WO2017144840A1

WO2017144840A1 - Apparatus for generating electricity from a flow of water

Info

Publication number: WO2017144840A1
Application number: PCT/GB2017/000022
Authority: WO
Inventors: William Edward BAXLEY; Bruce HEAFITZ; Patrick James Mulvey
Original assignee: Ocean Current Energy Llc
Priority date: 2016-02-23
Filing date: 2017-02-17
Publication date: 2017-08-31

Abstract

Apparatus (2) for generating electricity from a flow of water, which apparatus (2) comprises: (i) electricity generating means (4) which is for being rotated by the water in order to generate the electricity; and (ii) a housing (6) for directing the water to the electricity generating means (4), and the apparatus (2) being such that: (iii) at least a part of the housing (6) tapers inwardly towards the electricity generating means (4); (iv) the housing (6) is a collapsible housing (6) which is movable between a collapsed position and an erected position; and (v) the apparatus (2) is configured as movable apparatus (2) which is able to be transported to the water with the housing (6) in the collapsed position, which is able to be used at the water with the housing (6) being moved at the water from the collapsed position to the erected position, and which is able to be collapsed for transportation after use with the housing (6) being moved at the water from the erected position to the collapsed position.

Description

APPARATUS FOR GENERATING ELECTRICITY

FROM A FLOW OF WATER

This invention relates to apparatus for generating electricity from a flow of water.

There are many different known types of apparatus for generating electricity from a flow of water. Often the known types of apparatus are permanent constructions in the water. Where the known types of apparatus are not permanent constructions, then they may be such that they are not easily transported to and from places of use.

It is an aim of the present invention to obviate or reduce the above mentioned problem,

Accordingly, in one non-limiting embodiment of the present invention, there is provided apparatus for generating electricity from a flow of water, which apparatus comprises:

(i) electricity generating means which is for being rotated by the water in order to generate the electricity; and

(ii) a housing for directing the water to the electricity generating means, and the apparatus being such that: (iii) at least a part of the housing tapers inwardly towards the electricity generating means;

(iv) the housing is a collapsible housing which is movable between a collapsed position and an erected position; and

(v) the apparatus is configured as movable apparatus which is able to be transported to the water with the housing in the collapsed position, Which is able to be used at the water With the housing being moved at the water from the collapsed position to the erected position, and which is able to be collapsed for transportation after use with the housing being moved at the water from the erected position to the collapsed position.

The apparatus of the present invention is advantageous in that it is easily transported to and from places of use.

In the collapsed position of the housing, the apparatus is able to be more easily moved and stored than would be the case if the housing were still in the erected position. For example, in the collapsed position of the housing, a plurality of units of the apparatus may be stacked on top of one another and/or side by side, and in considerably less space than would be the case if the housing were to be in the erected position.

Because the apparatus is easily able to be transported and stored, the apparatus is easily able to be moved to countries or regions that may be requiring emergency aid. For example, the apparatus may easily be transported to a country or region having a natural disaster such for example as an earthquake, or a man-made disaster such for example as a war. The transportation may be by a person or by a vehicle. The vehicle may be a land vehicle, a ship, or an aircraft. The transportation may be a combination of a vehicle or vehicles and a person. For example, an aircraft or ship may be used to transport a plurality of units of the apparatus to a country or region needing aid, then a road vehicle may be employed, and then a person may be employed if the location is not accessible by the road vehicle, for example a lorry.

The apparatus of the present invention may operate with any available flow of water, for example a stream, a river, or a tidal flow along a coast. After use, the apparatus is able to be collapsed and taken away, for example taken away by reversing the manner in which the apparatus was transported to the flow of water.

During use, the apparatus of the present invention may be deployed to face against the direction of flow of the water, whereby the housing increases the rate of flow of the water as the water enters the housing and progresses towards the electricity generating means. Alternatively, if desired, the apparatus of the present invention may be deployed to face with the direction of flow of the water, whereby the housing may act as a diverging device, for example to decrease water pressure at the end of the apparatus containing the electricity generating means, and thereby to improve flow through the electricity generating means. The apparatus may be one in which the collapsible housing comprising a plurality of parts which are movable between the collapsed position and the erected position. There may be two or more of the parts.

