JP2017012007A - Photovoltaic power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic power generation system that can flexibly cope with changes in kinds of field crop in a farmland, suppresses reduction in the production volume of field crop, and can sufficiently secure a power generation amount.SOLUTION: A photovoltaic power generation system comprises: a panel P installed above a farmland; a database 12 which stores a solar radiation amount D1 of light L from the sun T which is irradiated on the farmland, and an optical saturation point D8 of field crop cultivated in the farmland by each kind of field crop; and a controller 11 which changes an inclination angle θ of a light-receiving surface P1 of the panel P to an incident direction of the light L. The controller 11, in the case where the solar radiation amount D1 of the light L acquired by the database 12 is the optical saturation point D8 or more stored by the database 12, changes the inclination angle θ so as to bring the inclination angle θ closer to a right angle compared with the case where the solar radiation amount D1 is less than the optical saturation point D8.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a photovoltaic power generation system.

  Conventionally, great attention has been paid to solar power generation systems, and many solar modules are installed in structures such as roofs of houses. On the other hand, when constructing a large-scale photovoltaic power generation system, a vast space for arranging many modules is required. Therefore, for example, there are many farmlands in Japan, and there are many places with good sunlight on such farmlands. Therefore, solar sharing is also known in which solar power generation is also performed while farming on farmland by installing solar panels on the farmland.

  Patent Document 1 describes a farm and solar power generation system in which a solar power generation system is installed on a farm. This farm / solar power generation system includes a plurality of columns installed in a commercial plant, a beam extending horizontally at the upper end of the column, and a plurality of solar modules supported in an inclined state on the beam. Yes. In this farm-cum-photovoltaic power generation system, the inclination angle of the solar module with respect to the horizontal plane is determined in advance, and is 10 ° to 15 ° with respect to the horizontal plane.

Japanese Unexamined Patent Publication No. 2015-17489

  In the farm / solar power generation system described above, since the inclination angle of the panel is fixed, it is not possible to flexibly cope with changes in the type of crops on the farmland or the amount of solar radiation. In addition, when panels are arranged above the farmland, if there are too many panels to be placed, the crops on the farmland will not be sufficiently exposed to light, resulting in insufficient crop growth and reduced crop production. It is possible. On the other hand, if the number of panels to be arranged is limited in consideration of the growth of crops, the amount of power generated by the panels cannot be sufficiently secured although the growth of crops is not affected.

  The present invention has been made in view of the circumstances described above, and can flexibly cope with changes in the type of crops in the farmland, suppress a decrease in the production amount of the crops, and sufficiently generate power. An object is to provide a solar power generation system that can be secured.

  A photovoltaic power generation system according to one aspect of the present invention includes a solar panel installed above a farmland, a solar radiation amount acquisition unit that acquires the solar radiation amount irradiated on the farmland, and a crop grown on the farmland A light saturation point storage unit that stores the light saturation point for each type of crop, and an angle change unit that changes the inclination angle of the light receiving surface of the solar panel with respect to the incident direction of sunlight. When the solar radiation amount acquired by the solar radiation amount acquisition unit is greater than or equal to the light saturation point stored by the light saturation point storage unit, compared to the case where the solar radiation amount is less than the light saturation point, the inclination angle Change the tilt angle so that is closer to a right angle.

  In the photovoltaic power generation system according to one aspect of the present invention, the angle changing unit adjusts the inclination angle of the solar panel using the light saturation point and the solar radiation amount determined for each crop. Therefore, the inclination angle can be adjusted flexibly as compared with the case where the inclination angle of the panel is fixed. In addition, when the amount of solar radiation is equal to or higher than the light saturation point, the amount of light to the crop is sufficient and no further light irradiation is necessary. In such a case, by making the inclination angle of the light receiving surface of the solar panel with respect to the incident direction of sunlight close to a right angle, it is possible to reduce the amount of light to the crops and increase the amount of power generated by the solar panel. . In this way, the amount of power generated by the solar panel can be maximized within a range that does not hinder the growth of the crop while the crop can obtain the minimum necessary light. Therefore, optimization can be achieved by balancing the production amount of agricultural products and the amount of power generated by the solar panel. In addition, when the type of crop grown on the farmland is changed from a crop with a large light saturation point to a crop with a small light saturation point, unnecessary (surplus) light for the crop increases. The amount of power generation can be increased by bringing the angle close to a right angle. As described above, since the inclination angle can be changed according to the type of crop, optimal rotation control of the solar panel according to the crop can be performed.

