A system for the generation of hydroelectric power

Abstract

An energy storage system comprises a submersible reservoir 200 and a floating platform 300 with a wind turbine 303 mounted thereon. The reservoir 200 has a releasably sealable water charging inlet 201

Description

“A system for the generation of hydroelectric power” Introduction This invention relates to a system for the generation of hydroelectric power. Hydroelectric power generation has been used for many years to produce electricity for households and businesses. Hydroelectric power generation is seen as a more environmentally friendly and a more sustainable way of generating electricity than, say, the burning of fossil fuels. Therefore, as society looks to satisfy their electricity needs in a more environmentally friendly manner, hydroelectric power generation is seen as one useful choice. There are a number of disparate systems for the generation of hydroelectric power. For example, there are the conventional hydroelectric power generation plants that have a large body of water such as a natural lake or a reservoir built with a man-made dam, that is gradually emptied by allowing the water to pass over a turbine and then flow into a river at a lower height. There are also pumped storage plants that consist of two bodies of water at different heights. Pumped storage plants allow for the controlled discharge of water from the upper reservoir, over a turbine, to the lower reservoir during the day when it is necessary to meet increased electricity demand. Then, when the demand for electricity reduces, for example at night-time, the water is pumped from the lower reservoir back up to the upper reservoir for use the following day during peak hours. A problem with these systems is that they typically require substantial investment, involve large infrastructure building projects, take several years to implement and require the right geographical configuration to be practical and feasible. In addition to the conventional hydroelectric power generation plants and pumped storage plants, there is a current trend towards providing submersible hydroelectric power generation plants. These submersible hydroelectric power generation plants operate in a fashion similar to the pumped storage plants in that they can be used to generate electricity at peak times and thereafter be pumped out at off-peak times for use the following day during peak times. Heretofore, none of the known submersible systems has been entirely satisfactory as they are relatively expensive and difficult to maintain. It is an object of the present invention to provide a system for the generation of hydroelectric power that overcomes at least some of the shortcomings of the known systems. It is a further object of the present invention to provide a system for the generation of hydroelectric power that can be commissioned quicker than large fixed infrastructure projects, typically in months or less rather than years. It is a further still object of the present invention to provide a useful choice to the entity responsible for electricity generation. Statements of Invention According to the invention there is provided a system for the generation of hydroelectric power comprising: a submersible reservoir having a releasably sealable water charging inlet, a water conduit extending inwardly from the water charging inlet feeding a reservoir chamber, a turbine in the water conduit, a generator operatively connected to the turbine, a releasably sealable water discharge outlet, a gas compressor and a gas supply; a floating platform secured to the submersible reservoir, the floating platform having at least one stabilizer, and a wind turbine mounted on the floating platform. By having such a system, the submersible reservoir may be brought to a desired location and then submerged below the surface of the water to an appropriate depth, for example resting on the sea bed floor with a head height of water of the order of 50 metres above the charging inlet. Water is allowed into the submersible reservoir and passes over the turbine to generate electricity. The electricity is stored or transferred to an electricity grid. The floating platform with the wind turbine can provide an additional source of electricity if needed. Advantageously, the platform and / or the submersible reservoir can be moved to other locations if desired. If it is desired to move the submersible reservoir, the submersible reservoir is simply “floated” and moved to the next location. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the submersible reservoir comprises an adjustable ballast system for adjusting the ballast of the submersible reservoir. This is seen as a particularly effective way of operating the submersible reservoir. The depth of the submersible reservoir may be chosen to provide an adequate head of water above the charging inlet to provide sufficient water pressure over the turbine. In some ways, the system may be seen to operate in a fashion similar to a submarine ballast system. Similarly, if it is necessary to move the submersible reservoir, the adjustable ballast system could be operated to “float” the submersible reservoir so that it can be moved. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the adjustable ballast system comprises at least one ballast tank. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the adjustable ballast system comprises a plurality of ballast tanks spaced apart around the periphery of the reservoir chamber. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the submersible reservoir comprises an upright service shaft for engagement of the floating platform. This is seen as a particularly good way to connect the submersible reservoir with the floating platform and provide conduits for services between the floating platform and the submersible reservoir. In addition, by having the upright service shaft, the upright service shaft may provide a guide for the submersible reservoir as it is submerged and / or floated. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the wind turbine is operatively connected to the generator. In this way, the wind turbine may be used to power equipment in the submersible reservoir, such as, but not limited to, compressors, pumps, winches and the like. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the floating platform comprises a plurality of spaced apart platform stabilizers. By having a plurality of stabilizers, the platform will be steady and can be held on station above the submersible reservoir. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the floating platform comprises three spaced apart platform stabilizers. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the floating platform is provided with at least one anchor and tether connected to the anchor. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the submersible reservoir comprises means to detect the level of water in the reservoir chamber and releasably seal the water charging inlet upon the water reaching a predetermined level in the reservoir chamber. In this way, it is possible to control the level of water in the reservoir chamber and ensure that the turbine does not become flooded. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which there is provided a battery storage unit for storage of electricity generated in the generator. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which there is provided a wired connection to the electricity mains grid for distribution of the electricity generated in the generator. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which the floating platform is releasably secured to the submersible reservoir. This is seen as a particularly preferred configuration of system according to the invention. by having the floating platform releasably secured to the submersible reservoir, the floating platform can be moved independently of the submersible reservoir and can be used on multiple disparate submersible reservoirs in different locations as and when needed. In addition, the floating platform can be brought for repair or servicing to a remote location without moving the submersible reservoir. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which there is provided a propulsion system for moving the floating platform. In this way, the floating platform can be moved from one location to another location when required. In one embodiment of the invention there is provided a system for the generation of hydroelectric power in which there is provided a propulsion system for moving the submersible reservoir. In this way, the submersible reservoir can be moved from one location to another location when required. Detailed Description of the Invention The invention will now be more clearly understood from the following description of some embodiments thereof given by way of example only with reference to the accompanying drawings, in which:- Figure 1 is a diagrammatic representation of a system for the generation of hydroelectric power according to the invention; Figures 2(a) to 2(d) are diagrammatic representations of the components of the system for the generation of hydroelectric power being constructed; Figures 3(a) to 3(e) inclusive are diagrammatic representations of the submersible reservoir of the system according to the invention; Figures 4(a) and 4(b) are diagrammatic representations of the floating platform of the system according to the invention; and Figures 5(a) and 5(b) are diagrammatic representations of another embodiment of a system for the generation of hydroelectric power according to the invention. Referring first of all to Figure 1, there is shown a system for the generation of hydroelectric power, indicated generally by the reference numeral 100, comprising a submersible reservoir 200 and a floating platform 300. The submersible reservoir has a releasably sealable water charging inlet 201, a water conduit 203 extending inwardly from the water charging inlet and feeding a reservoir chamber (not shown) internal the submersible reservoir. There is provided a turbine (not shown) in the water conduit 203 and a generator (not shown) operatively connected to the turbine. A releasably sealable water discharge outlet (not shown) allows for the evacuation of water from the reservoir chamber. There is further provided a gas compressor and a gas supply (not shown). The floating platform 300 is secured to the submersible reservoir 200 and has at least one stabilizer 301, and a wind turbine 303 mounted on the floating platform. Referring now to Figures 2(a) to 2(d) inclusive, there is shown various views of the components of the system 100 for the generation of hydroelectric power being constructed. In Figure 2(a), the submersible reservoir 200 and the floating platform are shown separate from each other. The submersible reservoir has an upright service shaft 205 for engagement of the floating platform and for delivery of services between the platform and the submersible reservoir. The upright service shaft also provides a vent for air from the reservoir chamber as water is allowed to enter the chamber (as will be discussed in greater detail below). The floating platform and the submersible reservoir are both predominantly above the water level 400. The submersible reservoir has a reservoir chamber 207 that may be filled with water, and an adjustable ballast system comprising a plurality of ballast tanks 209. In addition, the turbine 211 and the generator 213 are shown. Referring specifically to Figure 2(b), there is shown a view in which the adjustable ballast system has been actuated to flood the ballast tanks 209 and submerge the submersible reservoir 200 substantially below the water level 400. In this position, the submersible reservoir is still above the sea bed 500. Referring now to Figure 2(c), the floating platform 300 and the submersible reservoir 200 are manoeuvred relative to each other so that the floating platform 300 is substantially above the submersible reservoir 200. In this position, the floating platform may be connected to the upright service shaft 205 of the submersible reservoir. Referring now to Figure 2(d), once the upright service shaft has been connected to the floating platform (the floating platform will preferably be able to move upwards and downwards in a reciprocal fashion about the shaft), the submersible reservoir is “sunk” by actuating the adjustable ballast system by evacuating more air from the ballast tanks 209 and flooding the ballast tanks. The submersible reservoir will settle on the sea bed 500. Anchors (not shown) connected to tethers 305 which in turn are connected to the floating platform 300, are lowered to the sea bed 500 to provide additional stability to the floating platform and hold it in position. Referring now to Figures 3(a) to 3(e) inclusive, there is shown diagrammatic representations of the submersible reservoir of the system according to the invention. the submersible reservoir comprises an upright services conduit 205 with air vent, a water inlet 201, a water conduit 203 fed from the water inlet 201 to the reservoir chamber 207, and a turbine 211 in the water conduit. The turbine is connected to a generator 213. It can be seen from Figures 3(b) to 3(e) inclusive that there are four ballast tanks, circumferentially spaced around the container. In use, when the submersible reservoir is submerged to the desired depth below the water, a closure (not shown) is removed from the water inlet 201 to allow water to flow through the inlet, along the water conduit 203 and over the turbine. The turbine, as it turns, is connected to the generator where the rotation of the turbine is converted into electricity. The manner in which electricity is generated from a turbine is well known in the art and a full description thereof is deemed unnecessary for the purposes of this specification. A battery pack 215, as shown in Figure 3(d) is used to store electricity and a cable (not shown) is used to transfer the electricity to the electricity grid (not shown). The water passing over the turbine continues down through the water conduit into the reservoir chamber 207. Air from the chamber is vented through the air vent in the services conduit 205. When the water level in the reservoir chamber and water conduit is just below the turbine, the closure is closed once more to prevent further ingress of water into the reservoir chamber. Referring now to Figures 4(a) and 4(b), there are shown diagrammatic representations of the floating platform of the system according to the invention. In Figure 4(a), the floating platform is shown with three stabilisers 301, in the absence of the submersible reservoir. In Figure 4(b), there is shown a view from above with the floating platform 300 shown superimposed on top of the submersible reservoir 200 in its operating position. Referring to Figures 5(a) and 5(b), there is shown diagrammatic representations of another embodiment of a system for the generation of hydroelectric power according to the invention, indicated generally by the reference numeral 600, where like parts have been given the same reference numeral as before. The floating platform has been omitted for clarity. Referring specifically to Figure 5(b), there is shown a cross-sectional view of the submersible reservoir, with the turbine below the water inlet. Water flows through the water inlet, over the turbine 211, which is converted into electricity by the generator 213. When the water in the reservoir chamber reaches the cut-off level 601, the charging water inlet is closed with a closure (not shown) to prevent further water ingress, and the water outlets 603, also referred to as shores, are opened up (by, for example, moving a closure relative to the shore). Air is pumped into the reservoir chamber to evacuate the water from the reservoir chamber. Once the water has been evacuated from the reservoir chamber, the outlet shores may be closed once more and the inlet opened to continue the process of electricity generation. It can be seen that the adjustable ballast system's ballast tanks 209 are located below the reservoir chamber rather than along the sides of the chamber and compressed air may be stored in these ballast tanks to allow the air to be injected into the reservoir chamber to evacuate the water from the chamber. A base 605 is provided below the ballast tanks. In this specification the term “comprise, comprises, comprised and comprising” and the terms “include, includes, included and including” are all deemed totally interchangeable and should be afforded the widest possible interpretation. The invention is not solely limited to the embodiments hereinbefore described but may be varied in both construction and detail within the scope of the appended claims.

