Solar battery array and photovoltaic power generation unit

Abstract

To provide a solar battery array or the like which is unlikely to be damaged even when sea surface is rough.SOLUTION: A solar battery array 20 has a plurality of photovoltaic power generation units 30, and each of the photovoltaic power generation units 30 has a solar battery panel 31, and a float 35 provided in a lower surface side of the solar battery panel 31. The float 35 has a shape of monotonically decreasing as a cross section in a section parallel to the solar battery panel 31 is separated from the solar battery panel 31.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a solar cell array and a solar power generating unit. [Background technology]

[0002] A floating solar power generation system has been proposed in which a floating island is moored to a mooring buoy that is moored to the seabed, and multiple floating solar cell panels are connected to the surrounding sea surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-7874 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the solar power generation system of Patent Document 1, the floating island can be detached from the mooring buoy and the floating island and the floating solar panel can be towed to another location. Therefore, when rough seas are expected, such as when a typhoon is approaching, the floating solar panel can be evacuated to a safe place to prevent damage to the solar power generation system.

[0005] However, it takes time and effort to tow a floating solar panel to a safe location and then reinstall it in its original location after safety has been confirmed.

[0006] In one aspect, an object of the present invention is to provide a solar cell array and the like that is resistant to damage even when the sea surface is rough. [Means for solving the problem]

[0007] The solar cell array comprises a plurality of solar power generation units, each of which comprises a solar panel and a float arranged on the underside of the solar panel, the float having a shape such that the cross-sectional area in a cross section parallel to the solar panel monotonically decreases with increasing distance from the solar panel. Effect of the Invention

[0008] In one aspect, it is possible to provide a solar cell array or the like that is less likely to be damaged even when the sea surface is rough. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram illustrating an overview of a solar power generation system. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a perspective view of a solar power generation unit. [Figure 4] FIG. 13 is a perspective view of a solar power generation unit according to modified example 1-1. [Diagram 5] FIG. 13 is a three-view diagram of a solar power generation unit according to modified example 1-1. [Figure 6] FIG. 13 is a perspective view of a solar power generation unit according to modified example 1-2. [Figure 7] FIG. 13 is a three-view diagram of a solar power generation unit according to modified example 1-2. [Figure 8] FIG. 11 is a cross-sectional view of a solar power generation unit according to modified example 1-3. [Figure 9] FIG. 13 is a perspective view of a solar power generation unit according to modified example 1-4. [Figure 10] FIG. 11 is a perspective view of a solar power generation unit according to modified example 1-5. [Figure 11] FIG. 11 is a perspective view of a solar power generation unit according to modified example 1-6. [Figure 12] FIG. 11 is an explanatory diagram of a solar power generation unit according to a modified example 1-6. [Figure 13] FIG. 11 is an explanatory diagram of a solar power generation unit according to a modified example 1-6. [Figure 14]FIG. 13 is a perspective view of a solar power generation unit according to modification example 1-7. [Figure 15] FIG. 11 is an explanatory diagram of a solar power generation unit according to a modified example 1-8. [Figure 16] FIG. 11 is a perspective view of a solar cell array according to a second embodiment. [Figure 17] FIG. 2 is an explanatory diagram of a solar power generation unit according to a modified example 2-1. [Figure 18] FIG. 13 is an explanatory diagram of a solar power generation unit according to a modified example 2-2. [Figure 19] FIG. 11 is a perspective view of a solar cell array according to a third embodiment. [Figure 20] 20 is an enlarged view of the XX portion in FIG. 19 as viewed from directly above. [Figure 21] 11A and 11B are explanatory diagrams illustrating the effect of a contact prevention portion. [Figure 22] 11A and 11B are explanatory diagrams illustrating the effect of a contact prevention portion. [Diagram 23] FIG. 13 is a perspective view of a solar cell array according to a modified example 3-1. [Figure 24] 24 is an enlarged view of part XXIV in FIG. 23 as viewed from directly above. [Diagram 25] FIG. 13 is a perspective view of a solar cell array according to a modified example 3-2. [Figure 26] 13 is an explanatory diagram illustrating the effect of the contact prevention portion of the modified example 3-2. FIG. [Figure 27] FIG. 13 is a perspective view of a solar cell array according to a modified example 3-3. [Figure 28] 13 is an explanatory diagram illustrating the effect of the contact prevention portion of the modified example 3-3. FIG. [Figure 29] FIG. 13 is a perspective view of a solar cell array according to a modified example 3-4. [Diagram 30] 13 is an explanatory diagram illustrating the effect of the contact prevention portion of the modified example 3-4. FIG. [Diagram 31] 13 is an explanatory diagram illustrating the effect of the contact prevention portion of the modified example 3-4. FIG. [Diagram 32] FIG. 13 is a perspective view of a solar cell array according to a modified example 3-5. [Diagram 33] FIG. 11 is an explanatory diagram illustrating the configuration of a solar power generation unit according to a fourth embodiment. [Diagram 34]FIG. 13 is an explanatory diagram illustrating a configuration of a solar power generation system according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Embodiment 1] As part of efforts to protect the Earth from climate change caused by global warming, the use of renewable energy sources with low carbon dioxide emissions is being encouraged. Furthermore, in order to supply cheap and safe electric energy to everyone, it is more desirable for electricity generated by large-scale power generation facilities to be provided to consumers via the power grid, rather than for consumers such as ordinary households to have their own small-scale power generation facilities.

[0011] Solar power generation is one type of renewable energy. In Japan, the Feed-in Tariff (FIT) system, a fixed price purchase system for renewable energy, was launched in July 2012. The FIT system is a system in which the government guarantees that electric power companies will purchase electricity generated by renewable energy at a fixed price for a certain period of time. After the introduction of the FIT system, many power generation facilities using renewable energy, including solar power generation facilities, were installed in Japan.

[0012] According to statistics from fiscal year 2019, Japan has the world's largest solar power generation capacity per land area. However, in recent years, a shortage of land for installing new solar power generation facilities has become an issue. For example, there are plans to use abandoned farmland due to farmers abandoning farming as solar power generation facilities, but the high cost of developing abandoned farmland that has turned into forest is becoming an issue.

[0013] Large-scale solar power generation facilities are sometimes installed on sloping land to effectively utilize the land. By installing solar power generation facilities on a south-facing slope, it is expected that the power generation efficiency will be improved. However, it is known that solar power generation facilities installed on sloping land pose a risk of increasing the likelihood of disasters such as landslides during bad weather.

[0014] Flat land at the bottom of a slope is often used for residential areas, etc. In order to realize sustainable urban development where people living in such residential areas can continue to live safely, it is desirable to install solar power generation facilities in places other than on slopes.

[0015] Furthermore, solar power generation facilities that have been affected by landslides will be unable to generate electricity until repairs are completed. Depending on the severity of the landslide, repairs may have to be abandoned. In order to create a sustainable, disaster-resistant power infrastructure, it is desirable to install solar power generation facilities in locations other than on sloping ground.

