AU2016358308A1

AU2016358308A1 - Hydroelectric installation

Info

Publication number: AU2016358308A1
Application number: AU2016358308A
Authority: AU
Inventors: Etienne Herman HELBERG; Stephen HELBERG; Vincent Elmar HELBERG
Original assignee: Helberg Holdings Pty Ltd
Current assignee: Helberg Holdings Pty Ltd
Priority date: 2015-11-23
Filing date: 2016-11-22
Publication date: 2017-07-20
Also published as: WO2017088011A1

Abstract

In an aspect the invention concerns a hydroelectric installation (10). The hydroelectric installation (10) comprises a turbine (12) for operative location within an aquatic environment. The turbine (120) comprises a first blade and a second blade formation (14, 16) disposed about a turbine hub (18). The turbine hub (18) longitudinally extends about a turbine hub axis (20). The hydroelectric installation (10) further comprises a turbine support (22) for operative support of the turbine hub (18) within the aquatic environment. The turbine hub (18) is secured to the turbine support (22) so as to be pivotal about the turbine hub axis (20) responsive to water flow across the first and second blade formations (14, 16). The first blade formation (14) is operatively adapted to be driven by water flow in a first direction and the second blade formation (16) is operatively adapted to be driven by water flow in a second opposite direction.

Description

WO 2017/088011 PCT/AU2016/051140 1

HYDROELECTRIC INSTALLATION

FIELD

[0001] The invention concerns a hydroelectric installation, in particular but not exclusively, a hydroelectric installation for harvesting tidal water flow. The invention further concerns a turbine for use in a hydroelectric installation.

BACKGROUND

[0002] Wind and solar energy are examples of renewable energy sources. Those sources, however, suffer various drawbacks. Wind, for example, is unreliable while solar efficiencies decrease in overcast conditions. Tidal currents, which do not suffer from such unreliability issues in that they are regular and predicable, have to date largely been unexploited as a form of renewable energy.

[0003] Tidal energy results from the interaction between the gravitational fields and relative motion of the sun, moon and earth which in particular locations give rise to regular patterns of high-speed currents. The speed of current flows are magnified at certain locations due to local topographical features such as headlands, inlets to inland lakes and rivers. The tidal systems of seas and oceans involve large volumes of water movement twice a day. Harnessing such movement potentially could generate large amounts of electricity without any polluting emissions.

[0004] Although the supply of tidal energy is reliable and plentiful, converting tidal energy into useful electrical energy is difficult and various potential solutions have been proposed and tested. Factors which hamper exploitation of tidal energy include the harsh and corrosive environment created by sea water and that underwater locations present particular difficulty for installation and maintenance of underwater power stations.

OBJECT

[0005] It is an object of the present invention substantially to address or ameliorate one or more of the drawbacks currently associated with harnessing tidal energy or at least to provide a useful alternative. PCT/AU2016/051140 WO 2017/088011 2

SUMMARY

[0006] According to a first aspect of the present invention there is disclosed herein a hydroelectric installation comprising: a turbine for operative location within an aquatic environment, the turbine comprising a first blade and a second blade formation disposed about a turbine hub, the turbine hub longitudinally extending about a turbine hub axis; and a turbine support for operative support of the turbine hub within the aquatic environment, wherein the turbine hub is secured to the turbine support so as to be pivotal about the turbine hub axis responsive to water flow across the first and second blade formations, the first blade formation operatively adapted to be driven by water flow in a first direction and the second blade formation operatively adapted to be driven by water flow in a second opposite direction.

[0007] Preferably the first and second blade formations are axially spaced apart along the turbine hub axis.

[0008] Preferably the turbine hub comprises a central hub body and a first and a second hub end, the first and second hub ends being located on opposite sides of the central hub body.

[0009] Preferably the first and second hub ends each extend outwardly from the hub body and taper towards the turbine hub axis.

[0010] Preferably the first blade formation comprises a first blade portion spirally wound about the first hub end and the second blade formation comprises a second blade portion spirally wound about the second hub end.

[0011] In a preferred embodiment the central hub body defines a hub cavity for holding a solenoid.

[0012] Preferably the turbine includes a turbine axle, the turbine hub being coaxially mounted onto the turbine axle.

[0013] In an embodiment the turbine support comprises an upright pillar longitudinally extending about a pillar axis. PCT/AU2016/051140 WO 2017/088011 3 [0014] Preferably the upright pillar includes two transverse support arms outwardly extending from the upright pillar, the turbine axle operatively suspended between the support arms.

