WIND TURBINE SUITABLE FOR MOUNTING ON EXISTING MAST SUCH AS STREET LAMP

Abstract

A wind turbine comprising a two-part collar; a two-part turbine blade assembly, wherein the two parts are coupled together and the turbine blade assembly is rotatably coupled to the collar; an electrical generator comprising a rotor and a stator, the electrical generator being operatively coupled to the turbine blade assembly such that rotation of the turbine blade assembly relative to the collar results in a corresponding rotation of the rotor.

Claims

1-23. (canceled)

24. A wind turbine comprising: a two-part collar; a two-part turbine blade assembly, wherein the two parts are coupled together and the turbine blade assembly is rotatably coupled to the collar; and an electrical generator comprising a rotor and a stator, wherein the electrical generator is operatively coupled to the turbine blade assembly such that rotation of the turbine blade assembly relative to the collar results in a corresponding rotation of the rotor.

25. A wind turbine according to claim 24, wherein the wind turbine includes a pair of collars and the turbine blade assembly is rotatably coupled to both collars.

26. A wind turbine according to claim 24, wherein the wind turbine includes a bearing arrangement between the or each collar and the turbine blade assembly.

27. A wind turbine according to claim 26, wherein the bearing arrangement includes a rolling-element bearing.

28. A wind turbine according to claim 24, wherein the wind turbine further includes an inner spacer located internally of the or each collar.

29. A wind turbine according to claim 24, wherein each part of the two-part collar includes a recessed fixing element.

30. A wind turbine according to claim 24, wherein the turbine blade assembly defines an axis of rotation and includes two or more blades which project outwardly away from the axis of rotation.

31. A wind turbine according to claim 30, wherein the turbine blade assembly includes an upper body portion and a lower body portion and the blades are located between the upper and lower body portions.

32. A wind turbine according to claim 30, wherein the turbine blade assembly includes a central cylindrical body portion and the blades project outwardly from the central cylindrical body portion.

33. A wind turbine according to claim 30, wherein each blade defines a plane which is angled with respect to a radius from the axis of rotation.

34. A wind turbine according to claim 33, wherein the plane defined by each blade subtends an angle from the corresponding radius which is from 10 degrees to 75 degrees.

35. A wind turbine according to claim 34, wherein each angle is from 30 degrees to 60 degrees.

36. A wind turbine according to claim 30, wherein each blade is substantially planar.

37. A wind turbine according to claim 24, wherein: the turbine blade assembly carries a drive gear, the electrical generator rotor includes a rotor gear wheel, and the rotor gear wheel is meshed with the turbine blade assembly drive gear.

38. A wind turbine according to claim 24, wherein the turbine includes a gearbox located between the turbine blade assembly and the electrical generator.

39. A wind turbine according to claim 24, wherein the electrical generator includes an electrical output connected to an electrical energy storage arrangement.

40. A wind turbine according to claim 39, wherein the electrical energy storage arrangement comprises one or more rechargeable batteries.

41. A wind turbine according to claim 24, wherein the turbine further includes a housing body coupled to the collar.

42. A wind turbine according to claim 41, wherein the housing body houses one or more sensors.

43. An item of street furniture comprising: a vertical post; and a wind turbine as defined in claim 24, wherein a first part of the two-part collar is located on one part of the post and a second part of the two-part collar is located on an opposite part of the post.

44. An item of street furniture according to claim 43, wherein an axis of rotation of the turbine blade assembly corresponds to the longitudinal axis of the post.

45. An item of street furniture according to claim 43, wherein: an outwardly facing surface of the post is non-cylindrical; the turbine assembly includes an inner spacer located between the post and the two-part collar; the internal shape of the spacer corresponding to the shape of the outwardly facing surface of the post; and the outwardly facing surface of the spacer is cylindrical.

46. An array of items of street furniture, wherein: the array includes two or more items of street furniture as defined in claim 43; the array includes a single electrical energy storage arrangement; and each of the electrical generators includes an electrical output which is connected to the electrical energy storage arrangement.

Description

[0035] An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0036] FIG. 1 shows a front elevational view of a wind turbine according to the first aspect of the invention coupled to a street lamp post;

[0037] FIG. 2 shows a cross-sectional view from above of an array of street lamp posts located in a central reservation portion of a road system;

[0038] FIG. 3 shows an exploded view of the embodiment shown in FIG. 1;

[0039] FIG. 4a shows an exploded vertical cross-section taken through the upper collar shown in FIG. 3;

[0040] FIG. 4b shows an exploded horizontal cross-section taken through the embodiment shown in FIG. 3; and

[0041] FIG. 5 shows a second embodiment of a wind turbine according to the first aspect of the invention coupled to a street lamp post.

[0042] For the avoidance of doubt, the skilled person will appreciate that in this specification, the terms “up”, “down”, “front”, “rear”, “upper”, “lower”, “width”, etc. refer to the orientation of the components as found in the example when installed for normal use as shown in the Figures.

