaft 3 so as to be rotatable.

[0021] For example, the height of the solar panel P from the ground is 3 m or more and 4 m or less (3.5 m as an example). The solar panel P rotates with the rotation of the axis 3, and for example, the inclination angle θ of the light receiving surface P1 of the solar panel P with respect to the incident direction of the sunlight L is uniform. In this case, the solar power generation system 1 has a configuration in which the solar panel P rotates on a single axis, and the inclination angle θ of the solar panel P is adjustable.

[0022] Fig. 2 is a block diagram showing the functions of the solar power generation system 1. As shown in Fig. 1 and Fig. 2, the solar power generation system 1 includes a panel adjuster 4 that operates the solar panel P to adjust the size of the shadow S falling on the farmland N, a pyranometer 5 that measures the amount of solar radiation D1 of sunlight L on the farmland N, and a thermometer 6 that measures the temperature D2 of the farmland N. The solar power generation system 1 further includes a wind gauge 7 that measures the wind volume D3 and wind direction D4 on the farmland N, a brightness detection unit 8 that detects whether it is nighttime or not on the farmland N, and a controller 10 that controls each unit of the solar power generation system 1. Each of the panel adjuster 4, the pyranometer 5, the thermometer 6, the wind gauge 7, and the brightness detection unit 8 is capable of communicating with the controller 10.

[0023] The panel adjuster 4 includes, for example, a motor that rotates the shaft 3. The panel adjuster 4 rotates the solar panel P uniformly by rotating the shaft 3. The tilt angle θ is variable by the panel adjuster 4 rotating the solar panel P, and by varying the tilt angle θ, the area of ​​the shadow S on the farmland N can be adjusted. For example, when the tilt angle θ is equal to or greater than a certain value, the ratio of the area of ​​the shadow S to the area of ​​the farmland N is higher than when the tilt angle θ is less than the certain value.

[0024] The actinometer 5 is a sensor that detects the amount of solar radiation D1 of sunlight L irradiating the farmland N, and outputs the detected amount of solar radiation D1 to the controller 10. The thermometer 6 is a sensor that detects the air temperature D2 of the farmland N, and outputs the detected air temperature D2 to the controller 10. The timing at which the actinometer 5 outputs the amount of solar radiation D1 to the controller 10 and the timing at which the thermometer 6 outputs the air temperature D2 to the controller 10 may be in real time or at predetermined intervals.

[0025] The wind measuring instrument 7 includes, for example, an anemometer. The wind measuring instrument 7 measures the wind volume D3 in the farmland N and outputs the measured wind volume D3 to the controller 10. The wind measuring instrument 7 measures the wind direction D4 in the farmland N and outputs the measured wind direction D4 to the controller 10. The wind measuring instrument 7 may be an anemometer. As an example, the wind measuring instrument 7 is a propeller type anemometer. However, the wind measuring instrument 7 may be something other than a propeller type anemometer, and may be a thermal anemometer, a cup anemometer, or an ultrasonic anemometer.

[0026] The brightness detection unit 8 detects whether it is nighttime on the farmland N from the brightness of the farmland N. For example, the brightness detection unit 8 has a light receiving element that receives light in the farmland N, and a determination unit that determines whether it is nighttime on the farmland N. The determination unit of the brightness detection unit 8 determines whether it is nighttime on the farmland N from the amount of light received by the light receiving element of the brightness detection unit 8. The determination result of whether it is nighttime on the basis of the determination unit of the brightness detection unit 8 is output to the controller 10.

[0027] The controller 10 has a control unit 11 that controls the panel adjuster 4. The control unit 11 drives the panel adjuster 4 to adjust the tilt angle θ of the solar panel P. The control unit 11 changes the tilt angle θ of the solar panel P to adjust the amount of sunlight L entering the farmland N and adjust the ratio of the area of ​​shadow S to the total area of ​​the farmland N. In this way, the control unit 11 adjusts the amount of sunlight L and changes the ratio of the area of ​​shadow S, thereby preventing the growth of the crops C on the farmland N from being hindered.

[0028] The controller 10 is configured to include, for example, a CPU (Central Processing Unit) and a storage unit such as a ROM (Read Only Memory) or a RAM (Random Access Memory). Each function of the controller 10 is realized, for example, by loading a program stored in the ROM into the RAM and executing the program by the CPU.

