Floating body-type solar power generation panel

Abstract

[Problem] To provide a floating body-type solar power generation panel for which the operation cost for power transmission is low and which is capable of transmitting power in consideration of power supply-and-demand balance without the provision of a large-scale power storage facility. [Solution] A floating body type solar power generation panel (1) is configured so as to comprise: a floating body (4) that floats on the sea and has a predetermined area; a solar cell module (2) that generates power by sunlight; and a power storage module (5) that stores and discharges power. The solar cell module (2) is provided on the upper surface of the floating body (4). The power storage module (5) is provided on the lower side of the solar cell module (2).

Description

Floating photovoltaic power panel

[0001] The present invention relates to a floating photovoltaic power panel that floats on the ocean to generate power, and relates to, but is not limited to, a floating photovoltaic power panel configured to float in a state where a plurality of panels are connected in a relatively wide sea area.

[0002] Floating photovoltaic power panels that float on the ocean and generate power from sunlight are well known, as disclosed in, for example, Patent Documents 1 and 2, and are generally constituted by a floating body and a solar cell module provided on the upper surface of the floating body. A plurality of floating photovoltaic power panels are arranged and floated on the ocean to efficiently generate power from sunlight. The generated power is transmitted to land via power transmission cables. Alternatively, hydrogen is generated from electric power on the ocean and stored, and then periodically transported to land for use as energy.

[0003] Re-Publication No. 2016-136891, Re-Publication No. 2011-048981

[0004] Floating photovoltaic power panels have relatively few installation restrictions, and can utilize ocean areas that are difficult to use for other purposes. A plurality of panels can be arranged on a large scale, and sunlight is not blocked by other structures, so a large amount of power can be efficiently generated, which is advantageous.

[0005] However, there are still problems to be solved. For example, when hydrogen is generated from generated power, stored, and periodically transported to land, the system can be used even in sea areas far from land, but has the problem of increased costs required for hydrogen transportation. This is because hydrogen transportation requires a dedicated recovery vessel, and labor costs for vessel operation are also required. Furthermore, a hydrogen storage facility is also required on the land side. Additionally, there is a disadvantage that energy loss occurs when generating hydrogen from electric power and when obtaining electric power from hydrogen.

[0006] On the other hand, when electricity generated by floating solar panels is transmitted to land via transmission cables, energy loss is minimal, and there are no costs associated with transporting / storing hydrogen, resulting in low operating costs. However, electricity transmitted from floating solar power is only available during the day, and there is no electricity at night. Furthermore, even during the day, the amount of electricity transmitted varies depending on the amount of sunlight. In this case, in order to stably supply electricity to consumers while considering the balance of electricity supply and demand, it becomes necessary to frequently operate and shut down other power generation facilities such as thermal power plants. To solve these problems, it is possible to install energy storage facilities on the land side that receives electricity from floating solar power panels. In this case, any surplus electricity transmitted from floating solar power can be stored in the energy storage facilities and supplied from the storage facilities during times when electricity is insufficient, such as at night. However, if energy storage facilities are installed on the land side in this way, it is necessary to store a large amount of surplus electricity from floating solar power panels, so the electrical capacity needs to be large. However, providing a large-capacity energy storage system would require large-scale energy storage equipment, making implementation difficult.

[0007] Other challenges also exist. As mentioned above, floating solar panels are excellent for marine use because they can generate electricity in the open sea, where the value of other uses such as offshore areas is relatively low. However, there appears to be room for further promotion of their use. For example, there is the challenge that the use of the water beneath floating solar panels is not sufficient.

[0008] The present invention aims to solve the above-mentioned problems. Specifically, it aims to provide a floating solar power generation panel that has low operating costs for power transmission and can transmit power while considering the balance of power supply and demand without preparing large-scale energy storage facilities. Furthermore, another objective is to provide a floating solar power generation panel that can be fully utilized even in the water beneath it.