[0043] FIG. 1 shows a wind turbine apparatus 2 attached to a post 4 forming part of a street light. The wind turbine apparatus 2 comprises a two-part turbine blade assembly 6 rotatably coupled to an upper two-part collar 8 and a lower two-part collar 10.

[0044] The lower collar 10 contains an electrical energy generator (not shown) which is generally known and contains a rotor that is driven to rotate via the rotation of the turbine blade assembly 6 and a stator. Electrical energy is generated in a conventional manner as a result of the rotation of the rotor relative to the stator. The electrical energy generated by the electrical generator flows to an electrical energy storage assembly in the form of a rechargeable battery arrangement 12, which may either be located at the base of the post 4 or located underground. An underground location of the rechargeable battery arrangement 12 would have the benefit of insulating the rechargeable battery arrangement 12 from the environment and providing a degree of security for it against damage or theft.

[0045] Excess electrical energy from the rechargeable battery arrangement may be fed into an external electrical grid 14, if desired.

[0046] FIG. 2 shows the location of an array of two wind turbine arrangements 2, wherein the two wind turbine arrangements are located on adjacent street light posts 4 which are in turn located in a central reservation portion 16 of a road system comprising a road 18a, 18b each side of the central reservation 16. The arrows in FIG. 2 indicate the direction of travel of vehicles 20a, 20b using the roads 18a, 18b and the direction of rotation of the turbine blade assemblies 6.

[0047] The skilled person will appreciate that the movement of air generated by the vehicles 20a, 20b moving along their respective roads 18a, 18b causes the rotation of the turbine blade assemblies 6.

[0048] It will be noted from FIG. 2 that blades 22 located within the turbine blade assemblies 6 are angled by 30° with respect to radii from the axis of rotation of the turbine blade assemblies 6. This angling of the blades 22 increases the efficiency with which the turbine blade assemblies are rotated by the air movements caused by passing vehicles 20a, 20b.

[0049] FIG. 3 shows an exploded view of the apparatus 2 shown in FIG. 1. The apparatus 2 includes a protective conical housing 24, which again is in two-part form to permit the retrofitting of the apparatus 2 to an existing street light post 4. The conical housing 24 comprises a first part 24a and a second part 24b which are secured together about the post 4 via conventional couplings (e.g. screws). The housing 24 houses and protects from the elements a sensor array 26, which is also in two part form. The housing 24 also protects from the elements the upper collar 8.

[0050] As shown in FIG. 3, the upper collar 8 is in two parts and includes a first part 8a and a second part 8b which are secured together in a conventional manner (e.g. via screws or “nut and bolt” arrangement) about a portion of the post 4. Each of the collar parts 8a, 8b define on their lower portions a frustoconical bearing formed by a first bearing part 28a and a second bearing part 28b, which together engage a corresponding, inwardly facing, frustoconical upper portion 30 of the turbine blade assembly 6. A rotating element bearing (not shown) is located between the corresponding frustoconical bearing surfaces 28a, 28b, 30 to reduce friction when the turbine blade assembly 6 rotates relative to the upper collar 8.

[0051] A similar arrangement is provided towards the bottom of the turbine blade assembly 6. As such, the lower collar 10 is in two parts and includes a first part 10a and a second part 10b which are secured together in a conventional manner (e.g. via screws or “nut and bolt” arrangement) about a portion of the post 4. Each of the lower collar parts 10a, 10b define on their upper portions a frustoconical bearing formed by a first bearing part 32a and a second bearing part 32b, which together engage a corresponding, inwardly facing, frustoconical upper portion 34 of the turbine blade assembly 6. A rotating element bearing (not shown) is located between the corresponding frustoconical bearing surfaces 32a, 32b, 34 to reduce friction when the turbine blade assembly 6 rotates relative to the lower collar 10.

[0052] FIGS. 4a and 4b show an inner sleeve 36a, 36b which is located between the collars 8, 10 (only the sleeve associated with the upper collar 8 is shown in the Figures) such that the collars 8, 10 form a tight fit around the post 4.

[0053] As can be seen in the Figures, the inner sleeve part 36a is semi-annular and has an internal diameter which corresponds to the outer diameter of the post 4. In this way, the inner sleeve part 36a engages a semi-circular portion of the outer surface of the post 4. Additionally, the inner sleeve part 36a has an external diameter which corresponds to the internal diameter of the collar part 8a. In this way, the inner sleeve fits snugly inside the collar part 8a.

[0054] The other inner sleeve part 36b has a corresponding relationship with the other upper collar part 8b.

[0055] An arrangement which utilises a collar and inner sleeve, a common collar may be used with a variety of different posts 4, simply by selecting an appropriate inner sleeve.

[0056] Also shown in FIG. 4b, each collar part 8a, 8b, 10a, 10b includes internal bores 40a, 40b, 42a, 42b which have recessed end portions. These bores 40a, 40b, 42a, 42b permit the collar parts 8a, 8b, 10a, 10b to be coupled together via conventional fixings, such as screws or a “nut and bolt” arrangement, wherein the fixings are wholly retained within the collar parts 8a, 8b, 10a, 10b and do not project from them.