[0029] The controller 10 may be, for example, a general-purpose personal computer, a server on the Internet, or a cloud system. Furthermore, a part of the controller 10 may be separated from the rest. The controller 10 may be provided near the farmland N, or may be provided in a remote location away from the farmland N. The controller 10 is connected to a network 20, for example, the Internet. The network 20 does not have to be the Internet, and may be, for example, an intra-facility network (intranet). For example, a part of the controller 10 may be disposed near the solar panel P, and the rest of the controller 10 may be disposed in a remote location away from the solar panel P. In this way, the form and location of the controller 10 are not particularly limited.

[0030] For example, the controller 10 has a database 12 that stores information about the solar power generation system 1. The database 12 stores information used by the control unit 11 when adjusting the tilt angle θ of the solar panel P. The database 12 stores a date D5, a time D6, a trajectory D7, and shadow information D8. The trajectory D7 is information indicating the trajectory of the sun T as seen from the farmland N, and is stored for each date D5. The trajectory D7 indicates the position (height and direction) of the sun T at regular intervals (e.g., every minute) in a day, and varies according to the date D5. This trajectory D7 makes it possible to know what time of day and to what extent the shadow S is formed.

[0031] The shadow information D8 is information that indicates the ratio of the area of ​​the shadow S to the area of ​​the farmland N. For example, as shown in FIG. 3, the shadow information D8 has a table Z that indicates the relationship between the inclination angle θ and the ratio of the shadow S of the farmland N. The shadow information D8 may be information that indicates the ratio of the shadow S to which part of the farmland N is formed. The shadow information D8 is, for example, information that indicates the ratio of the shadow S of the farmland N for each inclination angle θ. Furthermore, the shadow information D8 may be information that indicates the ratio of the shadow S of the farmland N for each date D5, each time D6, and each inclination angle θ.

[0032] 1 and 2, the database 12 stores a crop D9 indicating the type of crop C cultivated in the farmland N. Furthermore, the database 12 is a light saturation point memory unit that stores the light saturation point D10 (unit: klx (kilolux)) of the crop C. The light saturation point D10 is stored for each crop D9. The light saturation point D10 is a value that is uniquely determined for each type of crop D9, and even if sunlight L that is equal to or greater than the light saturation point D10 is applied to the crop C, the amount of photosynthesis of the crop C does not increase.

[0033] The database 12 functions as a solar radiation amount acquisition unit that acquires the amount of solar radiation D1 of the farmland N from the actinometer 5, and stores the acquired amount of solar radiation D1. The database 12 may acquire the amount of solar radiation D1 for each date D5 or for each time D6 in advance, instead of acquiring the amount of solar radiation D1 from the actinometer 5 each time. Furthermore, the controller 10 may calculate the amount of solar radiation D1 from the date D5, the time D6, and meteorological information D11 described later, and the database 12 may acquire the amount of solar radiation D1 calculated by the controller 10.

[0034] The database 12 is a temperature acquisition unit that acquires the temperature D2 of the farmland N from the thermometer 6, and stores the acquired temperature D2. Note that the database 12 may store in advance the temperature D2 acquired from, for example, meteorological information D11, instead of acquiring the temperature D2 from the thermometer 6. Also, the controller 10 may estimate the temperature D2 from the date D5 and time D6, and the database 12 may acquire the temperature D2 estimated by the controller 10.

[0035] The database 12 is an air volume acquisition unit that acquires the air volume D3 of the wind blowing into the farmland N from the air volume measurement device 7. The database 12 is also a wind direction acquisition unit that acquires the wind direction D4 of the wind blowing into the farmland N from the air volume measurement device 7. As above, the database 12 may store in advance the air volume D3 and wind direction D4 acquired from the meteorological information D11. Also, the controller 10 may estimate the air volume D3 and wind direction D4 of the wind after a certain time has elapsed from the wind state measured by the air volume measurement device 7, and the database 12 may acquire the air volume D3 and wind direction D4 estimated by the controller 10.

[0036] The database 12 is a weather information acquisition unit that acquires weather information D11 from the network 20. The timing of acquisition of the weather information D11 by the database 12 may be real time or at regular intervals. Furthermore, the database 12 stores the amount of power generation D12 obtained from the solar panel P.

[0037] The control unit 11 is an angle changing unit that outputs a control signal to the panel adjuster 4 to control the driving of the panel adjuster 4 and change the tilt angle θ of the solar panel P. The control unit 11 has a function of performing various calculations. For example, the solar power generation system 1 may be equipped with multiple cameras that photograph farmland N, and the control unit 11 may calculate the ratio of the area of ​​the shadow S to the area of ​​the farmland N from images photographed by the multiple cameras. The ratio of the area of ​​the shadow S calculated by the control unit 11 is stored in the database 12. Furthermore, the control unit 11 controls the panel adjuster 4 using various information stored in the database 12 and changes the tilt angle θ of the solar panel P.

