WO2023211288A1

WO2023211288A1 - Floating solar power plant

Info

Publication number: WO2023211288A1
Application number: PCT/NO2023/050095
Authority: WO
Inventors: Bjørn Helset
Original assignee: Inseanergy As
Priority date: 2022-04-25
Filing date: 2023-04-25
Publication date: 2023-11-02
Also published as: NO347706B1; NO20220464A1

Abstract

Floating solar cell power plant (10) comprising at least one floating collar (12) surrounding the solar cell power plant (10), where the floating collar ensures buoyancy and anchoring of the solar cell power plant, as well as a number of freshwater basins (20) placed on the inside of the floating collar (12), where each freshwater basin (20) comprises several interconnected solar cell panels (16). Each freshwater basin (20) comprises a basin cover (24) attached to a basin barrier (22) which delimits each freshwater basin (20). Said interconnected solar cell panels (16) are flexible solar cell panels (16) suspended in a height above the basin cover (24), and the solar cell panels (16) are mechanically fastened (26) to each other in order to create a group of solar cell panels (16), and where the group of solar cell panels (16) is suspended to the basin barrier (22) and is floating in each freshwater basin (20).

Description

The field of the invention

The present invention concerns a floating solar cell power plant with solar cell panels for generating photovoltaic energy. In particular, the floating solar cell power plant comprises, in accordance with the invention, at least one floating collar surrounding the solar cell power plant, where the floating collar ensures buoyancy and anchoring of the solar cell power plant, as well as a number of freshwater basins placed within the floating collar. Every freshwater basin comprises several interconnected solar cell panels, and every freshwater basin comprises a basin cover attached to a basin barrier that delimits each freshwater basin.

The background of the invention

Fish farms are often placed in sparsely populated areas along the coast, where electrification can be quite costly. Often utilized alternatives are diesel-driven power generators. This is not an environmentally friendly solution which also requires regular maintenance and supply of diesel.

Disclosure of prior art

From NO343405 B1 , a solution is known where electricity is supplied by floats containing solar cell panels, floating on the ocean. The solar cells are naturally cooled by the water. A study conducted by ABB concludes that the natural cooling effect on the underside of the panels makes the solar cells up to eleven percent more effective than comparable solutions for utilization on land.

EP3465907, EP3799297 and EP3799297 all show floating photovoltaic energy constructions, comprising a foldable mat floating on the water, and where several photovoltaic modules have been mounted on these.

One disadvantage with these types of constructions is that these must be cleaned often due to algae, algae build-up, which thrives in saline water. Also, salt crystals will appear and stick to the solar cell panels. The efficiency of the solar cell panels will be reduced significantly.

From DE 19908645 A1 , a solution is known where a floating solar cell construction has solar cells attached between two sheets. In the resulting mat, bamboo canes are attached that stretch out the mat, ensuring buoyancy. Furthermore, we refer to WO2021187993A1 (NO345478 B1 ) which describes a floating solar cell power plant comprising at least one floating element surrounding the solar cell power plant, where the floating element ensures buoyancy and anchoring of the solar cell power plant, a first cover stretching over the entire area surrounded by the floating element, which is fixed to said floating element, thereby creating a saltwater barrier, as well as a number of basins placed on the first cover, each comprising a frame and a second cover which forms the bottom of the basin, as well as a number of solar cell elements connected with a third cover, which is connected to the frame and placed in the basin, as the basin contains non-saline water.

Objects of the present invention

It is an object of the present invention to provide a solar cell power plant in the form of a floating solar cell construction, which requires a lower degree of maintenance, for example making it easier to replace defective solar cell panels.

Furthermore, dirt and filth underneath the solar cell panels may be easily removed.

It is also an object to provide a floating solar cell power plant with attached wind turbines, facilitating a combined and “complete” floating power plant with an improved effect output.

One object is also to combine a floating fish farming construction with the floating solar cell power plant according to the invention.

The solar cell power plant according to the invention can be utilized to gather renewable solar energy, and can be utilized as an addition to land-based electricity or fossil energy sources, such as diesel generators. The solar cell power plant may also be utilized by itself, provided it can produce sufficient energy.

Full scale, floating solar cell power plants can be installed in reusable net cage rings, or as module-based, scalable floating collars. The system will be able to function in a grid system between the solar cell power plant, battery, and diesel generator.

