Photovoltaic tank and power generation system thereof

Abstract

The invention provides a photovoltaic tank and a power generation system thereof. A photovoltaic battery assembly and an air compression tank form the photovoltaic tank which integrates power generation and energy storage, is arranged at intervals and shares the same space and land; when sunlight is sufficient, power is supplied to the air compressor, compressed air is generated, and energy is stored in the photovoltaic tank; when sunlight is insufficient, compressed air is released to the air engine to drive the generator to generate electricity. The air energy storage cost per kilowatt hour in the whole life cycle is reduced, the air energy storage efficiency is improved, and a new low-cost technical path is developed for replacing thermal power by photovoltaic power generation.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic power generation and air energy storage technology, and specifically relates to a photovoltaic tank and a power generation system thereof. Background Art

[0002] As a clean energy technology, the cost of photovoltaic power generation has dropped significantly in recent years. It is reported that the cost of some photovoltaic power stations has dropped to RMB 0.10 per kilowatt-hour over their entire life cycle. Although the cost of photovoltaic power generation is already very low, the cost of energy storage remains high, which has become the main obstacle to large-scale replacement of traditional thermal power.

[0003] The development of energy storage technology has undergone decades of evolution, and currently has formed a variety of forms including battery energy storage, pumped energy storage, compressed air energy storage, flywheel energy storage, hydrogen energy storage, etc. Each energy storage technology has its own unique characteristics in terms of energy storage, release speed, capacity and application scenarios. Battery energy storage has a high energy conversion efficiency (usually between 85% and 95%), flexible application and rapid response, and is suitable for short-term and high-frequency energy storage needs. At present, the most mature electrochemical energy storage technology is lithium iron phosphate battery technology, but its cost is still high. The latest report shows that the full life cycle cost is RMB 0.62 / kWh, and it faces uncertainties in the supply chain of raw materials (such as lithium, cobalt, and nickel) and environmental impacts. Moreover, the cost of battery energy storage is high, the life span is limited, and the environmental protection treatment of waste batteries has not been fully resolved. Pumped energy storage technology is mature, has high economic efficiency, can provide large-scale, long-term energy storage solutions, and is suitable for peak and frequency regulation of power systems. The latest report shows that it is RMB 0.21 / kWh, but its initial construction investment is large, the site selection requirements are high, and its applicability is limited. However, its energy conversion efficiency is slightly low (between 70% and 85%), and it has high requirements for geographical conditions and huge initial investment. Compressed air energy storage has the potential for large-scale long-term energy storage, but its energy conversion efficiency is relatively low (between 40% and 70%), the system is complex and depends on geological conditions. Although advanced technology has improved efficiency, overall economic efficiency still needs to be improved. Flywheel energy storage is known for its high power density, long life and fast response, and is suitable for short-term energy storage and high-frequency regulation. However, its low energy density and high manufacturing cost limit its application in large-scale energy storage. Hydrogen production by water electrolysis and hydrogen energy storage can achieve ultra-long-term energy storage, which is particularly suitable for combination with renewable energy. However, its energy conversion efficiency is low (less than 50%), the cost of hydrogen production is high, and hydrogen storage and transportation face challenges.

[0004] Existing compressed air energy storage projects usually use abandoned mines as gas storage space, and use these underground resources to store compressed air. This method not only reduces the demand for new gas storage space, but also reduces engineering costs and environmental impacts to a certain extent, making compressed air energy storage systems more economical and sustainable. Although compressed air energy storage technology has many advantages such as large-scale and long-term energy storage potential, it faces technical difficulties such as high energy consumption in the compression process, large investment in high-pressure storage tank equipment, and high maintenance costs in actual applications, and it is dependent on geological conditions. Due to the intermittent and unpredictable nature of solar energy, photovoltaic power generation needs to be equipped with efficient and low-cost energy storage systems to ensure the continuity and stability of power supply. Therefore, reducing energy storage costs and reducing investment in energy storage systems have become the only technical way out for photovoltaic power generation to replace thermal power in the energy structure.