[0038] The control unit 11 may change the tilt angle θ of the solar panel P in accordance with the weather information D11 acquired by the database 12. For example, the controller 10 may include multiple control units 11, and the weather information D11 may be sent from the database 12, which is located in a remote location away from the farmland N, to the multiple control units 11 to simultaneously control the tilt angles θ of the multiple solar panels P. In this case, it is possible to optimally control the solar panels P in accordance with the weather in the farmland N.

[0039] As a specific example, in the event of heavy snowfall, the inclination angle of the solar panel P with respect to the horizontal plane is increased and the solar panel P is set up vertically, thereby preventing snow from accumulating on the solar panel P. As a specific example, in the event of a typhoon, the inclination angle of the solar panel P with respect to the horizontal plane is decreased and the solar panel P is laid horizontally, thereby preventing the solar panel P from being subjected to a load due to wind.

[0040] The controller 10 has, for example, a communication unit 14 and a high temperature damage determination unit 15. The communication unit 14 is, for example, a communication device used when the controller 10 communicates with devices other than the controller 10. The communication unit 14 enables the controller 10 to communicate with an information terminal 16 located outside the controller 10. The information terminal 16 is, for example, a personal computer. However, the information terminal 16 may be an information terminal other than a personal computer, for example, a mobile terminal. The term "mobile terminal" refers to a portable information terminal, for example, a mobile phone including a smartphone, a tablet, or a notebook computer. The tilt angle θ of the solar panel P can be adjusted by operating the controller 10 from the information terminal 16 located away from the farmland N via the communication unit 14.

[0041] For example, the controller 10 has a high temperature damage determination unit 15 that determines whether high temperature damage will occur in the crop C cultivated in the farmland N based on the temperature D2 of the farmland N. In this disclosure, "high temperature damage" may include not only high temperature damage itself but also temperature damage in general. For example, the high temperature damage determination unit 15 determines that high temperature damage will occur in the crop C when the temperature D2 of the farmland N is above a certain value for a certain period of time. The high temperature damage determination unit 15 has a high temperature damage determination table H that indicates the temperature threshold and time threshold that will cause high temperature damage for each type of crop C, as shown in FIG. 4, for example.

[0042] The temperature threshold indicates the temperature at which high temperature damage will occur to crop C. If the temperature continues to be equal to or higher than the temperature threshold for a time threshold or longer, high temperature damage may occur to crop C. The high temperature damage determination unit 15 compares the temperature of farmland N with the temperature threshold in the high temperature damage determination table H and determines whether the temperature continues to be equal to or higher than the temperature threshold for a time threshold or longer. When the high temperature damage determination unit 15 determines that the temperature of farmland N is equal to or higher than the temperature threshold and that the temperature continues to be equal to or higher than the time threshold, the high temperature damage determination unit 15 determines that high temperature damage will occur to crop C. For example, when the high temperature damage determination unit 15 determines that the temperature of farmland N has been equal to or higher than 34°C for 7 hours or longer, the high temperature damage determination unit 15 determines that high temperature damage will occur to crop A. When the high temperature damage determination unit 15 determines that the temperature of farmland N has been equal to or higher than 30°C for 12 hours or longer, the high temperature damage determination unit 15 determines that high temperature damage will occur to crop B.

[0043] As shown in Fig. 1 and Fig. 2, when the high temperature damage determination unit 15 determines that a high temperature damage will occur and the brightness detection unit 8 determines that it is not nighttime (it is daytime), the control unit 11 controls the panel adjuster 4 to increase the area of ​​the shadow S on the farmland N. For example, when the high temperature damage determination unit 15 determines that a high temperature damage will occur, the control unit 11 increases the tilt angle θ of the solar panel P to increase the area of ​​the shadow S on the farmland N by N times (N is a positive real number). The value of N is, for example, 1.5 or more and 2.0 or less. When the high temperature damage determination unit 15 determines that a high temperature damage will not occur and the brightness detection unit 8 determines that it is not nighttime, the control unit 11 may control the panel adjuster 4 to reduce the area of ​​the shadow S on the farmland N.

[0044] The above describes an example in which the control unit 11 increases the inclination angle θ of the solar panel P to increase the area of ​​the shadow S of the farmland N. When the control unit 11 increases the inclination angle θ, it is possible to increase the area of ​​the shadow S and the amount of power generated by the solar panel P. However, the method of increasing the area of ​​the shadow S of the farmland N using a solar panel is not limited to the above example. Figures 5(a), 5(b), and 5(c) each show modified examples of a solar panel.