[0009] The invention described in claim 1 is configured as a floating solar power generation panel comprising a floating body of a predetermined area that floats on the ocean, a solar cell module that generates electricity from sunlight, and a storage module that stores and discharges energy. The solar cell module is provided on the upper surface of the floating body, and the storage module is provided below the solar cell module. The invention described in claim 2 has a structure in which multiple sets of supercapacitor units are stacked for the storage module. The supercapacitor unit consists of a pair of conductive concrete plates arranged at a predetermined interval, a separator made of an insulating material provided between the pair of conductive concrete plates, and an electrolyte filled between the pair of conductive concrete plates. It is configured to store energy when a positive or negative voltage is applied to the pair of conductive concrete plates, and to discharge when the voltage is removed. The conductive concrete contains carbon nanoparticles or carbon black in a predetermined proportion, thereby making it conductive concrete. The invention described in claim 3 is configured to house the conductive module in a recess formed near the center of the floating body. The invention described in claim 4 is configured to provide a seaweed attachment structure on the underside of the floating body for seaweed to attach to.

[0010] According to the invention of claim 1, the floating solar power generation panel comprises a floating body of a predetermined area that floats on the sea, a solar cell module provided on the upper surface of the floating body that generates electricity from sunlight, and a storage module provided on the lower side of the solar cell module on the floating body that stores and discharges electricity. In this case, when transmitting electricity from the floating solar power generation panel to land, it is possible to transmit electricity not only during the day but also at night, and it becomes possible to transmit electricity in accordance with the balance of power supply and demand. In order to implement such a stable supply of electricity, it is not always necessary to provide a storage facility on land. Furthermore, since the solar cell module and the storage module are in close proximity, the generated electricity can be stored with virtually no loss, resulting in high efficiency. Electricity generation by solar cell modules is easily affected by weather conditions and the amount of electricity generated tends to fluctuate, but by placing the storage module nearby and performing fine-tuned storage and discharge, the effects can be mitigated. Moreover, since a storage module is provided for each floating solar power generation panel, the electricity is stored in a distributed manner. By distributing the storage, the burden on individual storage modules is reduced compared to centrally storing a large amount of electricity all at once, and power loss is reduced. Furthermore, since it is no longer necessary to transmit a large amount of power all at once, the burden on the power transmission equipment is reduced, and the losses required for power transmission can be suppressed. Moreover, since the energy storage module is located below the solar cell module, the energy storage module does not take up space and does not obstruct the light reception of the solar cell module. In other words, it does not affect the power generation efficiency. According to the invention described in claim 2, the energy storage module is formed from a structure in which multiple sets of one set of supercapacitor units are stacked. The supercapacitor unit consists of a pair of conductive concrete plates arranged at a predetermined interval, a separator made of an insulating material provided between the pair of conductive concrete plates, and an electrolyte filled between the pair of conductive concrete plates. When a positive or negative voltage is applied to the pair of conductive concrete plates, energy is stored, and when the application is removed, it is discharged. The conductive concrete contains carbon nanoparticles or carbon black in a predetermined proportion, thereby making it conductive concrete.Conductive concrete is not only inexpensive but also durable and does not deteriorate over long periods, so the energy storage module can be used stably for a long time. This is superior to using lithium batteries, which are expensive and deteriorate with long-term use. Furthermore, even if this energy storage module breaks down, the conductive concrete slab is non-toxic and will not pollute the ocean. If a low-toxicity electrolyte is selected, even if the electrolyte leaks, it will not affect the ocean. In other words, the energy storage module described in claim 2 is not only stably usable for a long period, but is also superior because it does not pollute the ocean even if it is damaged. According to the invention described in claim 4, a seaweed attachment structure is provided on the underside of the floating body for seaweed to attach to. This allows useful seaweed, which can be used for food or as a material for biofuels, to grow on the underside of the floating solar power generation panel. The water under the floating solar power generation panel can also be fully utilized.

[0011] This is a perspective view showing the components of a floating solar power generation panel according to this embodiment. This is a perspective view of a floating solar power generation panel according to this embodiment. This is a perspective view of a floating solar power generation panel according to a second embodiment of this product. This is a schematic diagram showing the state of energy storage in a supercapacitor unit constituting an energy storage module according to this embodiment. This is a schematic diagram showing the state of discharge in a supercapacitor unit constituting an energy storage module according to this embodiment. This is a perspective view of an offshore power generation block consisting of a plurality of floating solar power generation panels according to this embodiment floating on the ocean.

[0012] <Floating Solar Power Generation Panel> The embodiment of this invention will be described below. The floating solar power generation panel 1 according to this embodiment is shown in Figure 1 for its constituent members, and in Figure 2 for the assembled state from the constituent members. As shown in Figure 1, the floating solar power generation panel 1 consists of a solar cell module 2, a floating body 4, an energy storage module 5 placed in the floating body 4, and a frame 7 that houses these.