  In addition, the temperature changer includes an air temperature acquisition unit that acquires the temperature of the farmland, and the angle changing unit is configured to make the inclination angle closer to a right angle when the temperature of the farmland acquired by the air temperature acquisition unit is higher than a predetermined threshold. May be changed. As described above, the temperature acquisition unit acquires the temperature in the farmland, and the angle changing unit tilts the light receiving surface of the solar panel with respect to the incident direction of sunlight when the acquired temperature exceeds a predetermined threshold. By making the angle close to a right angle and reducing the amount of light entering the farmland, the shadow of the farmland is increased. By increasing the shadow of the farmland in this way, the temperature of the farmland can be lowered, and a decrease in crop production due to the temperature being too high can be suppressed.

  Moreover, the weather information acquisition part which acquires the weather information of farmland may be provided, and an angle change part may change the inclination angle of a solar panel according to the weather information of the farmland acquired by the weather information acquisition part. In this case, since the angle changing unit changes the inclination angle according to the weather information acquired by the weather information acquisition unit, it is possible to optimally control the inclination angle according to the weather of the farmland. Specifically, for example, in the case of heavy snow, it is possible to avoid the accumulation of snow on the solar panel by increasing the inclination angle of the solar panel relative to the horizontal plane, and in the case of typhoon, the inclination of the solar panel relative to the horizontal plane By reducing the angle, the solar panel can be prevented from being subjected to a wind load.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to respond | correspond flexibly even if the kind of crop in a farmland changes, the fall of the production amount of a crop can be suppressed and electric power generation amount can fully be ensured.

It is a side view which shows the installation state of the panel in the solar energy power generation system of embodiment. It is a block diagram which shows the solar energy power generation system of embodiment. (A) is a chart which shows the light saturation point for every crop, (b) is a graph which shows the relationship between the illumination intensity (sunlight amount) of light, and the amount of photosynthesis. It is a flowchart which shows the inclination angle change process of the solar energy power generation system of 1st Embodiment. It is a flowchart which shows the inclination angle change process of the solar energy power generation system of 2nd Embodiment.

  Hereinafter, the photovoltaic power generation system according to the embodiment will be described in detail with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
As shown in FIG. 1, in the solar power generation system 1 of the present embodiment, solar panels (hereinafter referred to as panels) P configured by a plurality of solar modules are arranged above the farmland N. In this state, the panel P performs solar power generation. The panel P has, for example, a rectangular shape, and has a light receiving surface P1 that receives light L from the sun T. When the panel P receives the light L at the light receiving surface P1, the panel P generates power according to the amount of light received.

  The same kind of crop C is planted in the farmland N, and the crop C is cultivated in this farmland N. In the solar power generation system 1, the number of panels P is, for example, several hundreds, and a plurality of panels P are arranged vertically and horizontally in a plan view. Therefore, the light L from the sun T is equally applied to the crop C of the farmland N, and the shadow S of the panel P is formed on the farmland N. The shape and size of the shadow S change with the movement of the sun T over time.

  The solar power generation system 1 includes a support structure 2 that supports a plurality of panels P above the farmland N. The support structure 2 includes a plurality of support columns 2a extending vertically upward from the farmland N, and a beam member 2b that bridges the plurality of support columns 2a on top of the plurality of support columns 2a. A shaft 3 is attached to the beam member 2b, and a panel P is rotatably supported on the shaft 3. The panel P rotates with the rotation of the shaft 3, and the inclination angle θ of the light receiving surface P1 of the panel P with respect to the incident direction of the light L is uniform. As described above, the photovoltaic power generation system 1 has a configuration in which the panel P rotates about one axis, and the inclination angle θ of the panel P can be adjusted.

