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Title:
ELECTRICITY GENERATING APPARATUS
Document Type and Number:
WIPO Patent Application WO/2013/116899
Kind Code:
A1
Abstract:
A compact electricity generating apparatus for use in tidal flows and streams with flow depths as low as 0.2 m uses an Archimedes screw located in a channel within a housing. Water flowing through the channel drives the screw and the rotation is used to directly generate electricity by locating permanent magnets in the blades of the screw which act as a rotor for stator coils located in the housing. Three phase power can then be provided to remote (i.e. on shore) power conversion and management apparatus. The apparatus are modular to allow rapid deployment and removal. Allowing multiple units to be mounted to support structures to form tree deployments. The trunks of such trees can be used to house power cables. Multiple trees can be deployed to create a forest deployment to allow scaling up power generation whilst maintaining ease of installation and maintenance.

Inventors:
TREVETHAN MARK (AU)
Application Number:
PCT/AU2013/000106
Publication Date:
August 15, 2013
Filing Date:
February 06, 2013
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
HERMATIKA PTY LTD (AU)
International Classes:
F03B13/26; F02K7/18; F03B13/04; F03B13/10; F03C2/00
Domestic Patent References:
WO2003083292A12003-10-09
WO2010149983A22010-12-29
WO2007111546A12007-10-04
Foreign References:
US20120007364A12012-01-12
US4367413A1983-01-04
KR20070025041A2007-03-08
EP2375529A12011-10-12
Attorney, Agent or Firm:
MADDERNS (Adelaide, South Australia 5001, AU)
Download PDF:
Claims:
CLAIMS

1. An apparatus for generating electricity when immersed in moving liquid the apparatus including: an elongated housing, the elongated housing including a channel extending from a first opening located at one end of the housing to a second opening located at an opposed end of the housing, the channel forming a liquid flow conduit to allow liquid to flow between the first and second openings; a rotating member including one or more blades rotatably mounted within the channel to convert the kinetic energy of liquid flowing through the channel to rotational energy;

an electricity generating assembly to generate electricity from the rotational energy of the rotating member, the electricity generating assembly including a rotor component including one or more permanent magnets located in the one or more blades and a stator component forming part of the housing of the apparatus.

2. The apparatus as claimed in claim 1, wherein the one or more permanent magnets are rare earth magnets.

3. The apparatus as claimed in claim 2, wherein the one or more permanent magnets are Neodymium magnets.

4. The apparatus as claimed in any one of claims 1 to 3, wherein the one or more permanent magnets are elongated having a length greater than their width, and the length dimension is radially directed with respect to the rotation axis of the rotating member.

5. The apparatus as claimed in claim 4, wherein the one or more permanent magnets are rod shaped and have a length at least twice their diameter.

6. The apparatus as claimed in claim 5, wherein the one or more permanent magnets have a length substantially equal to the length of the blade they are located within.

7. The apparatus as claimed in any one of the preceding claims wherein the one or more blades contain one or more cavities for receiving a permanent magnet, and in use a permanent magnet is inserted into a cavity and sealed in place with a magnetic cap.

8. The apparatus as claimed in any one of the preceding claims, wherein the one or more permanent magnets includes a plurality of permanent magnets and the stator component includes a plurality of coils and the plurality of magnets are plurality of coils are arranged in one or more clusters, each cluster substantially located in a plane perpendicular to the axis of the rotating member, 'and in which the plurality of coils in a cluster are equiangularly spaced around the axis of the rotating member.

9. The apparatus as c laimed in any one of the preceding claims, wherein the apparatus is configured so that its electricity generating capacity is substantially independent of the direction of flow of liquid within the channel upon immersion of the apparatus.

10. The apparatus as claimed in any one of the preceding claims, wherein the configuration of the apparatus is substantially symmetrical about a horizontal midplane.

1 1. The apparatus as claimed in any one of the preceding claims, wherein the elongated housing is substantially tubular.

12. The apparatus of any one of the preceding claims, wherein the elongated housing is configured to increase the velocity of liquid flowing through the channel.

13. The apparatus of claim 12, wherein the elongated housing is configured to increase the velocity of liquid flowing through the channel by reducing the sectional area as liquid moves from the first opening towards the channel.

14. The apparatus of claim 13, wherein the first opening includes inwardly sloping walls forming an inlet to the channel.

1 5. The apparatus of any one of the preceding claims, wherein the rotating member is an impeller screw.

16. The apparatus of claim 15, wherein the impeller screw is an Archimedes screw.

17. The apparatus of any one of claims 1 to 14, wherein the rotating member includes a plurality of propellers spaced along the channel.

18. The apparatus of any one of the preceding claims, wherein the electricity generating assembly generates three phase alternating current electricity.

19. The apparatus as claimed in claim 18, wherein the one or more permanent magnets includes a plurality of permanent magnets and the stator component includes one or more groups of six coils, wherein each group of six coils includes three pairs of coils for generating one phase of the three phases, and each group is located in a plane perpendicular to the axis of the rotating member.

20. The apparatus of any one of the preceding claims, wherein the apparatus includes a mounting region located on the elongate housing, the mounting region connectable to a mounting means and providing a waterproof electrical connection when connected to the mounting means to convey electricity generated by the electricity generating apparatus.

21. The apparatus of any one of the preceding claims, wherein the electricity generating apparatus is configured to operate in a depth of approximately 0.5 metres.

22. The apparatus of any one of the preceding claims, wherein the electricity generating apparatus is configured to operate in a depth of approximately 0.2 metres.

23. An electricity generating arrangement including one or more electricity generating apparatus as claimed in any one of claims 1 to 22, which in use is operatively connected to a remote power conversion apparatus for providing a conditioned electrical signal from the electrical signals generated from the one or more electricity generating apparatus.

24. The electricity generating arrangement as claimed in claim 23, wherein the one or more electricity generating apparatus are a plurality of electricity and further including a mounting means for mounting the plurality of modular electricity generating apparatus below the surface of the flowing liquid at a predetermined depth, wherein the mounting means is operable to preserve the orientation of the plurality of modular electricity generating apparatus with respect to a direction of the flowing liquid as the direction to changes.

25. . The electricity generating arrangement as claimed in claim 23 wherein the one or more electricity generating apparatus are a plurality of electricity generating apparatus, and further including:

mounting means for mounting the plurality of modular electricity generating apparatus below the surface of a flowing liquid at an initial depth, and

flotation means operable to preserve the initial depth of the plurality of modular electricity generating apparatus as the level of the surface of the flowing liquid changes.

26. The electricity generating arrangement as claimed in claim 23 wherein the one or more electricity generating apparatus are a plurality of electricity generating apparatus and further including a trunk structure and one or more branches located underwater, wherein the individual electricity generating apparatus are mounted to the trunk structure and/or to the one or more branches to form an underwater TREE deployment.

27. The electricity generating arrangement of claim 26, wherein each of the electricity generating apparatus is mounted to the TREE deployment by a water proof electrical connection.

28. The electricity generating arrangement of claim 27, wherein electricity is conveyed from each of the electricity generating apparatus via the water proof electrical connection and by separate cabling to the surface for electrical conditioning.

29. The electricity generating arrangement of claim 27, wherein electricity is conveyed from each of the electricity generating apparatus via the water proof electrical connection and by separate cabling to the trunk of the TREE deployment for electrical conditioning.

30. The electricity generating arrangement of any one of claims 26 to 29 further including a plurality of TREE deployments to form a FOREST deployment.

3 1. A method for generating a conditioned electrical signal from one or more apparatus immersed in a moving liquid, the method including:

receiving, by a power conversion apparatus, one or more unconditioned electrical signals from one or more electricity generating apparatus via one or more cables, wherein each of the one or more electricity generating apparatus includes:

an elongated housing, the elongated housing including a channel extending from a first opening located at one end of the housing to a second opening located at an opposed end of the housing, the channel forming a liquid flow conduit to allow liquid to flow between the first and second openings; a rotating member including one or more blades rotatably mounted within the channel to convert the kinetic energy of liquid flowing through the channel to rotational energy; and

an electricity generating assembly to generate an unconditioned electrical signal from the rotational energy of the rotating member, the electricity generating assembly including a rotor component including one or more permanent magnets located in the one or more blades and a stator component forming part of the housing of the apparatus; and

converting the received one or more electrical signals into an output power signal.

Description:
ELECTRICITY GENERATING APPARATUS PRIORITY DOCUMENTS

[0001 ] The present application claims priority from Australian Provisional Patent Application No.

2012900423 entitled "ELECTRICITY GENERATING APPARATUS" filed on 6 February 2012, the content of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to the generation of electricity. In a particular form, the present invention relates to the generation of electricity from flowing water arising from fluvial, tidal, ocean currents or the like.

BACKGROUND

[0003] Presently there is a growing interest in developing energy devices that utilise clean renewable energy sources. To date the main focus and effort has been towards the extraction of power from solar, wind and wave energy. However the inconsistent presence of these sources implies that such renewable energy sources can only be used to supplement energy demands rather than provide a realistic permanent replacement for fossil fuels. One of the more underutilised sources of renewable energy is from flowing water (e.g. hydroelectricity, tidal currents). Unlike other sources of renewable energy, natural sources of flowing water such as tidal currents are completely predictable and constant. Alternatively, sources of flowing water can be created and controlled through artificial structures such as dams or weirs such as employed in hydroelectric installations.

[0004] Large scale hydroelectricity plants presently supply approximately twenty percent of the world's energy needs. These schemes use large artificially constructed structures (e.g. dams) to control the flow of water through large turbines. However such schemes are extremely expensive to construct and maintain, and cause a tremendous amount of irreversible damage to the environment surrounding these structures.

[0005] There are presently two methods for extracting energy from the tides, these being tidal barrages and tidal stream generators. Like hydroelectricity, tidal barrages are extremely expensive to construct and maintain as well as having a dramatic impact on the local environment. Alternatively, tidal stream generators use the momentum of the flowing water created by the tides to turn some form of impeller to generate electricity. However, tidal stream energy generators are generally too big to be deployed in shallow depths and as such they have to be implemented at depths for energy extraction where they compete with shipping. This competition for space has to date made it difficult to develop effective large scale tidal energy schemes. [0006] The water depth requirement of current devices has also affected the viability of this type of renewable energy source for another important reason. For a given tidal range, the local flow velocity generated by the tidal flow is larger in shallower depths and smaller cross-sectional areas and as such the vast amounts of energy within these shallower depth tidal regions represents a significant potential source of electric power that to date cannot be effectively utilised by current tidal flow devices.

[0007] There is accordingly a need for apparatus capable of generating electricity from sources of flowing water such as tidal flows and the like.

