GB2457443A

GB2457443A - Ship uses propeller for energy generation

Info

Publication number: GB2457443A
Application number: GB0802546A
Authority: GB
Inventors: Michael Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-02-12
Filing date: 2008-02-12
Publication date: 2009-08-19
Also published as: GB0802546D0

Abstract

A vessel 24 generates power from water flow 28 in a river or tidal flow. The water rotates the propeller 32 of the vessel, and may drive the engine 36 (acting as a generator), or may drive a dynamo 40. Construction costs are low as existing ships may be used at the end of their working life.

Description

ENERGY CONVERSION

[001] The present invention relates to a energy conversion, and in particular to the conversion of kinetic energy of a flowing fluid into another form of energy.

[002] Presently the use of and demand for electricity is growing at an ever increasing rate.

It has therefore become necessary to provide arrangements for providing electricity at a similar rate. Traditionally, such arrangements have been power stations, and these power stations have usually taken the form of coal fuelled power stations, gas fuelled power stations, or oil fuelled power stations. It is now well recognised that the use of such power stations is polluting the global environment, and are more than likely causing or contributing to the well known problem of global warming. It is for these reasons that alternatives to fossil fuel powered power stations such as those mentioned above have been contemplated. Such alternatives include, for example, the use of nuclear power. While nuclear power is considered in some respects to be cleaner and less polluting than the use of fossil fuels, nuclear power still has disadvantages associated with it. For instance, there is the issue of how to deal with radioactive waste generated by nuclear power stations, and also the fact that many people are still of the view that nuclear power stations are not safe. It is for these and other reasons that more ecological and potentially safer power generation arrangements are being looked into and used.

(003] Examples of more ecological electricity generation arrangements are the use of solar panels, wind power and tidal power. Such alternatives have no hazardous waste associated with their use, and are considered to be generally safe to, for example, people who live and work in the vicinity of such arrangements.

[004] Although more ecological alternatives to the generation of electricity are being put forward, trialled and even used commercially to generate electricity, they still have disadvantages associated with them. For example, many of these alternatives are expensive to set up and run. Many of the alternatives are also considered to be potentially damaging to the environment in which they are used. The damage may not be in the form of pollution, but can be instead range from noise pollution to having an affect on the lives of animals and the like.

[005] It is therefore an aim of the present invention to provide a method of converting, generating or extracting energy which obviates or mitigates at least one disadvantage of the prior art, whether identified herein or elsewhere.

[006] According to a first aspect of the present invention there is provided a method comprising: using a flow of a liquid to move at least a part of a first energy conversion arrangement with which a vessel is provided in order to convert kinetic energy of the flow of liquid into an other form of energy.

[007] Preferably, the other form energy is electrical energy.

[008] Preferably, the first energy conversion arrangement is arranged to convert kinetic energy into electrical energy. The first energy conversion arrangement may comprise at least a part of a propulsion arrangement of the vessel. The at least a part of the propulsion arrangement may comprise a propeller, a turbine, an engine, or a shaft.

The at least a part of the propulsion arrangement may comprise one or more paddles.

[009] The first energy conversion arrangement may comprise a dynamo, an alternator, or a turbine.

[010] The method may comprise locating the vessel such that at least a part of the first energy conversion arrangement is located in the flow of liquid.

[011] The vessel may further comprise a second energy conversion device. The second energy conversion device may comprise a photovoltaic cell, a solar panel or an air flow driven turbine.

[012) Movement of the vessel may be restrained to one of a number of positions. The vessel may be anchored.

[013) Preferably the liquid is substantially water.

[0141 The other form of energy may be electrical energy, potential energy, or kinetic energy of apparatus with which the vessel is provided.

[0151 According to a second aspect of the present invention there is provided apparatus for converting energy from one form into another, the apparatus comprising: a vessel suitable for location in a flow of liquid, the vessel comprising an energy conversion device, which, in use, is arranged to convert kinetic energy of the flow of liquid into an other form of energy.

[016] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying Figures, in which: [017] Figures 1 a and 1 b schematically depict a tidal barrage for generating electricity in plan view and side view respectively; [018] Figure 2 schematically depicts an underwater turbine for generating electricity; [019] Figure 3 schematically depicts apparatus for converting energy in accordance with an embodiment of the present invention; [020] Figure 4 schematically depicts the apparatus of Figure 3 in more detail; and [021] Figures 5a to Sd schematically depict operating principles of an embodiment of the present invention.

