AU2008202294A1

AU2008202294A1 - Electricity generating apparatus

Info

Publication number: AU2008202294A1
Application number: AU2008202294A
Authority: AU
Inventors: Tony Asplet
Original assignee: New Space Designs Pty Ltd
Current assignee: New Space Designs Pty Ltd
Priority date: 2007-05-23
Filing date: 2008-05-23
Publication date: 2008-12-11

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: Actual Inventor: T. Asplet Tony Asplet Address for Service is: SHELSTON IP Margaret Street SYDNEY NSW 2000 CCN: 3710000352 Attorney Code: SW Telephone No: Facsimile No.

(02) 97771111 (02) 9241 4666 Invention Title: ELECTRICITY GENERATING APPARATUS Details of Associated Provisional Application No. 2007902735 dated 23 May 2007 The following statement is a full description of this invention, including the best method of performing it known to me/us:- File: 55093AUP00 501563095_1.DOCJ5844 00 -2-

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FIELD OF THE INVENTION The present invention relates to an electricity generating apparatus and in particular to an apparatus for generating electricity from a jet stream. However, it will be appreciated that the invention is not limited to this particular field of use.

BACKGROUND OF THE INVENTION The following discussion of the prior art is intended to place the invention in an 00 appropriate technical context and enable the associated advantages to be fully understood. However, any discussion of the prior art throughout the specification should not be considered as an admission that such art is widely known or forms part of the common general knowledge in the field.

Conventional devices for harnessing wind power are normally in the form of wind machines or 'windmills' having a tower mounted wind turbine employing two or three blades cantilevered from a central axle. Tower heights range from 12 metres to metres or more, depending on the site. The arrangement being such that the wind propels the turbine to drive a ground mounted generator to produce electricity.

However, these wind machines are subject to several problems and limitations.

Firstly, they must be located where there is sufficient wind available. To this end, a tower that is too short will provide disappointing results. Further, it is commonly known that the magnitude and direction of the wind available can be erratic, changing by the hour. There may be no wind at all one day and a howling gale the next. It may blow hard at times when electricity demand is low, and be a mere gentle breeze when demand is high. Accordingly, consistent power generation is difficult to achieve.

Furthermore, due to the inherent noise generated by the moving components required, these wind machines must be positioned in areas where they cannot disturb the local population.

For these reasons, wind power has been unable to realistically provide a substitute for fossil fuel power systems. Ideally, what is needed is a source of wind power that it constantly available, has consistent wind direction and is of sufficient magnitude to reliably provide an alternative to fossil fuel power generation systems.

A jet stream is the narrow belt of strong, upper atmosphere winds, consistently blowing at speeds of over 45 m/s, located at between 7.5 and 14 km above the earth's 00 -3- 0 surface. Energy contained within a jet stream has always been thought of as a reliable source of clean energy. As yet, however, there have not been any systems or methods devised that can reliably and consistently harness this clean wind energy.

Cc It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

N SUMMARY OF INVENTION

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According to a first aspect, there is provided an apparatus for generating 00 electricity from a jet stream, the apparatus including: a wing locatable within the jet stream; a wind-powered electricity generating means supported by the wing for generating electricity from the jet stream; and at least one flexible tether for anchoring the wing with respect to the ground such that the wing develops at least self-supporting lift and the jet stream powers the electricity generating means to produce electricity.

It should be understood that throughout this specification the term 'jet stream' will be interpreted as the narrow belt of strong, upper atmosphere winds, blowing at speeds of over 45 m/s, located at between 7.5 and 14 km above the Earth's surface.

Preferably, the wing has a substantially airfoil cross-sectional shape.

In one embodiment, the wing includes at least one hingedly connected pitch flap.

The at least one pitch flap is preferably rotatable to alter the angle of attack of the wing.

In one embodiment, the wing includes a hingedly connected rudder for controlling the direction of the wing while in the jet stream.

In one embodiment, the wind-powered electricity generating means includes at least one turbine rotatable about a primary axis, said at least one turbine being adapted for propulsion by the jet stream. The at least one turbine is preferably additionally rotatable about a gimbal axis, the gimbal axis being substantially perpendicular to the primary axis.

In one embodiment, the apparatus includes an actuation means adapted for selectable rotation of the pitch flap, rudder and turbine rotation about the gimbal axis.

The actuation means preferably includes one or more electric, magnetic, hydraulic, pneumatic or solenoid actuators or a combination thereof 00 -4- O In one embodiment, the at least one tether includes a power cable for transferring the produced electricity to a ground base station.

In one embodiment, the wing includes a plurality of sensors for detecting Cc position, altitude, angle of attack and the jet stream velocity and temperature. The sensors preferably include a global positioning system (GPS), a thermocouple sensor, a wind speed indicator, a Piezio gyro and an artificial horizon indicator.