SUMMARY

[0008] In a first aspect the present invention accordingly provides an apparatus for generating electricity when immersed in moving liquid the apparatus including:

an elongated housing, the elongated housing including a channel extending from a first opening located at one end of the housing to a second opening located at an opposed end of the housing, the channel forming a liquid flow conduit to allow liquid to flow between the first and second openings; a rotating member including one or more blades rotatably mounted within the channel to convert the kinetic energy of liquid flowing through the channel to rotational energy;

an electricity generating assembly to generate electricity from the rotational energy of the rotating member, the electricity generating assembly including a rotor component including one or more permanent magnets located in the one or more blades and a stator component.

[0009] In another form the one or more permanent magnets are rare earth magnets.

[0010] In another form the one or more permanent magnets are Neodymium magnets.

[001 1] In another form the one or more permanent magnets are elongated having a length greater than their width, and the length dimension is radially directed with respect to the rotation axis of the rotating member.

[001 2] In another form the one or more permanent magnets are rod shaped and have a length at least twice their diameter.

[001 3] In another form the one or more permanent magnets have a length substantially equal to the length of the blade they are located within.

[0014] In another form the one or more blades contain one or more cavities for receiving a permanent magnet, and in use a permanent magnet is inserted into a cavity and sealed in place with a magnetic cap. [0015] In another form the one or more permanent magnets includes a plurality of permanent magnets and the stator component includes a plurality of coils and the plurality of magnets are plurality of coils are arranged in one or more clusters, each cluster substantially located in a plane perpendicular to the axis of the rotating member, and in which the plurality of coils in a cluster are equiangularly spaced around the axis of the rotating member.

[0016] In another form the apparatus is configured so that its electricity generating capacity is substantially independent of the direction of flow of liquid within the channel upon immersion of the apparatus.

[0017] In another form, the configuration of the apparatus is substantially symmetrical about a horizontal midplane.

[001 8] In another form, the elongated housing is substantially tubular.

[0019] In another form, the elongated housing is configured to increase the velocity of liquid flowing through the channel.

[0020] In another form, the elongated housing is configured to increase the velocity of liquid flowing through the channel by reducing the sectional area as liquid moves from the first opening towards the channel.

[0021] In another form, the first opening includes inwardly sloping walls forming an inlet to the channel. [0022] In another form, the rotating member is an impeller screw. [0023] In another form, the impeller screw is an Archimedes screw.

[0024] In another form, the rotating member includes a plurality of propellers spaced along the channel.

[0025] In another form, the rotor component of the electricity generating assembly includes at least one permanent magnet forming part of the rotating member.

[0026] In another form, the electricity generating assembly generates three phase alternating current electricity. In another form the one or more permanent magnets includes a plurality of permanent magnets and the stator component includes one or more groups of six coils, wherein each group of six coils includes three pairs of coils for generating one phase of the three phases, and each group is located in a plane perpendicular to the axis of the rotating member. [0027] In another form, the apparatus includes a mounting region located on the elongate housing, the mounting region connectable to a mounting means and providing a waterproof electrical connection when connected to the mounting means to convey electricity generated by the electricity generating apparatus.

[0028] In another form, the electricity generating apparatus is configured to operate in a depth of approximately 0.5 metres. In one form the electricity generating apparatus is configured to operate in a depth of approximately 0.2 metres.

[0029] In a second aspect the present invention accordingly provides a method of deploying an electricity generating apparatus configured to generate electricity when immersed in a flowing liquid, the method including:

conveying the electricity generating apparatus to an underwater location;

connecting a mounting region located on a housing of the electricity generating apparatus to a mounting means located at the underwater location to form a waterproof electrical connection between the mounting means and the electricity generating apparatus, wherein the step of connecting the mounting region to the mounting means includes:

isolating the mounting region and the mounting means by forming a containment region around the mounting means and mounting region;

evacuating water from the containment region;

connecting the mounting region to the mounting means in a dry environment to form a waterproof electrical connection; and

removing the containment region.

[0030] In another form, the electricity generating apparatus is conveyed to the underwater location by a diver.

[003 1 ] In another form, the diver wears a vest to which the electricity generating apparatus and the means for forming a containment region are attached to.

[0032] In a third aspect the present invention accordingly provides an electrical generation system including one or more electricity generating apparatus as described in the first aspect, operatively connected to a remote power conversion apparatus for providing a conditioned electrical signal from the electrical signals from the one or more electricity generating apparatus.

[0033] In a fourth aspect the present invention accordingly provides a method of removing an electricity generating apparatus configured to generate electricity when immersed in a flowing liquid from an underwater location, the electricity generating apparatus mounted to a mounting means via a mounting region located on the electricity generating apparatus to form a waterproof electrical connection, the method including: forming a containment region surrounding the mounting means and mounting region;

evacuating water from the containment region;

disconnecting the mounting means from the mounting region;

isolating the mounting region to form a water tight region surrounding the mounting region; conveying the electricity generating apparatus having the isolated mounting region from the underwater location to the surface.

[0034] The electricity generating apparatus may be the electricity generating apparatus of the first aspect. The electricity generating apparatus may be connected to a remote power conversion apparatus of the third aspect.

[0035] In another form, the electricity generating apparatus incorporating the isolated mounting region is conveyed to the surface by a diver.

[0036] In another form, the diver wears a vest to which the electricity generating apparatus and the means for forming the isolated mounting region are attached to.

[0037] In a fifth aspect the present invention accordingly provides an electricity generating arrangement consisting of a plurality of modular electricity generating apparatus, each of the plurality of modular electricity generating apparatus configured to generate electricity when immersed in a flowing liquid, the arrangement including mounting means for mounting the plurality of modular electricity generating apparatus below the surface of the flowing liquid at a predetermined depth, wherein the mounting means is operable to preserve the orientation of the plurality of modular electricity generating apparatus with respect to a direction of the flowing liquid as the direction to changes. The electricity generating apparatus may be the electricity generating apparatus of the first aspect. The electricity generating apparatus may be connected to a remote power conversion apparatus of the third aspect. In a sixth aspect the present invention accordingly provides an electricity generating arrangement consisting of a plurality of modular electricity generating apparatus, each of the plurality of modular electricity generating apparatus configured to generate electricity when immersed in a flowing liquid, the arrangement including:

mounting means for mounting the plurality of modular electricity generating apparatus below the surface of the flowing liquid at an initial depth, and

flotation means operable to preserve the initial depth of the plurality of modular electricity generating apparatus as the level of the surface of the flowing liquid changes.

[0038] The electricity generating apparatus may be the electricity generating apparatus of the first aspect. The electricity generating apparatus may be connected to a remote power conversion apparatus of the third aspect. [0039] In a seventh aspect the present invention accordingly provides an electricity generating arrangement including a trunk structure and one or more branches located underwater, wherein individual electricity generating apparatus are mounted to the trunk structure and/or to the one or more branches to form an underwater TREE deployment. The electricity generating apparatus may be the electricity generating apparatus of the first aspect. The electricity generating apparatus may be connected to a remote power conversion apparatus of the third aspect.

[0040] In another form, each of the electricity generating apparatus is mounted to the TREE deployment by a water proof electrical connection.

[0041] In another form, electricity is conveyed from each of the electricity generating apparatus via the water proof electrical connection and by separate cabling to the surface for electrical conditioning.

[0042] In another form, electricity is conveyed from each of the electricity generating apparatus via the water proof electrical connection and by separate cabling to the trunk of the TREE deployment for electrical conditioning.

[0043] In an eighth aspect the present invention accordingly provides an electricity generating arrangement consisting of a plurality of TREE deployments in accordance with the seventh aspect of the present invention to form a FOREST deployment.

[0044] In an ninth aspect the present invention accordingly provides an apparatus for generating electricity when immersed in moving water, the apparatus including:

an elongated housing, the elongated housing including a channel extending from a first opening located at one end of the housing to a second opening located at an opposed end of the housing, the channel forming a liquid flow conduit to allow liquid to flow between the first and second openings; an impeller screw mounted within the channel to convert the kinetic energy of liquid flowing through the channel to rotational energy;

an electricity generating assembly to generate electricity from the rotational energy of the rotating member, the electricity generating assembly including a rotor component comprising permanent magnets integrated into the rotating member and a stator component forming part of the housing of the apparatus.

[0045] In a tenth aspect the present invention accordingly provides a method for deploying a plurality of electricity generating apparatus, the electricity generating apparatus operative to generate electricity when immersed in moving water, the method involving:

forming underwater a trunk support structure, the trunk support structure extending from an environmental feature;

forming one or more branches extending from the trunk structure; and mounting a plurality of electricity generating apparatus to the trunk and/or one or more branches. [0046] In a eleventh aspect the present invention accordingly provides a method for generating a conditioned electrical signal from one or more apparatus immersed in a moving liquid, the method including:

receiving, by a power conversion apparatus, one or more unconditioned electrical signals from one or more electricity generating apparatus via one or more cables, wherein each of the one or more electricity generating apparatus includes:

an elongated housing, the elongated housing including a channel extending from a first opening located at one end of the housing to a second opening located at an opposed end of the housing, the channel forming a liquid flow conduit to allow liquid to flow between the first and second openings; a rotating member including one or more blades rotatably mounted within the channel to convert the kinetic energy of liquid flowing through the channel to rotational energy; and

an electricity generating assembly to generate an unconditioned electrical signal from the rotational energy of the rotating member, the electricity generating assembly including a rotor component including one or more permanent magnets located in the one or more blades and a stator component forming part of the housing of the apparatus; and

converting the received one or more electrical signals into an output power signal.

[0047] It is to be understood that the invention is not limited to the various aspects or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions to suit particular applications and environments.