[0016] The solar power generation system disclosed in Patent Document 1, which combines a floating island and floating solar cell panels, can eliminate the drawbacks of solar power generation systems installed on sloping ground. However, it cannot generate power during the period from when the floating solar cell panels must be towed to a safe location to when they are reinstalled in their original location after safety has been confirmed.

[0017] For example, if a typhoon approaches the Japanese archipelago, rough seas are predicted in a wide area of ​​the seas near Japan, causing many solar power plants to stop operating. Therefore, it is difficult to provide high-quality, reliable, sustainable, and disaster-resistant infrastructure using only the solar power generation system of Patent Document 1.

[0018] In consideration of the above circumstances, in this embodiment, a solar power generation system that is installed on the sea surface and does not need to be evacuated even when rough seas are predicted will be described. Fig. 1 is an explanatory diagram illustrating an overview of a solar power generation system 10.

[0019] The solar power generation system 10 includes a solar cell array 20 in which a number of solar power generation units 30 are connected via connecting parts 38. Each solar power generation unit 30 includes a solar cell panel 31, a float 35, and a frame part 33. The float 35 is fixed to the underside of the solar cell panel 31 via the frame part 33. The solar power generation system 10 of this embodiment is installed in the open ocean.

[0020] Unlike inland seas such as bays, seawater does not stagnate in the open ocean, so there is little impact on the environment caused by covering the sea surface with the solar cell array 20. In other words, installing the solar power generation system 10 in the open ocean rather than in the inland sea avoids serious adverse effects on marine and coastal ecosystems and contributes to protecting marine resources.

[0021] Furthermore, compared to installing the solar power generation system 10 on the surface of a lake, it is possible to avoid any impact on the ecosystem of inland freshwater areas. Therefore, installing the solar power generation system 10 on the open ocean instead of on a lake contributes to protecting the richness of the natural blessings provided by the ecosystem on land and enabling a diverse range of living organisms to live.

[0022] The float 35 has a shape in which the cross-sectional area in a plane parallel to the solar cell panel 31 monotonically decreases with increasing distance from the solar cell panel 31. Details of the shape of the float 35 will be described later. The float 35 has a smaller specific gravity than seawater, and receives a buoyancy from seawater to the extent that the solar cell panel 31 fixed to the upper side of the float 35 can float on the sea surface. The two-dot chain line diagrammatically indicates the sea surface under normal conditions.

[0023] The solar cell array 20 is moored to the seabed via a mooring rope 15. Fig. 1 shows a schematic diagram of a state in which the sea level has risen to a height exceeding the slack in the mooring rope 15, as described below. The solar cell array 20 cannot rise beyond the length of the mooring rope 15, and is submerged below the sea level. Note that one solar power generation system 10 may include multiple solar cell arrays 20.

[0024] The power generated by each solar power generation unit 30 is transmitted to a power conditioning system (PCS) (not shown), for example, via a wireless power transmission antenna (not shown). The solar power generation unit 30 may be connected to the PCS via a power transmission cable.

[0025] Instead of each solar power generation unit 30 having a wireless power transmission antenna, a plurality of solar power generation units 30 connected via a power transmission cable may be connected to a single wireless power transmission antenna.

[0026] The communication between the solar cell array 20 and the PCS is also performed via a wireless communication antenna (not shown). The solar cell array 20 may be connected to the PCS via a communication cable. A cable for transmitting power may also serve as the communication cable.

[0027] 2 is a top view of the solar cell array 20. Solar power generation units 30, each having a rectangular solar cell panel 31 on its upper surface, are arranged in four vertical rows and four horizontal rows. Hatching indicates the gaps between the solar power generation units 30. The solar power generation units 30 are arranged with a gap between adjacent solar power generation units 30.

[0028] The four sides of the solar cell panel 31 are surrounded by a frame portion 33. The frame portion 33 is dish-shaped or frame-shaped with a recess corresponding to the outer shape of the solar cell panel 31, and functions as a reinforcing material to prevent damage to the solar cell panel 31 due to external forces. Note that in FIG. 2, the float 35 is hidden under the solar cell panel 31 and the frame portion 33.

[0029] The solar power generation units 30 are connected to each other by connecting parts 38. The four solar power generation units 30 inside the solar cell array 20 are each connected to the left and right solar power generation units 30 by connecting parts 38. The connecting parts 38 are, for example, a rope with both ends fixed to the solar power generation units 30. The connecting parts 38 may be a shaft coupling such as a universal joint. The connecting parts 38 may be extendable and contractible.

[0030] 2 are merely examples and are not intended to be limiting. For example, the number of solar power generation units 30 in the vertical direction may be different from the number of solar power generation units 30 in the horizontal direction. The solar cell panels 31 may be arranged in any manner, such as a substantially L-shape or a ring shape.

[0031] Similarly, the number and arrangement of the connecting portions 38 shown in Fig. 2 are examples and are not limited thereto. For example, each solar power generation unit 30 may be connected to four or eight surrounding solar power generation units 30. The connecting portions 38 may be connected to the middle of the sides of the solar power generation unit 30. The shape of the solar cell panel 31 is also an example. The solar cell panel 31 may be, for example, a square.

[0032] 3 is a perspective view of the solar power generation unit 30. The float 35 has a quadrangular pyramid shape with its rectangular bottom surface facing upward. The solar cell panel 31 is fixed to the bottom surface of the float 35 via a frame portion 33. A gap may be provided between the float 35 and the frame portion 33.

[0033] The float 35 is made of, for example, a foamed resin in which many closed bubbles are dispersed. The float 35 may be shell-shaped with a cavity inside. The float 35 may be a container-shaped float with an opening at the top, and the frame 33 and the solar panel 31 may function as a lid to close the opening watertightly. The float 35 may have an air chamber filled with gas inside.

[0034] Returning to Fig. 1 for further explanation, if the mooring ropes 15 are too long, the position of the solar cell array 20 will vary significantly along the water surface. For example, in the case of a photovoltaic power generation system 10 including multiple solar cell arrays 20, if the mooring ropes 15 are too long, there is a risk that the mooring ropes 15 of adjacent solar cell arrays 20 will become entangled.

[0035] Therefore, the mooring ropes 15 are set to a length that allows the solar cell array 20 to float on the sea surface within the range of normal sea level fluctuations due to tides, waves, etc. In other words, the mooring ropes 15 are set to a length that allows some slack within the range of normal sea level fluctuations. In Fig. 1, the two-dot chain line diagrammatically indicates the water surface when the solar cell array 20 is floating on the sea surface.

[0036] 1 shows a state where the sea surface becomes rough due to the combination of high tide, a storm surge, and very strong waves, causing the sea surface to rise above the normal range of sea level fluctuations. Because the water depth is deeper than the length of the mooring rope 15, the solar cell array 20 cannot keep up with the sea surface fluctuations and is submerged below the sea surface.