In one embodiment, the apparatus includes a programmable central processing unit (CPU) having a memory, the CPU cooperating with the sensors and actuation means 00 to control the pitch, rudder and gimbal rotation to substantially maintain a preselected position of the wing in the jet stream.

In one embodiment, the at least one tether includes a control cable for controlling and monitoring the wing.

According to a second aspect, there is provided a method of generating electricity from a jet stream using the apparatus according to the first aspect, the method including the steps of: locating the wing in the jet stream; and anchoring the wing with respect to the ground using the at least one flexible tether such that the wing develops at least self-supporting lift and the jet stream powers the electricity generating means to produce electricity.

In one embodiment, the action of the electricity generating means is generally adapted to reverse thereby allowing the wing to propel itself into the jet stream from a ground location.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of an apparatus for generating electricity from a jet stream according to the invention; Figure 2 is an enlarged perspective view of the wing of Figure 1; Figure 3 is an enlarged side view of the wing of Figure 1; Figure 4 is an enlarged plan view of the wing of Figure 1; Figure 5 is an enlarged end view of the wing of Figure 1; 00 SFigure 6 is side view of the wing of Figure 1, showing the forces acting upon it (.i during flight; Figure 7 is a diagrammatical summation of the forces of Figure 6; Cc Figure 8 is a diagrammatical summation of the moments acting on the wing of as a result of the forces of Figure 6; Figure 9 is a schematic view of one method of launching the wing of Figure 1; Figure 10 is a schematic view of another method of launching the wing of Figure 1; and 00 Figure 11 is a schematic view of yet another method of launching the wing of Figure 1.

PREFERRED EMBODIMENT OF THE INVENTION Referring to the accompanying drawings and initially to Figure 1, there is provided an apparatus 10 for producing electricity from the high velocity winds contained within a jet stream 12. The apparatus includes a wing 14 having a generally aerofoil cross-sectional shape. The wing is connected to a flexible tether 16, which in turn, is anchored to a ground based station 18. The arrangement is such that the tether 16 anchors the wing against the jet stream so that lift is generated to maintain the wing at jet stream altitudes.

Referring to Figures 2 to 5, the wing includes a pair of pitch flaps 20 hingedly connected to its aft portion. Through the use of corresponding pitch actuators 22 (not shown), the pitch flaps have the ability to extend upwardly. Upon extension, the drag on the top part of the wing of increases thereby altering the wing's angle of attack with respect to the jet stream and, as a result, generates lift.

A rudder 26, which is hingedly connected to a fin 28, is used in a similar way as it is in an aircraft to steer the wing while in the jet stream as well as provide stability.

An electric or hydraulic rudder actuator 30 (not shown) is provided to govern the rotation of the rudder 26 in operation.

The apparatus 10 further includes a wind powered electricity generator 32 supported by the wing 14 for capturing the energy contained in the high velocity winds of the jet stream. In the illustrated embodiment, the electricity generator is located within the wing structure and therefore generally concealed from the jet stream flow.

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The generator includes a turbine 34, rotatable about a primary axis, for propulsion by the high velocity winds of the jet stream to drive the electricity generator thereby producing electricity. As best shown in Figure 1, the generated electricity is sent down to the ground based station 18 through a power cable 36, which in the illustrated embodiment, is integral with the tether 16. The produced electricity is then stored, immediately used or transmitted into the main power grid as required.

As best seen by reference to Figures 2 and 4, the turbine 34 is adapted for further rotation about a gimbal axis 38, which is perpendicular to the primary axis.

00 Advantageously, this allows the angular position of the turbine to adjust with respect to the wing's angle of attack so that it is always facing directly into the prevailing high velocity winds. As a result, the wing 14 is able to remain stable in flight and compensate for any non-uniform flow of the jet stream. A gimbal actuator 40 (not shown) is additionally provided to govern rotation of the turbine about the gimbal axis.

In order to control of the actuation of the pitch flaps 20, rudder 26 and turbine rotation about the gimbal axis 38, a central processing unit (CPU) 42 having a memory is provided and is located on-board the wing 14. To this end, the CPU (not shown) provides respective programmable control of the pitch actuators 22, rudder actuator and gimbal actuator 40. Alternatively, in other embodiments, the CPU may be located remotely but perform the same task.

A number of sensing devices (not shown) including a global positioning system (GPS), a thermocouple, a wind speed indicator, Piezio gyro and an artificial horizon indicator are located and distributed about the wing. These devices communicate to the CPU 42 the various atmospheric and location conditions present such as position, altitude, angle of attack, jet stream velocity and wind temperature. In this way, the CPU may cooperate with the on-board sensors to automatically maintain the wing at a predetermined elevation and position with respect to the ground by individual actuation of the aforementioned actuators.