BRIEF DESCRIPTION OF DRAWINGS

[0048] Various illustrative embodiments of the present invention will be discussed with reference to the accompanying drawings wherein:

[0049] Figure 1 A is a side sectional view of an apparatus for generating electricity when immersed in moving water according to an illustrative embodiment;

[0050] Figure IB is an end on sectional figurative view of the apparatus illustrated in Figure 1 A depicting an electricity generating cluster including rotor and stator components;

[0051] Figure 1 C is a side sectional view of a small portable apparatus for generating electricity when immersed in moving water according-to an illustrative embodiment;

[0052] Figure 2A is a side sectional view of an alternative outer-casing design of an apparatus illustrated in Figure 1 according to a further illustrative embodiment; [0053] Figure 2B is a side sectional view of an alternative outer-casing design of an apparatus illustrated in Figure 1 according to a yet another illustrative embodiment;

[0054] Figure 3A is a detailed side sectional view of the apparatus illustrated in Figure 1 showing the mounting arrangement for the impeller blade according to an illustrative embodiment;

[0055] Figure 3B is a detailed side sectional view of an alternative mounting arrangement to that shown in Figure 3A for an impeller blade;

[0056] Figure 4A is a detailed side sectional view of an alternative arrangement of the rotating member as compared to the apparatus illustrated in Figure 1 according to an illustrative embodiment;

[0057] Figure 4B is an end on section view of the rotating member illustrated in Figure 4A;

[0058] Figure 5A is a first figurative view of a mounting arrangement for the electricity generating apparatus illustrated in Figure 1 ;

[0059] Figure 5B is a is a second figurative view of a mounting arrangement for the electricity generating apparatus illustrated in Figure 1 ;

[0060] Figure 6A is a figurative view of fixed small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 attached to a concrete block of a creek bed;

[0061 ] Figure 6B is a figurative view of fixed small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 attached to the pylons of a jetty;

[0062] Figure 6C is a figurative view of fixed small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure I attached to the support of a bridge;

[0063] Figure 6D is a figurative view of fixed small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 attached to a support designed to be lifted out of a water channel;

[0064] Figure 7A is a figurative view of a floating small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 attached by mounting brackets to a float assembly;

[0065] Figure 7B is a figurative iew of a floating small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 attached by mounting brackets to a tethered but otherwise free floating pontoon; [0066] Figure 7C is a figurative view of a floating small scale deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 attached to a two armed float assembly;

[0067] Figure 8A is a figurative view of an exemplary TREE deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 ;

[0068] Figure 8B is a figurative view of an alternative exemplary TREE deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 ;

[0069] Figure 8C is a figurative view of an another alternative exemplary TREE deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 ;

[0070] Figure 8D is a figurative view of a yet another alternative exemplary TREE deployment incorporating a plurality of the electricity generating apparatus illustrated in Figure 1 ;

[0071] Figure 9 is a figurative perspective view of an exemplary FOREST deployment consisting of a plurality of the TREE deployments illustrated in Figure 8C according to an illustrative embodiment;

[0072] Figure 10 is a figurative view of an underwater mechanism for in-situ installation/retrieval of an electricity generating apparatus such as that illustrated in Figure 1 ;

[0073] Figure 1 1 is a figurative view of portable version of the electricity generating apparatus illustrated in Figure 1 in accordance with an illustrative embodiment as deployed in a creek;

[0074] Figure 12 is a figurative view of an electricity generating apparatus as illustrated in Figure 1 deployed on small watercraft; and

[0075] Figure 13 is a figurative view of a multiple electricity generating apparatus as illustrated in Figure 1 deployed on large watercraft.

[0076] In the following description, like reference characters designate like or corresponding parts throughout the several views of the drawings.

DESCRIPTION OF EMBODIMENTS

[0077] Referring now to Figure 1 A, there is shown an apparatus 100 for generating electricity when immersed in moving water in accordance with an illustrative embodiment of the present invention. As apparatus 100 is symmetrical about a longitudinal mid plane A2 bisecting the apparatus only the left hand side has been depicted in Figure 1 . [0078] Apparatus 100 is configured to be deployed in shallow water depths, for example less than 0.5 m or 0.2m and/or low flow velocities such as those around or less than 1 m/s, but as would be apparent to those of ordinary skill in the art, this electricity generating apparatus 100 may be scaled appropriately as required. As will be discussed below the overall size of the apparatus and number of electricity generating clusters (rotor magnets and stator coils) can be selected to match the expected flow depth and velocities at a location. Of course whilst the apparatus may be designed for a particular range of flow conditions (e.g. minimum flow depth and/or minimum flow velocity) an apparatus may be used outside of that design range, typically resulting in less efficient energy generation. Further whilst an apparatus may be designed to have a small vertical height (or otherwise designed) for use in a low flow depths, such units may be suspended or mounted in deeper water flows. Apparatus 100 includes an elongated tubular housing 1 10 whose outer diameter is less than one-third of its length, having a first opening 120 located at one end of housing 1 10 and a second opening 130 located at the opposed end of housing 1 10. Between first and second openings 120, 130 there extends a channel 140 forming a liquid flow conduit functioning to allow water to flow between first and second openings 120, 130. Housing 1 10 further includes a centrally disposed mounting region 1 12 which in this illustrative embodiment is implemented as a cut-out portion in the housing 1 10.

[0079] Rotatably mounted within channel 140 is a rotating member 150 which in this illustrative embodiment is in the form of an impeller and in particular in the form of Archimedean screw type impeller having a screw type blade portion 151 . The screw blade portion may comprise a single blade, or alternatively the blade portion may comprise multiple blades (e.g. two, three, four, five, six, seven, eight, nine or ten blades or more). The sleek elongated design of apparatus 100 is primarily based on the use of an Archimedes screw type impellor, however could comprise any other form of rotating member(s) that has a symmetrical form allowing for the generation of electricity in either direction for reversible flows. One alternative example would be to have a series of symmetrical propellers spaced at set distances along the main channel 140. Other alternative rotating member embodiments include, but are not limited to, a symmetrical ribbon type impellor, an inverse Archimedes screw (i.e. a cylindrically shaped tube with screw type blades extending inwards from its inner wall), or a series of small propellers with symmetrical blades at set distances along channel 140 such as depicted in Figure 4 (see below).

[0080] Rotating member 150 functions to convert the kinetic energy of the water flowing through channel 140 to rotational energy due to the orientation and configuration of the blade portion 151.

Electricity generating apparatus 100 further includes an electricity generating assembly 200 including a rotor component 210 formed in this illustrative embodiment using a cluster of permanent magnets 211 located in the blade portion 151 of impeller 150 at spaced apart locations and a stator component 220 consisting of a series of coils 221 forming part of the housing 1 10 and generally aligned with the locations of the individual groupings of permanent magnets 21 1. [0081 ] In this embodiment, relatively small but strong permanent rod magnets 211 are integrated into the impeller blade portion 151 about the rotational axis Al of impeller 150 and effectively act as the rotors of electricity generating assembly 200 of apparatus 100. At set distances along each blade portion 151 , magnets of a cylindrical shape are placed into holes (or cavities) in the blades, with the number of magnets at each position determined by the number of blades for the impelior screw 150. The magnets are sealed in place by a thin lidded cap 158 (e.g. Figure IB), which are designed to conform to the contours of the blade portion 151 and isolate (i.e. seal) the magnets 21 1 from the water. The cap 158 may be made of magnetic plastic to enhance the transfer of magnetic flux between the magnets and the coils while protecting the magnets from the water. Other arrangements may be used to seal the magnets in place. Further the magnets may be integrated into the blades during manufacture of the blades. The length of the magnets can be selected so that the magnets extend along the full radial extent of the blades as shown in Figures 1 A to IC. Alternatively if the length of the magnets is less than the radial extent of the blades (e.g. 3/4, 2/3, 1/2, 1/3, 1/4 etc), the cavities can be designed so that the magnets will start at the outer edge of the blades and extend inward.

[0082] These relatively small but strong permanent magnets integrated into the impeller blade portion 151 substantially simplify apparatus 100 by reducing the number of working components. As the water flows through channel 140, the impeller 150 spins and the magnets 21 1 within the impeller blade portion 151 at each location along the impeller 150 pass by the associated stator coils 221 located in housing 1 10 spaced equally about circumference of channel 140 (as best shown in Figure I B). The permanent magnets 21 1 and coils 221 may be arranged in a one or more electricity generating clusters. As shown in Figure I A, each cluster is substantially located in a plane perpendicular to the axis of the impeller (or rotating member). Clusters can be distributed at spaced locations along the axis as shown in Figure 1 A (in which three of six clusters are shown) and within each plane the coils 221 in a cluster are distributed around (or about) the axis of the rotating member. Depending upon the exact geometry of apparatus (e.g. number of blades, size of components, etc), the axis of magnets and coils may not necessarily all lie in this plane, but may be sl ightly offset or angled out of this virtual plane. However the offsets from this plane for the components of a cluster are much smaller compared to the distance between components in different clusters. That is when viewed along the axis the between cluster spacing is much greater than the within cluster spacing.

[0083] As shown in Figure 1 B, which is an end on sectional view of an electricity generating cluster, the coils 221 are distributed equiangularly around the shaft 152. In this illustrative embodiment which is directed to the generation of three phase electricity, the relative orientation of each stator coil/magnet arrangement is offset by a set number of degrees corresponding to 1/3 of a cycle from its neighbouring stator coil/magnet arrangement. That is the six coils shown in Figure 1 B are distributed uniformly around the axis (i.e. the angle between adjacent stator coils is 60 degrees) and the opposite coils are grouped together to form three pairs 224 226 228, each of which generate one of the electrical phases. The pairs 224 226 228 are each offset with each other by 120 degrees (1/3 of a cycle, or shaft rotation). . [0084] The number, type, size and arrangements of these coils within apparatus 100 can be varied to suit its potential energy output, which is dependent on the size of apparatus 100 and the local geophysical flow conditions. The elongated shape of channel 140 means that clusters of coils can be positioned around the inner wall 141 at set distances along the channel 140 to align with the position of the magnets 21 1. The example embodiment shown in Figure I B will generate unconditioned or wild three phase power at a frequency corresponding to the rotational speed of the shaft. However other coil (stator) and magnet (rotor) arrangements, as well as wiring configurations may be used to produce a range of raw power signals (e.g. single phase). This may include dispensing with electricity generating clusters and instead locating the coils and magnets at any selected locations. The selected locations could be determined based upon simulations or other testing. For example a system may be designed for installation in a location with a known flow environment in which case simulations could be performed to determine the optimum arrangement of magnets and coils to maximise electricity generation.

[0085] Some alternative stator 220 arrangements for apparatus 100 include but are not limited to: a number of large coi ls whose length is similar to that of channel 140 equally spaced about perimeter of the channel wall 141 and multiple coils that are of a size which encapsulates and collects rotational energy from multiple magnet groupings. For all these stator coil arrangements the gap between permanent magnets 21 1 and the respective stator coils 221 is generally minimised by reducing the clearance between the impeller 150 and the inner wall 141 of channel 140 and optimising the thickness of inner wall 141 in the immediate vicinity of the stator coils 221 to provide efficient transfer of rotational energy.