[0015] Preferably the pillar axis and the turbine hub axis are operatively transversely orientated.

[0016] Preferably the turbine axle is operatively associated with a generator for converting rotational energy of the turbine axle into electrical energy.

[0017] Preferably the turbine axle longitudinally extends between a fist axle end and a second axle end, the first axle end supporting a first housing holding the generator.

[0018] Preferably the second axle end supports a second housing holding a second generator.

[0019] Preferably the first and second housings are of substantial conical shape.

[0020] Preferably the turbine is fitted with electronic monitoring equipment to monitor performance of the turbine.

[0021] Preferably the turbine includes location equipment to locate the turbine should it be dislodged from the support.

[0022] In a preferred embodiment the support supports a plurality of turbines.

[0023] In a preferred embodiment the support comprises two parallel, co-extensive upright pillars, the turbine being suspended between the two upright pillars.

[0024] Preferably each upright pillar includes a guide slot, the guide slots in the upright pillars opposing one another.

[0025] Preferably the guide slots are sized so as to cooperate with the first and second hub ends so that a portion of the first hub end is held within one guide slot and a portion of the second hub end is held within the opposing guide slot.

[0026] In a preferred embodiment the turbine hub is of cylindrical shape.

[0027] In a further preferred embodiment the central hub body is enclosed within a hub casing. PCT/AU2016/051140 WO 2017/088011 4 [0028] Preferably the turbine hub includes a transverse hub attachment formation operatively associated with a support attachment formation located on a support arm of the turbine support to provide an electrical coupling to conduct electricity generated by the turbine to the turbine support.

[0029] Preferably the hub attachment formation comprises a hub electrical contact operatively associated with a support arm electrical contact of the support attachment formation.

[0030] Preferably the hub electrical contact and the support arm electrical contact are biased towards one another so as operatively to engage one another be maintained in contact.

[0031] According to a second aspect of the present invention there is disclosed herein a turbine for operative location within an aquatic environment, the turbine comprising a first blade and second blade formation disposed about a turbine hub, the turbine hub longitudinally extending about a turbine hub axis, wherein the turbine hub is adapted to be secured to a turbine support so as to be pivotal about the turbine hub axis responsive to water flow across the first and second blade formations, the first blade formation operatively adapted to be driven by water flow in a first direction and the second blade formation operatively adapted to be driven by water flow in a second opposite direction.

[0032] According to a third aspect of the present invention there is disclosed herein a hydroelectric installation comprising a turbine and a turbine support for supporting the turbine within an aquatic environment, the turbine including a hub attachment formation operatively associated with a support attachment formation of the turbine support, the hub attachment formation being adapted to co-operate with the support attachment formation to provide an electrical coupling for conducting electricity generated by the turbine, wherein the hub attachment formation comprises a hub electrical contact operatively associated with a support arm electrical contact of the support attachment formation, the hub electrical contact and the support arm electrical contact being biased towards one another so as operatively to engage one another and be maintained in contact.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Preferred embodiments of the invention will be described hereinafter, by way of examples only, with reference to the accompany drawings, wherein: PCT/AU2016/051140 WO 2017/088011 5 [0034] Figure 1 is a schematic perspective view of a first embodiment hydroelectric installation; [0035] Figure 2 is a schematic end view of the hydroelectric installation of Figure 1; [0036] Figure 3 is a schematic top view of the hydroelectric installation of Figure 1; [0037] Figure 4 is a schematic side view of the hydroelectric installation of Figure 1; [0038] Figure 5 is a schematic perspective view of a second embodiment hydroelectric installation; [0039] Figure 6 is a schematic cross-sectional view of the hydroelectric installation of Figure 5; [0040] Figure 7 is a schematic top view of the hydroelectric installation of Figure 5; [0041] Figure 8 is a schematic side view of the hydroelectric installation of Figure 5; [0042] Figure 9 is a schematic perspective view of a third embodiment hydroelectric installation; [0043] Figure 10 is a schematic cross-sectional view of the hydroelectric installation of Figure 9; [0044] Figure 11 is a schematic top view of the hydroelectric installation of Figure 9; [0045] Figure 12 is a schematic side view of the hydroelectric installation of Figure 9; [0046] Figure 13 is a schematic representation of a plurality first embodiment hydroelectric installations forming a field of hydroelectric installations for harvesting water flow in an aquatic environment; [0047] Figure 14 is a schematic perspective view of a fourth embodiment hydroelectric installation; [0048] Figure 15 is a schematic side view of the hydroelectric installation of Figure 14; and [0049] Figure 16 is a top view of the hydroelectric installation of Figure 14. PCT/AU2016/051140 WO 2017/088011 6

DESCRIPTION OF PREFERRED EMBODIMENTS

[0050] In the description below like reference numerals will be used to indicate like components.