[022] Figure la depicts a plan view of a tidal barrage arrangement for generating electricity (or in other words, electrical energy). The arrangement comprises a tidal barrage 2 which extends from a first land mass 4 to a second land mass 6, for example opposite banks of a river or shore lines defining an estuary or the like. As well as extending between the two land masses 4, 6, the tidal barrage 2 also effectively divides a volume of water flowing between the land masses 4, 6 into two sections, for example water located in an estuary 8 and water located in the sea 10. However, it is important to note that the tidal barrage 2 allows water to flow through it. When water flows through the tidal barrage 2, electricity can be generated.

[023] Figure lb shows the arrangement of Figure 1 a in a side view. In the example shown, it can be seen that the water within the estuary 8 has a higher level than the water in the sea 10. The Figure may therefore be representative of a situation when the tide has gone out. By allowing water from the estuary 8 to flow through the tidal barrage 2 via one or more turbines 12 (or the like) and into the sea 10, electricity can be generated in a known manner.

[024] Electricity may also be generated when the level of the sea 10 is higher than the level of the water in the estuary 8, for example when the tide has come in. In this situation, water will flow from the sea 10 into the estuary 8 via the turbine 12, turning the turbine 12 and generating electricity. It will be understood that electricity can be generated reliably (for example when the level of water is higher on one side of the barrage 2 than the other). Furthermore, the generation of electricity does not involve the generation or liberation of carbon dioxide or other greenhouse gases. Thus, the arrangement shown in Figures la and lb is often considered to be a viable option for the generation of electricity in countries throughout the world.

[025] Although the arrangement of Figures 1 a and lb can be used to generate electricity without the generation or liberation of, for example, carbon dioxide, the arrangement still has disadvantages associated with it. For instance, it may be very expensive to build such a tidal barrage, and such a barrage may take a long time to construct. As well as being expensive in monetary and time terms, the actual construction of the tidal barrage may involve the generation or liberation of vast amounts of carbon dioxide, for example in the transportation of raw materials to and from the site of the tidal barrage and in the construction of the barrage itself. Furthermore, by its very nature a tidal barrage is a barrier to the tide. This means that the level of water retained by the tidal barrage within, for example, an estuary will at times be greater than if the tidal barrage was not present. This could have a negative effect on the ecology of and around the estuary or whichever body of water the tidal barrage is constructed across. For instance, the presence of the tidal barrage may mean that mudflats are no longer exposed for wading birds and the like to feed from. Also, marine life may find it difficult or impossible to pass through the tidal barrage and this may have an effect on their migration, feeding or breeding patterns. Although it has been estimated that such tidal barrages could provide a large amount of the electricity required for the surrounding area, the ecological disadvantages may outweigh the electricity generation benefits.

[026] Figure 2 illustrates an arrangement which overcomes some of the ecological disadvantages associated with a tidal barrage. Figure 2 schematically depicts a turbine 14 which is fixed in position on a seabed 16 using a retaining structure 18.

The retaining structure 18 may be a large weight, or may comprise a fixing which has been drilled into the seabed 16, or any other suitable arrangement which is able to fix the turbine 14 in position relative to the seabed 16.

[027] The turbine 16 and support structure 18 are fixed in position on the seabed 16 where there is some flow (indicated by arrows 20) in a body of water 22. For instance, the flow 20 of the water 22 could be a tidal flow, or could be the flow of water leaving a river mouth or estuary or the like. As water 22 flows through the turbine 14 component parts of the turbine 14 are rotated or moved to generate electricity.

[028] The arrangement shown in Figure 2 does not affect the tides of an estuary, or the like, and does therefore not have many of the problems associated with the use of a tidal barrage. However, the arrangement shown in Figure 2 may still be difficult to construct and maintain, given that the arrangement will be located at the bottom of a body of water such as on a seabed or a riverbed.