[0005] The survey shows that within the pressure range of 1 to 6 MPa, the cost of gas storage tanks will be affected by many factors, such as storage capacity, materials, manufacturing process, installation location (above ground or underground) and specific safety design requirements. In general, the cost of low-pressure (1-6 MPa) gas storage tanks is as follows. Unit cost of above-ground metal gas storage tanks: Conventional 1-6 MPa above-ground metal gas storage tanks (such as carbon steel and stainless steel materials) have an international market cost of about US$200 to US$500 per cubic meter. If the capacity is 1,000 cubic meters and the pressure is 6 MPa, the cost is between US$200,000 and US$500,000. Unit cost of underground gas storage caves (such as salt caves and mines): The cost of using natural or modified underground gas storage facilities (such as salt caves) is lower, and the international market is generally between US$10 and US$30 per cubic meter. If the capacity is 100,000 cubic meters and the pressure is 3-6 MPa, the total cost is about US$1 million to US$3 million, but it depends on the geological conditions and the difficulty of mining. Unit cost of reinforced concrete gas tanks: Some low-pressure large-capacity energy storage systems use reinforced concrete tanks. The cost of this design is about $50 to $150 per cubic meter. For example, the cost of a 5,000 cubic meter gas tank in the international market is about $250,000 to $750,000. In general, the cost of low-pressure gas tanks is much lower than that of high-pressure gas tanks, especially the use of reinforced concrete structures can significantly reduce the unit capacity cost. Summary of the invention

[0006] One of the purposes of this application is to provide a photovoltaic tank power generation system to reduce the energy storage cost throughout the life cycle and open up a new low-cost technical path for photovoltaic power generation to replace thermal power.

[0007] The second purpose of this application is to provide a photovoltaic tank to reduce the energy storage cost throughout the life cycle, and to open up a new low-cost technical path for photovoltaic power generation to replace thermal power.

[0008] In order to achieve the above-mentioned purpose of the invention, the present application provides a photovoltaic tank power generation system as follows.

[0009] The present application provides a photovoltaic tank power generation system, including a photovoltaic cell assembly and a compressed air storage tank, namely, an air pressure tank, characterized in that: ① The photovoltaic cell assembly is installed on the air compression tank (below it) to cover the air compression tank (to prevent exposure to the sun and rain); the photovoltaic cell assembly and the air compression tank constitute a photovoltaic tank in which photovoltaic power generation and air energy storage share the same space and geographical location, so as to reduce land occupation and improve resource utilization; ② Many photovoltaic tanks are placed at a safe distance from each other on the same piece of land to form a photovoltaic tank array; ③The photovoltaic tank is connected to the air compressor via the air pipe; ④ When there is sufficient sunshine or during off-peak hours, (photovoltaic cell modules or the power grid) supply power to the air compressor to generate compressed air, converting electrical energy into the pressure potential energy of the air; the compressed air is sent to the photovoltaic tank through the air pipe, and the pressure potential energy of the air is stored in the photovoltaic tank; ⑤ When there is insufficient sunlight (including at night and on rainy days), the photovoltaic tank releases compressed air to the air engine (such as turbines, piston engines, rotary engines, expanders, hydraulic systems and other air engines), drives the generator to generate electricity, and converts pressure potential energy into electrical energy to supply the power grid or electrical equipment.

[0010] Preferably, the photovoltaic tank power generation system is characterized in that the photovoltaic tank is a medium-low pressure gas storage tank with a pressure range of 0.1 to 6 MPa. In this way, the energy consumption of the compression and release process can be reduced, the investment in tank equipment can be reduced, and the operation and maintenance costs can be reduced; for example, a low-cost reinforced concrete gas storage tank can be used.

[0011] Preferably, the photovoltaic tank power generation system is characterized in that the air compression tank is used to support (fix) the photovoltaic cell assembly (instead of the photovoltaic bracket of the existing ground power station), and the photovoltaic cell assembly and the air compression tank constitute a photovoltaic tank that integrates photovoltaic power generation and air energy storage.

[0012] Preferably, the photovoltaic tank power generation system is characterized in that: the photovoltaic tank (the air pressure tank in it) includes a rigid outer shell (i.e., an outer wall, a protective wall, etc.) and a flexible inner tube (i.e., an air bag, an air bag, etc.); compressed air is stored in the flexible inner tube. It is best to have a pressure relief vent (commonly known as a ventilation vent) connected to the outside world on the rigid outer shell. During the process of sending compressed air into the air pressure tank, the flexible inner tube expands and stores compressed air, and the gas (e.g., air) between the flexible inner tube and the rigid outer shell is squeezed out through the pressure relief vent to maintain the balance between the air pressure inside the tire and the atmospheric pressure; during the process of sending compressed air out of the air pressure tank, the flexible inner tube contracts, and the space between the flexible inner tube and the rigid outer shell inhales gas from the pressure relief vent to maintain the balance between the air pressure inside the tire and the atmospheric pressure.

[0013] Preferably, the photovoltaic tank power generation system is characterized in that: the photovoltaic tank is a reinforced concrete tank; preferably, the photovoltaic tank is fully buried or half buried in the ground; the height of the photovoltaic tank is preferably 0.322 meters to 4.15 meters. Studies have shown that if the electricity generated by the photovoltaic cell assembly per unit area per day is used to produce 0.1 to 6MPa compressed air, only a storage space of 0.322 meters to 4.15 meters high is required below the photovoltaic cell assembly. If the tank is shorter than 0.322 meters, even if 6MPa compressed air is stored, the space is not enough for one day; if the tank is higher than 4.15 meters, even if 1MPa compressed air is stored, the space is enough for one day, and it is not necessary to be higher. In short, the space of 0.322 meters to 4.15 meters below the photovoltaic cell assembly (using the technical solution of this application) is sufficient to store the electricity generated by the photovoltaic cell assembly on that day.

[0014] Preferably, the photovoltaic tank power generation system is characterized in that the horizontal projection area of ​​a single air compression tank is ≤ the horizontal projection area of ​​all photovoltaic cell assemblies covered on the single air compression tank.

[0015] Also preferably, the photovoltaic tank power generation system is characterized in that: a plurality of photovoltaic tanks are connected in series or / and in parallel to an air compressor and an air engine via an air pipe; an electric valve is connected between the photovoltaic tank and the air pipe, and the electric valve is used to control the release / storage of compressed air.

[0016] In order to achieve the above-mentioned purpose of the invention, the present application provides a photovoltaic tank as follows.

[0017] A photovoltaic tank, including a photovoltaic cell assembly and a compressed air storage tank - an air compression tank, characterized in that: the photovoltaic cell assembly is installed on the air compression tank (below it), the air compression tank is used to support (fix) the photovoltaic cell assembly (instead of the photovoltaic bracket of the current ground power station), and the photovoltaic cell assembly is used to cover the air compression tank; the photovoltaic cell assembly and the air compression tank constitute a photovoltaic storage device that shares the same space and geographical location and integrates photovoltaic power generation and air energy storage, so as to reduce land occupation and improve resource utilization.

[0018] Preferably, the photovoltaic tank is characterized in that: the air compression tank is a medium-low pressure gas storage tank with a pressure range of 1 to 6 MPa; a plurality of air compression tanks are spaced a certain safe distance from each other, dispersedly placed in the same piece of land, and arranged into a photovoltaic tank array; the air compression tank is connected to the air compressor via an air pipe.

[0019] Preferably, the photovoltaic tank is characterized in that: the air compression tank includes a rigid outer shell (i.e., an outer wall, a protective wall, etc.) and a flexible inner tube (i.e., an air bag, an air bag, etc.); compressed air is stored in the flexible inner tube. It is preferable that a pressure relief vent (commonly known as a ventilation vent) connected to the outside is provided on the rigid outer shell. When compressed air is fed into the air compression tank, the flexible inner tube expands and stores compressed air. The gas (e.g., air) between the flexible inner tube and the rigid outer shell is squeezed out through the pressure relief vent to maintain the balance between the air pressure inside the tube and the atmospheric pressure. When compressed air is fed out of the air compression tank, the flexible inner tube contracts, and the space between the flexible inner tube and the rigid outer shell inhales gas from the pressure relief vent to maintain the balance between the air pressure inside the tube and the atmospheric pressure.