[0051] Figures 1 to 4 show a first embodiment hydroelectric installation, generally indicated with the reference numeral 10, for operative location within an aquatic environment such as an ocean or river. The hydroelectric installation 10 comprises a plurality of turbines 12 for operative location within the aquatic environment. Each turbine 12 comprises a first blade and a second blade formation 14, 16 disposed about a turbine hub 18. The turbine hub 18 extends longitudinally about a turbine hub axis 20.

[0052] The hydroelectric installation 10 further comprises a turbine support 22 for operative support of the turbine hub 18 within the aquatic environment. The turbine support 22 comprises an upright pillar 24 which extends longitudinally about a pillar axis 26. To support the hydroelectric installation 10 in an upright orientation, the upright pillar 24 includes a concrete foundation 28.

[0053] As shown, each turbine hub 18 is secured to the turbine support 22 so as to be pivotal about their respective turbine hub axes 20 responsive to water flow 30 across the first and second blade formations 14, 16. The first blade formation 14 is operatively adapted to be driven by water flow in a first direction 32, whilst the second blade formation 16 is operatively adapted to be driven by water flow in a second, opposite direction 34. The change in direction of water flow will be occasioned by a change in tide of the aquatic environment in which the hydroelectric installation 10 is located. The first and second blade formations 14 and 16 are configured so as to generate unidirectional rotation irrespective of the direction of flow of the water occasioned by the change in tide. It will of course be appreciated that the hydroelectric installation need not only be constructed in a water body subject to changes in water flow direction, but could also be installed in a river having a single flow direction only.

[0054] The first and second blade formations 14, 16 are axially spaced apart along the turbine hub axis 20. In this embodiment, with particular reference to Figure 4, the pillar axis 26 divides the turbine 12 in two halves, with the first blade formation 14 located on the right-hand side of the pillar axis 26 and the second blade formation 16 located on the left-hand side of the pillar axis 26. PCT/AU2016/051140 WO 2017/088011 7 [0055] The turbine hub 18 comprises a central hub body 36 as well as first and second hub ends 38, 40. The first and second hub ends 38,40 are located on opposite sides of the central hub body 36. As shown, the first and second hub ends 38, 40 each extend outwardly from the hub body 36 and tapers towards the turbine hub axis 20.

[0056] The first blade formation 14 comprises a first blade portion 42 spirally wound about the first hub end 38. The second blade formation 16 comprises a second blade portion 44 spirally wound about the second hub end 40.

[0057] Each turbine includes a turbine axle 46 with the turbine hub 18 coaxially mounted onto the turbine axle 46. The upright pillar 24 includes a plurality of transverse support arm pairs 48 outwardly extending from the upright pillar 24. The turbine axle 46 of each turbine 12 is operatively suspended between a support arm pair 48. As shown, the pillar axis 26 and the turbine hub axis 20 of each turbine 12 is operatively transversely orientated.

[0058] Each turbine axle 46 is operatively associated with a generator, not shown, for converting rotational energy of the turbine axle 46 into electrical energy. In this embodiment the turbine axle 46 longitudinally extends between a fist axle end 50 and a second axle end 52. The first axle end 50 supports a first housing 54 which holds the non-illustrated conventional generator for converting rotational energy of the turbine axles 46 into an electrical current in the manner well understood by persons skilled in the art. In this embodiment the second axle end 52 supports a second housing 56 holding a second non-illustrated generator. Each of the first and second housings 54, 56 also include a non-illustrated gearbox for transmitting torque from the rotating turbine 12 to the non-illustrated generator.

[0059] In this embodiment the first and second housings 54, 56 not only hold the non-illustrated generators, but also act as stops for securing the respective turbine axles 46 in position on their respective support arm pairs 48. The first and second housings 54, 56 are of substantial conical shape so as to facilitate streamlined water flow across the turbines 12.