[0037] 1 occurs, a strong water current is generated around the solar cell array 20. In particular, when the sea level becomes higher than the solar cell array 20 that was originally floating on the sea level, seawater that was below the solar cell array 20 flows into the upper side of the solar cell array 20, generating an upward water current with respect to the solar cell array 20.

[0038] Because the float 35 has a quadrangular pyramid shape, the upward water current flows along the surface of the float 35 and passes through the gaps between the solar power generation units 30 to reach the upper side of the solar cell array 20. In other words, the side surface of the float 35 guides the upward seawater into the gaps between the solar power generation units 30, thereby preventing damage to the solar cell array 20 due to the water current.

[0039] Even when the sea level returns to its original height, the seawater above the solar cell array 20 passes through the gaps between the solar power generation units 30, so that the solar cell array 20 quickly returns to floating on the sea surface. At this time, too, the seawater flows along the surface of the float 35, so the generation of turbulence on the underside of the float 35 is prevented. Therefore, damage to the solar cell array 20 due to turbulence can be prevented.

[0040] Seawater flows smoothly along the surface of the float 35, reducing the force applied to the mooring rope 15 that moor the solar cell array 20. Since the strength required for the mooring system that moored the mooring rope 15 to the seabed or the like is reduced, the cost of the mooring system can be reduced.

[0041] According to this embodiment, it is possible to provide a solar cell array 20 that is not easily damaged even when the sea surface is rough. As shown in Fig. 1, when the solar cell panel 31 is submerged under the sea surface, the power generation efficiency is lower than usual, but when the sea surface condition returns to normal, it is possible to provide a solar cell array 20 that quickly starts generating power as usual.

[0042] The solar power generation system 10 may be installed in an inland sea. For example, it is possible to provide a solar power generation system 10 that is not easily damaged even in an inland sea with high waves caused by ship navigation. The solar power generation system 10 may be installed in a lake. For example, it is possible to provide a solar power generation system 10 that is not easily damaged even in a lake with large fluctuations in the amount of water flowing in and out of the river, or in a lake with high waves caused by ship navigation.

[0043] The mooring rope 15 may be moored to the seabed via, for example, an offshore wind power generation facility. By combining the power generated by the wind power generation facility and the power generated by the solar power generation system 10, a large-capacity renewable energy power generation system can be provided.

[0044] The mooring rope 15 may be moored to an offshore plant such as an offshore oil and natural gas plant. Electricity can be supplied from the solar power generation system 10 to the offshore plant.

[0045] [Variation 1-1] Fig. 4 is a perspective view of a solar power generation unit 30 of modified example 1-1. Fig. 5 is a three-view diagram of the solar power generation unit 30 of modified example 1-1. Fig. 5 shows a front view, a left side view, and a plan view of the solar power generation unit 30 in third angle projection. This modified example relates to a solar power generation unit 30 in which the tip of the float 35 has a substantially rounded quadrangular pyramid shape. Descriptions of parts common to the first embodiment will be omitted.

[0046] The portion of the float 35 close to the solar cell panel 31 is substantially truncated pyramid-shaped with the outer shape of the frame portion 33 as the larger bottom surface. The portion of the float 35 farther from the solar cell panel 31 is substantially rounded rectangular pyramid-shaped with the bottom surface being a substantially rounded rectangle with rounded corners, which is substantially similar to the outer shape of the frame portion 33, as shown by the dashed line in the plan view of Fig. 5. The substantially truncated pyramid-shaped portion and the substantially rounded rectangular pyramid-shaped portion are smoothly connected and formed as one unit.

[0047] According to this modification, since little turbulence occurs at the corners of the float 35, it is possible to provide a solar cell array 20 in which damage due to the solar power generation unit 30 capsizing or the like is unlikely to occur.

[0048] [Variation 1-2] Fig. 6 is a perspective view of a solar power generation unit 30 of modified example 1-2. Fig. 7 is a three-view diagram of the solar power generation unit 30 of modified example 1-2. Fig. 7 shows a front view, a left side view, and a plan view of the solar power generation unit 30 in third angle projection. This modified example relates to a solar power generation unit 30 in which the side surface of the float 35 has a concave shape. Descriptions of parts common to modified example 1-1 will be omitted.

[0049] Point C in Fig. 6 indicates the center of solar panel 31, i.e., the intersection point of the diagonal lines. A straight line N that passes through point C and is perpendicular to solar panel 31 is indicated by a dashed dotted line. As shown in Fig. 6, straight line N does not pass through the apex of float 35. The foot of a perpendicular line drawn from the apex of float 35 to solar panel 31 is located to the right of point C in Fig. 6.

[0050] The portion of the float 35 close to the solar cell panel 31 has a generally truncated pyramid shape with the outer shape of the frame portion 33 as the larger bottom surface, as in the case of the modified example 1-1. The cross section of the portion of the float 35 far from the solar cell panel 31 has a generally rounded rectangular shape with rounded corners, which is roughly similar to the outer shape of the frame portion 33, as shown by the dashed line in the plan view of FIG.

[0051] Compared to embodiment 1-1, the cross-sectional area of ​​float 35 is reduced less near the tip, and the thin portion extends longer. As shown in the front and side views of Fig. 7, the side of float 35 is vertically concave. The apex of float 35 is biased to the right side in Fig. 7 from the center of solar panel 31.

[0052] According to this modification, the tip of the float 35 is submerged deep, so it is possible to provide a solar cell array 20 that is less susceptible to damage due to capsizing of the solar power generation unit 30. According to this modification, it is possible to provide a solar cell array 20 that is less susceptible to damage due to water pressure by reducing the upward water pressure.

[0053] [Variation 1-3] 8 is a cross-sectional view of a solar power generation unit 30 according to Modification 1-3. This modification relates to a solar cell array 20 that uses a light-transmitting bifacial solar cell panel 31. Descriptions of parts common to the first embodiment will be omitted.

[0054] The frame portion 33 of this modified example is frame-shaped, and the bottom surface of the solar cell panel 31 is not covered by the frame portion 33. The float 35 of this modified example is container-shaped, formed by four of the five surfaces that form a quadrangular pyramid, excluding the bottom surface. The thickness of each surface that constitutes the float 35 is approximately uniform. The solar cell panel 31 is fixed via the frame portion 33 to a location that corresponds to the bottom surface of the quadrangular pyramid. The float 35, the frame portion 33, and the solar cell panel 31 are fixed to each other in a watertight manner so that seawater does not enter the inside of the solar power generation unit 30.

[0055] A reflector 36 is formed on the inner surface of the float 35 using a metal film or the like applied by plating, vapor deposition, etc. If the float 35 is made of a material with high light transmittance, the reflector 36 may be formed on the outer surface of the float 35.

[0056] Part of light L, such as sunlight, incident on the front surface of the solar cell panel 31 is converted into electricity, and part of the light is transmitted through the solar cell panel 31. The transmitted light is reflected by the reflecting mirror 36 and enters the rear surface of the solar cell panel 31. The solar cell panel 31 also converts the light incident from the rear surface into electricity.

