Maintenance and service vessel for floating solar cell plants

Abstract

Present invention relates to a maintenance and service vessel (7) for installation maintenance and cleaning of solar cell panels (6) and solar cell modules (1) in a floating solar cell plant, said vessel (7) comprising at least two parallel elongated pontoons (8) and at least two transverse beams (9) connecting the pontoons (8), wherein the pontoons (8) are hollow and provides buoyancy for the vessel (7) at least one end (11) of each pontoon (8) are angular to make it possible for the vessel to pass over mooring lines (2) connecting the solar cell modules (1) without damaging the mooring lines (2).

Description

MAINTENANCE AND SERVICE VESSEL FOR FLOATING SOLAR CELL PLANTSTechnical Field

[0001] Present invention relates to a maintenance and service vessel for a floating solar cell plant. More specific, present invention relates to a vessel that can be used for cleaning of the surface of solar cell plants floating on a body of water and maintenance, installation and replacement of solar cell panels and / or solar cell modules floating on a body of water.Background Art

[0002] Floating solar cell plants for production of electric power comprise a large number of solar cell modules, which usually have a substantially square or rectangular shape, where each solar cell module comprises a buoyancy member floating in the sea surface and a solar cell panel placed on top of the individual buoyancy element. The buoyancy elements keep the solar cell panels at an adequate height above the water surface. The individual solar cell modules are connected to adjacent solar cell modules both with power lines and supporting lines. The supporting lines are keeping the individual solar cell modules a certain distance apart from each other and also connect the solar cell modules with appropriate anchoring means, such as mooring lines, keeping the whole solar cell plant in the correct position on the water surface. Normally two solar cell modules are placed adjacent to each other and constitute a solar module pair. A number of such module pairs are connected to other module pairs and form a longitudinal row of module pairs. The distance between each module pair is quite small and necessary cables to connect the solar panels are provided in the space between the solar panel modules in each pair. Each longitudinal rows of module pairs are connected to adjacent rows of module pairs with a certain distance between such rows. These longitudinal rows of module pairs are connected to the adjacent row with mooring lines. The distance between the longitudinal row of module pairs is larger than the distance between each module in a module pair.

[0003] Over time, the solar cell panels will be covered with dust, salt and other contaminants, that gradually will reduce the amount of sunlight absorbed by the solar cells and thereby reduce their power output. In order to overcome this problem and maintain a steady and high power production, it is therefore necessary to clean the surface of the solar panels to allow a high power production. For land-based solarparks the cleaning of the surface of the solar panels can be performed by using rotating brushes, waterjets, ultra-sound, shaking of the solar panels, where the equipment for performing the cleaning most usually is connected to a vehicle or a robot, which moves the cleaning equipment from solar panel to solar panel.

[0004] However, such solutions are not possible with solar plants flowing on a sea surface, since the individual solar cell panel will not be accessible for cleaning equipment used for land-based plant.W02015136107 relates to a corded lattice based floating photovoltaic solar field with independent floating solar modules. Fig. 9 and the corresponding text in this publication describes a mobile floating service gantry including a deck supported by two floating pontoons.

[0005] It is therefore an intention with present invention to provide a maintenance and service vessel that can be used during installation, maintenance and service of floating solar cell modules.Summary of invention

[0006] These and other advantages are obtained with a maintenance and service vessel for installation maintenance and cleaning of solar cell panels and solar cell modules in a floating solar cell plant, said vessel comprising at least two parallel elongated pontoons and at least two transverse beams connecting the pontoons, wherein the pontoons are hollow and provides buoyancy for the vessel at least one end of each pontoon are angular to make it possible for the vessel to pass over mooring lines connecting the solar cell modules (1 ) without damaging the mooring lines.

[0007] Preferably, each pontoon further comprising propulsion means to move the vessel along a row of solar cell modules, said propulsion means are preferably water jets.

[0008] The vessel further preferably comprising a cleaning means for cleaning the surface of the solar cell panels, said cleaning means are preferably rotating brushes or high pressure washers, arranged between the parallel pontoons.

[0009] In a preferred embodiment, the vessel further comprising a deck covering a part of the area between the parallel pontoons, and the uncovered part of this area is dimensioned to make it possible to install and remove solar cell panels and / or solar cell modules from the sea surface onto the deck or vice versa.

[0010] Preferably, the pontoons, on the longitudinal sides facing each other, are equipped with cleaning means for cleaning the sides of the solar cell modules and the mooring lines.Brief description of drawings

[0011] Figure 1 depicts a floating solar cell plant.

[0012] Figure 2 depicts a maintenance and service vessel according to the invention.

[0013] Figures 3 and 4 depicts the maintenance and service vessel in a typical use situation.Detailed description of the invention

[0014] Figure 1 depicts a typical floating solar cell plant comprising a plurality of solar cell modules (1 ). The solar cell modules (1 ) are configured in parallel rows, where each row in the longitudinal direction comprises a plurality of pairs of modules (1 ). The distance between each module (1 ) in a pair is relatively small and the electric cables necessary to transport electricity from the solar cell panels are provided between each solar cell module in a pair. As shown in Fig. 1 , each row of module pairs is located parallel to the next rows with a spacing D (Fig. 4) between each row. Typically, each row comprises 10-30 modules (1 ). Each row is connected to the adjacent row by transverse mooring lines (2) and each solar cell module (1 ) is connected to the next solar cell module (1 ) in the longitudinal direction of the row with longitudinal mooring lines (3). The ends of both transverse and longitudinal mooring lines (2, 3) are connected to one or more anchoring assemblies (4).