[029] Figure 3 depicts an arrangement for converting the kinetic energy of a flowing liquid into electrical energy (or any other form of energy, such as kinetic energy of apparatus, potential energy, etc.) in accordance with an embodiment of the present invention. Figure 3 shows a vessel 24 (which includes every description of water craft or other artificial contrivance used, or capable of being used, as a means of transportation on water or another liquid). The vessel 24 is shown as floating upon a body of fluid (for example, water, such as in a river, estuary, sea, ocean, etc). The direction of flow of the water 26 is indicated by arrows 28. Movement of the vessel 24 on the water 26 is restricted, since the vessel 24 is retained substantially within a range of positions by means of an anchor 30. Of course, movement of the vessel may be restrained to one of a number of positions using any suitable arrangement, for example by tying or fixing the vessel 24 to a mooring or the like.

[030] It can be seen that the vessel 24 is provided with a propulsion arrangement 32, such as a propeller. In normal use, the vessel 24 may be provided with an engine which is used to rotate the propulsion arrangement 32 in a clockwise or anti-clockwise direction in order to propel the vessel 24 forwards or backwards in the water 26.

However, the present invention works in an opposite manner. That is, the vessel is kept relatively stationary, while the flowing water 26 is used to cause rotation of the propulsion arrangement 32. Rotation of the propulsion arrangement 32 can be used to generate electricity, either from the engine or other driving arrangement to which the proportion arrangement 32 is attached, or by additional equipment which is configured to generate electricity from rotation of the proportion arrangement 32. In general, kinetic energy of the flowing fluid can be converted using any energy conversion arrangement, such as a turbine, a dynamo, alternator, etc. [031] Figure 4 depicts the arrangement of Figure 3 in more detail. It can be seen that the propulsion arrangement 32 is attached to a shaft 34. The flowing water 26 causes rotation of the proportional arrangement 32 and therefore also the shaft 34. Rotation of the shaft 34 may cause an engine 36 with which the vessel 24 is provided to operate in a reverse direction, and thereby generate electricity which may be provided to an output 38. Alternatively or additionally, further apparatus such as a dynamo 40 may be connected to the shaft 34 by a connecting means, such as a belt, or chain, or gearbox, or driving mechanism, or the like. Rotation of the propulsion arrangement 32, and therefore shaft 34, will therefore be used to cause movement of a part of the dynamo 40, thereby allowing electricity to be generated and provided to the output 38. Cables or wires or the like may be connected to the output 38 in order to deliver generated electricity from the vessel to a coastline or shoreline or the like.

Alternatively or additionally, generated electricity maybe stored on the vessel, for example in a battery or a capacitor or the like.

[032] The arrangement shown in Figures 3 and 4 generates electricity without the generation of carbon dioxide or other harmful greenhouse gases. Since the electricity is generated using a vessel, the vessel can be easily moved into an area of useful fluid flow, for example the mouth of an estuary, or in a river, or in a tidal flow, etc. The vessel can then be retained substantially in position using an anchor or the like, such that fluid flowing past and around the vessel may be used to cause rotation of a propulsion arrangement with which the vessel is provided. The fluid flow could also be used to cause movement of other energy generation arrangements with which the vessel is provided, for example turbines or the like attached to the hull of the vessel.

[033] As mentioned above, electricity can be generated using an engine or the driving arrangement with which the vessel is provided. Alternatively other generation equipment could be added to the vessel to generate the required electricity. The vessel could also be provided with one or more solar panels, photovoltaic and/or air flow (i.e wind) driven turbines for generating further amounts of electricity. Since the electricity is being generated using a vessel, the vessel can be moved easily, for example to account for the seasonal migration of animals or if electricity generation is no longer viable in the area in which the vessel is located. Furthermore, the costs associated with electricity generation according to the described embodiment are low, since existing vessels can be used to generate the electricity. There is no need to spend millions or even billions of pounds building a permanently located tidal barrage, when instead a plurality of vessels can be used to extend across the mouth of an estuary or the like and generate electricity.

[0341 Any suitable vessel may be used to generate the required electricity. It is not necessary that the vessels are new, or that they have been constructed specifically for the purpose of generating electricity. Indeed, in some circumstances, it may be preferable to use redundant vessels for generating electricity (e.g. vessels which are no longer in use). This is because such redundant vessels may be on the verge of being scrapped or scuttled, whereas they may last many decades generating electricity in accordance with the method described above. The vessel need not float on a body of fluid, but could be located within the body of fluid, for example like a submarine.