[0020] Preferably, the photovoltaic tank is characterized in that: the air compression tank is a reinforced concrete tank; preferably, the air compression tank is fully buried or half buried in the ground; the height of the air compression tank is preferably 0.322 meters to 4.15 meters. Studies have shown that if the electricity generated by the photovoltaic cell assembly per unit area per day is used to produce 0.1 to 6MPa compressed air, only 0.322 meters to 4.15 meters of storage space is required below the photovoltaic cell assembly. If the tank is shorter than 0.322 meters, even if 6MPa compressed air is stored, the space is not enough for one day; if the tank is higher than 4.15 meters, even if 1MPa compressed air is stored, the space is enough for one day, and it is not necessary to be higher.

[0021] Preferably, the photovoltaic tank is characterized in that the horizontal projection area of ​​a single air compression tank is ≤ the horizontal projection area of ​​all photovoltaic cell assemblies covered on the single air compression tank.

[0022] Also preferably, the photovoltaic tank is characterized in that: a plurality of air compressor tanks are connected in series or / and in parallel to the air compressor via an air delivery pipe; an electric valve is connected between the air compressor tank and the air delivery pipe, and the electric valve is used to control the release / deposit of compressed air. In short, the air compressor tank is connected to an electric valve, and the electric valve is used to control the release / deposit of compressed air.

[0023] Compared with the prior art, the present application has the following beneficial technical effects.

[0024] First, the air compressor tank combines the functions of the existing ground power station photovoltaic bracket. Photovoltaic panels and other photovoltaic cell components also serve as a canopy to protect against wind and rain and prevent exposure to the sun, achieving two uses in one and complementary functions, saving bracket materials and piling and installation costs, and reducing the overall cost of photovoltaic power generation and compressed air energy storage.

[0025] Second, sharing of land resources. The land and space under and near existing photovoltaic panels and other photovoltaic cell modules are originally idle land and space resources. This application will use them to store empty compressed air tanks, turning waste into treasure without paying additional land rent or occupying additional land resources.

[0026] Third, it is safe and has no hidden dangers. The photovoltaic tank, like the current centralized photovoltaic cell array, can be placed in the wilderness, desert, and Gobi, far away from human habitation. Even if an accidental explosion occurs, it will not endanger people. Moreover, the photovoltaic tanks are separated by a certain safe distance from each other. Even if an air compressor tank leaks and explodes, it will not damage the adjacent air compressor tanks.

[0027] Fourth, the cost of medium and low pressure gas storage tanks is much lower than that of high pressure gas storage tanks, especially the use of reinforced concrete structure, which can significantly reduce the unit capacity cost. According to estimates, the cost of energy storage per kilowatt-hour over the entire life cycle can be reduced to 0.31 yuan / kilowatt-hour, which is close to the cost level of pumped storage and 50% of the cost of electrochemical energy storage (0.62 yuan / kilowatt-hour).

[0028] Fifth, the energy conversion efficiency is greatly improved. The current high-pressure air energy storage technology consumes 10-15% of electrical energy during the air compression and release process, while this application is low-pressure energy storage with a small compression ratio, and the energy conversion efficiency can be increased by 10-15%. This efficiency improvement greatly reduces the energy storage cost per kilowatt-hour throughout the life cycle, and the economic value is very considerable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the appearance structure of a photovoltaic tank in the present application (Example 1).

[0030] Figure 2 This is a schematic structural diagram of a photovoltaic tank power generation system of the present application (Example 1).

[0031] Figure 3 This is a schematic diagram of the appearance structure of another photovoltaic tank in the present application (Example 2).

[0032] Figure 4 for Figure 3 A schematic diagram of the cross-sectional structure of a photovoltaic tank.

[0033] Figure 5 To be placed Figure 3 Schematic diagram of the appearance structure of the flexible inner tube in the photovoltaic tank shown.

[0034] Figure 6 This is a schematic diagram of the cross-sectional structure of a semi-buried photovoltaic tank.

[0035] Figure 7 This is a schematic diagram of the appearance structure of an upright cylindrical air compression tank in the present application (Example 3).

[0036] Figure 8 This is a schematic diagram of the appearance structure of an upright cylindrical photovoltaic tank in the present application (Example 3).

[0037] Fig. 9 for Figure 8Schematic diagram of photovoltaic tanks dispersedly installed on the same land at a certain safe distance.

[0038] Fig.10 This is a schematic diagram of the appearance structure of a reinforced concrete photovoltaic tank in the present application (Example 4).

[0039] Fig.11 for Fig.10 Schematic diagram of the cross-sectional structure of a reinforced concrete photovoltaic tank.

[0040] Fig.12 Schematic diagram of the current centralized photovoltaic cell array installed in the desert Gobi far away from human habitation.

[0041] Fig.13 This is a schematic structural diagram of a photovoltaic tank power generation system of the present application (Example 5).

[0042] Explanation of the accompanying numbers: 1-photovoltaic cell assembly, 2-air compression tank, 3-gas pipeline, 4-air compressor, 5-turbine generator, 6-pressure relief vent, 7-compressed air, 8-reinforced concrete, 9-earth, 10-photovoltaic tank, 11-photovoltaic wire, 12-grid, 13-electric valve, 14-flexible inner tube, 15-underground gas storage space, 16-reinforced concrete box. DETAILED DESCRIPTION

[0043] In order to make the technical means, creative features, objectives and effects achieved by this application easy to understand, this application is further explained below in conjunction with specific implementation methods.

[0044] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "inner", etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present application.

[0045] It should be noted that, unless otherwise expressly specified and limited, the terms "installation", "placement", etc. should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] Embodiment 1.

[0047] like Figure 1 , Figure 2As shown, a photovoltaic tank power generation system includes photovoltaic cell components such as photovoltaic panels 1, air compressor 4 units, and turbine generator 5 units; the photovoltaic panel 1 is installed on the air compressor 2 (below it) to protect the air compressor 2 from wind and rain, and the air compressor 2 is used to support (fix) the photovoltaic panel 1 (instead of the photovoltaic bracket of the current ground power station), and the photovoltaic panel 1 and the air compressor 2 constitute a photovoltaic tank 10 that complements each other, integrates into one, and shares (shares) the same piece of land 9. Many photovoltaic tanks 10 (units) are separated by a certain safe distance (for example, 1-5 meters) and dispersedly placed on the land 9, and arranged into an array of photovoltaic tanks 10. The air compressor 2 is connected to the air compressor 4 unit via the gas pipeline 3 and its electric valve 13. In this way, when there is sufficient sunshine or during the off-peak period, the photovoltaic panel 3 (or the power grid) can supply power to the air compressor 4 unit to generate compressed air 7, and convert the electrical energy into the pressure potential energy of the air and store it in the photovoltaic tank 10. When there is insufficient sunlight (including at night and on rainy days), the photovoltaic tank 10 can release compressed air 7 and drive the turbine generator 5 to generate electricity, thereby converting the pressure potential energy into electrical energy to supply the power grid 12 or electrical equipment.

[0048] Preferably, the photovoltaic tank 10 is a low-pressure gas storage tank with a pressure range of 1 to 6 MPa. In this way, the energy consumption of the compression and release process can be reduced, the investment in high-pressure storage tank equipment can be reduced, and the operation and maintenance costs can be reduced.

[0049] Preferably, the height of the photovoltaic tank 10 is preferably 0.322 meters to 4.15 meters. Studies have shown that if the electricity generated by photovoltaic panels 1 and other photovoltaic cell components per unit area per day is used to produce 1 to 6 MPa compressed air 7, only 0.322 meters to 4.15 meters of storage space below the photovoltaic panels 1 and other photovoltaic cell components is required. If the tank is shorter than 0.322 meters, even if 6 MPa of compressed air 7 is stored, the space is not enough for one day; if the tank is higher than 4.15 meters, even if 1 MPa of compressed air 7 is stored, the space is enough for one day, and it is unnecessary to make it higher.