Preferably, where the collapsible housing comprises a plurality of the parts, then the parts are screw threaded parts having screw threads which enable the parts to be moved between the collapsed arid erected positions. The screw threads may typically be on parallel sided portions of the screw threaded parts. Alternative constructions may be employed so that, instead of employing screw threaded parts, the various parts may be arranged to open, close and align with any suitable and appropriate means. For example, the parts may be constrained to open, close and align as required using telescopic arrangements, flexible guide rods, aligned cylinders, flexible fabrics, or conical compression springs.

Where the parts are screw threaded parts, then the screw threads are preferably of a sufficient length and configuration that they enable the parts to be securely held together when the housing is in the erected position and the apparatus is in use. When the apparatus is in use, the apparatus will be under the influence of the water, and drag loads from the flow of water may be substantial

Usually, when the collapsible housing comprises the plurality of parts, then the parts will progressively decrease in diameter such as to form the inward taper towards the electricity generating means.

The apparatus may include retainer means for retaining the parts together. The retainer means may be one or more stops. Other types of retainer means may be employed. With screw threaded parts, then the retainer means may be one or more stops which prevent the parts from being unscrewed so far that they become apart. If the parts were to come apart, then reassembly may be inconvenient. Also, parts that have come apart are easily lost, which is desirably prevented.

When the parts are screw threaded parts, then the retainer means may act as normal for the erecting and collapsing, but may additionally act to allow separation of the parts if the parts are unscrewed in another way. The separation of the parts may be desirable for maintenance and repair. When maintained as required, the parts can be re-connected together by reversing the unscrewing procedure.

Where the housing comprises two or more of the parts, then the last part is preferably such that it has a smooth exterior.

With a housing comprising two or more screw threaded parts, then the last part will usually be such that it only has internal threads. Thus the last part of the housing may be, for example, such that it has a smooth exterior and only internal threads.

The apparatus may be one in which the electricity generating means is disc-shaped. A disc-shaped electricity generating means, for example a discshaped electrical generator, may be flat, and therefore easier to transport and store than electricity generating means of some other shape.

The apparatus may include orientation-maintaining means for use in maintaining the apparatus in a set orientation in the flow of water. The orientation-maintaining means may be a rudder arrangement. Other types of orientation-maintaining means may be employed.

A preferred type of rudder arrangement comprises:

(a) first and second rudder formations which are pivotable between a closed position in which the first and second rudder formations form a cover on the housing and thereby act to protect the electricity generating means, and a plurality of open positions whereby an open position is able to be chosen which is able to maintain the apparatus in the required orientation in the flow of water and also prevent rotation of the housing in the water; and

(b) adjustable securing means for securing the first and second rudder formations in their chosen open position and thereby to ensure maintained positional stability of the apparatus.

The first and second rudder formations are preferably centrally positioned on the apparatus. The first and second rudder formations may be positioned elsewhere if desired.

The first and second rudder formations are preferably of substantially the same shape and size. First and second rudder formations of different shapes and sizes may however be employed. Preferably, the first arid second rudder formations are of the same shape and size and they are semi-circular in plan view. Other shapes for the first and second rudder formations are hexagonal or square. Generally, when the first and second rudder formations are of the same shape and size, they may be of any suitable and appropriate shape and size that is able to be symmetrically folded to the closed position.

The first and second rudder formations may pivot about pivots which are mounted on a larger end of the housing, and which are centrally positioned on the housing. Typically, each first and second rudder formation will have its own pivot arrangement. A single pivot formation may however be employed for both the first and second rudder formations if desired.

The adjustable securing means may be extendable in length, and then fixable at that length. In this case, the adjustable securing means may be a device having internal screw threads which connect two rods to regulate their length. Preferably the adjustable securing means is a turnbuckle. Other types of adjustable securing means may be employed so that, for example, the adjustable securing means may be a hydraulic piston and cylinder or a linear actuator.

The apparatus may include a mooring device for connecting the apparatus to a fixture. Any suitable and appropriate fixture may be employed including a land-based bollard, cleat, ring, tree or pylon.

The mooring device may be a two-leg bridle. Other types of mooring devices may be employed. The apparatus may include locking means for locking the first and second rudder formations in the closed position.

Preferably the locking means is an integral locking means but a separate locking means may be employed if desired.