[035] The present invention has the benefits of being able to generate electricity cheaply, and without having large detrimental effects on the ecology of the environment in which the vessel is used to generate electricity. Furthermore, the cost of converting an existing vessel to generate electricity will be relatively low in comparison with the building and construction of a purpose built turbine for anchoring on the seabed or a tidal barrage. Additionally, the maintenance and decommission of a vessel used to convert electricity (or in other words, convert, extract or generate energy) in accordance with an embodiment of the present invention will be cheap in comparison with prior art methods. This is because a vessel can simply be maintained on site, or can be moved to a dry-dock or the like. This is in comparison with the prior art, where there may be a no need to use expensive equipment to maintain, or decommission an underwater turbine or a large permanently located tidal barrage.

[036] Figures 5a to 5d schematically depict arrangements for converting kinetic energy of a fluid flow into electricity in accordance with an embodiment of the present invention.

Figure 5a shows how a single vessel may be located in an estuary defined by shorelines 46, 48. Kinetic energy may be converted into electrical energy from a tidal or river flow, for example. The electricity generated using the vessel 42 may be stored on board the vessel 42, or may be provided to an electrical supply system on the shore lines 46, 48 using electrical cabling or the like. Figure 5b shows how a plurality of vessels 42 may extend across the estuary 44 between the shorelines 46, 48. Figure 5c shows how a plurality of vessels 42 may be grouped together on the estuary 44. Figure 5d shows how a plurality of vessels 42 may be arranged in a linear manner on the estuary 44.

[037] Referring to Figures 5a to 5b, it will be appreciated that since vessels are used to generate the electricity, the vessels may be located in any suitable manner, and any suitable location. This allows electricity to be generated where it is needed, and as efficiently as possible. Since moveable vessels are used, any location or positioning of the vessels does not need to be permanent, but can easily be modified to take into account changes in the water flow or the passing of ships, etc. [038] In the above embodiments, the flow of liquid has been described as causing movement of, for example, a propeller or turbine. Such movement is likely to be rotation about an axis substantially parallel to the direction of fluid flow. However, other arrangements are possible. For example, the rotation could be about an axis substantially perpendicular to the flow direction, as would be the case when one or more paddles (for example of a paddle wheel) are driven by the fluid flow. One or more paddles, or a paddle wheel, may be particularly useful in shallow water, and/or water with a low flow rate.

[039] It will be appreciated that the above embodiments have been given by way of example only. It can therefore be appreciated that various modifications may be made to these described embodiments, and indeed other embodiments not described, without departing from the invention as defined by the claims that follow.

Claims

CLAIMS1. A method comprising: using a flow of a liquid to move at least a part of a first energy conversion arrangement with which a vessel is provided in order to convert kinetic energy of the flow of liquid into an other form of energy.
2. The method as claimed in claim 1, wherein the other form energy is electrical energy.
3. The method as claimed in claim I or claim 2, wherein the first energy conversion arrangement is arranged to convert kinetic energy into electrical energy.
4. The method as claimed in any preceding claim, wherein the first energy conversion arrangement comprises at least a part of a propulsion arrangement of the vessel.
5. The method as claimed in claim 4, wherein the at least a part of the propulsion arrangement comprises a propeller, a turbine, an engine, or a shaft.
6. The method as claimed in any preceding claim, wherein the at least a part of the propulsion arrangement comprises one or more paddles.
7. The method as claimed in any preceding claim, wherein the first energy conversion arrangement comprises a turbine, a dynamo, or an alternator.
6. The method as claimed in any preceding claim, comprising locating the vessel such that at least a part of the first energy conversion arrangement is located in the flow of liquid.
9. The method as claimed in any preceding claim, wherein the vessel further comprises a second energy conversion device.
10. The method as claimed in claim 9, wherein the second energy conversion device comprises a photovoltaic cell, a solar panel or an air flow driven turbine.
11. The method as claimed in any preceding claim, wherein movement of the vessel is restrained to one of a number of positions.
12. The method as claimed in any preceding claim, wherein the vessel is anchored.
13. The method as claimed in any preceding claim, wherein the liquid is water.
14. The method as claimed in any preceding claim, wherein the other form of energy is electrical energy, potential energy, or kinetic energy of apparatus with which the vessel is provided.
15. Apparatus for converting energy from one form into another, the apparatus comprising: a vessel suitable for location in a flow of liquid, the vessel comprising an energy conversion device, which, in use, is arranged to convert kinetic energy of the flow of liquid into an other form of energy.