[0057] According to this modification, it is possible to provide a solar cell array 20 that can convert light into electricity more efficiently than when only light incident on the front surface is converted into electricity.

[0058] [Variation 1-4] 9 is a perspective view of a solar power generation unit 30 according to Modification 1-4. This modification relates to a solar cell array 20 in which a plurality of dimple-shaped depressions 371 are provided on the surface of a float 35. Descriptions of parts common to the first embodiment will be omitted.

[0059] The depressions 371 are substantially hemispherical, with a diameter of about 10 to 20 centimeters and a depth of about 5 to 10 centimeters. The depressions 371 are arranged over the entire side surface of the float 35. Depressions 371 of different dimensions may be arranged in a mixed manner.

[0060] The presence of the recess 371 can reduce the generation of Karman vortices around the float 35. This can reduce the generation of vibrations in the solar power generation unit 30 due to the Karman vortex street, and can prevent damage to the solar cell array 20 due to, for example, resonance.

[0061] The dimple-shaped depression 371 may be provided in the float 35 of the solar power generation unit 30 described in Modification 1-1 or Modification 1-2. The shallow and small dimple-shaped depression 371 may be provided in the float 35 of the solar power generation unit 30 described in Modification 1-3.

[0062] [Variation 1-5] 10 is a perspective view of a solar power generation unit 30 according to Modification 1-5. This modification relates to a solar cell array 20 in which a weight is disposed on the top of the float 35. Descriptions of parts common to Modification 1-1 will be omitted.

[0063] In this embodiment, a weight 39 having a generally elliptical cone shape is disposed at the tip of float 35. Weight 39 is, for example, made of a high-density resin. For example, float 35 having weight 39 can be formed by forming the tip of float 35 from a non-foamed resin and the remaining portion from a foamed resin. Weight 39 and float 35 can be manufactured integrally from the same material.

[0064] The dimple-like depression 371 described in Modification 1-4 may be provided in the float 35. The weight 39 may be in the shape of a substantially elongated cone or a substantially rounded quadrangular pyramid.

[0065] The float 35 is in the shape of a container with an open top, and the weight 39 may be seawater poured into the float 35. By mounting a pump that adjusts the amount of seawater on the float 35, the weight 39 can be used as ballast water that adjusts the depth to which the solar power generation unit 30 is submerged. The pump is an example of an injection / drainage mechanism that injects and drains water into and from the float 35.

[0066] In addition, shallow and small dimple-shaped depressions 371 may be provided on the outer surface of the container-shaped float 35.

[0067] According to this modification, the center of gravity of the solar power generation unit 30 can be lowered, so that a highly stable solar power generation unit 30 can be provided.

[0068] [Variation 1-6] 11 is a perspective view of a solar power generation unit 30 according to Modification 1-6. This modification relates to a solar power generation unit 30 including a cylindrical float 35. Descriptions of parts common to Modification 1-1 will be omitted.

[0069] The float 35 is in the shape of a tapered cylinder, and the solar cell panel 31 is attached to one end via a dish-shaped frame portion 33. The end of the float 35 on the side where the solar cell panel 31 is attached has a shape that corresponds to the outer shape of the frame portion 33. The end of the float 35 farther from the solar cell panel 31 forms a substantially circular float opening 351 that is smaller than the solar cell panel 31. The side of the float 35 smoothly continues from the end connected to the frame portion 33 to the float opening 351.

[0070] The joint between float 35 and frame 33 is watertight. Therefore, if solar power generation unit 30 is submerged straight into seawater with float opening 351 facing down and solar panel 31 horizontal, air inside float 35 does not flow out and almost no seawater enters float 35.

[0071] 12 and 13 are explanatory diagrams of the solar power generation unit 30 of Modification 1-6. Fig. 12 shows a schematic vertical cross section of the solar power generation unit 30 floating on the sea surface during use. Note that the thickness of the float 35 is omitted, and is shown diagrammatically by a single outline.

[0072] In this modification, each solar power generation unit 30 is moored to the seabed by a mooring rope 15. As shown in Fig. 12, seawater is injected up to a height of about 20 percent from the bottom of the float 35. An appropriate amount of seawater is injected when the solar power generation unit 30 is installed on the sea surface.

[0073] For example, seawater can be injected into float 35 by inserting the nozzle of an air pump into float 35 through float opening 351 and removing the air. Similarly, the amount of seawater in float 35 can be reduced by injecting air into float 35 through float opening 351 using an air pump. Seawater in float 35 is appropriately replaced with fresh seawater through float opening 351.

[0074] According to this modification, when the solar power generation unit 30 swings, the seawater in the float 35 functions as a weight. Therefore, a highly stable solar power generation unit 30 can be provided.

[0075] 13 is a schematic diagram showing a state in which, after the solar power generation unit 30 has been operated for a long period of time, attachment 65 such as shellfish and seaweed is attached to the surface of the float 35. Seawater equivalent to the weight of the attachment 65 flows out of the float opening 351, causing the seawater level in the float 35 to drop. The weight of the solar power generation unit 30 including the seawater in the float 35 does not change before and after the attachment 65 is attached. Therefore, even if the attachment 65 is attached, the floating height above the sea surface does not change, and a solar power generation unit 30 that can be used stably for a long period of time can be provided.

[0076] [Variation 1-7] 14 is a perspective view of a solar power generation unit 30 according to Modification 1-7. This modification relates to a solar power generation unit 30 including fins 34. Descriptions of parts common to Modification 1-1 will be omitted.

[0077] The solar power generation unit 30 of this modified example includes an annular fin 34 that extends outward from the side of the float 35 and goes around the float 35. The fin 34 is approximately parallel to the solar cell panel 31, and when the solar power generation unit 30 is floated on a calm water surface, it is approximately parallel to the water surface. The fin 34 is, for example, a thin plate made of resin.

[0078] The fins 34 suppress the rocking of the solar power generation unit 30, thereby providing a solar power generation unit 30 that floats stably on the water surface.

[0079] [Variation 1-8] 15 is an explanatory diagram of a solar power generation unit 30 according to Modification 1-8. This modification relates to a solar power generation unit 30 that is moored by connecting a mooring rope 15 to a fin 34. Descriptions of parts common to Modification 1-7 will be omitted.

[0080] 15, in the solar power generation unit 30 of this modification, the mooring rope 15 is connected near the base of the fin 34. Therefore, the force of the mooring rope 15 is transmitted in a dispersed state to the outer periphery of the float 35 via the fin 34. Compared to a case where the mooring rope 15 is directly fixed to the float 35, a solar power generation unit 30 that is less likely to be damaged by being pulled by the mooring rope 15 can be provided.

[0081] For example, by appropriately replacing the fins 34 during regular maintenance, a solar power generation unit 30 that can be used for a long period of time can be provided.

[0082] [Variation 1-9] The solar cell array 20 may be configured by appropriately combining the solar power generation units 30 of a plurality of shapes described in the first embodiment and the respective modified examples.