[0045] For example, as shown in Fig. 5(a), the area of ​​the shadow S may be increased by using a solar panel Q having multiple cylinders Q1. The solar panel Q has an axis 3A, a pair of cylinders Q1 extending from the axis 3A, a pair of first plate-like members Q2 fixed to the opposite side of each cylinder Q1 from the axis 3A, and a second plate-like member Q3 that houses the axis 3A, the pair of cylinders Q1, and a part of the pair of first plate-like members Q2. Each cylinder Q1 expands and contracts when driven by a panel adjuster 4.

[0046] For example, the amount of projection of the first plate-shaped member Q2 relative to the second plate-shaped member Q3 is variable by the extension and contraction of the cylinder Q1. For example, when the high temperature damage determination unit 15 determines that a high temperature damage will occur, the control unit 11 may extend the cylinder Q1 to increase the amount of projection of the first plate-shaped member Q2 relative to the second plate-shaped member Q3, thereby increasing the area of ​​the shadow S of the farmland N.

[0047] For example, as shown in FIG. 5(b), a sliding solar panel R may be used to increase the area of ​​the shadow S. The solar panel R has an axis 3B, a first plate member R1 extending from the axis 3B, and a pair of second plate members R3 that slide relative to a main surface R2 of the first plate member R1. Each second plate member R3 is supported by the first plate member R1 via a plurality of slide rails R4. In the solar panel R, the second plate member R3 slides relative to the first plate member R1, thereby varying the amount of protrusion of each second plate member R3 relative to the first plate member R1.

[0048] For example, when the high temperature damage determination unit 15 determines that a high temperature damage will occur, the control unit 11 may increase the area of ​​the shadow S of the farmland N by sliding each second plate-shaped member R3 relative to the first plate-shaped member R1 to increase the amount of protrusion of each second plate-shaped member R3 relative to the first plate-shaped member R1. In the example of Fig. 5(b), the second plate-shaped member R3 and the slide rail R4 are provided on the surface opposite the light receiving surface of the solar panel P. Therefore, the effect on power generation by the solar panel P can be suppressed.

[0049] For example, as shown in FIG. 5(c), the area of ​​the shadow S may be increased by using a solar panel X having a hinge mechanism X1. The solar panel X includes a pair of hinge mechanisms X1, a first plate-shaped member X2 including an axis 3C, and a pair of second plate-shaped members X3 supported by the first plate-shaped member X2 via each hinge mechanism X1. The pair of hinge mechanisms X1 are fixed to the surface of the first plate-shaped member X2 opposite to the light-receiving surface X5, and support each of the second plate-shaped members X3 rotatably relative to the first plate-shaped member X2. In this way, the pair of hinge mechanisms X1 and the pair of second plate-shaped members X3 are provided on the opposite side to the light-receiving surface X5, thereby suppressing the influence of power generation on the solar panel P. The panel adjuster 4 controls the hinge mechanism X1 to change the angle Y of each of the second plate-shaped members X3 relative to the first plate-shaped member X2.

[0050] For example, when the high temperature damage determination unit 15 determines that a high temperature damage will occur, the control unit 11 rotates each second plate-shaped member X3 to increase the angle Y. For example, when the air volume D3 measured by the wind measurement device 7 is equal to or greater than an air volume threshold, the control unit 11 may decrease the angle Y to reduce the area of ​​the portion of the solar panel X that receives the wind. In this case, it is possible to prevent the solar panel X from being subjected to excessive stress due to the wind.

[0051] As shown in FIG. 1, for example, the solar power generation system 1 includes a blower 9. For example, a plurality of blowers 9 are provided in the farmland N, and each blower 9 is fixed to a support structure 2. For example, the blower 9 is disposed between a pair of solar panels P. As an example, each blower 9 is provided at an intersection of a support 2b and a beam member 2c. Wind W is blown downward (or diagonally downward) from the blower 9. The wind W from the blower 9 lowers the temperature of the farmland N, suppressing the occurrence of high-temperature damage to the crops C.