[0057] FIG. 5 shows a second embodiment of the invention. In this embodiment, the wind turbine is similar to the turbine shown in FIG. 1 and described above, with the exception that the electrical energy generator is located externally of the lower collar. For ease of reference, the features shown in FIG. 5 which correspond to the features shown in FIG. 1 will have the same reference numerals, but with a preceding “1” or “10”. Thus, upper collar 8 in FIG. 1 becomes upper collar 108 and so on.

[0058] Accordingly, FIG. 5 shows a wind turbine apparatus 102 attached to a post 104 forming part of a street light. The wind turbine apparatus 102 comprises a two-part turbine blade assembly 106 rotatably coupled to an upper two-part collar 108 and a lower two-part collar 110.

[0059] A lower body portion of the turbine blade assembly 106 carries a drive gear wheel 150. Coupled to this is an electrical energy generator 152 comprising a rotor shaft 154 extending from a body of the generator 152 and a rotor gear wheel 156 secured to a distal end of the rotor shaft 154. The rotor gear wheel 156 is meshed with the drive gear wheel 150 carried by the turbine blade assembly 106, such that rotation of the turbine blade assembly 106 by moving or displaced air causes a corresponding rotation of the drive gear wheel 150. This in turn causes a rotation of the rotor gear wheel 156 and the rotor shaft 154. Rotation of the rotor shaft 154 within the body of the electrical energy generator causes electrical energy to be generated in the conventional way.

[0060] The electrical energy generated by the electrical energy generator 152 is transferred to a rechargeable battery arrangement 112 via an electrical cable 158.

[0061] The skilled person will appreciate that in this embodiment, there will be brackets supporting the electrical generator, which may either be coupled to the post 104 or to the stationary lower collar 110 and a housing enclosing the generator. These are not shown for reasons of clarity.

[0062] Studies have established a correlation between vehicle speed and the associated wind speed generated by the movement of the vehicle. These are shown in the following Tables:

TABLE-US-00001 TABLE 1 Wind velocity generated by an average-sized car MPH M/S Wind Velocity(m/s) 50 22.4 5.4 60 26.8 5.9 70 31.2 6

TABLE-US-00002 TABLE 2 Wind velocity generated by a large car, such as an MPV or SUV MPH M/S Wind Velocity (m/s) 50 22.4 5.8 60 26.8 6.22 70 31.2 6.78

TABLE-US-00003 TABLE 3 Wind velocity generated by a large vehicle, such as a bus or HGV (lorry) MPH M/S Wind Velocity(m/s) 50 22.4 7.77 60 26.8 8.22 70 31.2 8.55

[0063] From the above average generated wind velocities, it is possible to estimate the power that may be generated by the wind turbines of the present invention according to the following equation:

Power=constant×(air velocity).sup.3×air density×collection area

[0064] The wind turbine shown in the Figures and described hereinabove had a collection area of 94.24 m.sup.2, the constant is 0.5, the air density at sea level is 1.875 and the generated wind velocity is based on an average-sized car travelling at 60 MPH or 26.9 m/s. Accordingly:

Power=0.5×(5.9).sup.3×1.875×94.24

Power=18.15 kW.

[0065] In other words, working at 100% efficiency, each wind turbine can generate 435.49 kWh per day. Allowing for less than 100% efficiency, each wind turbine could generate 217.74 kWh at 50% efficiency or 130.65 kWh at 30% efficiency.

[0066] The above calculation assumes an installation at the side of a single carriageway. However, if each wind turbine is installed between opposing carriageways as shown in FIG. 2, the effective wind speed that impacts the turbine blade assembly is doubled. This would generate a power output from the wind turbine of 145.16 kW, as the generated wind velocity is cubed, so a doubling of the generated wind velocity results in an 8-fold increase in power generated.

[0067] This results in a daily (24 hour) power output of 3.48 MWh. Again, assuming less than 100% efficiency, this would equate to a daily power output of 1.74 MWh at 50% efficiency or 1.05 MWh at 30% efficiency.

[0068] In order to validate the average speed assumptions, data was collected for traffic flow between Junctions 1&2 (both Eastbound and Westbound) of the M2 motorway in the UK and between Junctions 2&3 (both Eastbound and Westbound) of the M2 motorway in the UK.

[0069] The data showed the following average vehicle speeds across all four of the measured areas:

TABLE-US-00004 Time Average vehicle speed (m/s) 0700 28.77 1200 30.01 1800 29.58 2200 23.33

[0070] This indicates that the assumed speed for the above calculations (26.8 m/s) is a reasonable assumption.

[0071] There are 410 street lamps between Junctions 1 and 3 of the M2 motorway. Assuming that a wind turbine according to the invention is installed on each of these street lamps, the following graph indicates the annual power generation that may be possible, where the Y axis indicates the generated power in MWh, the lower line is the power generated assuming a 30% efficiency and the upper line is the power generated assuming a 50% efficiency.

[0072] Accordingly, over the course of a year, the 410 wind turbines could generate 32.1 GWh at 50% efficiency or 19.2 GWh at 30% efficiency.