[0083] [Embodiment 2] This embodiment relates to a solar cell array 20 having solar power generation units 30 that are circular in plan view. Description of parts common to the first embodiment will be omitted.

[0084] 16 is a perspective view of a solar cell array 20 according to a second embodiment. Each solar cell array 20 includes a spherical shell-shaped float 35 and a disk-shaped solar cell panel 31 arranged on a plane passing through the center of the float 35. The float 35 has high light transmittance at least on the light-receiving surface side of the solar cell unit 30. The float 35 is arranged so that the solar cell units 30 are on the same plane.

[0085] According to this embodiment, it is possible to provide a solar cell array 20 in which gaps are formed between the solar power generation units 30 even when the solar power generation units 30 are arranged in close contact with each other.

[0086] A weight may be placed under the float 35. A device such as a wireless power transmission antenna (not shown) may also serve as the weight. The solar power generation unit 30 may be fixed inside the float 35 via a frame portion 33 (not shown).

[0087] The dimple-shaped depression 371 described in the modification 1-3 may be provided in the float 35.

[0088] [Variation 2-1] 17 is an explanatory diagram of a solar power generation unit 30 according to Modification 2-1. This modification relates to a solar power generation unit 30 having a substantially conical shape and a groove 372 on the side surface. Descriptions of parts common to the second embodiment will be omitted.

[0089] The solar cell panel 31 of this modification includes a plurality of circular solar cells 32 arranged in a substantially circular shape. The solar cell panel 31 is fixed to a frame portion 33. The outer periphery of the frame portion 33 is a circle having substantially triangular projections and recesses.

[0090] The float 35 has a cone shape with a frame portion 33 on the bottom surface. That is, a groove 372 corresponding to the outer periphery of the frame portion 33 is provided on the side surface of the float 35. The groove 372 becomes thinner and shallower as it approaches the top of the float 35.

[0091] According to this modification, turbulence is unlikely to occur because the water flowing above and below the solar cell array 20 passes through the grooves 372. Therefore, it is possible to provide a solar cell array 20 that is unlikely to be damaged by turbulence.

[0092] The presence of the grooves 372 can reduce the generation of Karman vortices around the float 35. This can reduce the generation of vibrations in the solar power generation unit 30 due to the Karman vortex street, and can prevent damage to the solar cell array 20 due to, for example, resonance.

[0093] [Variation 2-2] 18 is an explanatory diagram of a solar power generation unit 30 according to Modification 2-2. This modification relates to a substantially egg-shaped solar power generation unit 30. Descriptions of parts common to the second embodiment will be omitted.

[0094] The float 35 of this embodiment has a spheroidal shape obtained by rotating an ellipse around its major axis. A plurality of solar cell panels 31, each having a substantially trapezoidal shape, are arranged on the surface of the float 35. The solar cell panels 31 are, for example, in the form of a bendable sheet, and are attached along the surface of the float 35.

[0095] The solar cell panel 31 may be in the form of a hard plate, and the center of the solar cell panel 31 may be fixed to the surface of the float 35. The float 35 may have a surface portion scraped off to form a flat surface, and the solar cell panel 31 may be fixed to the flat surface.

[0096] According to this modification, since the orientations of the multiple solar cell panels 31 are different, it is possible to provide a solar power generation unit 30 in which the amount of power generation is less likely to fluctuate even if the direction of the sun changes. Since the solar power generation unit 30 is configured by fixing multiple solar cell panels 31 to one float 35, it is possible to provide a solar power generation unit 30 that requires little installation work.

[0097] The dimple-shaped depression 371 described in the modification 1-4 may be provided in the lower part of the float 35.

[0098] [Variation 2-3] The solar cell array 20 may be configured by appropriately combining the solar power generation units 30 having a plurality of shapes described in the second embodiment and each of the modified examples. The solar cell array 20 may be configured by appropriately combining the solar power generation units 30 described in the first embodiment and each of the modified examples of the first embodiment and the solar power generation units 30 having a plurality of shapes described in the second embodiment and each of the modified examples of the second embodiment.

[0099] [Embodiment 3] This embodiment relates to a solar cell array 20 in which the solar power generation units 30 are unlikely to be damaged even if the sea becomes rough and the connecting parts 38 become detached. Descriptions of parts common to the first embodiment will be omitted.

[0100] Fig. 19 is a perspective view of a solar cell array 20 according to a third embodiment. Fig. 20 is an enlarged view of a portion XX in Fig. 19 viewed from directly above. In Fig. 20, one solar power generation unit 30 is indicated by a solid line, and the other solar power generation units 30 are indicated by a two-dot chain line. In Figs. 19 and 20, the float 35 is hidden under the solar cell panel 31 and the frame portion 33.

[0101] The solar cell array 20 includes a plurality of rectangular solar cell panels 31. The edges of each solar cell panel 31 are surrounded by a frame portion 33. The frame portions 33 are connected to each other by connecting portions 38. The connecting portions 38 are, for example, hinge-shaped. The connecting portions 38 may connect the frame portions 33 to each other with a gap (not shown) provided therebetween. The frame portions 33 may be provided with a through-hole through which seawater can pass.

[0102] Contact prevention parts 45 protrude from the center of the solar cell panel 31 and from the centers of the four sides of the frame part 33. The contact prevention parts 45, which are arranged in the center of the solar cell panel 31 and on the sides that form the outer periphery of the solar cell array 20, are substantially cylindrical in shape.

[0103] The contact prevention portion 45 arranged on the side adjacent to another solar power generation unit 30 has a semicylindrical shape with a chord substantially perpendicular to the side of the solar power generation unit 30 and a semicircle on one side of the chord as the bottom surface. The contact prevention portions 45 provided on adjacent solar power generation units 30 join together to form a substantially cylindrical shape. Note that it is desirable that the edge of the upper surface of the contact prevention portion 45 has, for example, a R-chamfered shape.

[0104] The contact prevention portion 45 is desirably made of a material that is highly light-transmitting and flexible, such as a transparent silicone resin, a transparent polyurethane resin, or a transparent acrylic rubber resin.

[0105] 21 and 22 are explanatory diagrams illustrating the effect of the contact prevention part 45. Fig. 21 and Fig. 22 typically illustrate a state in which the coupling parts 38 have come off due to rough waves or the like, causing the solar power generation units 30 to break apart and be buffeted by the waves.

[0106] 21, the float 35 of the solar power generation unit 30 shown on the right side runs up onto the solar power generation unit 30 shown on the left side. The presence of the contact prevention portion 45 prevents the float 35 from directly running up onto the solar cell panel 31. Therefore, the solar cell panel 31 is less likely to be damaged, such as cracked.

[0107] 22, one solar power generation unit 30 is turned upside down by a wave and rides up on top of the other solar power generation units 30. The presence of the contact prevention portion 45 prevents the solar cell panels 31 from coming into direct contact with each other. The solar cell panels 31 are hard and are less likely to be damaged, such as scratched or cracked, by direct contact with each other.