The solar cell power plant will reduce CO2 emissions, as well as reduce noise from fish farms through a reduction of the use of diesel generators on feed barges. The solar cell power plant is especially suitable for those in the fish farming industry who have already installed hybrid constructions with batteries and reduced diesel generator installations, in that these can easily be connected to the solar cell power plant in order to make the hybrid construction even more environmentally friendly.

The solar cell power plant can be delivered with batteries and guidance systems, readily assembled with reuse of net cage rings included, or as module-based, scalable solar cell systems, based on other types of floating elements, batteries and guidance systems delivered in containers to a destination.

Summary of the invention

The abovementioned objects are achieved with a floating solar cell power plant comprising at least one floating collar surrounding the solar cell power plant, where the floating collar ensures buoyancy and anchoring of the solar cell power plant. A number of freshwater basins are placed internally in the floating collar, where each freshwater basin comprises several interconnected solar cell panels, and each freshwater basin comprises a basin cover attached to a basin barrier delimiting each freshwater basin, as said interconnected solar cell panels are flexible solar cell panels suspended in a height above the basin covers. The solar cell panels are mechanically attached to each other to create a group of solar cell panels, and where the group of solar cell panels are suspended to the basin barriers and floating in each freshwater basin.

Each freshwater basin comprises non-saline water, and the solar cell panels are suspended while submerged in said water, floating in each freshwater basin.

Alternatively, a bottom cover can stretch across the entire area surrounding the floating collar, and is fixed to said floating collar, thereby creating a saline water barrier under the basin cover of the freshwater basins.

In the floating solar cell power plants, the floating collars may comprise a number of windmills placed circumferentially around the floating collar.

The freshwater basins may be fastened with artificial fiber rope or equivalent to pole supports on the floating collar. The floating solar cell power plant may also further comprise sensors that control the saline content in the water in the area within the floating collar or in the freshwater basins, as well as pumps for supply of non-saline water in case the saline content exceeds a predetermined value.

The floating solar cell power plant may also comprise level sensors for surveillance of the level of non-saline water in the area within the floating collar or the freshwater basins, and which are arranged to start said pumps for supply of non-saline water in case the level drops below a predetermined value.

The floating solar cell power plant may further comprise a battery pack for storage of power coming from the solar cell panels and/or the wind turbines.

Description of the figures

Preferred embodiments of the invention shall subsequently be referred to in more detail, with reference to the enclosed figures, in that:

Figure 1 shows a solar cell power plant according to the invention.

Figure 2 shows a windmill for utilization on the solar cell power plant.

Figure 3 shows a flexible solar cell panel included in the solar cell power plant. Figure 4 shows several interconnected solar cell panels.

Figure 5 shows several groups of interconnected solar cell panels.

Figure 6 shows several freshwater basins included in the solar cell power plant.

Figure 7 shows a bottom cover that can be utilized in the solar cell power plant.

Figure 8 shows a floating collar included in the solar cell power plant.

Figure 9 shows a cutout segment in a freshwater basin with suspended solar cell panels.

Description of preferred embodiments of the invention

The solar cell power plant 10 according to the invention comprises an assembly with a floating element in the form of a floating collar 12 surrounding a bottom cover 18, and is designed to float in sea water. In this construction, a number of freshwater basins 20 are provided, which contain clean/fresh/non-saline water, preferably rainwater. In the freshwater basins 20 solar cell panels 16 have been placed, which provide electricity. The purpose of this assembly is that the solar cell panels 16 can be cooled by the underlaying seawater and be placed in freshwater, which prevent fouling. The bottom cover 18 is optional, but when utilized, it will create an extra barrier between the saline seawater and the basin cover 24 in the freshwater basins 20.

The invention is in one embodiment based on a technological integration in floating elements utilized in the fish farming industry. Usually, these floating elements come in a circular shape, and sometimes with a circumference of up to 120 meters, but the system can be adapted to any shapes and sizes.

Figure 1 shows an example of a solar cell power plant 10 according to the invention, comprising a surrounding floating collar 12 as a floating element. Internally in the floating collar 12, a plurality of freshwater basins 20 are provided, where each are provided by a basin barrier 22 and a basin cover 24.

Each floating collar 12 frames a plurality of freshwater basins, where each comprises groups of solar cell panels 16. Typically, the floating collar 12 will frame four of said freshwater basins 20, but is not limited to this. The freshwater basins 20 are delimitated and interconnected by the basin barriers 22. These are then attached together on opposite sides, and mounted to said floating collar 12 on the sides adjacent to the floating collar 12. Altogether, this provides a stable and flexible assembly securing solar cell power plants 10 against unnecessary fatigue and wear and tear.