When the locking means is an integral locking means then the integral locking means may be a centre section of the collapsible housing, and in which the centre section of the collapsible housing screws into a position which effects the locking.

The apparatus of the present invention may include protector means for protecting portions of the apparatus. Thus, for example, the protector means may protect inner portions of the movable parts and/or the electricity generating means.

The protector means may be a cover. Other types of protector means may be employed.

The apparatus may include debris-deflecting means.

The debris-deflecting means may be a pointed rod arrangement. Other debris-deflecting means may be employed for deflecting debris of the type found in the flowing ater, and thereby preventing the debris from entering the apparatus and causing damage. Thus, for example, an alternative debris- deflecting means may be a mesh arrangement.

The housing may have a hexagonal frame at its outer end. The hexagonal frame is convenient for connecting to other housings with hexagonal frames and/or to other structures having hexagonal configurations. The hexagonal frame may enable stable and rigid connections to be made, The electricity generated by the apparatus may be used in a variety of ways. Thus, for example, the generated electricity may be taken from the apparatus and used elsewhere, or it may be retained in the apparatus for use. Where the generated electricity is taken from the apparatus and used elsewhere, then this may be done by providing the apparatus with an output electrical cable for transporting the generated electricity from the apparatus to a place of use. The place of use may be an intermediate electricity storage facility and/or an electricity dispensing facility and/or one or more specific end user facilities.

If the generated electricity is not run from the apparatus, then it may be stored in the apparatus. In this case, the generated electricity may be stored in any suitable and appropriate electrical-storage means, for example one or more batteries, capacitors or other devices. Where the generated electricity is stored in the apparatus, then the apparatus may be removed from the water after the electricity has been generated and stored, and then used as a rechargeable electrical pack for a variety of uses.

When the apparatus of the present invention includes electrical- storage means, then the electrical-storage means may be mounted on one side of the apparatus, or on the bottom of the apparatus. Such mounting of the electrical-storage means may facilitate the positioning and/or stability of the apparatus in the flow of water. This applies especially when the electrical- storage means is in the form of one or more batteries.

The apparatus of the present invention may be physically fixed in a position in the flow of water, so that the apparatus is not able to be moved by the flow of water and/or be rotated in its entirety by the flow of water. Such fixing may be achieved by mounting the apparatus on the bottom of a waterbed, or alternatively mounted to a pylon or other fixture mounted on the waterbed. Other means may be employed for physically securing the apparatus in position.

Where the apparatus is such that it floats in the flow of water, then the apparatus may advantageously include auxiliary compensating means for compensatihg for small variations in the flow of the water. The water may vary slightly in speed and/or direction, for example in dependence upon environmental conditions.

A preferred auxiliary compensating means is a spring. Other types of auxiliary compensating means may be employed, for example a bungee cord.

Where the apparatus is designed to float in water, then the apparatus may include buoyancy means. The degree of buoyancy provided by the buoyancy means may be chosen such that the apparatus floats at a desired position in the flow of water. Thus, for example, the buoyancy means may be chosen such that the apparatus typically floats near the surface of the water.

When the apparatus includes the buoyancy means, then the apparatus may be one in which one half of the apparatus contains the buoyancy means, and the other half of the apparatus contains the electrical-storage means, for example one or more batteries. In this case, the half of the apparatus containing the buoyancy means will have a positive buoyancy. The half of the apparatus containing the electrical-storage means will have a negative buoyancy. The buoyancy means will typically be chosen such that the overall apparatus has a lower density than that of water so that the apparatus floats as desired.

Ballast may be employed to adjust the buoyancy. The ballast may be in the form of ballast weights.

The apparatus of the present invention may include solar means for generating electricity using solar energy. The solar means will typically be employed when the apparatus is out of the water, for example when it is being carried on a person's back. If desired the solar means could generate electricity whilst the apparatus is in the water.

Preferably, the solar means is mounted on the first and/or second rudder formations.

Embodiments of the invention will now be described solely by way of example and With reference to the accompanying drawings in which:

Figure 1 is an exploded perspective view from one side and one end of first apparatus for generating electricity from a flow of water;

Figure 2 is a perspective view like Figure 1 but from the other end of the apparatus;

Figure 3 is a side view of the apparatus with its housing in a collapsed position;

Figure 4 is a side view of the apparatus with the housing in an erected position;

Figure 5 is a perspective view showing the inside of the apparatus in the collapsed position shown in Figure 3; Figure 6 is a perspective view showing the inside of the apparatus in the erected position shown in Figure 4;

Figure 7 is a section though the apparatus with the housing in the collapsed position shown in Figure 3;

Figure 8 is a section through the apparatus with the housing in the erected position shown in Figure 4;

Figure 9 is a perspective view from one end of second apparatus for generating electricity from a flow of water;

Figure 10 shows how the apparatus shown in Figures 1 - 8 may be transported With the collapsible housing in a collapsed position, and then being moved to an erected position for use;

Figure 1 is a perspective view of part of electricity generating means forming part of third apparatus of the present invention, with the electricity generating means including electricity-storage means for storing the generated electricity;

Figure 12 is a section through the electricity-generating means shown in Figure 1 1 ;

Figure 13 is a perspective view of the apparatus shown in Figure 11 , and with a cover portion which has been removed in Figure 11 in order to illustrate the electricity storage means;

Figure 14 is a perspective view of fourth apparatus of the present invention, with first and second rudder formations being shown in a closed position;

Figure 15 is a side view of the apparatus as shown in Figure 15; Figure 16 is a perspective view like Figure 14 but shows the first and second rudder formations in an open position;

Figure 17 is a top view which is similar to that shown in Figure 16 and which additionally shows the electricity generating means employed in the apparatus;

Figure 18 is a side view of fifth apparatus of the present invention; and Figure 19 is a perspective view of sixth apparatus of the present invention.

Referring to Figures 1 - 8, there is shown first apparatus 2 for generating electricity from a flow of water. The apparatus 2 comprises electricity generating means 4 which is for being rotated by the water in order to generate the electricity. The apparatus 2 also comprises a housing 6 for directing the water to the electricity generating means 4.

The apparatus 2 is such that the housing 6 tapers inwardly towards the electricity generating means 4. The housing 6 is a collapsible housing which is movable between a collapsed position as shown in Figures 3, 5 and 7, to an erected position as shown in Figures 4, 6 and 8.

The apparatus 2 is configured as movable apparatus which is able to be transported to the water with the housing 6 in the collapsed position, which is able to be used at the water with the housing 6 being moved at the water from the collapsed position to the erected position, and which is able to be collapsed for transportation after use with the housing 6 being moved at the water from the erected position to the collapsed position. The apparatus 2 is thus conveniently transported to the water. The apparatus 2 is also conveniently able to be assembled at the water. The apparatus is further easily able to be collapsed for re-transportation after use. Still further, when not in use, the apparatus 2 is easily stored. The provision of the collapsible housing ensures that the apparatus 2 is able to be much more compact for the transportation and storage than will be the case if the housing were not to be collapsible.

The collapsible housing comprises a plurality of parts 8 which are movable between the collapsed position and the erected position. The parts 8 are screw threaded parts having screw threads 10 which enable the parts 8 to be moved between the collapsed and erected positions. The screw threads are on parallel sided portions of the parts 8 as shown. The screw threads 10 are of a sufficient length and configuration that they enable the parts 8 to be securely held together when the housing 6 is in the erected position and the apparatus 2 is in use. The outermost part 8 progressively decreases in diameter such that it forms the inward taper towards the electricity generating means 4. The outer part of the housing 6 is thus of a funnel shape.

The apparatus 2 includes retainer means in the form of stops for preventing the parts becoming unscrewed so far that the parts 8 become separated. This prevents the need to re-assemble the parts 8 and it also prevents inadvertent loss of the parts 8. The retainer means in the form of the stops may act as normal for the erecting and collapsing of the housing 6. In addition they may actually allow separation of the parts 8 if the parts are screwed and unscrewed in another way to the normal screwing and unscrewing. This may then enable the parts 8 to be separated for maintenance and repair.

The outermost part 8 has a smooth exterior. The outermost part 8 also only has internal threads. Other parts will typically have internal and external threads 10. In this connection, and as can be seen from Figure 1 , the electricity generating means 4 has external threads 12 which enable it to be screwed into the adjacent part 8, with the external threads 12 on the electricity generating means 4 mating with the internal threads 10 on the adjacent part 8.

As can also be seen from Figure 1 , the electricity generating means 4 is disc-shaped. Thus the electricity generating means 4 is relatively flat. This helps to facilitate the formation of a compact design for the apparatus 2 which in turn facilitates transportation and storage.

Referring now to Figure 9, there is shown second apparatus 14 of the present invention. Similar parts as in the first apparatus 2 have been given the same reference numerals for ease of comparison and understanding. In the second apparatus 14, the end part 8 of the housing 6 includes a pointed arrangement 16. The pointed arrangement 16 comprises a plurality of cables 18 which extend from the outermost part 8 to an attachment point 20. The cables 18 may be thin, and they may be made of a metal or a synthetic fibre. The pointed arrangement 16 may be used to restrain the second apparatus 14 against a current. A rope or other tether may be attached to the attachment point 20. The other end of the rope or other tether may then be attached to an anchor point such for example as a tree, rock or anchor. The cables 18 are shown as rigid, as they would be during use of the apparatus 14 when it will be subject to water drag. The pointed arrangement 16 is also able to act as a debris-deflecting means for deflecting debris from turbine blades in the electricity generating means 4, and thereby preventing damage. The cables 18 also help to contribute to the portability of the apparatus 14. Because they are able to be flexible, they are able to be coiled for storage. Rigid rods may be employed if desired, for example where storage is not a problem and/or where the apparatus 14 is easily able to be transported and/or where debris requiring deflection is of a significant size.

The apparatus 14 is also such that the housing 6 has a hexagonal frame 22 at its outer end. As can be seen from Figure 9, the hexagonal frame 22 is positioned on the end of the outermost part 8. The rods 18 are connected to the hexagonal frame 22. The hexagonal frame 22 provides a shape which is good for connecting to other housings of sirhilar shapes and/or other structures of similar shapes, with the resulting connections being rigid and robust.

Figure 10 illustrates schematically how the apparatus is able to be transported in a collapsed position on a back 24 of a person 26. Figure 10 also illustrates schematically how the person 26 is able to deploy the apparatus 2 such that the housing is moved from the collapsed position shown on the back 25 of the person 26 to an erected condition in which the apparatus 2 is then able to be placed in a flow of water 28. Figure 10 shows the apparatus 2 such that the largest end of the funnel shape formed by the erected housing 6 faces upstream. In this orientation, the funnel shape of the erected housing 6 will cause the water 28 to increase in velocity as it approaches the electricity generating means 4 at the other end of the apparatus 2. If desired, the apparatus 2 could be turned through 180° so that the larger open end of the erected housing 6 faces downstream. In this case, the housing 6 may operate as a diverging device, which decreases pressure at the rear of the apparatus 2 as deployed, and thereby improves flow through the electricity generator means 4.

Referring to Figures 11 , 12 and 13, there is shown electricity generating means 34 comprising an outer casing 36 which is provided with screw threads 38. The screw threads 38 are for enabling the electricity generating means 34 to be connected to other parts of apparatus of the present invention, in the same manner as the screw threads 12 on the electricity-generating means 4 in the apparatus 2 shown in Figures 1 - 8. The electricity-generating means 34 is provided With an inner casing 40. The inner casing 40 contains a rotor 42 and a stator 44. The rotor 42 has blades 46 as shown. The rotor 42 may be of a standard construction.

The outer casing 36 and the inner casing 40 define between them a space 48. This space 48 houses electricity storage means in the form of a plurality of batteries 50. Some of the batteries 50 have been omitted in Figure 1 in order to better illustrate the space 48. Figure 13 shows how the space 48 and the batteries 50 are enclosed by a cover 52.

The electricity-generating means 4 may form part of the apparatus of the present invention. When the electricity has been generated, it is stored in the batteries 50. The batteries 50 are rechargeable batteries so that they can be recharged with electricity as and when appropriate. When the batteries 50 have been charged, then the apparatus containing the electricity-generating means 34 is able to be used as a rechargeable battery pack. The rechargeable battery pack can be used for any suitable and appropriate use. The rechargeable battery pack is able to be removed from the water and used where desired.

It can be seen from Figure 1 1 that the electricity generator means 34 can still be of a preferred disc shape. All the space 48 and the batteries 50 have done is to increase the diameter of the electricity-generating means 34, as compared with the electricity-generating means 34 if it were not used with electricity storage means in the form of the batteries 50.