[0060] It will be noted from Figure 2 that, and as a result of the shape of the turbine hub 12, a peripheral surface 60 of the first blade portion 42, located towards the first axle end 50, is radially displaced from the turbine hub axis 20 a lesser distance than a peripheral surface 62 of the first blade portion 42 located towards the longitudinal centre of the turbine hub 18. It will further be noted that there is a gradual transition in the radial displacement of the peripheral surface of the PCT/AU2016/051140 WO 2017/088011 8 first blade portion 42 between the first axle end 50 and (he longitudinal centre 64 of the turbine hub 18. In this embodiment the second blade portion 44 is a mirror image of the first blade portion 42.

[0061] Each turbine 12 is fitted with non-illustrated electronic monitoring equipment, located within the first and second housings 54, 56 or attached thereto via magnets, to monitor performance of the turbine and to communicate such performance to a location remote from the turbine. Each turbine 12 further includes non-illustrated location equipment to facilitate location of a turbine should it be dislodged from the turbine support 20 and be swept away by a water current. In this embodiment the location equipment includes a GPS system.

[0062] The turbine 12 is produced by moulding such that the first and second blade formations 14, 16 are of unitary construction with the turbine hub 18. In this embodiment the turbine is produced from a plastics material which is selected for its durability in a marine environment. It will, however, by appreciated that the turbine 12 could be produced from a range of materials including composite materials. Examples of suitable materials include high modulus aluminium, elasticity glass, carbon or aramid fibre, such as Kevlar™ or a combination of those.

[0063] The turbine hub 18 defines a non-illustrated buoyancy cavity. The purpose of the buoyancy cavity is to ensure that the turbine 12 has a neutral buoyancy to assist with the installation and maintenance of the hydroelectric installation 10.

[0064] The first and second blade portions 42, 44 are shaped so as to enable rotation of the turbine 12 in one direction only. This configuration eliminates the need for dual rotational gearboxes with an associated reduction in the complexity and maintenance of the hydroelectric installation 10.

[0065] The hydroelectric installation 10 will typically be installed as one of many hydroelectric installations 10 in a hydroelectric installation field 58, illustrated in Figure 13. Although not illustrated the hydroelectric installation 58 is in electronic communication with an electricity substation. The sub-station will typically be land based.

[0066] A second embodiment hydroelectric installation 70 is illustrated in Figures 5 to 8. Similar to the hydroelectric installation 10, the hydroelectric installation 70 comprises a plurality of turbines 12 for operative location within the aquatic environment. The hydroelectric PCT/AU2016/051140 WO 2017/088011 9 installation 70 also comprises a turbine support 22 for operative support of the turbines 12 within the aquatic environment.

[0067] The hydroelectric installation 70 differs from the hydroelectric installation 10 in that the turbine support 22 comprises two parallel, co-extensive upright pillars 72. The turbines 12 are suspended one above the other between the two upright pillar's 72. Each upright pillar 72 includes a plurality of guide slots 74 with respective guide slots 74 in the upright pillars 72 opposing one another. The guide slots 74 are sized to cooperate with the first and second hub ends 38 and 40 so that a portion of the first hub end 38 is held within one guide slot 74 and a portion of the second hub end 40 is held within the opposing guide slot 74. The guide slots 74 serve to assist personnel during installation of the turbines 12 to the pillars 72 in an aquatic environment.

[0068] The pillars 72 further each include opposing in-register pillar bores 76 which define a plurality of pillar bore pairs 78. Each pillar bore pair 78 is configured to secure a turbine 12 in position on the turbine support 22. The first axle end 50 is located in a first pillar bore 76 of a pillar bore pair 78. The second axle end 52 is located in a corresponding pillar bore 76 of the pillar bore pair 78 on the other pillar. The first and second axle ends 50, 52 of each turbine axle 46 are located within the corresponding pillar bores 76 of a pillar bore pair 78. As shown, the first and second housings 54, 56 serve to act as stops to secure the turbines 12 in position on the turbine support 22 when they are located on outer surfaces 79 of the pillars 72.

[0069] A third embodiment hydroelectric installation 80 is illustrated in Figures 9 to 12. Similar to the hydroelectric installations 10 and 70, the hydroelectric installation 80 comprises a plurality of turbines 12 for operative location within an aquatic environment as well as a turbine support 22 for operative support of the turbines 12 within the aquatic environment. The turbine support 22 of the hydroelectric installation 80 comprises a single upright pillar 24 which supports four turbines 12. Two turbines 12 are located on one side of the turbine support 22 with the other two turbines 12 mirroring the location of the first two turbines 12.