[0052] As shown in FIG. 1 and FIG. 2, when the high temperature damage determination unit 15 determines that a high temperature damage will occur, the control unit 11 controls the blower 9 to send air (wind W) into the farmland N. For example, when the high temperature damage determination unit 15 determines that a high temperature damage will occur and the brightness detection unit 8 determines that it is nighttime, the control unit 11 controls the panel adjuster 4 to tilt the solar panel P so as to promote radiative cooling in the farmland N. Thus, at night, the solar panel P is tilted to release heat from the farmland N. That is, the panel adjuster 4 is controlled to tilt the solar panel P so that more heat is released from the farmland N. As an example, in order to reduce the area of ​​the solar panel P located above the farmland N, the tilt of the solar panel P may be controlled by the panel adjuster 4 so that the light receiving surface P1 of the solar panel P extends along the vertical direction. In this case, it is possible to further promote radiative cooling in the farmland N. In addition, the control unit 11 may tilt the solar panel P so that the light receiving surface P1 is parallel to the wind direction D4 measured by the wind measurement device 7. In this case, it is possible to allow more wind to penetrate into the farmland N.

[0053] When the high temperature damage determination unit 15 determines that a high temperature damage will occur and the brightness detection unit 8 determines that it is nighttime, the control unit 11 may control the blower 9 to blow wind W into the farmland N from the blower 9. In this case, it is also possible to allow more wind W to enter the farmland N. For example, when the wind volume D3 measured by the wind measurement device 7 is equal to or greater than the wind volume threshold, the control unit 11 controls the panel adjuster 4 to tilt the solar panel P so that the light receiving surface P1 of the solar panel P for receiving sunlight L is parallel to the wind direction D4 measured by the wind measurement device 7. The wind volume threshold is a threshold value of the wind volume at which the stress applied to the solar panel P by the wind becomes excessive, which may cause damage to the solar panel P. In this embodiment, even if the solar panel P is installed at a high position of 3 m or more and 4 m or less, the stress on the solar panel P can be suppressed from becoming excessive.

[0054] For example, the solar power generation system 1 includes a nozzle unit 30 having a water spray nozzle 31 that sprays water on farmland N, and a pesticide / fertilizer spray nozzle 32 that sprays pesticide / fertilizer on farmland N. FIG. 6 is a diagram showing a schematic diagram of the nozzle unit 30. As shown in FIGS. 1, 2, and 6, the solar power generation system 1 includes a plurality of nozzle units 30, and each nozzle unit 30 is fixed to a support structure 2. For example, each nozzle unit 30 is fixed to a beam member 2c. As an example, the nozzle unit 30 is disposed between a pair of solar panels P.

[0055] The nozzle unit 30 includes a water spray nozzle 31 and an agricultural chemical fertilizer spray nozzle 32. For example, the water spray nozzle 31 automatically sprays water E under the control of the control unit 11, and the agricultural chemical fertilizer spray nozzle 32 automatically sprays agricultural chemical fertilizer F under the control of the control unit 11. The water spray nozzle 31 is a nozzle that sprays water E to the farmland N. The agricultural chemical fertilizer spray nozzle 32 is a nozzle that sprays agricultural chemical fertilizer F to the farmland N. In the present disclosure, the term "agricultural chemical fertilizer" refers to at least one of an agricultural chemical and a fertilizer. The "agricultural chemical" is a growth promoter or a drug for the agricultural product C. The "fertilizer" refers to a substance that promotes the growth of the agricultural product C, and includes, for example, at least one of nitrogen, phosphorus, and potassium. The "fertilizer" may be an inorganic fertilizer or an organic fertilizer. The type of agricultural chemical fertilizer F sprayed from the agricultural chemical fertilizer spray nozzle 32 may be changeable. The type of agricultural chemical fertilizer F may be changed for each type of agricultural product C.

[0056] Next, the high temperature damage suppression method according to this embodiment will be described with reference to FIG. 7. FIG. 7 is a flow chart showing an example of steps of the high temperature damage suppression method according to this embodiment. First, the brightness detection unit 8 judges whether it is nighttime or not in the farmland N (step S1 of judging whether it is nighttime or not). For example, the judgment unit of the brightness detection unit 8 judges whether the amount of light received by the light receiving element of the brightness detection unit 8 is equal to or greater than a certain value, and it is judged whether it is nighttime or not in the farmland N from the result of this judgment. The result of this judgment is output to the controller 10.

[0057] If the brightness detection unit 8 determines that it is not nighttime in the farmland N (NO in step S1), the controller 10 determines whether the temperature D2 of the farmland N is equal to or higher than the temperature threshold (step S2, a process for determining whether the temperature of the farmland is equal to or higher than the temperature threshold). Specifically, the high temperature damage determination unit 15 of the controller 10 determines whether the time during which the temperature D2 is equal to or higher than the temperature threshold continues for equal to or higher than the time threshold.