In Figures 14 - 17, there is shown fourth apparatus 58 of the present invention. The apparatus 58 Is like the apparatus 2 shown in Figure 1. The apparatus 58 includes a rudder arrangement 60 comprising a first rudder formation 62 and a second rudder formation 64. The first and second rudder formations 62, 64 are pivotable between a closed position as shown in Figures 14 and 15 to a plurality of open positions as can be appreciated from Figures 16 and 17. In the closed position, the first and second rudder formations 62, 64 form a cover on the housing 6 and thereby act to protect the electricity generating means 4. The open position shown in Figures 16 and 17 is one of a plurality of open positions which are able to be chosen to maintain the apparatus 58 in the required orientation in the flow of water, and also to prevent rotation of the housing 6 in the water. The apparatus 58 also comprises adjustable securing means (not shown) for securing the first and second rudder formations 62, 64 in their chosen open position, and thereby to ensure maintained positional stability of the apparatus.

The first and second rudder formations 62, 64 are centrally positioned on the apparatus 52 as shown. The first and second rudder formations 62, 64 are of substantially the same shape and size. More specifically, the first and second rudder formations 62, 64 are semi-circular in plan view as can best be appreciated from Figure 14.

The first and second rudder formations 62, 64 pivot about pivots 66, 68. As can best be appreciated from Figure 15, the pivots 66, 68 are mounted at the larger end of the housing 6. Also, the pivots 66, 68 are centrally positioned on the housing 6.

Referring now to Figure 18, there is shown fifth apparatus 70 which is like the apparatus 58, but which includes an example of adjustable securing means for securing the first and second rudder formations 62, 64 in their chosen open position and thereby to secure the maintained positional stability of the apparatus 70. Thus the apparatus 70 includes adjustable securing means 72. The adjustable securing means 72 is extendable in length, and then it is fixable at that length. The adjustable securing means 72 is in the form of a turnbuckle which includes screw threads 74 which connect to rod members 76 to regulate the length of the rod members 76. Each rod member 76 terminates in a ring 78. One ring 78 conhects to the rudder arrangement 60, for example via apertures 79, and the other ring 78 connects to the housing 6.

Figure 18 also shows how the apparatus 70 is able to be provided With a mooring device 80 for connecting the apparatus to a fixture (not shown) on shore. The fixture may be a bollard, cleat, ring, tree, pylon or any other suitable and appropriate fixture. The mooring device 80 is in the form of a two-leg bridle having a first leg 82 and a second leg 84. The mooring device 80 includes a mooring line 86 which connects to the above mentioned fixture on shore- In Figure 18, water flow direction is indicated by arrows 88. The net force on the rudder arrangement 60 is indicated by arrow 90.

Referring now to Figure 19, there is shown sixth apparatus 92 of the present invention. The apparatus 92 is similar to the apparatus 58 as shown in Figure 14. In the apparatus 92, the first and second rudder formations 62, 64 are each provided with solar means 94 for generating electricity using solar energy. The solar means 94 may be any suitable and appropriate solar means for generating electricity from solar energy. Thus, for example, the solar means 94 may comprise a plurality of cells for generating electricity from the sun.

In a further embodiment of the present invention, the illustrated apparatus of the invention may be provided with auxiliary compensating means for compensating for small variations in the flow of the water. By way of example, it is mentioned that the auxiliary compensating means may be a spring such for example as the coil spring 96 shown in broken lines in Figure 18 and able to be positioned in the adjustable securing means 72, for example in one of the rod members 76 as indicated. Splicing means other the coil spring 96 may be employed so that, for example, the compensating means may be a bungee cord.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the apparatus 2, 14 may include orientation-maintaining means for use in maintaining the apparatus 2, 14 in a set orientation in the flow of water 28. The orientation-maintaining means may be a rudder arrangement. The apparatus 2, 14 may also include protector means for protecting portions of the apparatus 2, 14. The protector means may be a cover, and the protector means may protect inner portions of the movable parts 8 and/or the electricity generating means 4. The apparatus 2, 14 may have different shapes to those shown. The apparatus 2, 14 may be made of any suitable and appropriate materials. The electricity generator means 4 may be of a known construction including a rotor 30 and a stator 32. Units of the apparatus 2, 14 may be connected together to provide increased production of electricity.