[0015] The solar cell module (1 ) comprises a buoyancy member (5) on which a solar cell panel (6) is attached (best shown in Fig. 3 and 4). The solar cell panel (6) is detachably mounted on top of the buoyancy member (5) and the buoyancy member (5) keeps the solar cell panel (6) above the sea surface. Over time, the surface of the solar cell panels (6) becomes contaminated with salt and other contaminants reducing the power generating ability of the solar cell panel. In order to overcome this reduced power generation, it will be necessary to clean the surface of the solar cell panels (6). Over time, it will also be necessary to replace the solar cell panels since the power output from the solar cells gradually will decrease over time.

[0016] Figure 2 depicts a maintenance and service vessel (7) which can be used for installation, maintenance and cleaning of the solar cell panels (6) and installation, maintenance and replacing the buoyancy members (5). The vessel (7) comprises at least two longitudinal pontoons (8) and two or more transverse beams (9) connecting the pontoons (8) to each other. The pontoons (8) are parallel to each other and provides buoyancy to the vessel (7). The vessel (7) also comprises longitudinal beams connecting the transverse beams (9) to provide a rigid frame. Further this frame can support a deck (12) covering a part of the frame. The area of the frame not covered by the deck (12) has a sufficient open area making it possible to install and replace the solar cell panels (6) or the complete solar cell modules (1 ) through this open area.

[0017] The distance between the parallel pontoons (8) is such that each pontoon (8) be positioned in the gap between adjacent rows of solar cell modules (1 ) and the horizontal cross section is less or equal to the distance (D) between each row of solar cell modules (1 ). One or both ends (11 ) of each pontoon (8) are angular such that when the pontoon (8) moves in the gap between the row of solar cell modules (1 ), it will push down the mooring lines connecting the solar cell modules (1 ) and pontoons (8) can move freely over the mooring lines without the risk of being stuck by or damaging the mooring lines.

[0018] Between the pontoons (8), the vessel (7) can be provided with equipment for cleaning the surface of the solar cell panels (6). This equipment can be one or more rotating brushes (13) or other kind of cleaning devices, which are able to clean the surface of the solar cell panels (6) between the pontoons (8). It is also conceivable that the cleaning devices are nozzles spraying water at high pressure onto the surface of the solar cell panels (6).

[0019] In one preferred embodiment, each pontoon (8) is provided with propulsion means at one or both ends (11 ) of the pontoons (8) to be able to move the vessel (7) along the row of solar cell modules (1 ). In an even more preferred embodiment, the propulsion means can be a waterjet device.

[0020] In yet another preferred embodiment, the pontoons (8) or the longitudinal beams (10) can be provided with means for cleaning the mooring lines (2, 3) and the sides of the solar cell modules (1 ), for example water jets.

[0021] Further, the vessel can be provided with a roof covering parts or all the upper area of the vessel (7). In addition, this roof can be provided with solar cell panels to produce electricity for the cleaning equipment and propulsion system.

[0022] In addition, the vessel is provided with the necessary equipment to power the propulsion means and cleaning means, such as power supply, pumps etc.LIST OF REFERENCE NUMERALSI solar cell modulesD distance between each pair of solar cell modules in a row 2 transverse mooring lines3 longitudinal mooring lines4 anchoring assemblies5 buoyancy member6 solar cell panel 7 maintenance and service vessel8 longitudinal pontoons9 transverse beam10 longitudinal beamI I end of pontoon 12 deck13 rotating brush

Claims

Claims1. Maintenance and service vessel (7) for installation maintenance and cleaning of solar cell panels (6) and solar cell modules (1) in a floating solar cell plant, said vessel (7) comprising at least two parallel elongated pontoons (8) and at least two transverse beams (9) connecting the pontoons (8), characterized in that the pontoons (8) are hollow and provides buoyancy for the vessel (7) at least one end (11) of each pontoon (8) are angular to make it possible for the vessel to pass over mooring lines (2) connecting the solar cell modules (1) without damaging the mooring lines (2).

2. The vessel (7) according to claim 1 , characterized in that each pontoon (8) further comprising propulsion means to move the vessel (7) along a row of solar cell modules (1), said propulsion means are preferably waterjets.

3. The vessel (7) according to any of the preceding claims, characterized in that the vessel (7) further comprising a cleaning means for cleaning the surface of the sola cell panels (6), said cleaning means are preferably rotating brushes (13) or high pressure washers, arranged between the parallel pontoons (8).

4. The vessel (7) according to any of the preceding claims, characterized in that the vessel (7) further comprising a deck (12) covering a part of the area between the parallel pontoons (8), and the uncovered part of this area is dimensioned to make it possible to install and remove solar cell panels (6) and / or solar cell modules (1) from the sea surface onto the deck (12) or vice versa.

5. The vessel (7) according to any of the preceding claims, characterized in that the pontoons (8), on the longitudinal sides facing each other, are equipped with cleaning means for cleaning the sides of the solar cell modules (1) and the mooring lines (2, 3).

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