[0013] <Solar Cell Module> Solar cell module 2 can be of any type as long as it receives sunlight and generates electricity, and can be made from conventional crystalline or amorphous silicon solar cells or compound semiconductor solar cells. However, it is preferable to use perovskite solar cells in the future. Perovskite solar cells have power generation efficiency comparable to silicon solar cells, yet can be made thin and lightweight, and can be manufactured from inexpensive materials. In terms of durability, long lifespans are being achieved through recent research and development.

[0014] <Floating Body> In this embodiment, the floating body 4 is formed from rigid urethane foam. It may also be formed from expanded polystyrene, or from another resin to form a hollow structure, as long as its specific gravity is sufficiently low to provide buoyancy. The floating body 4 is formed so that the shape of its upper surface is substantially the same as the shape of the solar power generation module 2, and the solar power generation module 2 is attached to the upper surface of the floating body 4. A predetermined recess 9 is formed in the center of the floating body 4. The energy storage module 5, which will be described later, is placed in this recess 9.

[0015] <Frame> The frame 7 is formed in the shape of a flat box with an open top surface, and in this embodiment, it houses and protects the floating body 4 and the solar cell module 2 provided on the top surface of the floating body 4. The frame 7 may be made of a metal such as stainless steel. However, in this embodiment, it is made of polycarbonate, which is inexpensive and highly durable. In this embodiment, the floating body 4 and the frame 7 are made of different materials, but they may be formed integrally. Even when formed integrally, it is sufficient that it has sufficient buoyancy and protects the solar cell module 2 and the energy storage module 5 which will be described next.

[0016] <Energy Storage Module> The energy storage module 5 stores all or part of the electricity generated by the solar cell module 2, and discharges the stored electricity to the outside when needed. The energy storage module 5 can be made up of a battery such as a lithium battery, or it can be made up of a capacitor. In this embodiment, the energy storage module 5 is a supercapacitor, or electric double-layer capacitor, made from a conductive concrete plate or the like. More specifically, the energy storage module 5 according to this embodiment is formed from a structure in which multiple sets of supercapacitor units are stacked.

[0017] Figure 3A shows a schematic side cross-sectional view of a set of supercapacitor units 11. The supercapacitor unit 11 consists of a pair of conductive concrete plates 13 and 14 made of conductive concrete and arranged at a predetermined distance apart, a separator 16 placed between these conductive concrete plates 13 and 14, and an electrolyte 17 filled between the pair of conductive concrete plates 13 and 14.

[0018] The conductive concrete material for conductive concretes 13 and 14 is described in detail in U.S. Patent Application Publication No. 2021 / 0276921, and consists of concrete containing carbon nanoparticles or carbon black, i.e., fine carbon particles, in a predetermined proportion. During the reaction between cement and water, tiny pores are generated within the hardened concrete, forming a continuous network. Carbon particles are distributed around these network-shaped pores. In other words, carbon particles are distributed in a network within the concrete. Therefore, the concrete becomes conductive. The pair of conductive concretes 13 and 14 are formed to have a predetermined area and to be thin.

[0019] The separator 16 can be made of any material as long as it allows the electrolyte 17 to pass through and acts as an insulator. For example, it may be made of a polyolefin resin with many small-diameter holes, or it may be made of a cellulose nonwoven fabric. In the supercapacitor unit 11, the pair of conductive concrete plates 13 and 14 are insulated by the separator 16.

[0020] The electrolyte 17 can be any aqueous solution in which the electrolyte is dissolved in an ionic state, but in case of leakage, it should be non-toxic or have low toxicity. For example, an aqueous solution of potassium chloride or an aqueous solution of calcium nitrate is preferred as the electrolyte 17.

[0021] The operation of the supercapacitor unit 11 will now be explained. As shown in Figure 3A, a DC voltage is applied to the pair of conductive concretes 13 and 14 of the supercapacitor unit 11. Negative ions in the electrolyte 17 gather near the conductive concrete 13 to which a positive voltage is applied, and positive ions gather near the conductive concrete 14 to which a negative voltage is applied. When a DC current is passed for a predetermined time, positive and negative charges are sufficiently accumulated in the conductive concretes 13 and 14, respectively. That is, they are charged. The application of the DC voltage is then removed. In other words, the circuit is opened. Next, as shown in Figure 3B, the pair of conductive concretes 13 and 14 are connected via a predetermined load. In other words, the circuit is closed. Then, current flows from the conductive concrete 13, which has accumulated positive charges, to the conductive concrete 14, which has accumulated negative charges. In other words, it can discharge and supply power to the outside.