[0086] In some embodiments the permanent magnets are rare earth magnets which produce much larger magnetic flux densities than convention ferrite magnet of the same size. One suitable type of rare earth magnet is a Neodymium magnet. In some embodiments the permanent magnets are elongated having a length greater than their width (or diameter). That is the length may be 1 , 1.5, 2, 2.5, 3, 5, 10 or more times the width or diameter. In some embodiments the magnets are rod shaped, such as cylinder with a length 2.5 times the diameter. Such arrangements have increased axial flux densities compared to squatter arrangements. For example a 10mm long 4mm diameter Neodymium rod magnets produces a magnetic pull strength of 0.662 kg and a magnetic flux density of 0.6472 T (i.e. 6,472 Gauss) acting axially thru the rod. In comparison a 25mm long, 25mm diameter Neodymium rod magnet (i.e. 1 : 1 length to diameter ratio) has a much larger magnetic pull strength of 26.0 kg but a smaller magnetic flux density of 0.5903 T (5,903 Gauss). As shown in Figures 1 A and IB, the magnets are installed so that their length dimension is radially directed with respect to the rotation axis of the rotating member. In some embodiments the permanent magnets are selected to have a length substantially equal to the length of the blade they are located within. That is the magnets extend radially away from the hub (shaft) over the same range as the blades. The length of the magnets may be slightly less the length of the blade to facilitate encapsulation and sealing of the magnet within the blade (e.g. to allow for a cap or seal over the magnet). Further by using magnets with large length to diameter ratios the width of the blade of the impeller can be kept small. [0087] As would be appreciated by those of ordinary skill in the art the magnetic pull strength in this case indicates the resistance/reactance force generated between the magnets and the stator coils that must be overcome for the impellor to rotate. Therefore by utilising small but powerful permanent Neodymium rod magnets with a large length/diameter ratio the magnetic flux density available for EMF induction is maximised while also minimising the magnetic resistance between the magnets and stator coils that must be overcome for the impellor to begin rotating and electricity generation begin. These rotor magnet properties are especially important for an electricity generating apparatus that is required to operate in low flow velocities (i.e. flow velocities less than m/s) which are observed within most natural ocean, tidal and river currents around the world.

[0088] Another benefit of having relatively small but strong magnets with large length/diameter ratio in the impellor blades is the shorter duration of magnetic flux pulses created as the magnets pass each stator coils. That is, the time it takes for the magnet to travel past the coil and the magnetic flux to go from zero to maximum (e.g. 0.6472 T) and back to zero is relatively short allowing for more magnetic flux pulses to occur especially as the rotational speed of the impellor increases with increasing flow velocity through the channel. As would be appreciated by those with prior knowledge in the art the change in magnetic flux with time (i.e. dB/dt) is directly related to the quantity of voltage that can be induced through the coil. Therefore the stronger and more rapid the changes in magnetic flux the greater the electricity output from the apparatus.

[0089] As would be appreciated by those of ordinary skill in the art, the rotational speed of the impellor 150 and therefore the frequency and voltage generated by the electricity generating assembly 200 of apparatus 100 varies directly with the fluctuations in flow velocity through channel 140 of apparatus 100. Therefore the interaction of the rotor component 210 and stator component 220 of the electricity generating assembly generates what is termed "wild" or unconditioned three-phase alternating current (AC) electricity. To simplify the electricity generating device this "wild" AC electricity remains unconditioned within the device, flowing directly from the stator coils via wiring to the sealed output socket 230. An external cable 260 and plug 290 arrangement can then be connected to the sealed output socket 230 to receive the electricity generated by apparatus 100. In this manner, electricity generating apparatus 100 may be connected externally without exposing any of the apparatus's 100 electronics to water.

[0090] Following transmission by cable 260, the unconditioned (raw or wild) electrical signal can then be connected to a remote (from the apparatus) power conversion apparatus for providing a conditioned electrical signal such as a 50/60 Hz 120/240 AC mains power signal and/or a DC (e.g. 12 V) signal which can be used to charge batteries or directly power electronic devices using techniques and apparatus well understood by those with ordinary skill in the art. The power conversion apparatus may be conventional power conversion apparatus as is known in the art and may include various components such as rectifiers, filters, transformers, power amplifiers, semiconductor switches, signal processing components including digital signal processing components, which are configured to convert the received raw signal to a conditioned output signal using a range of power circuit topologies and control strategies. The power conversion apparatus may include a processor (such as a microcontroller) and memory containing processor readable instructions for operating the power conversion apparatus. The power conversion apparatus may be designed to produce a single output signal type (e.g. 50 Hz 240V AC) or it may be designed to provide a range of selectable output signals. Similarly the power conversion apparatus may be designed for connection to a single energy generation device or it can be designed to allow connection of multiple devices and to process all of the received signals into a single output signal.

[0091] Processing of the raw electrical (power) signals generated by the electricity generating apparatus 100 by the power conversion apparatus is carried on remotely or out of the water (e.g. on land, on deck, or in a water tight enclosure in a mounting structure) for safety reasons, to increase the modularity and scalability of the system, and to reduce the complexity of maintenance and repair operations. For example several individual electricity generating apparatus 100 may be deployed in a water flow, and each of the individual cables 260 connected to a central power conversion apparatus which receives the individual wild (or raw) electrical signals and converts them to a desired output signal. The power conversion apparatus can also provide a monitoring function to monitor signals from individual apparatus and raise an alarm or warning in the event of abnormal or fault conditions which may indicate maintenance of an apparatus is required. As electricity generating apparatus 100 is configured to generate unconditioned (three-phase) AC electricity, the amount and complexity of the electronic circuitry required within the apparatus itself is minimal, thereby significantly reducing the cost and size of the apparatus as compared to prior art devices where there is local conditioning of the generated electricity. A method for generating a conditioned electrical signal from one or more apparatus immersed in a moving liquid can also be implemented. The method includes receiving, by a power conversion apparatus, one or more unconditioned electrical signals from one or more electricity generating apparatus via one or more cables and converting the received one or more electrical signals into an output power signal.

[0092] Electricity generating apparatus 100 is further configured so that its electricity generating capacity is substantial ly independent of the direction of flow of water along longitudinal axis Al within channel 140 upon immersion of apparatus 100. In this illustrative embodiment, the housing 1 10, impeller screw 150, channel 140 and the stator 220 and rotor 210 components of electricity generating assembly are configured substantially symmetrically about the longitudinal mid plane bisecting the apparatus 100 as depicted generally by A2 in Figure 1 , In this manner, operation of the electricity generating apparatus 100 is essentially symmetrical with respect to the direction of flow of water along channel 140 resulting in the same electricity generating capacity independent of the direction of flow of water in channel 140.

[0093] The symmetrical design of electricity generating apparatus 100 allows optimisation of energy collection in both flow directions of reversible tidal currents thereby maximising the energy harnessed over a tidal cycle. When apparatus 100 and therefore channel 140 is aligned with the primary flow direction the device can be fixed in this horizontal orientation allowing for the optimisation of electricity generation as the tide first flows in a direction substantially aligned with channel 140, and then on reversal, the tide then flows with equal intensity but in substantially the opposite direction through channel 140.

[0094] This symmetry capability of electricity generating apparatus 100 thus significantly reduces the complexity of the device and its deployment, especially when compared to those devices designed to rotate about a vertical axis when the flow direction changes. In addition, the ability to implement electricity generating apparatus 100 in a compact configuration implies that the apparatus may be deployed in relatively shallow depths of less than 1 metre.

[0095] The shape of the outer casing 1 10 is designed to minimise flow resistance around the apparatus 100 while maximising the flow velocity in channel 140 through openings 120 and 130. As would be appreciated by those with ordinary skill in the art, the optimal shape of the outer casing 1 10 is determined the local geophysical flow conditions and operational velocity range of apparatus 100, with different ideal shapes for high and low flow velocity conditions. The embodiment shown in Figure 1 is a simple low cost (i.e. easy to manufacture) version for apparatus 100 that is configured as an elongated tubular design for the outer casing 1 10 and a frusto-conical configuration for openings 120 and 130. However as may be appreciated by those of ordinary understanding in the art the outer casing 1 10 configuration represented in Figure 1 may not be the ideal shape for minimising flow resistance about apparatus 100 under all flow conditions with several variations from this configuration demonstrated in Figures 2A and 2B.

[0096] Figures 2A and 2B show sectioned views of two alternative embodiments for the outer casing 1 10 of apparatus 100 illustrating several key features/regions that can be modified to assist in minimising flow resistance around the outer casing 1 10, as well as into openings 120, 130 and thereby channel 140. These features/regions include but are not limited to the shape of the opening inner wall 121, outer casing wall 1 14, and separation edge 122 between inside conduit 140 and outside environment. Note in Figures 2A and 2B, as with Figure 1 , only half of the outer casing is shown due to the symmetry of its design.

[0097] Referring now to Figure 2A, there is an alternative embodiment of apparatus outer casing 1 10 as depicted in Figure 1 where the shape of the outer casing wall 1 14 is convex in nature. This convex outer casing shape is most evident about the outer wall leading edge 1 13 where there is a rapid increase in the diameter. In this embodiment the convex shape flattens out towards the centrally disposed mounting region 1 12 to allow for connection to the standardised mounting bracket 300 and use of standardised mounting system describe below. As would be appreciated by those of ordinary skill in the art, a convex shape to the outer casing 1 14 will assist the flow of water around and through apparatus 100.

[0098] In this embodiment and that demonstrated in Figure 2B, the shape of opening walls 121 also have a convex or trumpet shape rather than purely frusto-conical as depicted in the embodiment shown in Figure 1. As would be appreciated by those of ordinary skill in the art this trumpet shape is generally the most efficient method for compressing/channelling a fluid from the external environment into a narrow conduit. The convex shape and rate of change of opening inner diameter can by varied to suit the local flow conditions and is optimised for the operational velocity range required for each deployment.

[0099] Referring now to Figure 2B, there is shown a more complex embodiment of the outer casing as compare to those shown in Figures 1 and 2 A. In this embodiment, the peripheral edge region 122 separating inner channel 140 from the external environment is rounded to minimise pressure losses as fluid flows into the opening 120, especially under higher flow velocities. From these rounded edges 122, the leading edge 1 13 of outer casing 1 15 proceeds in a convex arc back to the standard cylindrical shaped outer casing 1 14 proximate to the centrally disposed mounting region 1 12. This convex leading edge design has two main functions, the first being to maximise the size of the openings 120, 130, while conceivably allowing an optimised central outer casing region diameter, this design then resulting in savings in materials, weight and costs. The second is to reduce the drag and therefore wake effects over the trailing edge 1 15 when water flows in the direction F2 over the apparatus 100.

[00100] Optimally, the configuration of the outer casing is also designed to be visual ly appealing so to minimise the ascetic impact, as it is likely to be situated in the natural environment and further given that several alternative energy systems such as wind turbines have struggled with acceptance due to their perceived visual impact on the local environment.

[00101 ] In these illustrative embodiments, housing 1 10 is generally formed from a plastic such as nylon and/or polyvinyl chloride (PVC) and where possible recycled plastics such as polyethylene ยท terephthalate (PET) to minimise the environmental footprint of manufacture of the device. In this example, plastics such as described above have been chosen because they are relatively cheap, light weight and can easily be moulded or machined into the various required shapes for the parts of the device. Plastics are also less likely to suffer from degradation through exposure to water than most metals and composites that are used in most current devices. Plastic is also a good insulator of electricity, thereby minimising the impact of the apparatus's electromagnetic system 200 on the local environment.

[00102] The materials utilised in manufacturing the outer casing 1 10 are not limited to plastics, with materials such as alloys and ceramics also feasible depending on the operating environment (e.g. geophysical flow conditions) in which the apparatus 100 will be deployed and the function of key features of the outer casing 1 10. For example alloys may be utilised in key regions (e.g. inner channel wall 141 , heat transfer fins) where a more conductive material than plastic may assist in the transfer of

electromagnetic energy or heat from one body to another.