Figures 1 and 6 show four quarter-circular shaped freshwater basins 20. This would constitute a natural separation in a circular floating collar 12. Should a floating collar 12 be utilized with a different geometrical shape, it would also be natural that the number and shapes of the freshwater basins 20 would be altered correspondingly.

As apparent from figures 1 and 2, the solar cell power plant 10 can also comprise wind turbines 14. The wind turbines 14 are placed circumferentially around the floating collar 12. The wind turbines 14 are mounted in a vertical alignment and for example on a bracket/plate 30 welded at the top of a pipe 32, like an aluminum pipe. The pipe 32 has a through pipe clamp 34 attached to a pole support, like a PE support, on the floating collar 12.

These vertical wind turbines possess a low self-weight (for example 20 kg), and are suitable for installation on a solar cell power plant 10 according to the invention. Inverters for the wind turbines are dimensioned based on the number of turbines and the installed effect (kWp). Battery packs for storage of electricity coming from the solar cell panels 16 can also be utilized for the wind turbines 14.

The wind turbine 14 comprises a turbine house placed on the plate 30, where the turbine house has an upwards aligned turbine shaft, where a turbine blade is mounted onto. These wind turbines can withstand high wind loads (for example 50 m/s), typical operational temperatures at -25°C to +40°C, and possess low maintenance requirements, making wind turbines quite suitable for coastal areas.

The solar cell panels 16 are flexible solar cell panels that do not require stiffened frames. The flexible solar cell panels are resistant against dynamic loads from waves and wind, as well as resistant against water penetration and corrosion. An example of max effect is 330 - 385 W per panel. They can be installed without foundation, and through the aid of a mechanical link between the panels. Figure 3 shows an example of a solar cell panel 16, and which is equipped with holes along the outer edges.

Figure 4 shows an example of connection of a plurality of solar cell panels 16. The solar cell panels 16 can be interconnected mechanically through strips 26, spring hooks, clamps, or the like.

Figure 5 shows four groups of interconnected solar cell panels 16, where each group of interconnected solar cell panels 16 has more or less a corresponding form vis-a- vis the freshwater basin 20, in which they are to be placed, as shown in figure 6. Figure 6 further shows the basin barrier 22 stretching about each freshwater basin 20. The basin cover(s) 24 is/are attached to the basin barriers 22. As a basin cover 24, one may utilize a cover made of environmentally friendly standard PVC material with a low self-weight, for example 900 g/m², and which can be installed detached above the bottom cover 18 if this is to be utilized.

Figure 7 shows an example of a bottom cover 18 for installation in a floating collar 12, such as the floating collar 12 shown in Figure 8. The bottom cover 18 can correspondingly be an environmentally friendly standard PVC cover, and will function as a barrier against seawater. Figure 9 shows a cross-section of a freshwater basin 20 with suspended solar cell panels 16. The basin barriers 22 are securely placed in the floating collar, and the group of mechanically interconnected solar cell panels 16 are suspended to the basin barrier 22, for example with the aid of fiber ropes 28, hooks, or other tools, so that the solar cell panels 16 are floating “weightless” in the water of the freshwater basin. The solar cell panels 16 can for example float in a distance A (for example approx. 50 mm) over the basin cover when the freshwater basin has been filled up with 100-200 mm of water. The solar cell panels 16 would consequently not be in contact with the basin cover 24, but would, due to natural causes, and especially in the middle of the basin, sometimes come into contact with the basin cover 24 due to a deflection of the suspended solar cell panels 16. In one embodiment, said interconnected solar cell panels 16 can be flexible solar cell panels 16 freely suspended in a height above the basin cover 24, and that the solar cell panels 16 are mechanically fastened 26 to each other to create a group of freely suspended solar cell panels, and where the group of solar cell panels 16 is directly suspended to the basin barrier 22 and is floating in each freshwater basin 20.

As mentioned, the solar cell panels 16 float in the freshwater basin 20 containing freshwater, where the source is either non-saline water, for example rainwater, or a supply from a non-saline water tank. The freshwater basin 20 will naturally fill up with rainwater.

Surplus rainwater can be transferred to a reservoir tank and be led back to the freshwater basin 20 if it is necessary in order to maintain the water level in the freshwater basin, or to ensure that the water in the freshwater basin has a low saline level. This reservoir tank can, if desired, be carried out in the form of another cover (not shown) placed underneath the bottom cover 18, creating a space below the floating collar 12.