[0070] Similar to the hydroelectric installations 10 and 70, the turbine hubs 18 of the turbines 12 of the hydroelectric installation 80 are secured to the turbine support 22 in such a manner as to be pivotal about their respective turbine hub axes. In this embodiment each respective turbine hub 18 is provided in the form of an elongate shaft which also constitutes the turbine axle 46. The first and second blade formations 14, 16 are axially spaced apart along the turbine hub axis 20. In this embodiment, with reference in particular to Figure 12, the first blade formation 14 is located PCT/AU2016/051140 WO 2017/088011 10 on the right-hand side of a hub casing 82, with the second blade formation 16 located on the left-hand side of the pillar axis 26. The central hub body 36 of the turbine hub 18 is located within the hub casing 82. The hub casing 82 houses a solenoid 83 which is co-axially disposed about the central hub body 36.

[0071] The turbine 12 of the hydroelectric installation 80 differs from those of hydroelectric installations 10 and 70 in that the first and second blade formations 14, 16 each comprises two blade portions 42a, 42b and 44a, 44b respectively. The blade portions 42a, 42b are equally radially spaced about the turbine hub axis with one being wound in a clockwise direction and the other in an anti-clockwise direction. This is also the case for the blade portions 44a and 44b.

[0072] As shown in Figure 11, each hub casing 82 comprises a transverse hub attachment formation 84 operatively associated with a support attachment formation 86 located on a support arm 88 of the turbine support 22. The hub attachment formation 84 is adapted to co-operate with the support attachment formation 86 so as to provide an electrical coupling 90 to conduct electricity generated by the turbine to the turbine support 22. The electrical coupling 90 comprises (a) a hub electrical contact 92 on the hub attachment formation 84 and (b) a support arm electrical contact 94 on the support attachment formation 86. The hub and support arm electrical contacts 92, 94 are biased towards one another so as operatively to engage one another and be maintained in contact. Each of the hub and support arm electrical contacts 92, 94 includes a spring 96 to enable such biasing.

[0073] In this embodiment the hub attachment formation 84 comprises a T-shaped male coupling member 98 slidably receivable within a U-shaped female coupling member 100 of the support arm attachment formation 86. The male and female coupling members 98, 100 are secured in a coupled orientation with locking pins 102. The male and female coupling members 98, 100 are enclosed within a non-illustrated housing. Providing electrical contacts 92, 94 which engage in the manner described provides a quick attach / release mechanism to facilitate ease of installation and removal of the turbines 12 to the turbine support 22 in an aquatic environment.

[0074] The turbines 12 are sized so as to fit within conventional shipping containers. Such sizing enables the turbines 12 to be transported via conventional road trucks, trains, boats or aircraft. The turbine supports 22 are typically produced in either of two lengths, conforming to standard shipping container lengths. The first standard length is 20 foot (6.058m). The second standard length is 40 foot (12.192m). Both container versions are of similar cross-sectional dimension. PCT/AU2016/051140 WO 2017/088011 11

The design of the turbines 12 is such that a single turbine 12 can be transported within a 20 foot container whilst two turbines 12 can be transported within a 40 foot shipping container. It will of course be appreciated that the turbines 12 may have a variety of sizes and may, in certain instances, be too large to fit within a standard shipping container.

[0075] A fourth embodiment hydroelectric installation 110 is illustrated in Figures 14 to 16. Similar to the previously described hydroelectric installations, the hydroelectric installation 110 comprises a turbine 12 for operative location within an aquatic environment as well as a turbine support 22 for operative support of the turbine 12 within the aquatic environment. The support 22 of the hydroelectric installation 110 comprises two parallel, co-extensive upright pillars 72.

[0076] The turbine 12 of the hydroelectric installation 110 comprises a cylindrically shaped turbine hub 18. The turbine hub 18 of this embodiment performs the same function as that of the turbine axle 46 of the above described embodiments. The turbine hub 18 includes first and a second blade formations 14, 16 shaped as shown. It will be noted that the blade formations 14, 16 are configured such that the radial length measured between their peripheral surfaces and a central axis of the turbine axle 46 increases as one moves respectively from the first and second axle ends 50, 52 towards the axial centre of the turbine hub 18. In this embodiment the turbine axle 46 does not define an internal cavity.

[0077] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

1. A hydroelectric installation comprising: a turbine for operative location within an aquatic environment, the turbine comprising a first blade and a second blade formation disposed about a turbine hub, the turbine hub longitudinally extending about a turbine hub axis; and a turbine support for operative support of the turbine hub within the aquatic environment, wherein the turbine hub is secured to (he turbine support so as to be pivotal about the turbine hub axis responsive to water flow across the first and second blade formations, the first blade formation operatively adapted to be driven by water flow in a first direction and the second blade formation operatively adapted to be driven by water flow in a second opposite direction.