[0108] Furthermore, even if the solar cell panels 31 are damaged, it is possible to prevent the occurrence of a short circuit between the positive and negative electrodes caused by contact between damaged solar cell panels 31 and the occurrence of a fire associated with the short circuit.

[0109] Although not shown, even if the solar cell array 20 turns up without the connecting portions 38 being detached, the contact prevention portions 45 can prevent the solar cell panels 31 from coming into contact with each other.

[0110] According to this embodiment, it is possible to provide a photovoltaic power generation system 10 that can prevent damage to the solar cell panel 31 and the outbreak of a fire even if the connecting part 38 becomes detached due to rough waves, etc. If damage and the outbreak of a fire can be prevented, restoration work can be carried out in a relatively short time after the weather calms down.

[0111] For example, in the event of extremely strong rough waves, the connecting parts 38 will come detached, allowing each solar cell array 20 to receive the waves, thereby preventing the solar power generation units 30 from being damaged by a large external force.

[0112] [Variation 3-1] This modification relates to a solar cell array 20 in which gaps are provided between the solar power generation units 30. Description of parts common to the third embodiment will be omitted.

[0113] Fig. 23 is a perspective view of the solar cell array 20 of the modified example 3-1. Fig. 24 is an enlarged view of the portion XXIV in Fig. 23 as viewed from directly above. In Fig. 24, one solar power generation unit 30 and a connecting portion 38 connected to the solar power generation unit 30 are indicated by solid lines, and other solar power generation units 30 and connecting portions 38 are indicated by two-dot chain lines. In Figs. 23 and 24, the float 35 is hidden under the solar cell panel 31 and the frame portion 33.

[0114] In this modification, each solar power generation unit 30 has a total of nine contact prevention parts 45, located at the center of the solar cell panel 31, the four corners of the frame part 33, and the centers of each of the four sides of the frame part 33. The solar power generation units 30 are connected to each other by connecting parts 38. The connecting parts 38 are, for example, ropes with both ends fixed to the solar power generation units 30. The connecting parts 38 may be shaft couplings such as universal joints. The connecting parts 38 may be extendable and contractible.

[0115] Since each solar power generation unit 30 has the same configuration, it is possible to provide a solar power generation unit 30 that can be easily installed.

[0116] The solar cell array 20 includes a plurality of rectangular solar cell panels 31. The edges of each solar cell panel 31 are surrounded by a frame portion 33. The frame portions 33 are connected to each other by connecting portions 38. The connecting portions 38 are, for example, hinge-shaped. The connecting portions 38 may connect the frame portions 33 to each other with a gap (not shown) provided therebetween. The frame portions 33 may be provided with a through-hole through which seawater can pass.

[0117] Contact prevention parts 45 protrude from the center of the solar cell panel 31 and from the centers of the four sides of the frame part 33. The contact prevention parts 45, which are arranged in the center of the solar cell panel 31 and on the sides that form the outer periphery of the solar cell array 20, are substantially cylindrical in shape.

[0118] The contact prevention portion 45 is desirably made of a material that is highly light-transmitting and flexible, such as a transparent silicone resin, a transparent polyurethane resin, or a transparent acrylic rubber resin.

[0119] [Variation 3-2] Fig. 25 is a perspective view of the solar cell array 20 of Modification 3-2. Fig. 26 is an explanatory diagram for explaining the effect of the contact prevention part 45 of Modification 3-2. This modification relates to a solar cell array 20 in which a lattice-shaped contact prevention part 45 is provided on the surface of each solar cell panel 31. In Fig. 25, the float 35 is hidden under the solar cell panel 31 and the frame part 33. Explanations of parts common to the third embodiment will be omitted.

[0120] The contact prevention part 45 is in the form of a lattice made up of three bars each in the vertical and horizontal directions, and is arranged parallel to the surface of the solar cell panel 31. At the ends and intersections of each bar, legs perpendicular to the solar cell panel 31 are provided and fixed to the solar cell panel 31.

[0121] The contact prevention portion 45 is desirably made of a material that is highly light-transmitting and flexible, such as a transparent silicone resin, a transparent polyurethane resin, or a transparent acrylic rubber resin.

[0122] 26, the connecting portion 38 is annular and connects the edges of the two solar power generation units 30. The solar power generation units 30 are connected to each other via the connecting portion 38 so as to be rotatable relative to each other.

[0123] According to this modification, it is possible to provide a solar cell array 20 that can prevent damage to the solar cell panels 31 caused by, for example, flying objects. For example, by using connecting parts 38 with a large diameter, it is possible to provide a solar cell array 20 in which the solar power generation units 30 are loosely coupled to each other and which can easily float on the sea surface by following the shape of the waves.

[0124] [Variation 3-3] Fig. 27 is a perspective view of the solar cell array 20 of Modification 3-3. This modification relates to a solar cell array 20 having a substantially U-shaped contact prevention portion 45 along the edge of the solar cell panel 31. In Fig. 27, the float 35 is hidden under the solar cell panel 31 and the frame portion 33. Descriptions of parts common to the third embodiment will be omitted.

[0125] Each solar power generation unit 30 has a substantially U-shaped contact prevention portion 45 along each of its four sides. Both ends of the contact prevention portion 45 are fixed to the frame portion 33. In Fig. 27, a total of two contact prevention portions 45 provided on adjacent solar power generation units 30 are omitted and illustrated by a single line.

[0126] Fig. 28 is an explanatory diagram illustrating the effect of the contact prevention part 45 of the modified example 3-3. Fig. 28 illustrates a state in which the photovoltaic power generation units 30 are separated from each other due to rough waves or the like, and are buffeted by the waves.

[0127] 28, the solar power generation unit 30 shown in the center rides up on the solar power generation unit 30 shown on the left, and the solar power generation unit 30 shown on the right rides up on that. In other words, the float 35 hidden behind the solar cell panel 31 and the frame part 33 is in contact with the contact prevention part 45.

[0128] The presence of the contact prevention portion 45 prevents the float 35 from directly riding on the solar cell panel 31. Therefore, damage such as cracks is unlikely to occur in the solar cell panel 31. Since the contact prevention portion 45 is arranged like a fence around the solar cell panel 31, sunlight is unlikely to be blocked by the contact prevention portion 45. Therefore, even if a material with relatively low light transmittance is used for the contact prevention portion 45, it is possible to provide a solar cell array 20 with little decrease in power generation efficiency.

[0129] [Variation 3-4] Fig. 29 is a perspective view of the solar cell array 20 of Modification 3-4. This modification relates to a solar cell array 20 having a substantially hemispherical contact prevention portion 45 on the surface of the solar cell panel 31. In Fig. 29, the float 35 is hidden under the solar cell panel 31 and the frame portion 33. Descriptions of parts common to the third embodiment will be omitted.