[00103] In all illustrative embodiments, first and second openings 120, 130 are further configured to increase the velocity of the water flowing through channel 140 as compared to the velocity of the water entering apparatus 100. Taking opening 120 as an example (as opening 130 is the mirror image), the walls 121 are sloped inwardly to form a flow compressor in the form of a frusto-conical (e.g. Figure 1) or trumpet-shaped (e.g. Figures 2A and 2B) configuration where the tapered walls meet the end of channel 140. In this example, the ongoing reduction of the effective diameter and associated sectional area as water flows towards channel 140 results in a substantial increase in the velocity before it enters and flows through channel 140 due to the Venturi effect. As would be appreciated by those of ordinary skill in the art, the degree and rate of change for the tapering or diameter reduction will depend on the immersive environment of apparatus 100 and is optimised to suit the expected operational flow conditions.

[00104] One immersive environment where the use of this effect is especially important is regions which experience lower flow velocities. In this case, not only is a large outer diameter preferred for openings 120 and 130, but a large change in the inner diameter of the opening (i.e. at least by a factor greater than three) is employed to substantially increase the flow velocity through the device (e.g. by up to an order of magnitude) and therefore the amount of energy that can be extracted under those flow conditions. As would be appreciated by those of ordinary skill in the art, being efficient at extracting energy in low flow conditions (e.g. velocities less than 1 m/s) greatly increases the regions from which energy can be extracted from flowing water and increases the viability of this form of alternative energy.

[00105] Some examples of regions experiencing lower flow velocities include small tidal creeks, storm water channels, restricted entrance tidal inlets, large river deltas, and the submerged plains of tidal bays. These low flow regions generally are not utilised for shipping and represent vast regions of underutilised space where conceivably thousands of energy generating apparatus 100 could be deployed to supply megawatts of electricity.

[00106] Due to the symmetrical configuration of apparatus 100, and as the first opening 120 functioning as an "intake" is configured the same as second opening 130 functioning as an "outlet", the flow velocity of the water leaving channel 140 will decrease in velocity due to a reverse Venturi effect due to the expanding tapered conical walls 131 of opening 130. In this manner, the flow velocity of water on exit of apparatus 100 will approach that of the ambient flow velocity. This arrangement thereby will help to minimise any adverse consequences that may arise from local turbulent flow disturbances (e.g. wake eddies) created within channel 140 which could disturb the local marine environment. This feature and the sleek elongated design of the outer casing 1 10 results in electricity generating apparatus 100 having a minimum impact on the local flow properties about and behind the apparatus 100. The minimisation of the wake effects about the apparatus 100 means less space is required between multiple apparatus within that area, thereby further increasing the energy extraction density of the region.

[00107] Housing 1 10 may further include respective protective meshes 11 1 covering first and second openings 120, 130. The size of protective mesh 1 11 is optimised to prevent any negative impact on local fauna (i.e. fauna being injured by impeller) or fouling of the device by floating debris and sediment, while minimising the impact on the local flow properties within channel 140. For tidal flows, protective mesh 1 1 1 is essentially self-cleaning as debris or sediment caught in the mesh as water flows through an opening in one direction will be removed once the tides reverse and water flows through the device in the opposite direction.

[00108] The outer casing 1 10 will include features that allow for the dissipation of the heat that is created by the electromagnetic system 200 during the generation of electricity. As would be appreciated by those of ordinary skill in the art the amount of heat generated by the electromagnetic system 200 will depend on the size and configuration of the coils and the local geophysical flow conditions which are utilised to create rotational energy through the impellor 150. This heat will be absorbed by the air within the outer casing 1 10 and then transferred to the water flowing through and around apparatus 100.

[00109] It is also important that the heat transfer process between apparatus 100 and the environment be as efficient as possible to minimise any potential negative impacts on the local environment (i.e. a significant increase in water temperature in the immediate region about the apparatus). Therefore features including, but not limited to, alloy fins radiating inwardly from outer casing walls 1 14 and channels in the outer casing (i.e. casing shape more like that of a gear cog than a true cylinder) may be utilised in certain embodiments of the apparatus to facilitate the efficient transfer of heat from apparatus 100. These features will act to increase the rate of heat transfer from the apparatus

electromagnetic system 200 to the local environment, which prevents any significant build-up of heat within the apparatus 100 and thereby assists in minimising any impact on the local environment.

[001 10] Referring now to Figure 3 A there is shown a detailed view of the impeller 150 illustrated in Figure 1 depicting the mounting arrangement in accordance with an illustrative embodiment of the present invention. In this illustrative embodiment, the impeller 150 is based on an Archimedes screw as the symmetry of this type of impeller is well suited to the extraction of energy from reversible flows. Archimedes screws are efficient in generating electricity in low head flow conditions such as those observed in tidal flows.

[001 1 1 ] In addition, and consistent with the symmetrical operation of apparatus 100, the use of an

Archimedes screw allows for the symmetrical design i.e. the conversion of kinetic energy from the flow of water down channel 140 does not depend on the direction of flow within the channel 140, thereby allowing for the maximum energy extraction under both reversible and unidirectional flow conditions. As would be appreciated by those of ordinary skill in the art, the design of the Archimedes screw may be optimised by varying the pitch and number of blades to operate over the maximum flow velocity range observed for the proposed deployment site of electricity generating apparatus 100.

[001 12] Impeller 150 is rotatably mounted to housing 1 10 by a circular bearing arrangement 155 mounted in the inner wall 141 at each edge of channel 140. In this embodiment, circular bearing arrangement 155 receives blade portion 151, thereby minimising the impact on water flowing through the device. In this embodiment, ceramic bearings are employed which have the benefits of both being waterproof and non-conductive. The shaft end 154 of impeller 150 is also tapered to minimise the flow disturbance as the water interacts with the shaft 152 of the impeller 150.

[001 13] Referring now to Figure 3B, there is shown a further mounting arrangement for impeller

150 in accordance with another illustrative embodiment. In this embodiment, a circular bearing arrangement 157 is employed but this time operative on the shaft 152 of the impeller 150. Such an opening arrangement as embodied shown in Figure 3B could be used in a larger version of the apparatus 100 to mount the impellor 150 to the housing 1 10, when the impellor diameter may be too large for standard bearings under the arrangement embodied in Figure 3 A. In this embodiment, a smaller shaft 153 protrudes from the main impellor shaft 152 which is received by the circular bearing 157 located within streamlined housing 124.

[001 14] Streamlined bearing housing 124 is attached to the inner walls 121 of the opening (120 in this embodiment) by two aerofoil shaped mounting fins 123. These fins 123 extend from the bearing housing 124 to a position on the inner opening wall 121 which functions to minimise the fins 123 impact on the water flowing into the main channel 140. The shape of fins 123 is also designed to optimise the fins impact on the flowing water as the inner diameter of opening 120 decreases and flows into channel 140.

[001 15] In these illustrative embodiments, the impeller 150 is formed from plastic such as nylon or polyethylene terephthalate thereby providing a light weight, durable and cost effective impeller that is also relatively easy to manufacture. However, as with the materials utilised in the outer casing 1 10, the impellor may also be manufactured from alloys and ceramics as appropriate depending on the operating environment (e.g. geophysical flow conditions) in which the apparatus 100 will be deployed.

[001 16] Referring now to Figures 4A and 4B, there is shown another illustrative embodiment of apparatus 100 relating to an alternative rotating member design to the Archimedes screw impellor demonstrated in Figure 1. The embodiment in Figures 4A and 4B utilises a series of small individual free- floating propellers 160 with symmetrical blades at set distances along the inner channel 1 0 (shown in end view in Figure 4A). Each propeller 160 includes an even number of symmetrical blades 161 having a similar radius to that of inner channel 140 extending from a central hub 163 to a peripheral rim portion 62 that incorporates horizontally aligned small permanent magnets 211. In this configuration these horizontally aligned magnets 21 1 act as the rotors of the electromagnetic system 200. As the fluid flows through the channel 140 it interacts with blades 161 of each propeller 160 causing the rotor magnets 21 1 embedded within peripheral rim portion 162 to rotate past the clusters of stator coils 220 in multiples of three coils that are recessed within inner wall 140 and thereby generate "wild" three-phase electricity as discuss in previous embodiments of apparatus 100. [001 17] The rotating member could also be an inverse Archimedes screw with an outer ring and inwardly directed blades. A small hub could still be used to provide additional support for the blades, or the arrangement could be hubless. In this embodiment the magnets can be substantially located in the blades and end in the outer ring. However such arrangements are typically less efficient than an impellors with hub and no outer ring (such as those shown in Figures 1 A to 1 C) as providing an outer ring adds extra weight, volume and drag (particularly if a hub and an outer ring is used).

[001 18] Referring now to Figures 5 A and 5B, there is shown a mounting bracket 300 for mounting an electricity generating apparatus 100 in accordance with an illustrative embodiment of the present invention. As described previously, housing 110 of apparatus 100 includes a mounting region in the form of a cut-out portion 1 12 configured to receive mounting bracket 300 having a part cylindrical mating portion 3 10 that in this embodiment bolts to the cut-out portion 1 12 of housing 1 10, thereby substantially preserving the flow characteristics of housing 1 10. Extending from mating portion 310 is support portion 320 which in this illustrative embodiment is shaped in an aerofoil configuration to also minimise any flow disruption of water moving about electricity generating apparatus 100.

[001 19] As shown in Figure 5 A mounting bracket 300 also includes an integrated plug 290 designed to plug into socket 230 of apparatus 100 to form a waterproof electrical connection. Plug 290 is in turn connected to cable 260 (c.f. Figure 1 ) which extends through support portion 320 to carry electricity generated by apparatus 100. Other types of waterproof connection arrangements known in the art are also contemplated to be within the scope of the invention. As would be appreciated by those of ordinary skill in the art, the size and configuration of mounting bracket may be adapted to suit the configuration of the associated electricity generating apparatus 100 being mounted.

[00120] Such a standard mounting bracket system allows for the easy deployment and repair/replacement of electricity generating apparatus 100 independent of the deployment arrangement.

[00121] An illustrative embodiment of an energy generation apparatus will now be described. The embodiment described is a small portable embodiment designed to provide portable electricity in flowing water bodies (both natural and manmade) with flow depths as shallow as 0.2 m. The embodiment described, which will be referred to as a PWFEG (Portable Water Flow Electricity Generator), can easily be deployed in depths greater than 0.2 m and from the side of small (or large) water craft. Further these small scale embodiments could be used as module components of larger permanent or semi-permanent (i.e. long term) energy generation systems for use in tidal flows or other uni-directional flows.