[0058] If the controller 10 determines that the temperature D2 of the farmland N is not equal to or higher than the temperature threshold (NO in step S2), the series of steps is completed. If the controller 10 determines that the temperature D2 of the farmland N is equal to or higher than the temperature threshold (YES in step S2), the control unit 11 drives the panel adjuster 4 to operate the solar panels P so as to increase the shadow S (step of operating the solar panels so as to increase the shadow, step S3). At this time, the control unit 11 rotates each solar panel P so as to increase the tilt angle θ, for example, and then the series of steps is completed.

[0059] On the other hand, if the brightness detection unit 8 determines that the farmland N is at night (YES in step S1), similar to step S2, the controller 10 determines whether the temperature D2 of the farmland N is equal to or higher than the temperature threshold (step S4: a process for determining whether the temperature of the farmland is equal to or higher than the temperature threshold). Note that the temperature threshold used in step S2 (when it is not nighttime on the farmland) and the temperature threshold used in step S4 (when it is nighttime on the farmland) may be different from each other.

[0060] If the controller 10 determines that the temperature of the farmland N is not equal to or higher than the temperature threshold (NO in step S4), the series of steps is completed. If the controller 10 determines that the temperature D2 of the farmland N is equal to or higher than the temperature threshold (YES in step S4), the control unit 11 drives the panel adjuster 4 to tilt the solar panel P so that more wind enters the farmland N (step of tilting the solar panel so that more wind enters the farmland, step S5). At this time, each solar panel P is tilted so that the light receiving surface P1 is parallel to the wind direction D4 measured by the wind measuring device 7. After the above steps, the series of steps is completed.

[0061] Next, the effects of the photovoltaic power generation system 1 and the method for suppressing high temperature damage according to the present embodiment will be described. The photovoltaic power generation system 1 includes a high temperature damage determination unit 15 that determines whether high temperature damage will occur to the crops C cultivated in the farmland N based on the air temperature D2 of the farmland N, and a brightness detection unit 8 that detects whether the farmland N is at night. The photovoltaic power generation system 1 includes a control unit 11 that controls the adjustment of the size of the shadow S by the panel regulator 4. When it is determined that high temperature damage will occur and the brightness detection unit 8 determines that the farmland N is not at night, the control unit 11 operates the solar panel P to increase the area of ​​the shadow S formed on the farmland N. Therefore, when it is determined that high temperature damage will occur and the farmland N is not at night, the area of ​​the shadow S on the farmland N increases, thereby suppressing high temperature damage to the crops C on the farmland N.

[0062] When it is determined that a high temperature damage will occur and the brightness detection unit 8 determines that the farmland N is at night, the control unit 11 tilts the solar panel P so as to promote radiative cooling in the farmland N. By promoting radiative cooling in the farmland N, it is possible to prevent hot air from accumulating in the farmland N at night, thereby suppressing the occurrence of high temperature damage at night. In other words, it is possible to increase the heat dissipation property of the farmland N at night and suppress high temperature damage. Therefore, since the occurrence of high temperature damage can be suppressed not only during the day but also at night, it is possible to increase the harvest yield of the crops C while collecting electricity with the solar panel P.

[0063] In this embodiment, the solar power generation system 1 includes a water sprinkler nozzle 31 that sprinkles water E on the farmland N. When the high temperature damage determination unit 15 determines that high temperature damage will occur, the control unit 11 controls the water sprinkler nozzle 31 to sprinkle water E on the farmland N from the water sprinkler nozzle 31. Therefore, since water E is sprinkled on the farmland N from the water sprinkler nozzle 31 when it is determined that high temperature damage will occur, high temperature damage to the crops C can be suppressed even when the temperature is high. Furthermore, since the atmospheric temperature of the farmland N can be lowered by sprinkling the water E, the temperature of the solar panel P can be lowered and the amount of power generated by the solar panel P can be increased.

[0064] In this embodiment, solar power generation system 1 includes a pesticide fertilizer spraying nozzle 32 that sprays pesticide fertilizer F on farmland N. When high temperature damage determination unit 15 determines that high temperature damage will occur, control unit 11 controls pesticide fertilizer spraying nozzle 32 to spray pesticide fertilizer F from pesticide fertilizer spraying nozzle 32 on farmland N. Thus, since pesticide fertilizer F is sprayed from pesticide fertilizer spraying nozzle 32 when it is determined that high temperature damage will occur, it is possible to prevent farm crops C from withering due to high temperature damage.