In order to monitor the wing 14 while in flight, the tether includes a fibre optic control cable 44, which sends both control to and telemetry signals from, the wing. In this respect, the control cable allows the ground station to monitor the various sensor outputs and, if required, augment the programming while in flight. In accordance with an alternate embodiment (not shown), the CPU may be located in the ground station 18 and the control signals are sent through the control cable to the wing actuators.

Returning to Figure 1, in use, upon placement into the jet stream 12, the wing 14 is acted upon by the prevailing winds and yet is held in position by the tether 16. Along with the wing's angle of attack, which is trimmed by extending the pitch flaps 20, these n forces act to generate self-supporting lift and keep the wing in a predetermined elevation. Whilst in this position, the jet stream airflow propels the turbine 34 to generate electricity.

NIt should be understood that loading up on the generator will be progressive, N allowing the trimming of the wing to be maintained as the loads on the wing 14 changes 0 with the loading of the turbine through the generator. At the same time, the voltage generated will be increased and maintained at a high constant value to allow transmission through the power cable 36 to the ground station 18.

Through the on-board sensors, the CPU 42 monitors the wing's elevation and direction. If required, the elevation of the wing is automatically adjusted by the CPU sending signals to the pitch actuator. Similarly, if the wing's direction needs to be corrected, a control signal is sent to the rudder actuator. It will be further appreciated that the self-supporting lift generated will be sufficient to not only support the weight of the wing, but also the 7500 to 10,000 meters of flexible tether 16 which is secured to the ground station.

Once generating electricity, the wing automatically maintains the optimum altitude and angle of attack for maximum electricity generation. The ability for efficient energy generation is mainly due to the aerofoil shape of the wing, which reduces drag to enable the wing 14 to achieve higher altitudes and the corresponding increased power generation achievable at these altitudes. As mentioned earlier, these will be constantly monitored to maximise power generation but can also be reduced if power is not needed.

Figure 6 is free body diagram showing the forces acting upon the wing 14 while in flight. As can be seen, the jet stream force JF and the mass M, which acts directly upon the centre of gravity CG, is shown. The tether force TF and flight control force CF, which is the result of the jet stream acting on the pitch flaps 20, are further shown.

Finally the lift L generated by the jet stream acting upon the wing is shown.

These forces may be further appreciated by reference to Figure 7, which depicts a diagrammatic summation of these forces. As shown, the resultant sum of forces is zero, thereby defining an equilibrium condition in flight. Similarly, reference to Figure 8 depicts a summation of the resultant moments acting upon the wing 14 due the 00 O aforementioned forces. Again, as shown, the resultant sum of moments acting the wing 14 is also zero further indicating an equilibrium condition.

Referring to Figure 9, there is depicted one method of elevating the wing 14 to Cc jet stream altitudes. In this method, the operation of the on-board electricity generator 32 is reversed so as to act as an electric power plant or motor with power supplied from the ground station through the power cable 36. Accordingly, lift power is provided by turbine 34, which is driven by the power plant. For this reason, turbine 34 has the ability to reverse its role from being propelled to acting as a propeller. It will be appreciated 00 that the turbine's blades have suitable pitch and shape to facilitate this changing of roles.

Alternatively, the turbine's blades 34 have the ability to automatically vary their pitch via a supplemental computer controlled actuation means (not shown).

During initial lift off, rotation of the turbine is gradually increased until the airflow over the wing, and the vectored force provided, creates enough lift to start the wing's vertical motion. Typically, as the tether 16 is attached, the wing is restrained from lateral movement and is thereby forced vertically until it starts to reach the lower regions of jet stream, where constant airflow and direction is found. At the same time, the tether 16 is proportionally unreeled from the ground station so that it does not impede the wing's ascension.

Once the wing approaches its desired position, it begins directing itself into the jet stream 12 and the tether can gradually begin to apply a restricting force whilst the turbine rotation is reduced. In this way, a gradual transition between powered and nonpowered lift can be achieved. Once correctly oriented, the wing is trimmed to provide sufficient angle of attack as mentioned above, and powered rotation of the turbine is ceased. At this point, the wing is held in position by the lift generated and the force on the tether.

It will be appreciated that powered lift is only required to place the wing into the lower regions of the jet stream. Further elevation of the wing to the ideal regions of the jet stream having higher velocity wind flow and energy density, is achieved automatically by periodic trimming of the wing. The landing process is basically the reverse of the takeoff procedure, although a landing cradle (not shown) may be utilised.

Furthermore, it is envisaged that the CPU 42, based on user initiation, controls the whole process of takeoff, generation and landing autonomously.