The electricity-storage means may be other than the batteries 50. Also, the electricity storage means may be located at other positions on the electricity generating means 34, or alternatively on other parts of the apparatus of the present invention. If it is not desired to store the generated electricity somewhere on the apparatus of the present invention, then the electricity generating means may be provided with an output lead for running the generated electricity to an appropriate location from where the generated electricity can be further redirected as required and/or can be used at that location. If desired, the apparatus of the present invention may be configured to have both the facility of operating as an electricity-storage pack and as operating with an electrical output cable. Where batteries 50 are employed, then the batteries may be of any suitable and appropriate size arid electricity storing capacity. The batteries 50 may be loosely housed in the space 48, or they may be provided in their own containers. The cover 52 may be a screw fit on the external threads 54 or it may be otherwise fitted in position. The external threads 54 are for connecting the electricity generating means 34 to other parts of the apparatus as described in connection with Figures 1 - 8. The first and second rudder formations 62, 64 may be of another shape than that shown. The adjustable securing means 72 may be another device such for example as a hydraulic cylinder or a linear actuator. Other types of locking means for locking the first and second rudder formations 62, 64 in the closed position may be employed. The apparatus may include buoyancy means, for example buoyancy means made of a plastics foam material. Individual components shown in the drawings are not limited to use in their drawings and they may be used in other drawings and in all aspects of the invention. The invention also extends to the individual components mentioned and/or shown above, taken singly or in any combination.

Claims

1. Apparatus for generating electricity from a flow of water, which apparatus comprises:

(ii) a housing for directing the water to the electricity generating means, and the apparatus being such that:

(iii) at least a part of the housing tapers inwardly towards the electricity generating means;

2. Apparatus according to claim 1 in which the collapsible housing comprises a plurality of parts which are movable between the collapsed position and the erected positions.

3. Apparatus according to claim 2 in which the parts are screw threaded parts having screw threads which enable the parts to be moved between the collapsed and erected positions.

4. Apparatus according to claim 3 in which the screw threads are of a sufficient length and configuration that they enable the parts to be securely held together when the housing is in the erected position when the apparatus is in use.

5. Apparatus according to any one of claims 2 - 4 in which the parts progressively decrease in diameter such as to form the inward taper towards the electricity generating means.

6. Apparatus according to any one of claims 2 - 5 and including retainer means for retaining the parts together.

7. Apparatus according to any one of the preceding claims and including orientation-maintaining means for use in maintaining the apparatus in a set orientation in the flow of water.

8. Apparatus according to claim 7 in which the orientation-maintaining means is a rudder arrangement.

9. Apparatus according to claim 8 in which the rudder arrangement is such that it comprises:

10. Apparatus according to claim 9 in which the first and second rudder formations are pivotable about pivots which are mounted at a larger end of the apparatus, and which are controllably positioned on the housing.

11. Apparatus according to claim 9 or claim 10 in which the adjustable securing means is extendable in length, and then fixable at that length.

12. Apparatus according to any one of claims 9 - 11 and including a mooring device for connecting the apparatus to a fixture.

13. Apparatus according to any one of claims 9 - 12 and including locking means for locking the first and second rudder formations in the closed position.

14. Apparatus according to any one of the preceding claims and including protector means for protecting portions of the apparatus.

15. Apparatus according to any one of the preceding claims and including debris-deflecting means.

16. Apparatus according to any one of the preceding claims in which the housing has a hexagonal face at its outer end.

17. Apparatus according to any one of the preceding claims and including electrical storage means for storing generated electricity.

18. Apparatus according to claim 17 in which the apparatus is removable from the water after the electricity has been generated and stored and is then usable as a re-chargeable electrical pack.

19. Apparatus according to any one of the preceding claim and including auxiliary compensating means for compensating for small variations in the flow of the water.

20. Apparatus according to claim 19 in which the auxiliary compensating means is a spring.

21. Apparatus according to any one of the preceding claims and including buoyancy means.

22. Apparatus according to claim 21 in which the buoyancy means is contained in one half of the housing, and in which batteries are contained in the other half of the housing.

23. Apparatus according to any one of the preceding claims and including solar means for generating electricity using solar energy.