2. A hydroelectric installation according to claim 1, wherein the first and second blade formations are axially spaced apart along the turbine hub axis.

3. A hydroelectric installation according to claim 2, wherein the turbine hub comprises a central hub body and a first and a second hub end, the first and second hub ends being located on opposite sides of the central hub body.

4. A hydroelectric installation according to claim 3, wherein the first and second hub ends each extend outwardly from the hub body and tapers towards the turbine hub axis.

5. A hydroelectric installation according to claim 4, wherein the first blade formation comprises a first blade portion spirally wound about the first hub end and the second blade formation comprises a second blade portion spirally wound about the second hub end.

6. A hydroelectric installation according to claim 5, wherein the central hub body defines a hub cavity for holding a solenoid.

7. A hydroelectric installation according to claim 1, wherein the turbine includes a turbine axle, the turbine hub being coaxially mounted onto the turbine axle.

8. A hydroelectric installation according to claim 7, wherein the turbine support comprises an upright pillar longitudinally extending about a pillar axis.

9. A hydroelectric installation according to claim 8, wherein the upright pillar includes two transverse support arms outwardly extending from the upright pillar, the turbine axle operatively suspended between the support amis.

10. A hydroelectric installation according to claim 9, wherein the pillar axis and the turbine hub axis are operatively transversely orientated.

11. A hydroelectric installation according to claim 10, wherein the turbine axle is operatively associated with a generator for converting rotational energy of the turbine axle into electrical energy.

12. A hydroelectric installation according to claim 11, wherein the turbine axle longitudinally extends between a fist axle end and a second axle end, the first axle end supporting a first housing holding the generator.

13. A hydroelectric installation according to claim 12, wherein the second axle end supports a second housing holding a second generator.

14. A hydroelectric installation according to claim 13, wherein the first and second housings are of substantial conical shape.

15. A hydroelectric installation according to claim 1, wherein the turbine is fitted with electronic monitoring equipment to monitor performance of the turbine.

16. A hydroelectric installation according to claim 1, wherein the turbine includes location equipment to locate the turbine should it be dislodged from the support.

17. A hydroelectric installation according to claim 1, wherein the support supports a plurality of turbines.

18. A hydroelectric installation according to claim 1, wherein the support comprises two parallel, co-extensive upright pillars, the turbine being suspended between the two upright pillars.

19. A hydroelectric installation according to claim 18, wherein each upright pillar includes a guide slot, the guide slots in the upright pillars opposing one another.

20. A hydroelectric installation according to claim 1, wherein the turbine hub is of cylindrical shape.

21. A hydroelectric installation according to claim 1, wherein the turbine hub includes a transverse hub attachment formation operatively associated with a support attachment formation located on a support arm of the turbine support, the hub attachment formation and support attachment formation operatively adapted to provide an electrical coupling to conduct electricity generated by the turbine to the turbine support.

22. A hydroelectric installation according to claim 21, wherein the hub attachment formation comprises a hub electrical contact operatively associated with a support arm electrical contact of the support attachment formation.

23. A hydroelectric installation according to claim 22, wherein the hub electrical contact and the support arm electrical contact are biased towards one another so as operatively to be adapted to engage one another and be maintained in contact.

24. A turbine for operative location within an aquatic environment, the turbine comprising a first blade and second blade formation disposed about a turbine hub, the turbine hub longitudinally extending about a turbine hub axis, wherein the turbine hub is adapted to be secured to a turbine support so as to be pivotal about the turbine hub axis responsive to water flow across the first and second blade formations, the first blade formation operatively adapted to be driven by water flow in a first direction and the second blade formation operatively adapted to be driven by water flow in a second opposite direction.

25. A hydroelectric installation comprising a turbine and a turbine support for supporting the turbine within an aquatic environment, the turbine including a hub attachment formation operatively associated with a support attachment formation of the turbine support, the hub attachment formation being adapted to co-operate with the support attachment formation to provide an electrical coupling for conducting electricity generated by the turbine, wherein the hub attachment formation comprises a hub electrical contact operatively associated with a support arm electrical contact of the support attachment formation, the hub electrical contact and the support arm electrical contact being biased towards one another so as operatively to engage one another and be maintained in contact.