[0050] Preferably, the horizontal projection area of ​​a single air compression tank 2 is ≤ the horizontal projection area of ​​all photovoltaic cell assemblies covered on the single air compression tank 2 .

[0051] It is also preferred that a plurality of photovoltaic tanks 10 are connected in series or / and in parallel to the air compressor 4 via the gas pipe 3 ; an electric valve 13 is connected between the photovoltaic tank 10 and the gas pipe 3 , and the electric valve 13 is used to control the release / storage of compressed air 7 .

[0052] Embodiment 2.

[0053] like Figure 3 , Figure 4 , Figure 5As shown, referring to the above example, the air compression tank 2 can be configured as a rigid outer shell 15 (i.e., an outer wall, a protective wall, etc.) and a flexible inner tube 14 (i.e., a flexible container such as an air bag or an air bag), and the compressed air 7 is stored in the flexible inner tube 14. Of course, the air compression tank 2 without the flexible inner tube 14 can also be made of stainless steel alone. It is best to open a pressure relief air hole 6 (commonly known as a ventilation air vent) connected to the outside and equipped with an air filter on the rigid outer shell 15. During the process of the compressed air 7 being sent into the air compression tank 2, the flexible inner tube 14 expands and stores the compressed air 7, and the air between the flexible inner tube 14 and the rigid outer shell 15 is squeezed out through the pressure relief air hole 6 to maintain the balance between the air pressure in the tire and the atmospheric pressure; during the process of the compressed air 7 being sent out of the air compression tank 2, the flexible inner tube 14 contracts, and the space between the flexible inner tube 14 and the rigid outer shell 15 inhales air from the pressure relief air hole 6 to maintain the balance between the air pressure in the tire and the atmospheric pressure.

[0054] Embodiment three.

[0055] like Figure 7 , Figure 8 , Fig. 9 As shown, referring to the second example above, the compressed air tank 2 is a vertical cylindrical type. Photovoltaic panels 1 and other photovoltaic cell components are installed on the compressed air tank 2. The photovoltaic panels 1 are used to protect the compressed air tank 2 from wind and rain. The compressed air tank 2 is used to support (fix) the photovoltaic panels 1 (instead of the photovoltaic brackets of the current ground power station). The photovoltaic panels 1 and the compressed air tank 2 form a photovoltaic tank 10 with complementary functions and integration. Many photovoltaic tanks 10 are separated by a certain safe distance and dispersedly placed on the land 9 (for example Fig. 9 The photovoltaic tanks 10 are arranged in an array.

[0056] Embodiment 4.

[0057] like Fig.10 , Fig.11 As shown, referring to the above embodiment, a reinforced concrete box 16 cast on site on a concrete foundation 9 is used as the rigid outer shell 15 of the air pressure tank 2, a flexible inner tube 14 is placed in the reinforced concrete box 16, and a photovoltaic panel 1 is installed on the top of the reinforced concrete box 16 to cover the reinforced concrete box 16 (to prevent exposure to the sun and rain), and a pressure relief hole 6 is prefabricated at the upper end of the reinforced concrete box 16, and then a gas pipeline 3 is pre-buried to form a photovoltaic tank 10.

[0058] Embodiment five.

[0059] like Fig.13 As shown, referring to the above embodiment, the photovoltaic panel 1 is installed on the upper side of the semi-buried reinforced concrete air pressure tank 2, wherein most of the space of the air pressure tank 2 is buried underground. In other words, the air pressure tank 2 has a partial underground gas storage space 15. The photovoltaic panel 1 and the air pressure tank 2 form a photovoltaic tank 10 with complementary functions and sharing the same land 9.

[0060] What is disclosed above is only a preferred embodiment of the present application. The drawings are merely schematic structural diagrams and are not drawn according to the actual size ratio. They cannot be used to limit the scope of rights of the present application. Equivalent changes made based on the claims of the present application still fall within the scope covered by the present application.