[0130] Twelve roughly semicircular contact prevention portions 45 are arranged on the surface of each solar cell panel 31. The contact prevention portions 45 can be formed, for example, by dropping a liquid transparent resin onto the solar cell panel 31 and allowing it to harden.

[0131] 30 and 31 are explanatory diagrams illustrating the effect of the contact prevention part 45 of the modified example 3-4. Fig. 30 and Fig. 31 are schematic diagrams illustrating a state in which the photovoltaic power generation units 30 are separated from each other due to rough waves or the like, and are buffeted by the waves.

[0132] In Fig. 30, the float 35 of the solar power generation unit 30 shown on the right side runs up onto the solar power generation unit 30 shown on the left side. The presence of the contact prevention portion 45 prevents the float 35 from directly running up onto the solar cell panel 31. Therefore, the solar cell panel 31 is less likely to be damaged, such as cracked.

[0133] 31, one solar power generation unit 30 is turned upside down by a wave and rides up on top of the other solar power generation units 30. The presence of the contact prevention portion 45 prevents the solar cell panels 31 from coming into direct contact with each other. Damage such as scratches and cracks on the solar cell panels 31 caused by direct contact between hard solar cell panels 31 is unlikely to occur.

[0134] Furthermore, even if the solar cell panels 31 are damaged, it is possible to prevent the occurrence of a short circuit between the positive and negative electrodes caused by contact between damaged solar cell panels 31 and the occurrence of a fire associated with the short circuit.

[0135] [Variation 3-5] Fig. 32 is a perspective view of the solar cell array 20 of Modification 3-5. This modification relates to the solar cell array 20 having a contact prevention part 45 arranged parallel to the frame part 33. In Fig. 32, the float 35 is hidden under the solar cell panel 31 and the frame part 33. Descriptions of parts common to the first embodiment will be omitted.

[0136] The contact prevention section 45 includes support columns 451 and connection sections 452. The connection sections 452 are lattice-shaped and have approximately the same dimensions as the frame section 33 of the connected solar power generation unit 30. The support columns 451 are column-shaped and are arranged at positions on the periphery of the solar cell panel 31, close to the corners of the solar cell panel 31, in the frame section 33. The connection sections 452 connect the tips of the support columns 451 to each other, and are fixed to the solar cell panel 31 and the frame section 33 via the support columns 451.

[0137] According to this modification, it is possible to provide a solar cell array 20 in which the solar cell panels 31 are less likely to be damaged even if a large falling object falls.

[0138] [Variation 3-6] The solar cell array 20 may be configured by appropriately combining the solar power generation units 30 of a plurality of shapes described in the third embodiment and the respective modified examples.

[0139] The float 35 of each solar power generation unit 30 may be the float 35 described in the first embodiment and each of the modified examples of the first embodiment. The solar cell array 20 may include solar power generation units 30 having floats 35 of a plurality of shapes.

[0140] [Embodiment 4] This embodiment relates to a solar power generation system 10 that stops power generation when the solar cell panel 31 is damaged. Description of parts common to the first embodiment will be omitted.

[0141] Fig. 33 is an explanatory diagram illustrating the configuration of a photovoltaic power generation unit 30 according to embodiment 4. In Fig. 33, one solar cell panel 31 includes 72 solar cells 32 in total, 12 vertically and 6 horizontally.

[0142] The solar cells 32 are connected in the vertical direction in Fig. 33 and are connected in series by wiring members 51 that connect adjacent solar cells 32 alternately at the upper and lower ends of the solar panel 31. Each solar cell 32 functions as a diode, and is arranged so that when light is irradiated, a current flows from the right side to the left side in the wiring members 51 shown in Fig. 33 due to electromotive force.

[0143] Three bypass diodes 52 are connected to the wiring material 51 at the upper end of the solar cell panel 31. That is, each bypass diode 52 is connected in parallel to the 24 solar cell units 32 connected in series.

[0144] In the following description, 24 solar cell units 32 connected in parallel to one bypass diode 52 may be referred to as a cluster. In Fig. 33, one solar cell panel 31 includes three clusters. When a failure occurs in a solar cell unit 32 constituting a cluster and the electromotive force is no longer generated, the bypass diode 52 arranged in parallel with the cluster is automatically turned ON, and no current flows through the cluster.

[0145] 33 is an example. The number and arrangement of the solar cells 32 included in one solar panel 31 is appropriately determined based on the electromotive force of each solar cell 32 and the voltage that the solar panel 31 should output.

[0146] A brightness control panel 56 that crosses the three clusters is disposed on the surface of the solar cell panel 31. In FIG. 33, the brightness control panel 56 is disposed at the lower end of the solar cell panel 31, but the brightness control panel 56 may be disposed in the center of the solar cell panel 31.

[0147] The light-dark control panel 56 is a flat panel that can be switched between a light-transmitting state with a high light transmittance and a non-light-transmitting state with a low light transmittance. The light-dark control panel 56 is, for example, a liquid crystal panel. Power for operating the light-dark control panel 56 is supplied by, for example, the solar cell panel 31. The light transmittance of the light-dark control panel 56 is high when power is supplied, and is low when power is not supplied.

[0148] A short circuit detection sensor (not shown) is disposed on the solar cell panel 31. The light / dark control panel 56 and the short circuit detection sensor are connected in a hardware manner so that the light / dark control panel 56 is powered off when a short circuit occurs in the solar cell panel 31.

[0149] If a short circuit occurs in any of the solar cells 32, the light transmittance of the light / dark control panel 56 decreases, and the electromotive force of the solar cells 32 covered by the light / dark control panel 56 becomes almost zero. As in the case when a solar cell 32 is damaged, the bypass diode 52 automatically turns ON, and power generation in the entire solar panel 31 stops.

[0150] By stopping power generation for the entire solar cell panel 31 in which a failure has occurred, it is possible to prevent the outbreak of a fire caused by the damaged solar cell panel 31. It is also possible to prevent accidents such as electric shock during repairs.

[0151] The shape of the float 35 is arbitrary. For example, the shape of the float 35 may be any of the shapes of the float 35 described in the first embodiment and the modified example of the first embodiment. Adjacent solar cells 32 may be connected to each other by a conductive part formed integrally with the internal wiring of the solar cell 32.

[0152] Photovoltaic power generation unit 30 may have any of contact prevention parts 45 described in the third embodiment and the modified example of the third embodiment. For the portion covered by light / dark control panel 56, contact prevention part 45 may be provided on light / dark control panel 56. For the portion covered by light / dark control panel 56, contact prevention part 45 does not have to be provided.

[0153] [Embodiment 5] This embodiment relates to a solar power generation system 10 including a camera 61 disposed between a solar cell panel 31 and a float 35 in a direction to photograph the float 35 side. Descriptions of parts common to the first embodiment will be omitted.

[0154] Fig. 34 is an explanatory diagram illustrating the configuration of a solar power generation system 10 according to the fifth embodiment. A solar cell panel 31 is fixed to a dish-shaped frame portion 33. A camera 61 is fixed to the lower surface of the frame portion 33. The camera 61 preferably includes a so-called fisheye lens.