00 Referring to Figure 10, there is depicted another method of elevating the wing 14 to jet stream altitudes. In this method, a tether reel 44 is connected to a vehicle 46 and the wing is pulled along to create airflow across its upper and lower surfaces. The angle n of attack is then adjusted by the extension of the pitch flaps and lift is generated. The vehicle continues until the wing reaches the lower regions of the jet stream.

It is important to note that this method does not require the turbine 34 to provide ,i powered lift to launch the wing. Again, once of the lower regions of the jet stream are Sreached with the wing proceeds to achieve the ideal altitude in a similar way as the 00 method of Figure 9.

Referring to Figure 11, there is depicted yet another method of elevating the wing 14 to jet stream altitudes. In this method, the wing 14 is suspended from a balloon 46 and lifted to reach the lower jet stream altitude. Again, advantageously, this method does not require the turbine 34 to act as a propeller during initial lift into the jet stream.

Once of the lower regions of the jet stream are reached, with the wing proceeds to achieve the ideal altitude in a similar way as the method of Figure 9.

Notwithstanding any of the above, it should be noted that various methods and systems might be used to elevate the wing 14 to jet stream altitudes without departing from the scope of the invention.

It will be appreciated that the illustrated apparatus provides an effective means to capture the energy stored within a jet stream. Advantageously, the constant and high wind velocity available in a jet stream, provide a reliable and constant source of generated electricity with no pollutants created during electricity generation. Moreover, no powered mechanism is required to maintain the wing in position in the jet stream and the efficiency provided by its aerofoil shape reduces drag to a minimum to allow ideal jet stream altitudes to be reached.

It should be further understood that, for safety reasons, the illustrated apparatus would be generally implemented in aircraft no-fly zones.

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. An apparatus for generating electricity from a jet stream, said apparatus including: a wing locatable within said jet stream; a wind-powered electricity generating means supported by said wing for generating electricity from said jet stream; and at least one flexible tether for anchoring said wing with respect to the ground such that said wing develops at least self-supporting lift and said jet stream powers said Selectricity generating means to produce electricity. 00

2. An apparatus according to claim 1, wherein said wing has a substantially airfoil cross-sectional shape.

3. An apparatus according to claim 1 or claim 2, wherein said wing includes at least one hingedly connected pitch flap.

4. An apparatus according to claim 3, wherein said at least one pitch flap is rotatable to alter the angle of attack of said wing.

5. An apparatus according to any one of the preceding claims, wherein said wing includes a hingedly connected rudder for controlling the direction of said wing while is said jet stream.

6. An apparatus according to any one of the preceding claims, wherein said wind powered electricity generating means includes at least one turbine rotatable about a primary axis, said at least one turbine being adapted for propulsion by said jet stream.

7. An apparatus according to claim 6, wherein said at least one turbine is additionally rotatable about a gimbal axis, said gimbal axis being substantially perpendicular to said primary axis.

8. An apparatus according to claim 7, including actuation means adapted for selectable rotation of said pitch flap, rudder and turbine rotation about said gimbal axis.

9. An apparatus according to claim 8, wherein said actuation means includes one or more electric, magnetic, hydraulic, pneumatic or solenoid actuators or a combination thereof.

An apparatus according to any one of the preceding claims, wherein said at least one tether includes a power cable for transferring said produced electricity to a ground base station. 00

-11- O 11. An apparatus according to any one of claims 10 to 13, wherein said wing includes a plurality of sensors for detecting position, altitude, angle of attack and the jet stream velocity and temperature. Cc

12. An apparatus according to claim 11, wherein said sensors include a global positioning system (GPS), a thermocouple sensor, a wind speed indicator, a Piezio gyro and an artificial horizon indicator.

13. An apparatus according to claim 11 or claim 12, wherein said apparatus includes a Nprogrammable central processing unit (CPU) having a memory, said CPU cooperating 00 with said sensors and said actuation means to control said pitch, rudder and gimbal rotation to substantially maintain a preselected position of said wing in said jet stream.

14. An apparatus according to any one of the preceding claims, wherein said at least one tether includes a control cable for controlling and monitoring said wing.

An apparatus for generating electricity from a jet stream substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

16. A method of generating electricity from a jet stream using the apparatus according to any one of the preceding claims, said method including the steps of: locating said wing in said jet stream; and (ii) anchoring said wing with respect to the ground using said at least one flexible tether such that said wing develops at least self-supporting lift and said jet stream powers said electricity generating means to produce electricity.

17. A method according to claim 16, wherein the action of said electricity generating means is adapted to reverse thereby allowing said wing to propel itself into said jet stream.

18. A method of generating electricity from a jet stream substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.