[0065] In this embodiment, the solar power generation system 1 includes a plurality of nozzle units 30, and each nozzle unit 30 is fixed to the support structure 2 (beam member 2c). Therefore, a boom sprayer and a large tractor for spraying water or pesticides are not required. Furthermore, in this embodiment, the water spray nozzle 31 automatically sprays water, and the pesticide / fertilizer spray nozzle 32 automatically sprays pesticide / fertilizer, which contributes to labor saving.

[0066] In this embodiment, the solar power generation system 1 includes a wind gauge 7 that measures wind volume D3 and wind direction D4 in the farmland N. When the wind volume D3 measured by the wind gauge 7 is equal to or greater than the wind volume threshold, the control unit 11 controls the panel adjuster 4 to tilt the solar panel P so that the light receiving surface P1 of the solar panel P for receiving sunlight L is parallel to the wind direction D4 measured by the wind gauge 7. Thus, when the wind volume D3 is equal to or greater than the wind volume threshold, the solar panel P is tilted so that the light receiving surface P1 of the solar panel P is parallel to the wind direction D4 of the wind at that time. Therefore, when the wind is strong, the solar panel P is tilted so that the light receiving surface P1 of the solar panel P is parallel to the wind direction D4 of the wind, so that an increase in wind stress on the solar panel P can be suppressed.

[0067] In this embodiment, the solar power generation system 1 includes a blower 9 that blows wind W into the farmland N. When the high temperature damage determination unit 15 determines that high temperature damage will occur, the control unit 11 controls the blower 9 to blow wind W into the farmland N. Thus, since wind W is blown from the blower 9 into the farmland N when it is determined that high temperature damage will occur, high temperature damage to the crops C in the farmland N can be suppressed.

[0068] The above describes the embodiment of the solar power generation system according to the present disclosure. However, the solar power generation system according to the present disclosure is not limited to the above-mentioned embodiment, and can be appropriately modified within the scope of the gist of the claims. In other words, the configuration, function, shape, size, material, number, and arrangement of each part of the solar power generation system according to the present disclosure are not limited to the above-mentioned embodiment, and can be appropriately modified.

[0069] For example, in the above embodiment, a brightness detection unit 8 including a light receiving element and a determination unit was described, in which the determination unit determines whether it is nighttime or not based on the amount of light received by the light receiving element. However, the brightness detection unit may not include a light receiving element and a determination unit. For example, the brightness detection unit may compare the times of sunrise and sunset obtained from the date D5 and time D6 with the current time to determine whether it is nighttime or not on the farmland N.

[0070] For example, in the above-described embodiment, an example has been described in which the water spray nozzle 31 automatically sprays water E onto the farmland N, and the pesticide / fertilizer spray nozzle 32 automatically sprays the pesticide / fertilizer F onto the farmland N. However, the water spray nozzle 31 may manually spray the water E onto the farmland N (for example, by an operator pressing a button), and the pesticide / fertilizer spray nozzle 32 may manually spray the pesticide / fertilizer F onto the farmland N. In addition, the timing at which the water spray nozzle 31 sprays the water E and the timing at which the pesticide / fertilizer spray nozzle 32 sprays the pesticide / fertilizer F may be determined in advance, and the control unit 11 may control each of the water spray nozzle 31 and the pesticide / fertilizer spray nozzle 32 at the predetermined timing to spray the water E and the pesticide / fertilizer F onto the farmland N.

[0071] For example, in the above embodiment, the high temperature damage determination unit 15 determines whether or not there is a high temperature damage based on the air temperature D2, and when the high temperature damage determination unit 15 determines that there is a high temperature damage, the control unit 11 performs control to increase the size of the shadow S. However, the control unit 11 may further adjust the area of ​​the shadow S by taking into account the growth stage of the crop C in the determination result by the high temperature damage determination unit 15. For example, when the crop C, whose growth period is ⅓ or less of a year, is cultivated in the farmland N, the control unit 11 may perform control to reduce the area of ​​the shadow S only during that growth period. Furthermore, when the light saturation point is equal to or greater than the light saturation point D10 and sunlight L is not required, the control unit 11 may control the inclination of the solar panel P so that the inclination angle θ is 90°.