  As shown in FIG. 2, the solar power generation system 1 measures a motor 4 that rotates the shaft 3, a solarimeter 5 that measures the amount of solar radiation D <b> 1 of the light L to the farmland N, and a temperature D <b> 2 of the farmland N. A thermometer 6 and a control device 10 that controls driving of the motor 4 are provided. The motor 4, the pyrometer 5, and the thermometer 6 can communicate with the control device 10.

  The motor 4 rotates the panel P uniformly by rotating the shaft 3. The pyranometer 5 is a sensor that detects the amount of solar radiation D1 of the light L applied to the farmland N, and outputs the detected amount of solar radiation D1 to the control device 10. The thermometer 6 is a sensor that detects the temperature D <b> 2 in the farmland N, and outputs the detected temperature D <b> 2 to the control device 10. The timing at which the solar radiation meter 5 outputs the solar radiation amount D1 to the control device 10 and the timing at which the thermometer 6 outputs the air temperature D2 to the control device 10 may be real time or may be every predetermined time.

  The control device 10 performs control to adjust the inclination angle θ by rotating the panel P. The control device 10 drives the motor 4 to adjust the inclination angle θ of the panel P. The control device 10 changes the inclination angle θ of the panel P, adjusts the amount of light L entering the farmland N, and changes the size of the shadow S on the farmland N. In this way, the control device 10 adjusts the amount of light L to change the size of the shadow S so that the growth of the crop C on the farmland N is not hindered.

  The control device 10 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Each function of the control device 10 is realized by loading a program stored in the ROM into the RAM and executing it by the CPU. The control device 10 may be a general-purpose personal computer or a server on the Internet, for example. Further, a part of the control device 10 is separated from the remaining part. For example, a part of the control device 10 is arranged near the panel P, and the remaining part of the control device 10 is arranged at a remote place away from the panel P. May be. As described above, the configuration and location of the control device 10 are not particularly limited.

  The control device 10 includes a controller 11 that controls driving of the motor 4, a database 12 that stores information related to the solar power generation system 1, and a communication device 13. The control device 10 may be provided in the vicinity of the farmland N or may be provided in a remote place away from the farmland N. Moreover, the control apparatus 10 is connected to the network 20 which is the internet, for example. Note that the network 20 may not be the Internet, and may be an in-facility network, for example.

  The database 12 stores information used when the controller 11 adjusts the inclination angle θ of the panel P. The database 12 stores date D3, time D4, locus D5, and shadow information D6. The trajectory D5 is information indicating the trajectory of the sun T viewed from the farmland N, and is stored for each date D3. By this trajectory D5, the control device 10 can know how much shadows S are formed on the farmland N at what rate of what day. The shadow information D6 is information indicating how much shadow S is formed in which part of the farmland N. The shadow information D6 is stored for each date D3, every time D4, every inclination angle θ, and every crop C. The shadow information D6 also includes information on the ratio of the shadow S to the necessary amount of light L to the crop C.

  The database 12 stores a crop D7 indicating the type of the crop C cultivated in the farmland N. Further, the database 12 is a light saturation point storage unit that stores a light saturation point (unit: klx (kilolux)) D8 of the crop C. The light saturation point D8 is stored for each crop D7. Here, the light saturation point D8 is a value uniquely determined for each type of the crop C, and even if the light L above the light saturation point D8 is applied to the crop C, the photosynthesis amount of the crop C does not increase. The light saturation point D8 will be described later in detail.

  The database 12 functions as a solar radiation amount acquisition unit that acquires the solar radiation amount D1 of the farmland N from the solar radiation meter 5, and stores the acquired solar radiation amount D1. Moreover, the database 12 may acquire beforehand the solar radiation amount D1 for every year / month / day D3 or every time D4 instead of acquiring the solar radiation amount D1 from the solar radiation meter 5 each time. Furthermore, the controller 11 may calculate the solar radiation amount D1 from the date D3, the time D4, and weather information D9 described later, and the database 12 may acquire the solar radiation amount D1 calculated by the controller 11.

  The database 12 is an air temperature acquisition unit that acquires the air temperature D2 of the farmland N from the thermometer 6, and stores the acquired air temperature D2. Note that the database 12 does not acquire the temperature D2 from the thermometer 6, but may store the temperature D2 obtained from the weather information D9 in advance, for example. For example, the controller 11 may estimate the temperature D2 from the date D3 and the time D4, and the database 12 may acquire the estimated temperature D2.

  The database 12 is a weather information acquisition unit that acquires weather information D9 from the network 20. The acquisition timing of the weather information D9 by the database 12 may be real time or may be every predetermined time. Further, the database 12 stores the power generation amount D10 obtained from the panel P and the inclination angle θ.

  The controller 11 is an angle changing unit that outputs a control signal to the motor 4 to control driving of the motor 4 and changes the inclination angle θ of the panel P. The controller 11 has a function of performing various calculations. For example, the controller 11 calculates a shadow S formed on the farmland N and calculates shadow information D6. Further, the controller 11 controls the motor 4 using each information stored in the database 12 to change the inclination angle θ of the panel P.

  The controller 11 may change the inclination angle θ of the panel P according to the weather information D9 acquired by the database 12. Here, for example, the control device 10 may be provided with a plurality of controllers 11, or the weather information D <b> 9 signal may be sent to the plurality of controllers 11 from the database 12 at a remote location over the network and controlled simultaneously. Good. In this case, the optimal control of the panel P according to the weather of the farmland N becomes possible. Specifically, for example, in the case of heavy snow, it is possible to avoid the accumulation of snow on the panel P by increasing the inclination angle of the panel P with respect to the horizontal plane and standing the panel P vertically, and in the case of a typhoon, the horizontal plane It is possible to avoid the panel P from being subjected to a load by wind by laying the panel P horizontally by reducing the inclination angle of the panel P with respect to.

  The communication device 13 is a communication device used when the control device 10 communicates with other devices. The communication device 13 enables communication between the control device 10 and the PC 14 or the smartphone 15 located outside the control device 10. In addition, the control apparatus 10 may be communicable with apparatuses other than PC14 or the smart phone 15, such as a mobile phone. With this communication device 13, the controller 11 can be operated from the PC 14 or the smartphone 15 to adjust the inclination angle θ of the panel P. For example, the communication device 13 may have a wireless LAN access point communication function. In this case, the communication device 13 can wirelessly communicate with the PC 14 and the smartphone 15 at a remote location.

  By the way, about the photovoltaic power generation system installed in the farmland N, if there are too many panels to be installed, the crop C in the farmland N will not be sufficiently exposed to the light L. It is conceivable that the production volume decreases. Therefore, the photovoltaic power generation system installed on the farmland N is required not to affect the growth of the crop C. That is, even after the photovoltaic power generation system is installed, the production amount of the crop C in the farmland N is not reduced by a predetermined value or more, and the production amount of the crop C is required to be maintained.

  In general, even if the illuminance (irradiation amount) of the light L is constant, the amount of photosynthesis differs depending on the type of the crop C. As shown in FIG. 3A, a light saturation point is uniquely determined for each type of crop. For example, as shown in FIG. 3B, when the illuminance of light is small, the amount of photosynthesis of the crop C increases as the illuminance of light increases. However, in a state where the illuminance of light is equal to or higher than the light saturation point, the amount of photosynthesis of the crop does not increase even if the illuminance of light is further increased. That is, even if light above the light saturation point is applied to the crop, the amount of photosynthesis of the crop does not increase and does not affect the growth of the crop.