[00122] A side sectional view of an embodiment of the PWFEG 100 is illustrated in Figure 1C. In this embodiment the tubular housing 1 10 has an outer diameter of 160 mm and an overall length of 520 mm. Each frusto-conical opening 120 decreases from 160 mm at the opening to the 40 mm inner diameter of the centrally located flow conduit channel 140 which has a length of 320 mm. As would be appreciated by those with prior knowledge in the art such a fourfold change in the inner diameter of the frusto-conical opening will increase the flow velocity within the channel by approximately 16 times that of the ambient flow velocity (if losses are neglected). Even with significant losses through the opening, any increase in flow velocity in the channel will produce a substantial increase in the potential power that can be extracted within given flow conditions since the extractable power is directly related to the cube of the flow velocity through the channel.

[00123] Within the central flow channel 140 is a rotatably mounted Archimedes screw- type impellor 150, which consists of four screw type blades 151 wrapped around the main central shaft 152. The Archimedes screw is 320 mm long and has an overall diameter (i.e. shaft and blades) of 40 mm. The impellor has four blades equidistantly positioned about the circumference of impellor shaft. Each blade is 10 mm high and 8 mm wide with a pitch of 160 mm (i.e. each blade fully wraps around the shaft twice over the impellor length). The impellor is mounted to the housing, via a smaller shaft 153 (8 mm in diameter) which protrudes from the main impellor shaft 152 and is received by the circular ceramic bearing 157 located within a centrally located streamlined housing 124, which has a maximum diameter of 20 mm (i.e. same as the main impellor shaft). The streamlined bearing housing 124 is attached to the inner walls of the frusto-conical openings 121 by four aerofoil shaped mounting fins 123. In this embodiment the housing, channel openings and impellor are substantially formed from plastic.

[00124] The electricity generating assembly of the PWFEG consists of a rotor component 210

(i.e. the impellor) and a stator component 220 forming part of the channel and located within the housing. In this low flow velocity (i.e. less than 1 m/s) embodiment of the PWFEG the rotor component consists of three centrally located clusters of four permanent rod magnets (located within each blade of impellor) approximately 80 mm apart along the impellor. Aligned with rotor magnet clusters the stator component consists of three clusters of six coils situated along the flow channel 140 within the main housing.

Depending on the flow conditions of the intended location, up to nine rotor magnet/stator coil clusters can be incorporated along the impellor and channel wall of the PWFEG to improve performance under more extreme flow conditions (e.g. flow velocities greater than 2 m/s).

[00125] In this embodiment of PWFEG 10 mm long Neodymium rod magnets 211 with a diameter of 4 mm are used within the rotor. Each magnet is situated (located) in a hole strategically located within the impellor blades 151 and sealed in placed with thin magnetic plastic caps. Each magnet produces a magnetic pull strength of 0.662 kg and a magnetic flux density of 0.6472 T (i.e. 6,472 Gauss) acting axially thru the rod. The stator component consists of three centrally located clusters of six coils aligned with the rotor magnets spaced approximately 80 mm apart along the central flow channel 140 located within the main housing (i.e. along the screw axis). At each stator cluster position along the channel the six coils 221 are spaced equidistantly around the perimeter of the channel wall, with the bobbin core 222 of each coil located in a hole in the channel wall then sealed in place with a thin magnetic plastic cap shaped to match the inner perimeter of the main flow channel 140. This allows the transmission of the magnetic flux created by the rotation of the impellor to be transmitted to the stator coils while isolating the coils and other power electronic components (e.g. wires, cables) within the main housing from being exposed to water. The stator coil design was chosen to optimise each coils performance based on the properties of the magnets used in the rotor, especially the coil length.

[00126] For this example embodiment each coil has a length of 16 mm and a thickness of 24 mm consisting of approximately 2300 turns of 0.2 mm insulated copper wire wrapped around a 8 mm bobbin diameter which contains a 5 mm square laminated ferrite core. At the base of each coil bobbin there is a 8 mm protrusion which fits snugly into the holes in the channel wall and whose concave shape is designed to match perimeter of the channels inner wall (i.e. cylinder with a diameter of 40 mm) to minimise any interference with the rotor. The hollow of this protrusion is filled with magnetic plastic to allow the transmission of magnetic flux from the passing magnets to the coils core thereby allowing electromagnetic induction to occur.

[00127] As would be appreciated by those of ordinary skill in the art, the rotational speed of the impellor and therefore the frequency and voltage generated by the electricity generating assembly of the PWFEG varies directly with the fluctuations in flow velocity through the channel 140. Therefore in this low flow embodiment of the PWFEG the three clusters of six coils (i.e. 18 coils in total) are linked in such a fashion to generate "wild" or unconditioned three-phase alternating current (AC) electricity. To simplify the PWFEG this "wild" AC electricity remains unconditioned within the device, flowing directly from the stator coils via wiring to the sealed output socket. An external cable and plug arrangement can then be connected to the sealed output socket (not shown in Figure IC but shown in Figure 1 A) to receive the electricity generated by the PWFEG. In this manner, electricity generating apparatus 100 may be remotely connected to power conversion apparatus which generates a conditioned power signal (e.g. mains or DC), without exposing any of the apparatus's electronics to water. As the PWFEG is configured to generate unconditioned three-phase AC electricity, the amount and complexity of the electronic circuitry required within the device is minimal, thereby significantly reducing the cost and size of the apparatus as compared to prior art devices where there is local conditioning of the generated electricity. This reduced complexity of electronic circuitry within the device is especially important for developing a small portable electricity generator that can be utilised in shallow flows (e.g. depths of 0.2 m as in case of the PWFEG).

[00128] The above PWFEG embodiment is designed primarily for very shallow and low velocity flows. However singular or multiple PWFEG units may also be temporarily or permanently deployed in deeper flows which experience low flow velocities (e.g. tidal bays or ocean currents). Of course larger models can be manufactured specifically for deeper flows or higher velocity flows. In one embodiment, an apparatus could be approximately twice the size of the PWFEG to operate in flow velocities of greater than I m/s. In the embodiment the housing is 1200 mm long with a diameter 400 mm, a channel diameter of 100 mm diameter and 800 mm long (length) with a matching Archimedes screw (i.e. overall diameter of 100 mm and 800 mm long). Depending upon the size of the magnets used the screw may have more than 4 blades (e.g. 8) and the configuration of the coils (e.g. dimensions and number of turns), may be adapted to optimise their performance to the properties of the magnets. This design can also be upscaled to cater for extreme tidal and river flows with flow velocities greater than 4m/s. In any of these upscaled embodiments the number of electricity generating clusters could be increased to greater than 9 clusters depending on the relative size of the optimised stator components to that of the upscaled electricity generating apparatus 100.

[00129] The above described embodiments provide a self-contained symmetrical apparatus operative to maximise the amount of electrical energy that can be extracted from flowing water such as in man-made or natural channels and in particular those situations where there are substantially reversible flows flowing in opposite directions such as tidal flows. The device utilises electromagnetic principles to generate unconditioned AC electricity internally within the unit from the energy of flowing water. This unconditioned electricity may then be further processed for incorporation into mains power or used for the charging of batteries depending on requirements.

[00130] Multiple energy generating clusters can be located at desired positions (locations) along the axis of the impellor, such as an Archimedes screw. Impellors with multiple blades can be used to form a cluster of magnets at each location, in which one magnet is located in each blade. For example if an impellor has 4 blades then there are 4 magnets per cluster. Further the use of small Neodymium rod magnets with a relatively large length to diameter ratio can be used to allow manufacture of compact apparatus in which the blades provide structural support for the magnets. Such Neodymium magnets with large length/diameter provide large axial magnetic flux density and a relatively small magnetic pull when compared to large magnets with same magnetic flux density, thereby reducing the induced

resistance/reactance between coils and magnets, as well as providing quick pulses in magnetic flux which assist in improved electromagnetic inductance.

[00131 ] To generate three phase power signals, individual clusters of six stator coils are aligned with the rotor magnet clusters along the main flow channel contained within the housing. The coil properties are designed to optimise performance with magnets thereby maximising electricity output from apparatus 100. Further the number of clusters and number and size of magnets per cluster and number of coils can be selected to match expected flow conditions. Typically the greater the flow velocity the greater the number of coils that can be incorporated since increased number of coils equals increased resistance to impellor rotation. If a three phase output signal is produced then the number of coils used will be a multiple of six. Further the total number of coils (and total number of clusters) is also affected by choice of magnet. The ability to select different magnets, coils, and number of clusters also provides flexibility in meeting a power output design target. That is where a power output target is set a designer can use d ifferent combinations of magnet sizes (lengths, and length to diameter ratios), coil

configurations, and number of clusters to meet that target. [00132] Unlike prior art devices, the elongated tubular design allows the apparatus to be scaled to sizes where it can be deployed in water depths of less than 0.5 m and even as low as 0.2m as well as in the deepest oceans should this be required. As electricity generating apparatus 100 can be deployed in shallow flows as well as in deeper flows which experience low flow velocities this greatly expands the locations where energy can be extracted from flowing water. As such, this mode of energy generation becomes more of a viable option to non-renewable alternatives such as fossil fuels and the like. Being able to deploy electricity generating apparatus 100 in shallower waters also results in these devices being deployed significantly closer to land which reduces the infrastructure costs for construction and maintenance of the deployment and further the transmission of generated electricity to land as compared to deployments in deeper waters.

[00133] The self-contained design also means the device can be portable, allowing it to be deployed temporarily in remote locations near flowing water or from both small and large watercraft to recharge batteries or to provide electricity. A further advantage of electricity generating apparatus 100 is the reduction in the number of moving parts as compared to current state of the art devices.

[00134] Another benefit of the compact, symmetrical and self-contained design of apparatus 100 is that it is readily be deployed in a cellular or modular based structure where each "cell" consists of an individual electricity generating apparatus 100 such has been previously described. In this manner, a number of electricity generating apparatus 100 or individual cells or modules may be deployed to generate the equivalent electricity of one large device but with increased flexibility in how the multiple cells or modules are deployed within the combined structure and local region. This provides the capability that a deployment can be specifically customised as each cell or module within the structure can be optimised to suit the highly localised geophysical flow conditions in which it is deployed and thereby optimise the amount of electricity that can be extracted from the site.

[00135] Another advantage of a deployment based on a cellular or modular type structure is that when a single apparatus requires repair then only that cell or module requires replacement, while all the other units in the deployment continue to extract energy from the flowing water. This methodology which relies on the modular design of the electricity generating apparatus 100 allows for a vast array of deployment methods both large and small, which are designed to suit each specific deployment depending on the local flow conditions and energy needs.

[00136] In open channel flows (both natural and man-made), the flow velocity is not constant over the flow depth, with the flow velocity changing substantially between the bed and the water surface. As a consequence, in these regions there can be significant velocity shear (i.e. change in velocity magnitude with depth). Therefore another benefit of a multiple device deployment as compared to that of a larger single device is that the velocity shear over the impeller of any one individual device is significantly less because of the significantly smaller impeller diameter compared to a larger device. This then results in improved efficiency and operational velocity range of the device as compared to larger tidal energy devices where the impact of velocity shear over the impeller is one of the most significant factors that limit the performance of the device especially the velocity range in which it can safely operate.