[0072] In the above embodiment, an example was described in which the solar panel P is tilted so that more wind can enter the farmland N when it is determined that a high temperature damage will occur and the brightness detection unit 8 determines that the farmland N is at night. However, when the high temperature damage determination unit 15 determines that a high temperature damage will not occur and the air temperature D2 is equal to or lower than a certain temperature, the control unit 11 may control to increase the tilt angle θ. In this case, the farmland C is kept warm during a period when it is necessary to keep the farmland C warm, preventing frost, and the growth promotion effect of the farmland C is improved, enabling temperature management of the farmland C. Furthermore, in the present disclosure, events other than high temperature damage may be determined. For example, the controller 10 may determine whether or not low temperature and high humidity will occur, and in this case, if the farmland C is rice, the occurrence of rice blight in the rice can be suppressed by controlling the tilt of the solar panel P so that the farmland N is hot and dry. Furthermore, when the farmland C is rice and the controller 10 determines that low temperature and high humidity will occur, a pesticide for rice blight countermeasures may be sprayed from the pesticide and fertilizer spraying nozzle 32.

[0073] For example, in the above embodiment, an example was described in which the crop C was rice and the farmland N was a rice field. However, the crop C may be something other than rice, and the farmland N may be farmland (e.g., a field) other than a rice field. [Explanation of symbols]

[0074] 1...Photovoltaic power generation system, 2...Support structure, 2b...Support column, 2c...Beam member, 3, 3A, 3B, 3C...Axis, 4...Panel regulator, 5...Pyranometer, 6...Thermometer, 7...Wind meter, 8...Brightness detector, 9...Blower, 10...Controller, 11...Control unit, 12...Database, 14...Communication unit, 15...High temperature failure determination unit, 16...Information terminal, 20...Network, 30...Nozzle unit, 31...Water spray nozzle, 32...Pesticide fertilizer spray nozzle, C...Crop, D1...Solar radiation, D2...Temperature, D3...Wind volume, D4...Wind direction, D5...Date, D6...Time, D 7...Trajectory, D8...Shadow information, D9...Crops, D10...Light saturation point, D11...Weather information, D12...Power generation, E...Water, F...Pesticides and fertilizers, H...High temperature damage determination table, L...Sunlight, N...Agricultural land, P, Q, R, X...Solar panel, P1...Light receiving surface, Q1...Cylinder, Q2...First plate-shaped member, Q3...Second plate-shaped member, R1...First plate-shaped member, R2...Main surface, R3...Second plate-shaped member, R4...Slide rail, S...Shadow, T...Sun, W...Wind, X1...Hinge mechanism, X2...First plate-shaped member, X3...Second plate-shaped member, X5...Light receiving surface, Y...Angle, Z...Table, θ...Tilt angle.

Claims

1. A solar power generation system having solar panels installed above farmland, a high temperature damage determination unit that determines whether or not high temperature damage will occur to crops grown in the farmland based on the temperature of the farmland; A panel adjuster that operates the solar panel to adjust the size of the shadow formed on the farmland; A brightness detection unit that detects whether it is nighttime or not; a control unit that controls the adjustment of the size of the shadow by the panel adjuster; Equipped with The control unit is When the high temperature damage determination unit determines that a high temperature damage will occur and the brightness detection unit determines that it is not nighttime, the panel regulator is controlled to operate the solar panel so as to increase the area of ​​the shadow formed on the farmland; When the high temperature damage determination unit determines that a high temperature damage will occur and the brightness detection unit determines that it is nighttime, the panel adjuster is controlled to tilt the solar panel so as to promote radiative cooling in the farmland. Photovoltaic power generation system.

2. A water spray nozzle for spraying water on the farmland is provided, The control unit controls the water sprinkler nozzle to sprinkle water on the farmland from the water sprinkler nozzle when the high temperature damage determination unit determines that high temperature damage will occur. The solar power generation system according to claim 1 .

3. A pesticide fertilizer spraying nozzle for spraying pesticide fertilizer on the farmland is provided, The control unit controls the pesticide and fertilizer spraying nozzle to spray the pesticide and fertilizer onto the farmland from the pesticide and fertilizer spraying nozzle when the high temperature damage determination unit determines that a high temperature damage will occur. The solar power generation system according to claim 1 or 2.

4. A wind gauge is provided to measure the wind volume and wind direction of the farmland, When the air volume measured by the wind meter is equal to or greater than an air volume threshold, the control unit controls the panel adjuster to tilt the solar panel so that the sunlight receiving surface of the solar panel is parallel to the wind direction measured by the wind meter. The solar power generation system according to any one of claims 1 to 3.

5. A blower is provided to blow air into the farmland, The control unit controls the blower to send air into the farmland when the high temperature damage determination unit determines that high temperature damage will occur. The solar power generation system according to any one of claims 1 to 4.

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