  Therefore, in the solar power generation system 1 of the present embodiment, the light L exceeding the light saturation point of the crop C in the farmland N is sent to the power generation by the panel P. That is, the inclination angle θ of the panel P is changed according to whether or not the amount of solar light L applied to the crop C is equal to or greater than the light saturation point of the crop C. Below, the change process of inclination-angle (theta) of the panel P by the solar power generation system 1 is demonstrated using the flowchart shown by FIG. FIG. 4 shows an example of the change process of the inclination angle θ by the controller 11 of the photovoltaic power generation system 1. The process of the flowchart in FIG. 4 is automatically executed repeatedly every predetermined time (for example, every 30 minutes) after the activation of the control device 10, for example, but the execution timing is not particularly limited.

  When the change process of the inclination angle θ shown in FIG. 4 is started, the controller 11 acquires the crop D7 and the light saturation point D8 from the database 12 (step S1). Here, the controller 11 acquires the type of the crop C cultivated in the farmland N and the light saturation point D8 of the crop C.

  Subsequently, the controller 11 acquires the solar radiation amount D1 of the farmland N from the database 12 (step S2). In the process of step S2, the controller 11 grasps the solar radiation amount D1 of the farmland N at the current time. Then, the controller 11 acquires the current inclination angle θ of the panel P from the database 12 (step S3).

  Next, the controller 11 determines whether or not the acquired solar radiation amount D1 is greater than or equal to the light saturation point D8 of the crop C (step S4). In step S4, when the amount of solar radiation D1 is greater than or equal to the light saturation point D8, it is determined that the amount of light L with respect to the crop C is greater than or equal to the necessary amount, and the ratio of the shadow S of the farmland N is the predetermined shadow information D6. So that the set value of the inclination angle θ is close to a right angle (step S5). Here, setting the inclination angle θ to a value close to a right angle and making the inclination angle θ close to a right angle make the inclination angle θ a value close to a right angle by a predetermined angle from the inclination angle θ acquired in step S3. Alternatively, a predetermined value such as setting the inclination angle θ to 80 ° may be set as the inclination angle θ.

  On the other hand, if the amount of solar radiation D1 is not greater than or equal to the light saturation point D8 in step S4, it is determined that the amount of light L with respect to the crop C is less than the necessary amount, and the ratio of the shadow S of the farmland N is predetermined shadow information. The set value of the inclination angle θ is moved away from the right angle so that the ratio becomes D6 (step S6). Here, setting the tilt angle θ away from the right angle and moving the tilt angle θ away from the right angle make the tilt angle θ parallel (0 ° or 180 °) by a predetermined angle from the tilt angle θ acquired in step S3. It may be a close value, or a predetermined value such as a setting value of the tilt angle θ may be 10 °, for example, may be set as the set value of the tilt angle θ.

  In step S7, the controller 11 outputs the set value of the inclination angle θ to the motor 4 as a control signal, so that the motor 4 changes the inclination angle θ of each panel P and ends the series of processes.

  By the way, when the panel tilt adjustment is not performed in consideration of only the crop production amount (the tilt angle θ is not changed) as in the prior art, the tilt angle of the light receiving surface of the panel with respect to the light incident direction is kept away from the right angle. It is possible to avoid affecting the growth of crops by putting a lot of light on the farmland (close to parallel). However, in this case, the inclination angle of the light receiving surface of the panel with respect to the incident direction of light becomes nearly parallel more than necessary, which may cause a problem that the power generation amount of the panel is limited.

  On the other hand, in the solar power generation system 1 of the present embodiment, when the amount of solar radiation D1 of the light L applied to the crop C is less than the light saturation point D8 of the crop C, the inclination angle θ is kept away from the right angle. Thus, the shadow S formed on the farmland N is reduced, and control is performed so that more light L enters the farmland N. On the other hand, when the solar radiation amount D1 of the light L applied to the crop C is equal to or greater than the light saturation point D8 of the crop C, the shadow S formed on the farm land N is increased by bringing the inclination angle θ close to a right angle, Control is performed so that more light is applied to the panel P. Thus, the controller 11 performs control to change the ratio of the shadow S formed on the farmland N according to the light saturation point D8 of the crop C grown on the farmland N.