Claims

(1) A system for the generation of hydroelectric power comprising:5 a submersible reservoir having a releasably sealable water charging inlet, a waterconduit extending inwardly from the water charging inlet feeding a reservoir chamber, a turbine in the water conduit, a generator operatively connected to the turbine, a releasably sealable water discharge outlet, a gas compressor and a gas supply, and in which the submersible reservoir comprises an adjustable10 ballast system for adjusting the ballast of the submersible reservoir.;a floating platform secured to the submersible reservoir, the floating platform having at least one stabilizer, and a wind turbine mounted on the floating platform, and in which the floating platform is releasably secured to the15 submersible reservoir.(2) A system for the generation of hydroelectric power as claimed in claim 1 in which the adjustable ballast system comprises at least one ballast tank.20 (3) A system for the generation of hydroelectric power as claimed in claim 1 or 2 inwhich the adjustable ballast system comprises a plurality of ballast tanks spaced apart around the periphery of the reservoir chamber.(4) A system for the generation of hydroelectric power as claimed in any preceding25 claim in which the submersible reservoir comprises an upright service shaft forengagement of the floating platform.(5) A system for the generation of hydroelectric power as claimed in any preceding claim in which the wind turbine is operatively connected to the generator.30(6) A system for the generation of hydroelectric power as claimed in any preceding claim in which the floating platform comprises a plurality of spaced apart platform stabilizers.03 02 25(7) A system for the generation of hydroelectric power as claimed in claim 6 in which the floating platform comprises three spaced apart platform stabilizers.5 (8) A system for the generation of hydroelectric power as claimed in any precedingclaim in which the floating platform is provided with at least one anchor and tether connected to the anchor.(9) A system for the generation of hydroelectric power as claimed in any preceding 10 claim in which the submersible reservoir comprises means to detect the level ofwater in the reservoir chamber and releasably seal the water charging inlet upon the water reaching a predetermined level in the reservoir chamber.(10) A system for the generation of hydroelectric power as claimed in any preceding 15 claim in which there is provided a battery storage unit for storage of electricitygenerated in the generator.(11) A system for the generation of hydroelectric power as claimed in any preceding claim in which there is provided a wired connection to the electricity mains grid 20 for distribution of the electricity generated in the generator.(12) A system for the generation of hydroelectric power as claimed in any preceding claim in which there is provided a propulsion system for moving the floating platform.25(13) A system for the generation of hydroelectric power as claimed in any preceding claim in which there is provided a propulsion system for moving the submersible reservoir.

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