[0155] The float 35 is formed of, for example, a light-transmitting material, and is a container type with an opening at the top. The frame portion 33 and the solar panel 31 function as a lid that closes the opening watertightly. Power for each camera 61 is supplied from the solar panel 31. Power for the camera 61 may be supplied from a PCS (not shown) via a wireless power receiving antenna (not shown).

[0156] The images captured by the camera 61 are transmitted in real time via wireless communication to, for example, a control room that controls the solar power generation system 10. Note that, although all the solar power generation units 30 in Fig. 34 are equipped with a camera 61, solar power generation units 30 equipped with a camera 61 and solar power generation units 30 not equipped with a camera 61 may be mixed.

[0157] When the solar cell array 20 is operated for a long period of time, for example, attachments 65 such as shells and seaweed may adhere to the surface of the float 35. If the attachments 65 increase in number, the float 35 becomes more likely to sink, and therefore maintenance work is required to remove the attachments 65. The attachment of the attachments 65 varies depending on the seawater temperature, ocean currents, and the like.

[0158] In the control room, an operator can appropriately observe the images captured by the camera 61 to check the amount of deposits 65. If the operator determines that the amount of deposits 65 is large, he or she may operate the underwater drone 70 to observe the surface of the float 35. By using the underwater drone 70, parts that cannot be observed by the camera 61 can also be observed.

[0159] The operator makes a maintenance plan according to the state of the deposit 65. Note that the amount of deposit 65 may be automatically determined by image analysis, for example, and a notification may be given to the operator if there is a large amount of deposit 65.

[0160] A light for illumination may be arranged near the camera 61. For example, if the solar cell panel 31 is translucent, a light equipped with a solar cell and a storage battery can be used, and the light can be turned on during the day using power stored in the storage battery. The light may be connected to a storage battery that stores a portion of the power generated by the solar cell panel 31. Power for the light may be supplied from a PCS (not shown) via a wireless power receiving antenna (not shown). A solar power generation system 10 can be provided that allows the attachment 65 to be observed even during dark hours such as at night.

[0161] The float 35 is made of foamed resin with many closed bubbles dispersed therein, and the camera 61 may be embedded inside the float 35. During a time period when the outside light is bright, the camera 61 captures a dark image in the direction where the deposit 65 is attached and a bright image in the direction where the deposit 65 is not attached. Although it is difficult for the operator to capture a detailed image of the shape of the deposit 65, it is possible to determine whether or not a large amount of deposit 65 is attached.

[0162] The shape of the float 35 is arbitrary. For example, the shape of the float 35 may be any of the shapes of the float 35 described in the first embodiment, the modified example of the first embodiment, the second embodiment, and the modified example of the second embodiment.

[0163] The solar power generation unit 30 may have any of the contact prevention parts 45 described in the third embodiment and the modified example of the third embodiment.

[0164] According to this embodiment, it is possible to provide a photovoltaic power generation system 10 that is capable of appropriately determining the timing of maintenance for removing the attached matter 65.

[0165] The technical features (constitutive elements) described in each embodiment can be combined with each other, and by combining them, new technical features can be formed. The embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the scope and meaning equivalent to the claims.

[0166] Independent claims and dependent claims described in the claims may be combined with each other in any combination, regardless of the reference format. Furthermore, the claims may be written in a format in which a claim references two or more other claims (multiple claim format), but this is not limited to this format. The claims may also be written in a format in which a multiple claim references at least one other claim (multiple multiple claim format). [Explanation of symbols]

[0167] 10. Solar power generation system 15 Mooring rope 20 Solar array 30 Photovoltaic Units 31 Solar Panel 32 Solar Cell 33 Frame section 34 Fin 35 Float 351 Float opening 36 Reflector 371 Depression 372 Groove 38 Connecting part 39 Weight 45 Contact prevention part 451 Support column 452 Connection 51 Wiring material 52 Bypass Diode 56 Brightness Control Panel 61 Camera 65 Adhesion 70 Underwater Drone

Claims

1. Equipped with multiple solar power generation units, Each of the solar power generating units comprises: A solar panel; a float disposed on the underside of the solar panel, The float has a shape in which a cross-sectional area in a cross section parallel to the solar cell panel monotonically decreases with increasing distance from the solar cell panel. Solar array.

2. The float has a cone shape at the bottom. The solar cell array according to claim 1 .

3. The float has a spheroid shape at the bottom The solar cell array according to claim 1 .

4. The float is spherical, The solar panel is disposed inside the float. The solar cell array according to claim 1 .

5. The float has a plurality of dimple-like depressions on its surface. The solar cell array according to claim 1 .

6. The float is a container type having an opening at the top, A mechanism for filling and draining the float is provided. The solar cell array according to claim 1 .

7. The float is a container type having a float opening at the bottom. The solar cell array according to claim 1 .

8. A fin extends outward from the float and surrounds the float. The solar cell array according to claim 1 .

9. The float has translucency, A camera is provided between the solar panel and the float, and is oriented so as to photograph the float side. The solar cell array according to claim 1 .

10. The solar cell panel is bifacial, The float includes a reflector facing the solar panel. The solar cell array according to claim 1 .

11. the solar panel includes a plurality of series-connected clusters; The cluster includes a plurality of solar cells connected in series; a plurality of bypass diodes connected in parallel to each of the clusters; a light-dark control panel that covers a portion of each of the solar cells of each of the clusters and becomes opaque when a short circuit occurs in the solar panel; The solar cell array according to claim 1 .

12. The solar power generation units are arranged with gaps between them. The solar cell array according to claim 1 .

13. Each of the solar power generating units comprises: A contact prevention portion is provided to prevent contact between the solar cell panels. The solar cell array according to any one of claims 1 to 12.

14. The contact prevention portion is a columnar portion protruding from the surface of the solar panel. The solar cell array according to claim 13.

15. The contact prevention portion is a columnar portion protruding from the surface of the solar cell panel and from a frame portion surrounding the edge of the solar cell panel. The solar cell array according to claim 13.

16. The contact prevention portion is A support pillar protruding from a periphery of the solar panel; and a connection portion for connecting the tips of the support poles provided on the plurality of solar cell panels to each other. The solar cell array according to claim 13.

17. The contact prevention portion is A plurality of inverted U-shaped rods surround the periphery of the solar panel and protrude upward from the periphery of the solar panel. The solar cell array according to claim 13.

18. The contact prevention portion is a light-transmitting hemisphere disposed on the upper surface of the solar panel; The solar cell array according to claim 13.

19. A solar panel; a float disposed on the underside of the solar panel, The float has a shape in which a cross-sectional area in a cross section parallel to the solar cell panel monotonically decreases with increasing distance from the solar cell panel. Photovoltaic power generation unit.

20. A solar panel; a float disposed on the underside of the solar panel and having a plurality of dimple-shaped depressions on its surface; Photovoltaic power generation unit.

Images