Claims

1. A photovoltaic tank power generation system, which includes a photovoltaic cell assembly and a compressed air storage tank - an air pressure tank, characterized in that: ① The photovoltaic cell assembly is installed on the air compression tank to cover the air compression tank; the photovoltaic cell assembly and the air compression tank constitute a photovoltaic tank in which photovoltaic power generation and air energy storage share the same space and geographical location, so as to reduce land occupation and improve resource utilization; ② Many photovoltaic tanks are placed at a safe distance from each other on the same piece of land to form a photovoltaic tank array; ③The photovoltaic tank is connected to the air compressor via the air pipe; ④ When there is sufficient sunshine or during off-peak hours, power is supplied to the air compressor to generate compressed air, converting electrical energy into the pressure potential energy of the air; the compressed air is sent to the photovoltaic tank through the air pipe, and the pressure potential energy of the air is stored in the photovoltaic tank; ⑤ When there is insufficient sunlight, the photovoltaic tank releases compressed air to the air engine, driving the generator to generate electricity, converting the pressure potential energy into electrical energy to supply the power grid or electrical equipment.

2. The photovoltaic tank power generation system according to claim 1, characterized in that: PV tanks are medium and low pressure gas storage tanks with a pressure range of 0.1 to 6MPa.

3. The photovoltaic tank power generation system according to claim 1, characterized in that: The air compression tank is used to support the photovoltaic cell assembly. The photovoltaic cell assembly and the air compression tank constitute a photovoltaic tank that integrates photovoltaic power generation and air energy storage.

4. The photovoltaic tank power generation system according to claim 1, characterized in that: The photovoltaic tank includes a rigid outer shell and a flexible inner tube, and compressed air is stored in the flexible inner tube; or, the photovoltaic tank is a reinforced concrete tank; or, the photovoltaic tank is fully or semi-buried in the ground; or, the height of the photovoltaic tank is 0.322 meters to 4.15 meters; or, the horizontal projection area of ​​a single air compression tank is ≤ the horizontal projection area of ​​all photovoltaic cell assemblies covered on the single air compression tank.

5. The photovoltaic tank power generation system according to claim 1, 2, 3 or 4, characterized in that: A plurality of photovoltaic tanks are connected in series or / and in parallel to an air compressor and an air engine via an air pipeline; an electric valve is connected between the photovoltaic tank and the air pipeline, and the electric valve is used to control the release / storage of compressed air.

6. A photovoltaic tank, comprising a photovoltaic cell assembly and a compressed air storage tank, namely, an air pressure tank, characterized in that: The photovoltaic cell assembly is installed on the air compression tank, the air compression tank is used to support the photovoltaic cell assembly, and the photovoltaic cell assembly is used to cover the air compression tank; the photovoltaic cell assembly and the air compression tank constitute a photovoltaic storage device that shares the same space and geographical location and integrates photovoltaic power generation and air energy storage, so as to reduce land occupation and improve resource utilization.

7. The photovoltaic tank according to claim 6, characterized in that: Photovoltaic tanks are medium- and low-pressure gas storage tanks with a pressure range of 0.1 to 6MPa; numerous air compressor tanks are spaced a certain safe distance from each other and dispersedly placed on the same piece of land, arranged into a photovoltaic tank array; the air compressor tanks are connected to the air compressor via a gas pipe.

8. The photovoltaic tank according to claim 7, characterized in that: The air compression tank includes a rigid outer shell and a flexible inner tube, and the compressed air is stored in the flexible inner tube; or, the air compression tank is a reinforced concrete tank; or, the air compression tank is fully buried or half buried in the ground; or, the height of the air compression tank is 0.322 meters to 4.15 meters; or, the horizontal projection area of ​​a single air compression tank is ≤ the horizontal projection area of ​​all photovoltaic cell modules covered on the single air compression tank.

9. The photovoltaic tank according to claim 6, 7 or 8, characterized in that: The air compressor tank is connected with an electric valve, which is used to control the release / storage of compressed air.

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