Due to the freshwater basin 20 having an open top side, the basin water may experience the introduction of a certain degree of saline seawater. Particularly in the event of rough seas or storm conditions, saline water may end up in the freshwater basins. The saline levels can be registered by sensors placed in each freshwater basin 20, which will, when reaching certain saline levels, result in an alarm being triggered, which in turn will initiate circulation pumps, adding new non-saline water to the freshwater basins. The sensors can be of a conventional type that measure conductivity in the water. One may also install level sensors in every freshwater basin 20, which will provide signals to a micro controller when the level falls below a minimum level, which will trigger an alarm, which in turn will initiate said circulation pumps that will supply the freshwater basin 20 with new freshwater up to a predetermined desired level. The freshwater can be collected from said reservoir tank.

The support elements can be designed as boxes or containers, where the elements, partly or in whole around the third cover, will house batteries and technology tied to production and storage of energy. Typically, said construction will possess a square or rectangular cross-section, but otherwise may come in any suitable shape or form.

The circulation pump can be connected to the above-mentioned reservoir tank (not shown).

Together with a computer processing system comprising water level sensors and sensors for measurement of saline levels in the water, the pump system will ensure a correctly predetermined water quality and proper water levels in said basins.

Through this construction, the solar cell panels will receive adequate cooling from the underlying seawater, while the solar cell panels 16 at the same time also can be cooled in the water of the freshwater basins 20, and where in particular the undesired effects of seawater on the solar cell panels 16 are prevented. This will make it more attractive to utilize floating solar cell power plants also at sea. It also provides a solution for a simplified replacement of defective solar cell panels. Dirt and filth one may find underneath the solar cell panels can be pumped out with drainage pumps.

The figures illustrate the preferred embodiment of the invention. By utilizing freshwater basins placed on top of the bottom cover 18 and within the floating collar 12, one may actually walk on the bottom cover 18 between the freshwater basins 20 and reach the solar cell panels 16. This facilitates maintenance work on the solar cell panels 16. One may also utilize a pumping arrangement which will allow the area between the freshwater basins to remain dry.

Claims

1 . Floating solar cell power plant (10) comprising

- at least one floating collar (12) surrounding the solar cell power plant (10), where the floating collar ensures buoyancy and anchoring of the solar cell power plant, and

- a number of freshwater basins (20) placed on the inside of the floating collar (12), where every freshwater basin (20) comprises a plurality of interconnected solar cell panels (16),

- every freshwater basin (20) comprises a basin cover (24) mounted to a basin barrier (22) which delimits each freshwater basin (20), characterized by

- said interconnected solar cell panels (16) are flexible solar cell panels (16) suspended in a height above the basin cover (24), and that the solar cell panels (16) are mechanically fastened (26) to each other in order to create a group of solar cell panels, and where the group of solar cell panels (16) are suspended (28) to the basin barrier (22) and floats in each freshwater basin (20).

2. Floating solar cell power plant (10) according to claim 1 , characterized by each freshwater basin (20) comprising non-saline water, and that the solar cell panels (16) are suspended in said water, and floats in each freshwater basin (20).

3. Floating solar cell power plant (10) according to claim 1 , characterized by a bottom cover (18) stretching across the entire area surrounded by the floating collar (12), and are fastened to said floating collar (12), creating a saltwater barrier underneath the basin cover (24) of the freshwater basins (20).

4. Floating solar cell power plant (10) according to claim 1 , characterized in that the floating collar (12) comprising a plurality of windmills (14) placed circumferentially around the floating collar (12).

5. Floating solar cell power plant (10) according to claim 1 , characterized in that the freshwater basins (20) are fastened with fiber ropes or the like to pole supports on the floating collar (12).

6. Floating solar cell power plant (10) according to claim 1 , characterized by further comprising sensors deciding the saline content in the water in the area within the floating collar (12) or in the freshwater basins (20), as well as pumps for supply of non-saline water in the event that the saline levels exceed a predetermined value.

7. Floating solar cell power plant (10) according to claim 6, characterized by further comprising level sensors for surveillance of non-saline water levels in the area within the floating collar (12) or the freshwater basins (20), and which also is arranged to initiate said pumps for supply of non-saline water in an event where the level drops below a predetermined value.

8. Floating solar cell power plant (10) according to any of the preceding claims, characterized by further comprising a battery pack for storage of electricity generated by the solar cell panels (16) and/or the wind turbines (14).