  Thus, in this embodiment, since the inclination adjustment of the panel P is performed using the light saturation point D8 and the solar radiation amount D1 determined for each crop C, the adjustment of the inclination angle θ is more flexible than in the past. The power generation amount of the panel P can be increased by making the inclination angle θ closer to a right angle. Specifically, for example, when the type of the crop C is changed from rice to soybean, the light saturation point becomes smaller and the surplus light L increases, so that the power generation amount can be increased by bringing the inclination angle θ close to a right angle. it can. Thus, the inclination angle θ can be changed according to the type of the crop C, and the optimal rotation control of the panel P according to the crop C can be performed.

  Moreover, in the solar power generation system 1, it is also possible to perform automatic control of the rotation of the panel P by remote operation via the communication device 13, and the panel P is collectively rotated by this automatic control. Therefore, since the inclination angle θ is adjusted from the external device via the communication device 13, the network can be used effectively, and the trouble of the operator going to the farmland N to rotate the panel P is eliminated. .

  Further, for example, since the weather of the farmland N changes from year to day, it is preferable to perform control using the weather information D9. In this case, for example, when the farm land N is clear and the solar radiation amount D1 included in the weather information D9 is equal to or greater than a predetermined value, the controller 11 causes the inclination angle θ to approach a right angle. When it is raining and the solar radiation amount D1 included in the weather information D9 is less than a predetermined value, the inclination angle θ may be kept away from the right angle. Thus, by controlling the inclination angle θ according to the amount of solar radiation D1 included in the weather information D9, it is possible to control the inclination angle θ according to the weather condition of the farmland N. Therefore, the amount of light L hitting the crop C and the amount of light L hitting the panel P can be optimized. In addition, when using the solar radiation amount D1 contained in the weather information D9, the solar radiation meter 5 becomes unnecessary.

  In addition, continuous cropping failure may occur except when the crop C is rice, so when the crop C is not rice, the possibility that the same type of crop C is cultivated every year in the farmland N is low. Even in such a case, since the database 12 stores the crop D7 cultivated in the farmland N, the size of the shadow S is changed according to the type of the crop C to promote the optimal crop C. be able to. And the electric power generation amount by the panel P can be ensured, without reducing the production amount of the crop C. That is, the amount of power generated by the panel P can be maximized within a range that does not hinder the growth of the crop C while the crop C can obtain the minimum necessary light L. In this way, the balance between the production amount of the crop C and the power generation amount by the panel P can be optimized.

(Second Embodiment)
By the way, when the temperature of the farmland N is too high (for example, when it exceeds 30 degreeC), since the crop C uses energy for transpiration to cool itself, the influence on the growth of the crop C and the production of the crop C The amount can be reduced. In addition, there is a crop C in which the rate of photosynthesis decreases when the temperature is too high. Therefore, in the photovoltaic power generation system of the second embodiment, the inclination angle θ is controlled according to the temperature D2 of the farmland N.

  Below, the photovoltaic power generation system of 2nd Embodiment is demonstrated. In the description of the second embodiment, a description overlapping that of the first embodiment is omitted. The configuration of the photovoltaic power generation system of the second embodiment is the same as the configuration of the photovoltaic power generation system 1 of the first embodiment, and the processing content of the photovoltaic power generation system is different from that of the first embodiment. Below, the change process of inclination-angle (theta) of the panel P by the solar energy power generation system of 2nd Embodiment is demonstrated using the flowchart shown by FIG. FIG. 5 shows an example of the change process of the inclination angle θ by the controller 11, and the execution timing of this process is not particularly limited.