[0022] The energy storage module 5 according to this embodiment is formed in a structure in which multiple sets of such supercapacitor units 11 are stacked. Therefore, it is possible to store sufficient power.

[0023] <Offshore Power Generation Block> Figure 4 shows an offshore power generation block 100 according to this embodiment, which is composed of multiple floating solar power generation panels 1, 1, ... according to this embodiment. The offshore power generation block 100 is composed of, for example, about 1,000 floating solar power generation panels 1, 1, ..., which are floated on the sea at predetermined intervals and connected to each other. Each solar cell module of the floating solar power generation panels 1, 1, ... is connected in parallel. Similarly, each storage joule is connected in parallel. These are then connected to the control device 101.

[0024] A power transmission line 102 is connected to the control device 101, and although not shown in Figure 4, the power transmission line 102 is connected to a land-based power receiving facility. Therefore, during the day, the electricity generated by the floating solar power generation panels 1, 1, ... is collected by the control device 101 and transmitted from the power transmission line 102. At this time, the electricity may be transmitted as DC, or it may be converted to AC current in the control device 101 before transmission. It may also be transmitted at high voltage as needed. During the day, the control device 101 stores a predetermined percentage of the electricity generated by the solar cell modules in the energy storage modules. Specifically, it boosts the voltage of the electricity generated by the solar cell modules and supplies it to the energy storage modules. After supplying for a predetermined time, it can be stored. At night, etc., the control device 101 transmits the electricity stored in the energy storage modules from the power transmission line 102.

[0025] Power transmission does not necessarily have to be carried out in units of 100 offshore power generation blocks. For example, a farm can be formed by arranging, for example, 30 offshore power generation blocks 100 according to this embodiment. One power transmission device can be installed for the farm. Power can be collected from each offshore power generation block 100 and transmitted to land from a single power transmission device.

[0026] <Second Embodiment> A floating solar power generation panel 1A according to the second embodiment of this invention is shown in Figure 2B. The floating solar power generation panel 1A according to the second embodiment is characterized in that a seaweed attachment structure 20 is provided on the lower side of the frame 7. The seaweed attachment structure 20 can be any structure as long as it allows seaweed to attach and grow. In this embodiment, the seaweed attachment structure 20 is composed of a plurality of wire ropes 21, 21, ... Hemp rope or the like may be wrapped around the wire ropes 21, 21, ... as appropriate to facilitate the attachment of seaweed spores. The hemp rope or the like will dissolve and disappear after a long period of time, but once the seaweed attaches and grows, the seaweed will firmly attach to the wire ropes 21, 21, ... The seaweed that grows in the floating solar power generation panel 1A according to the second embodiment can be collected as appropriate and used for food. Alternatively, it can be used as a material for biofuel.

[0027] 1. Floating solar power generation panel 2. Solar cell module 4. Floating structure 5. Energy storage module 7. Frame 9. Recess 11. Supercapacitor unit 13. Conductive concrete slab 14. Conductive concrete slab 16. Separator 17. Electrolyte 20. Seaweed attachment structure 21. Wire rope 100. Offshore power generation block 101. Control device 102. Transmission line

Claims

1. A floating solar power generation panel comprising: a floating body of a predetermined area that can be floated on the ocean; a solar cell module provided on the upper surface of the floating body that generates electricity from sunlight; and a storage module provided on the floating body below the solar cell module that stores and discharges energy.

2. The floating solar power generation panel according to claim 1, wherein the energy storage module has a structure in which a plurality of sets of supercapacitor units are stacked, and the supercapacitor unit is composed of a pair of conductive concrete plates arranged at a predetermined interval, a separator made of an insulating material provided between the pair of conductive concrete plates, and an electrolyte filled between the pair of conductive concrete plates, and when a positive or negative voltage is applied to the pair of conductive concrete plates, energy is stored and when the voltage is removed, it is discharged, and the conductive concrete is concrete that contains carbon nanoparticles or carbon black in a predetermined proportion and is thereby conductive.

3. The floating solar power generation panel according to claim 1 or 2, wherein the conductive module is housed in a recess formed near the center of the floating body.

4. The floating solar power generation panel according to claim 1 or 2, wherein a seaweed attachment structure for seaweed to attach is provided on the lower side of the floating body.

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