[00137] Referring now to Figures 6A to 6D, there are shown some exemplary fixed small scale deployments consisting of less than ten units attached to an environment, apparatus or structure. These Small scale deployments are primarily used for the extraction of energy in shallow flow conditions such as those observed in small estuaries and streams, but can also be used in any location where artificial structures interact with flowing water. Such small scale deployments could be used to power local infrastructure (e.g. bridge/pier lights) or help supply electricity to houses and businesses located near flowing water. These small scale deployments can be used with respect to fixed (non-moving) environmental features including but not limited to bridges, pier, pylons, buoys, weirs, river or ocean beds, large rocks or indeed any other substantial natural or manmade structure located proximate to the flowing water.

[00138] As shown in Figure 6 A, several electricity generating apparatus 100 are deployed by attachment to a concrete block 410 located on the bed 41 1 of a small creek 400 that experiences a large tidal range (TR) as indicated. In Figure 6B, several electricity generating apparatus 100 are attached to the pylons 421 of a jetty 420 and aligned with the main flow direction F of water. In Figure 6C, the deployment consists of several apparatus 100 attached to the support 431 of a bridge 430 spanning a river via specifically customised brackets 435. In another illustrative deployment, Figure 6D depicts a small array of electricity generating apparatus 100 deployed from a frame 442 located safely on the bank 441 of a fast flowing river 440 where it would normally be too hazardous to deploy a single larger device because of extreme river currents. A frame 442 such as that shown in Figure 6D could conceivably be designed to be lifted out of the water to protect the apparatus from damage under extreme flood flow conditions.

[00139] Referring now to Figures 7 A to 7C, there are shown a number of exemplary deployments based on a floating system, wherein a small number of apparatus are attached to a float arrangement operative to move with the tidal range to ensure that the electricity generating apparatus 100 are always located in the region of maximum flow velocity which in open channel and coastal flows is predominantly just below the water surface. In one example, the deployment may be free floating such as tethered to a river or ocean bed or other artificial feature. In another example, the deployment may be mounted by slidable bracket arrangements to environmental features such as bridges, piers, pylons and the like.

[00140] As an example, Figure 7A shows several electricity generating apparatus 100 attached by mounting brackets 300 to a float assembly 500 that includes a support frame or structure 502 slidably attached to in this example a pylon 503 incorporating a customised rail arrangement 504 and a floatation member 501 attached to the support structure 502. In operation, float assembly 500 will move up and down pylon 503 of already existing structure (e.g. pier, bridge) with the tide ensuring that the electricity generating apparatus 100 are positioned immed iately below the surface of the water.

[00141 ] The example depicted in Figure 7B shows an array of electricity generating apparatus

100 attached by mounting brackets 300 to a free floating pontoon 510 consisting of a platform 514 supported by two spaced apart flotation members 513. Pontoon 510 is tethered underwater to in this case a concrete block 51 1 located on the bed by a cable 512. In operation, pontoon 510 can orient itself in line with the direction of flow while still ensuring that the electricity generating apparatus 100 are positioned immediately below the surface of the water.

[00142] The arrangement shown in Figure 7C is similar to the float assembly 500 depicted in

Figure 7A except that float assembly 520 includes two arms 521 that extend both sides of a purposely installed pylon or column 503 and joined by a central collar 522 that slidably moves along column 503 under the action of flotation members 526 located at ends of arms 521. This arrangement could be scaled up to contain a large number of apparatus 100 on a purposely deployed pylon 503. Depending on the type of collar 522, the two armed assembly may also rotate about the pylon 503 to orient itself generally with the flow of water in larger water bodies such as bays and oceans where the flows currents may not have one primary flow direction as observed in channels. Again, two armed float assembly 520 will substantially maintain the location of the electricity generating apparatus 100 immediately below the surface of water.

[00143] The modularity of electricity generating apparatus 100 leads to further advantageous aggregated deployments consisting of multiple apparatus each configured locally for the immediate flow environment. One such aggregation is a TREE deployment which as referred to throughout the specification relates to an arrangement consisting of a trunk structure which is attached to and extends from the relevant environmental feature such as the ocean or river bed or alternatively an artificial structure such as a pylon or base frame and further includes one or more branches extending from the trunk structure to which multiple electricity generating apparatus 100 are attached by in one example the mounting brackets 300 as illustrated in Figure 5. In a further embodiment, further branches may extend from the branches that already extend from the trunk structure.

[00144] Each TREE deployment can be specifically customised to suit the local flow conditions and human usage within the deployment region with the design of the one or more branches extending from the trunk specifically designed to optimise energy extraction from the local flow conditions while minimising the risk of damage to the structure. As discussed previously, the trunk structure connects the tree to the environmental feature, whether artificial or natural and is of a height or length to advantageously place the branches containing the electricity generating apparatus 100 within the upper boundary layer of the flow profile where the largest flow velocities are observed.

[00145] The trunk structure is designed to be strong enough to support its associated branches and numerous mounted electricity generating apparatus 100, and to resist the loads placed on the tree structure by the local flow conditions or impact by any large objects (e.g. boulders) that may move along the beds of regions with large flow velocities. In one embodiment, the profile of the trunk structure is that of a hollow cylinder with relatively thick walls to minimise flow resistance around the structure in geophysical flow conditions where the flow direction can vary considerably. Where the trunk structure is a column or pile, then this may be driven into the ocean or river bed or attached to a specially designed deployment frame supporting one or more TREE structures as the case may be. Similarly, each branch will be hollow or contain a conduit for cabling and be of a shape to minimise flow resistance about the branch structure with strengthening supports added between branches if required.

[00146] Referring now to Figures 8 A to 8D there are shown various examples of a TREE deployment of electricity generating apparatus 100. The TREE deployment 600 of Figure 8A includes a central trunk structure 610 extending from the ocean or river bed and a pair of opposed laterally extending branches 620 from which further vertical branches 625 extend from. Attached by mounting brackets 300 to the branches 620, 625 are rows of electricity generating apparatus 100. In this illustrative embodiment, electricity is fed through individual cables 260 for each apparatus 100, which continue through the hollow inner sections of the branches 620, 625 and the trunk 610 of the TREE and then out of the water to a substation 270 located out of the water where all electrical conditioning is undertaken before the electricity is utilised. In this illustrative embodiment, electrical conditioning conducted once on land converting wild AC electricity from each apparatus 100 into regulated AC electricity for use in mains power 280 or DC electricity for storage in large banks of batteries through processes that are well understood by those of ordinary skills in the art (e.g. rectification/inversion). In another embodiment, all or part of the electrical conditioning is undertaken in the trunk 610 of the TREE and this electricity is then conveyed to the surface.

[00147] The use of individual cabling for each electricity generating apparatus 100 is an important design feature of modular deployment structures such as the TREE because it ensures that the malfunction of one apparatus 100 or its cable 260 and subsequent repair does not influence the generation of electricity by the other apparatus in the TREE. The isolation of each unit means that individual apparatus 100 and cabling 260 can be isolated from the grid during repair/maintenance to ensure the safety of those conducting the repairs.

[00148] The TREE deployment 700 of Figure 8B includes a trunk structure 710 attached to the ocean or river bed and in this case predominantly vertical branches 720 to which multiple electricity generating apparatus 100 are attached in order to maximise energy extraction in deeper flows. [00149] The TREE deployment 800 of Figure 8C is directed to shallower flows such as in rivers and close to shore in coastal regions and includes a trunk structure 810 having predominantly horizontal branches 820 extending outwardly from the trunk structure 810. Again electricity from each electricity generating apparatus 100 travels along its individual cable 260 which carries the electricity to land. In this embodiment, TREE deployment 800 also includes four electricity generating apparatus 100 directly attached to the trunk structure 810 demonstrating the flexibility of the TREE deployment design to be customised for local flow conditions and energy needs.

[00150] The TREE deployment 900 of Figure 8D shows a more specialised design consisting of two horizontal branches 920 extending from trunk structure 910 with a vertical branch 925 extending from the horizontal branch 920 on one side. TREE deployment 900 could be utilised at the edges of shipping channels with the vertical branch 925 being just outside the main channel while the horizontal branch 920 penetrates slightly into the shipping channel at a depth well below that of the ships passing above.

[00151 ] As would be appreciated by those of ordinary skill in the art, a TREE deployment may be specifically designed to optimise energy extraction from the local flow conditions while also minimising the risk of damage to the structure from the environmental conditions. Furthermore, the flexibility in the TREE deployment design allows other considerations such as environmental impact, whether it is the effect of the TREE deployment on the waterway and/or the aesthetic appearance, to be taken into consideration.

[00152] In comparison to a large scale single device, the benefit of having many smaller units is that the TREE deployment can continue to generate electricity as an aggregate even if one or two units or apparatus 100 require repair or replacement.

[00153] A large scale TREE deployment could involve many tens of electricity generating apparatus 100 deployed in a single region that could be used to help power an industrial complex or a small community, which could be especially important in remote regions. The number of apparatus 100 that can be deployed will depend on the space available and how that region is used (e.g. shipping, recreation, national park).

[00154] The branches and in some cases the trunk structures of the TREE deployments will contain standard mounting arrangements such as the mounting brackets 300 described with respect to Figure 5, placed at set distances along the structure so that electricity generating apparatus may be attached. The distance between these attachment points will be designed to maximise the number of devices that can be contained on each TREE deployment, yet with enough room between the units to allow an individual unit to be conveniently installed and removed in-situ. In this embodiment, each standard mounting bracket 300 is connected to the TREE by a support portion 320 (see Figure 5), thereby facilitating easier installation/removal of each apparatus 100 and assisting in keeping the electronics within the unit and cabling within the TREE deployment isolated from water throughout the process via a specialised deployment system apparatus 1 100 (described below).

[00155] Referring now to Figure 9, and based on the modularity of electricity generating apparatus 100, there is depicted a further level of aggregation termed as a FOREST deployment 1000, which as referred to throughout the specification relates to an arrangement of electricity generating apparatus 100 consisting of multiple TREE deployments such as described previously. In this illustrative embodiment, FOREST deployment 1000 is comprised of a plurality of TREE deployments 800 analogous to those illustrated in Figure 8C. As would be apparent to those of ordinary skill in the art, a FOREST deployment may be comprised of numerous different types of TREE deployments depending on the environmental flow conditions.

[00156] Deploying multiple TREE deployments in a FOREST deployment allows for large scale energy extraction (i.e. megawatts of power depending on the local flow conditions) by allowing thousands of units to be deployed. The configuration of these FORESTS would be determined by the local bathymetry, water usage (e.g. shipping, recreational, national park) and the local/regional energy requirements. Within the FOREST, the energy extracted by each apparatus 100 within each TREE will flow down its own respective cable 260 with all these cables then directed towards a localised substation 270 (see Figure 8A) located on the most suitable piece of land nearby where this electricity can be conditioned for integration with mains power.