  When the change process of the inclination angle θ shown in FIG. 5 is started, the controller 11 acquires the temperature D2 from the database 12 (step S11). Here, for example, the controller 11 acquires the current temperature D2 on the ground surface of the farmland N (the surrounding environment of the crop C). Subsequently, the controller 11 determines whether or not the acquired temperature D2 exceeds a predetermined threshold value X (for example, 30 ° C.) (step S12). Here, the threshold value X is a criterion for determining whether or not the temperature D2 reaches a temperature at which the growth of the crop C can be hindered. This threshold value X is a value set in advance for each crop C, for example, and can be changed as appropriate.

  In step S12, when the temperature D2 exceeds the threshold value X, it is determined that the temperature of the farmland N is too high, and the inclination angle θ is increased so as to increase the shadow S by reducing the amount of light L falling on the crop C. The set value is brought close to a right angle (step S13). On the other hand, if the temperature D2 does not exceed the threshold value X in step S12, it is determined that the temperature of the farmland N is not too high, and the process proceeds to step S14 as it is. In step S14, the controller 11 outputs the set value of the tilt angle θ to the motor 4 as a control signal, so that the motor 4 adjusts the tilt angle θ of each panel P and ends the series of processes.

  As described above, in the solar power generation system of the second embodiment, when the database 12 acquires the temperature D2 in the farmland N from, for example, the thermometer 6, and the controller 11 exceeds the predetermined threshold value X. The panel P is rotated so that the inclination angle θ is close to a right angle to increase the shadow S of the farmland N. By increasing the shadow S of the farmland N in this way, the temperature of the farmland N can be lowered, and a decrease in the production amount of the crop C due to the temperature being too high can be suppressed.

  Although the embodiments have been described above, the present invention is not limited to the above-described embodiments, and the present invention is modified without departing from the gist described in each claim or applied to others. Also good. That is, the present invention can be variously modified without changing the gist of each claim.

  For example, the controller 11 determines that the light receiving surface P1 of the panel P is in the irradiation direction of the light L when the predetermined amount of time elapses from the sunrise time and the solar radiation amount D1 is less than the light saturation point D8. The inclination angle θ may be changed so as to be parallel (the inclination angle θ is 0 ° or 180 °). Then, when the amount of solar radiation D1 becomes equal to or greater than the light saturation point D8, the shadow S may be increased by bringing the inclination angle θ close to a right angle. Thus, by changing the inclination angle θ, the amount of light L received by the panel P and the amount of light L received by the crop C can be optimized.

  The solar power generation system 1 may include a sensor (for example, a photo detector) that detects the height or direction of the sun T viewed from the farmland N, and the motor 4 according to the detected height or direction of the sun T. May be adjusted by driving the tilt angle θ of the panel P. Furthermore, the controller 11 may adjust the inclination angle θ according to the atmospheric pressure, water vapor pressure, atmospheric turbidity coefficient, scattered light, or ultraviolet light in the farmland N. These atmospheric pressure, water vapor pressure, atmospheric turbidity coefficient, scattered light or ultraviolet rays affect the amount of solar radiation D1 and the growth of the crop C. Therefore, when the inclination angle θ is adjusted in accordance with these, the inclination is more accurate. The angle θ can be adjusted.

  Moreover, the solar power generation system 1 does not need to rotate the panel P uniformly. For example, the inclination angle θ of one panel P may be different from the inclination angle θ of another panel P. Further, the panel P may be configured to rotate around two or more axes.

  Moreover, the solar power generation system 1 may not have the solar radiation meter 5 or the thermometer 6, for example, the database 12 of the solar power generation system 1 may acquire the solar radiation amount D1 and the temperature D2 from another apparatus. . The database 12 may not acquire the weather information D9 via the network 20. Further, for example, the controller 11 may estimate the solar radiation amount D1 or the weather information D9 from the inclination angle θ, the position of the sun T (incident angle of the light L), and the power generation amount D10.

  Further, the solar power generation system 1 may include, for example, an imaging unit that captures the crop C of the farmland N and a growth state acquisition unit that acquires the growth state of the crop C. In this case, for example, the growth state acquisition unit may acquire the growth state of the crop C from the crop C photographed by the photographing unit, and the controller 11 may control the inclination angle θ of the panel P according to the growth state.

  Further, for example, when the crop C is rice, the vegetative growth period indicating from germination to the ear differentiation stage, the reproductive growth period indicating the ear differentiation stage to the heading stage, and the ripening period indicating the heading period to the maturation stage. There are three growth stages. As described above, the crop C has a plurality of growth stages, and the amount of solar light L required for the crop C may vary depending on the growth stage. In preparation for such a case, the database 12 may store the growth stage of the crop C, and the controller 11 may control the inclination angle θ according to the growth stage stored in the database 12. By controlling the inclination angle θ in this way, the amount of light L can be adjusted for each growth stage of the crop C, so that the amount of light L required for the crop C can be optimized. Furthermore, the database 12 may store the relationship between external conditions such as temperature and growth (or photosynthesis amount / rate).

  Moreover, the solar power generation system 1 may include, for example, an imaging unit that captures the crop C in the farmland N and an overlap state acquisition unit that acquires the degree of leaf overlap in the crop C. In this case, for example, the overlap condition acquisition unit acquires the overlap condition of the leaves in the crop C from the crop C photographed by the image capturing means, and the controller 11 controls the inclination angle θ of the panel P according to the overlap condition. Then, when the overlapping degree is larger than the predetermined value, the controller 11 keeps the inclination angle θ away from the right angle so that more light L is applied to the crop C, and when the overlapping degree is equal to or smaller than the predetermined value. The tilt angle θ may be close to a right angle so that more light L is applied to the panel P.

DESCRIPTION OF SYMBOLS 1 ... Photovoltaic power generation system, 2 ... Support structure, 2a ... Strut, 2b ... Beam member, 3 ... Axis, 4 ... Motor, 5 ... Solarimeter, 6 ... Thermometer, 10 ... Controller, 11 ... Controller (angle change) Part), 12 ... database (irradiation amount acquisition part, light saturation point storage part, temperature acquisition part, weather information acquisition part), 13 ... communication device, 14 ... PC, 15 ... smart phone, 20 ... network, C ... crop, D1 ... solar radiation, D2 ... temperature, D3 ... date, D4 ... time, D5 ... locus, D6 ... shadow information, D7 ... crop, D8 ... light saturation point, D9 ... meteorological information, D10 ... power generation, L ... light , N: farmland, P: panel (solar panel), P1: light receiving surface, S: shadow, T: sun, X: threshold, θ: inclination angle.

Claims (3)

Solar panels installed above the farmland;
A solar radiation amount obtaining unit for obtaining a solar radiation amount irradiated on the farmland;
A light saturation point storage unit for storing a light saturation point of a crop cultivated in the farmland for each type of the crop;
An angle changing unit that changes the inclination angle of the light receiving surface of the solar panel with respect to the incident direction of the sunlight, and
The angle changing unit is configured such that when the solar radiation amount acquired by the solar radiation amount acquiring unit is equal to or greater than the light saturation point stored by the light saturation point storage unit, the solar radiation amount is the light saturation point. The inclination angle is changed so that the inclination angle approaches a right angle compared to the case of less than
Solar power system. A temperature acquisition unit for acquiring the temperature of the farmland,
The angle changing unit changes the inclination angle so that the inclination angle approaches a right angle when the temperature of the farmland acquired by the temperature acquisition unit is higher than a predetermined threshold.
The photovoltaic power generation system according to claim 1. A weather information acquisition unit for acquiring weather information of the farmland,
The angle change unit changes the inclination angle of the solar panel according to the weather information of the farmland acquired by the weather information acquisition unit,
The photovoltaic power generation system according to claim 1 or 2.