[00157] Along with maximising the amount of energy that can be extracted from flowing water in the region, TREE and FOREST deployments could greatly assist the local aquatic fauna by providing protection for young species from predators and extreme weather conditions. This is possible because these energy extraction TREEs through their design can act in a similar fashion to plants where small fish and other marine fauna can hide/shelter if required. The smaller sweep area of electricity generating apparatus 100 as compared to most present state of the art devices and the protecti ve mesh 1 1 1 located on the outlets of electricity generating apparatus 100 also reduce the likelihood that any small aquatic animals will be harmed by the impeller arrangement.

[00158] It will be understood that for each deployment of multiple electricity generating apparatus of the type contemplated by the present invention (e.g. TREE, FOREST etc.) that apparatus comprising differing detailed housing, rotating member, and electricity generating assembly arrangements in accordance with the present invention may be combined to form the deployment.

[00159] Another major benefit of this relatively small self-contained apparatus 100 is the ease by which this apparatus 100 can be installed/retrieved from in-situ deployments when compared to the present state of the art devices. The compact lightweight design of apparatus 100 means that it can easily be deployed by one person once a deployment structure (e.g. TREE 800 in Figure 8C) has been set up. In shallow flow deployments, the apparatus 100 can easily be carried to the deployment location and quickly attached to the deployment structure (e.g. concrete block 410 in Figure 6A) through a standardised mounting bracket 300 such as depicted in Figure 5. If the structure is already submerged then an underwater attachment mechanism may be used to connect the apparatus 100 to the mounting bracket 300 without the electronics in either device being exposed to water.

[00160] Referring now to Figure 10, there is shown an illustrative embodiment of an underwater attachment mechanism 1 100 which is a lightweight arrangement designed to separate/attach an apparatus 100 from/to mounting bracket 300 while submerged underwater without exposing the electronics of either device to water. Underwater attachment mechanism 1 100 includes two main portions, these being the apparatus containment/transport portion 1 1 10 and the mounting bracket containment portion 1 120. Each portion can" be sealed from the outside environment via a sliding panel 1 1 11 and 1121 respectively, which once in place is fastened in position to the respective portion by standard fastening mechanisms (e.g. latch and hook).

[00161 ] When the apparatus containment/transport portion 1 1 10 and the mounting bracket containment portion 1 120 are locked together an intermediate portion 1130 initially separates portions 1 1 10 and 1 120. This intermediate portion 1 130 contains water evacuation system 1 140 consisting of an air inlet valve 1 141 and a water outlet valve 11 2. Thereby allowing compressed air to be pumped into the sealed mechanism 1 100 to expel any water before the apparatus 100 and mounting bracket 300 are connected or separated.

[00162] When the retrieval of an individual electricity generating apparatus 100 from an underwater deployment mechanism 1100 is placed around the apparatus 100, mounting bracket 300 and bracket support 320 and then fastened into position, sealing it from the outside environment. Compressed air is then pumped into inlet valve 1 141 forcing the water out of the mechanisms inside chamber 1 150 through the outlet valve 1 142. With the inside chamber 1 150 now free of water the apparatus 100 can now be pulled clear of the mounting bracket 300. Once the apparatus 100 and bracket 300 are separated the sliding panels 1 1 1 1 and 1121 can be pushed into the mechanism 1 100 and locked into place, thereby sealing the apparatus 100 and mounting bracket 300 within their individual portions of the mechanism ( 1 1 10 and 1 120 respectively).

[00163] With both mechanism portions 11 10 and 1 120 sealed, the mechanisms can be separated into these individual portions by releasing the fasteners located in the intermediate section 1 130. Once the portions 1 110 and 1 120 are separated, an operator undertaking this process can then move the individual apparatus 100 away from the deployment structure (e.g. 800 in Figure 8C) so that it can be

repaired/replaced. [001 64] During deployment of an apparatus 100, the two portions of mechanism 1 100 are aligned and fastened into position. Compressed air is then pumped into the mechanisms intermediate portion 1 130 through the inlet valve 1 141 to remove any water within this section during the joining of portions 1 1 10 and 1 120. Once all the water has been evacuated from the intermediate portion 1 130, the sliding panels 1 1 1 1 and 1 121 are unfastened and slide out of the way so that the apparatus 100 may be pushed onto the mounting bracket 300, thereby mating the apparatus and bracket electronics plugs 230, 290.

[001 65] With the electronics plugs 230 and 290 of the apparatus and mounting bracket successfully mated, the mechanism 1 1 10 can be unfastened and removed from about the apparatus 100 and bracket support 320. After the removal of mechanism 1100 the apparatus 100 is firmly secured to the mounting bracket 300 and the apparatus is ready to commence generating electricity.

[00166] For deeper water deployments, an apparatus 100 can be carried to the deployment location and then easily and quickly installed by a diver. To assist the diver in deploying each apparatus 100 a vest worn by the diver and removably attached to mechanism 1 100 is provided which allows the device to be carried without the diver having to use their hands. Once in position the apparatus 100 can be rotated to be aligned with mounting bracket 300, then connected to the deployment apparatus using mechanism 1 100, all while attached to the divers chest. Once the apparatus 100 is fully attached to the mounting bracket 300 the diver simply has to disconnect the mechanism 1 100 on the vest from around the apparatus 100 and mounting bracket 300 and swim away.

[001 67] The attachment of electricity generating apparatus 100 to vest via the underwater attachment mechanism 1 100 greatly simplifies the installation task of the diver and significantly reduces the chances of the apparatus 100 being dropped/damaged during the deployment process. Such a vest could also be used in shallow flow deployments to enhance the ease of the deployment process. In many suitable locations for the extraction of electricity from tidal currents, there may only be limited periods (e.g. less than one hour around slack tides) where it is safe for deployment and repair operations to be conducted due to the extreme flow conditions. Therefore it is important that the electricity generating apparatus 100 be easy and quick to deploy in order to minimise the time and cost it takes for the installation process so that electricity extraction can begin and set up costs recovered.

[00168] This electricity generating apparatus 100 can also be deployed temporarily while travelling/camping in remote locations near flowing water to allow battery recharging or to power electrical equipment (see. Figure 1 1) or off both small and large watercraft while these are travelling through the water (see Figures 12 and 13 respectively).

[00169] Such a portable device may be smaller and lighter than the standard device while maintaining design proportions, to assist with transportation and storage. The reduced size of the portable device will make it easy to deploy in remote locations and allow it to be deployed in the shallower flows observed in small creeks and streams. As with the standard device, the portable device would generate wild AC electricity, which is then transported along a cable to a rectifier, which converts it to DC electricity through processes known in the art.

[00170] Once the travellers arrive at their temporary camping location, they just have to unpack the device and deploy it in the local body of flowing water to begin generating electricity. Then, when they are ready to leave the travellers just have to retrieve the device and pack it back into whatever form of transport they are using (e.g. car, boat).

[00171] Referring now to Figure 1 1 there is shown an example of a temporary deployment of a portable apparatus 100 while camping near a stream. In Figure 1 1 an apparatus 100 is immersed in a stream 1300 with a flow direction F. The unconditioned AC electricity generated by apparatus 100 interacting with the flowing water travels up the cable 260 to a power conversion apparatus 240 (for example a rectifier arrangement) located near campsite 1310, which converts it to DC electricity. This DC electricity can then be used to recharge an independent battery 250 and/or the battery of vehicle 1320. From battery 250, electronic equipment such as light 1330 can be operated.

[00172] A portable version of apparatus 100 could also be used while travelling in both small and large watercraft, by utilising the momentum of the water flowing around the craft while it is moving. To deploy apparatus 100 on a moving watercraft, all the watercraft operator needs to do is deploy the apparatus 100 over the side of the craft using a customised deployment frame. Once in the water, apparatus 100 uses the momentum of the water flowing around the hull of the watercraft to generate wild AC electricity, which is then transported to a rectifier on the craft where it is converted to DC electricity which can be used to keep batteries charged or power important portable electronic devices. Such a portable electricity generating apparatus 100 in combination with small solar and/or wind energy generators could greatly assist small watercraft operators keep vital electronic equipment functioning on long journeys.

[00173] Referring now to Figure 12 there is shown a portable apparatus 100 deployed over the side of yacht 1400 moving through the ocean 1430. In Figure 12 the apparatus 100 is deployed below the waterline 1410 of the yacht 1400 via a custom designed frame 1410 which utilises the standardised mounting system 300 (e.g. see Figure 5). The electricity generated through the apparatus 100 interacting with the water flowing around the yacht 1400 travels through cable 260 to a rectifier 240. The rectifier 240 then converts the generated electricity from AC to DC so that it can be used to recharge the yachts batteries 250.

[00174] On large watercraft (e.g. container ships) large arrays of electricity* generating apparatus

100 could be deployed on specially design deployment frame so that the maximum amount of electricity can be generated from the water flowing around the ship. Alternatively a larger size unit could be developed to increase the amount of energy' generated by the motion of large ships to assist in the supply of these vessels large electricity needs. So that these apparatus 100 do not interfere with the ship docking, the apparatus 100 are deployed once the ship is underway and retrieved before the ship docks.

[00175] Referring now to Figure 13 there is shown an example of numerous apparatus 100 deployed over the side of a large container ship 1500. In Figure 13, three large clusters of apparatus 100 are attached to a customised deployment frame 1520 via the standardised attachment system 300 under the oceans waterline 1510. Each frame 1520 rest on the side of the container vessel 1500 and are suspended over the side of the vessel via two retractable arms 1530 which can be raised/lowered by winches 1540. The individual cables of each device 100 deployed on frame 1520 has an individual cable 260 to carry the electricity onto the ship 1500 where it can be processed through methods well understood by those of basic knowledge in the art (e.g. rectification/inversion) to help power the ships electronics.

[00176] As with small watercraft, the apparatus 100 deployed on large watercraft would use customised deployment systems to optimise the power generated and assist in the easy

deployment/retrieval. Such multi-device deployment systems that could be utilised on large watercraft benefit greatly from the standardised attachment system of this apparatus 100 which also allows for convenient exchange of individual apparatus 100 when maintenance or repair is required.

[00177] For ease of description, the various arrangements embodying the present invention are described above in their usual assembled position as shown in the accompanying drawings and terms such as front,. rear, upper, lower, horizontal, longitudinal etc., may be used with reference to this usual position. However, the arrangements may be manufactured, transported, sold, or used in orientations other than that described and shown herein.

[00178] Those of skill in the art would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[00179] Throughout the specification and the claims that follow, unless the context requires otherwise, the words "comprise" and "include" and variations such as "comprising" and "including" will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. [00180] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

[00181 ] It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims.