OA17047A - Power generating device using lightning - Google Patents

Abstract

A device to harvest energy from lightning. The electrical energy of the lightning is used to heat a fluid, which is then used to drive a turbine 19 to produce electricity. The electricity provided by the turbine is in a form suitable to either by used or stored. The lightning strikes an antenna 10 and is conducted through an insulated chamber 14, 15 where it heats the fluid.

Description

The invention relates to a power generating device and a method for generating power.

Lightning is an atmospheric elcctrostatic discharge and can occur with both positive and négative polarity. Négative lightning typically carries an clectric current of 30 kA, and transfers fifïeen coulombs of clectric charge and 500 MJ of energy. Positive lightning typically carries an clectric current of approximately 300 kA.

Known lightening harvesting dcviccs hâve proved unsuccessful as they fail to adequately store the electrical charge of a lightning strike.

A first aspect of the invention provides a power generating device comprising a pressure chamber and a conductor for receiving a lightning strike. The conductor passes through the pressure chamber, the pressure chamber is a réservoir for a fluid and the fluid is heated when the conductor reçoives a lightning strike. The electrical energy ofthe lightning is transformed into kinctic energy in the moiecules of the fluid. The storage of lightning energy in a form other than clcctricity allows for the energy to bc easily captured and safely stored.

Preferably, the power generating device further comprises an antenna elcctrically connected to the conductor to receive the lightning strike. The antenna provides an electric field to reduce the résistance of a path through the conductor compared to a path to the earth nut through the conductor.

Preferably, the pressure chamber is elcctrically insulated. The insulation rcsists flow of an clectric lightning charge through the walls of the pressure chamber to earth. The lightning must flow through the pressure chamber for a greater distance as possible to maximise the heating of fluid within the chamber.

Preferably, the conductor comprises a section of increased electrical résistance within the pressure chamber. The section of the conductor with increased résistance compared to the résistance along the other lengths of the conductor will generate more heat per conductor unit length than the rest of the conductor. The increased heat production along the conductor within the fluid will provide a greater transfer of heat energy to the fluid.

Preferably, the power generating device further comprises a turbine in fluid communication with the pressure chamber. Fluid flows from the pressure chamber to the turbine. The turbine converts the pressure provîded by the fluid flow from the pressure chamber into electrical energy.

Preferably, the power generating device further comprises a valve between the pressure chamber and the turbine, wherein the valve is opérable to isolate the pressure chamber from the turbine. Pressuriscd fluid may be stored in the chamber when the valve is closed and released to drive the turbine, thereby creating elcctricity, when required.

Preferably, the power generating device further comprises pressurising means to pressurise the pressure chamber. The fluid within the pressure chamber may be pressuriscd by pumping more fluid into the chamber. This allows more kinetic energy to be stored by the fluid contained within the pressure chamber. Altematively, the fluid in the pressure chamber may be pressuriscd by heating from a source excluding a lightning strike. The energy provîded by this heating will be recoverable by the turbine as well as the energy imparted to the fluid by the lightning strike.

Preferably, the power generating device further comprises a second pressure chamber and conductor coupled to the turbine. Multiple pressure chambers attached to a single turbine reduce the resources required to carry out the invention with multiple chambers. Also, multiple chambers will provide a more even flow of pressure generated by lightning strikes.

A second aspect of the invention provides a method of generating power comprising conducting a lightning strike through an electrically insulated pressurised chamber, and channelling fluid heated by the energy of the lightning strike to a turbine. The fluid is displaced by expansion of the heated fluid. The lightning energy is converted and temporarily stored by heat energy and/or as latent heat energy of the fluid. The fluid, when released from the chamber, drives a turbine generating electrical energy which is then in a manageable form.

Preferably, the lightning strike is conducted through the pressure chamber by an electrically conducting structure. The method further comprises propelling an electrically conducting device in electrical contact with the electrically conducting structure away from the pressure chamber. The electrically conducting device has an associated electrie field which, when targeted at charged areas of the atmosphère, will induce a lightning strike to the device. The lightning charge will be conducted to the electrically conducting structure and through the pressure chamber.

Preferably, the fluid is pressurised within the pressurised chamber prior to a lightning strike. The fluid within the pressure chamber may be pressurised by pumping more fluid into the chamber. This allows more kinetic energy to be stored by the fluid contained within the pressure chamber. Altematively, the fluid in the pressure chamber may be pressurised by heating from a source excluding lightning. The energy provided by this heating will be recoverable by the turbine as well as energy imparted to the fluid by the lightning strike.

The invention will now be described, by way of example only, with référence to the accompanying drawings, in which:

Figure 1 is a sectional view of a first embodiment of a power generating device;

Figure 2 is a sectional view of a chamber of a second embodiment of the power generating device;

Figure 3 is a sectional view of a first embodiment of a component of the power generating device;

Figure 4 is a perspective view of a second embodiment of a component of the power generating device;

Figure 5 is a sectional view of a third embodiment of a component of the power generating device;

Figure 6 is a sectional view of a third embodiment of a power generating device;

Figure 7 is a sectional view of a fourth embodiment of a power generating device;

Figure 8 is a schematic view of a first embodiment of a power generating System;

Figure 9 is a schcmatic view of a second embodiment of a power generating system;

Figure 10 is a sectional view of a fifth embodiment of a power generating device; and

Figure 11 is a sectional view of a sixth embodiment of a power generating device;

Figure 1 shows a power generating device having an antenna 10 suitable to conduct high voltage, high current electricity for a short amount of time. The antenna 10 is electrically coupled through a conductor 11 grounded section 12 which can pass charge, received by the antenna 10, to earth. The conductor 11 passes through a chamber 13 formed by side walls 14, an upper wall 15 and a lower wall. The walls surrounding the chamber 13 arc electrically and thermally insulated. The conductor passes through the upper 15 and lower wall. The chamber 13 is open to a pipe 16. The pipe 16 forms a channcl 17 whereby fluid can flow from the chamber 13, through the channel 17, to a turbine 19.

In use, the antenna 10 is struck by lightning and a charge is conducted by tlie conductor 11 through the chamber 13 where it is then passed to earth via the grounded section 12 of the conductor 11. The insulated upper wall 15, side walls 14 and lower wall stop the charge created by the lightning strike from being conducted to earth prior to passing through the chamber 13. The current crcated by the charge passing through the conductor 11 créâtes heat due to the electrical résistance of the conductor. The heat is transmitted by radiation, convection and conduction to a fluid contained within the chamber 13. The heated fluid expands within the chamber 13, thus increasing the pressure of the fluid within the chamber. The pressurised fluid flows along the pipe 16 and into the turbine 19. The power of the pressurised fluid flow is transduccd into electricity by the turbine 19.

Various modifications will be apparent to those skilled in the art. For example, chamber 13 can be cuboid, spherical, or any other shape suitable to form a chamber insidc the insulating walls. The shape of the antenna 10 of Figure 1 is merely représentative of a possible embodiment and is not intended to limit the scope an antenna used with this invention any single structure. The antenna may be a conducting rod with a spiked or roundcd tip, or any other shape suitable to receive a lightning strike.

Figure 2 shows an embodiment of the conductor 21, 22, 23 shapcd to increase the résistance ofa section 22 of the conductor contained within the chamber. The conductor comprises an upper section 21, a résistive portion 22, and a lower portion 23. The résistive portion 22 is of greater length and of lesser diameter than compared to the surrounding conducting portions. The résistive portion 22 increases the résistance of the conductor within the chamber, thus increasing the amount of heat generated by the lightning current passing along the conducting element, through the chamber.

Figure 3 shows another embodiment of a shaped conductor 32 for use within the chamber. The shaped conductor 32 forms a pleated résistive element comprising a number of straight sections connected by a number of shorter sections of the element. This shaped conductor element 32 provides for a greater area of heating than that of the previously described embodiment 22.

Figure 4 shows a further embodiment of a shaped conductor 32 for use within the chamber. The conductor 32 comprises a plurality of conductivc horizontal plates 41 vertically coupled by conductîng connecting portions 42. The connecting portions 42 arc shown with a small crosssection compared to their length, however, in a another further embodiment the vertical 5 connecting portions 42 hâve a width equal to that of the horizontal plates 41.

Figure 5 shows an additional embodiment of a shaped conductor comprising horizontal plates 51 and vertical plate connectors 52. The device further comprises insulating portions 53 disposed between the horizontal conductîng plates 51. The insulating portions 53 prevent electricity from 10 arcing through a diclectric fluid between any two horizontal plates. Arcing between plates may occur as a high electrostatic field is generated across the shaped conductor when subjected to the charge of a lightning strike.

Figure 6 shows an embodiment of a conductor 61 passing through a chamber. An upper part of 15 the conductor 61 is coupled to an extendable antenna 60, and a lower part of the conductor 61 is coupled to a grounded section 62. The extendable antenna 60 comprises a conductîng coil 65 and an antenna end 66. The coil 65 is flexible and can be straightened if drawn away from the conductor 61.

In use, the antenna end 66 is attached to a device to lengthen the conductîng coil 65 in a direction away from the conductor 61. The antenna end may be attached to a rocket, kite, balloon or any other device to lengthen the coil. The extendable antenna 60 is used to extend a grounded conductive portion towards a thunder storm to induce a lightning strike to the conductor 61 via the antenna 60.

Figure 7 shows an embodiment of the chamber 73 having a channel leading to a pressurising pipe 74, coupled to a first valve VI, and another channel leading to a second valve V2, coupled to a turbine channel 79. The turbine channel 79 leads to a turbine and pressurised fluid selcctively flows down the channel 79 and the flow of which is controlled by the second valve 30 V2. The first valve is opérable to control fluid flowing into the chamber 73, which is used to pressurise the chamber.

In use, pressurised fluid may be pumped through the first valve VI, through the pressurising pipe 74, and into the chamber 73. Alternat!vely, the first valve VI is opened to allow fluid into the 35 chamber. The first valve VI is then shut and the fluid within the chamber 73 is heated, thus the pressure within the chamber increascs. The natural température variation during a day may be used to fill the chamber 73 with relatively cold air early in the day, and then the beat of the day is used to heat the captured cold air.

The pressure within the chamber 73 is maintained once pressurised. The chamber pressure is further increased by a Iightnîng strike before being released by the second valve V2 to a turbine.

Figures S and 9 show a power generating system comprising a first pressure chamber 81,91 and a second pressure chamber 82, 92. The first and second pressure chambers 81, 82, 91, 92 function as described above and are opérable to rclease pressurised fluid resulting from lightning strike. The first and second pressure chambers 81, 82, 91,92 arc coupled to a turbine 89,99 by a network of pipes through which pressurised fluid flows. A first valve V3, V5 is associated with the first pressure chamber 81,91 output to control the flow of pressurised fluid out of the first chamber 81, 91 to the turbine 89, 99. A second valve V4, V6 is associated with the second pressure chamber 82, 92 output to control the flow of pressurised fluid flowing out of the second chamber 82,92.

Figure 8 shows the first and second valves V3, V4 coupled to the turbine 89 to supply pressurised fluid to drive the turbine 89.

Figure 9 shows pipes of the first and second valves V5, V6 having a connection point prior to a single pipe prior to them being coupled to the turbine 99. A third valve V7, may be included to control the amount of fluid flowing into the turbine 99. In this embodiment, the third valve V7 allows the contaïnment and storage of pressurised fluid within the connecting network between the first, second and third valves V5, V6, V7.

In the embodiments of Figures 8 and 9, multiple pressure chambers 81,82, 91,92 are connected to a turbine 89, 99. This reduces the amount of infrastructure required to provide the invention for a set number of pressure chambers. With an increased number of pressure chambers, the turbine is kept supplied with pressure more consistently.

Figure 10 shows a power generating device having an antenna suitable to receive a high voltage charge. The antenna is electrically coupled to a conductor 101 which passes through a pressure vessel 103, 104. The conductor 101 enters the pressure vcsscl 103, 104 through a first plugged opening 102 and exits the pressure vessel through a second plugged opening 103. The pressure vessel has a first wall 103 and a second wall 104 surrounding the first wall. The double wall pressure vessel 103, 104 provides a thcrmally insulative pressure vessel. An opening 106 in the top of the pressure vessel 103, 104 allows fluid communication by a pressure channel 107 with the space defined by the first pressure vessel 103. The top of the pressure vessel 103, 104 is the part of the vessel in a lowest gravitational field.

The conductor comprises a first section 101a within the bottom first pressure vessel 103 with a higher electrical résistance compared to the rest of the conductor sections. The bottom of the pressure vessel 103, 104 is the part of the vessel in a highest gravitational field. The conductor 10 101 further comprises a second section 101b within the pressure vessel 103 with electrical résistance lower than that of the first section 101a. A third section 101c of conductor is extcmal to the pressure vessel 103, 104 and coupled to the first section 101 a by the second section 101b.

The third section 101c of conductor is coupled to ground, but may pass through one or more additional pressure vessels prior to coupling to ground.

In use, charge entering the antenna flows along the conductor 101. Current flows through the first section 101 a of the conductor heating a fluid contained by the first pressure vessel wall 103.

The first fluid may be liquid water, for example. The water will surround the first section 10la as the water collccts at the bottom of the pressure vessel under gravity. The currcnt flowing 20 through the résistive first section 101a provides heat which is transmitted to the water. The water may boîl and tum into water vapour (steam) within the first pressure vessel wall 103. The water vapour is contained by the first pressure vessel wall 103 and further heated by the second section 101b of the conductor, which is heated by the current passing through the conductor. If the pressure channel 107 is closed, the pressure within the pressure vessel 103, 104 will increase.

The thermally insulating walls of the pressure vessel 103, 104, and the heated conducting portions 101a, 101b within the pressure vessel 103, 104 maintain water as water vapour within the pressure vessel. The pressurised steam within the pressure vessel 103, 104 is selectively released from the vessel through the pressure channel 107 to a turbine (not shown).

Figure 11 shows a power generating device with a double wall pressure vessel comprising a first wall 113 inside a second wall 114. The pressure vessel 113, 114 has an opening 116 through which fluid can flow into a pressure channel 117. A conductor 111 passes through the pressure vessel 113, 114. Within the pressure vessel 113, 114, the conductor has two sections - a first conductor section Ilia has a high electrical résistance and is situated near the bottom of first 35 wall 113 of the pressure vessel, and a second conductor section 111 b is in between the first 113 and second 114 walls of the pressure vessel. A third conductor section H le is coupled to the second 11 lb and extends from the pressure vessel to ground. The third conductor section 111c can couple directly to ground, or through another pressure vessel prior to connecting to ground.

In use, the conductor 111 is coupled to a lightening rod and receives a charge from a lightening strike. The inner first wall 113 of the pressure vessel is at lease partialIy filled with a liquid, such as water. The first conducting portion 111 a is submerged within the water and a current flowing through the first portion heats up the water. If the pressure within first wall 113 is sufïiciently low, the water will boil producing water vapour (steam). The second conducting portion 11 lb at least partially surrounds the exterior of the first wall 113 of the pressure vessel. Current passing through the second conductor section 11 lb heats up the inner first wall 113, thus any fluid contained by the inner wall is heated. If there is pressurised steam within the cavity defined by the inner wall 113, the steam is prevented from condensing into liquid water on the inner wall surface.

Electrically shielding material may be coated on the inner surface 103, 113 of the inner wall of the pressure vessel and optionally may be inserted between any adjacent conducting éléments 101, 101a, 101b, 101c to prevent arcing.

In one embodiment, the turbine is coupled to a power grid to supply the grid with power harvested from one or more lightning strikes. In another embodiment, a turbine is isolated from a power grid network and the power gcncratcd by the turbine is either stored or used locally.

In a yet further embodiment, the heated fluid provided to the turbine by a pressure chamber is further used to heat buildings after the fluid has powered the turbine. Buildings are either heated directly by the heated fluid, or instead a second fluid is heated by a heat exchange mechanism and the second fluid is then used for central heating a number of buildings.

In alternative embodiments, different types of fluids may be used to fil] the chambers. The fluids include gases, such as air and caibon dioxîde, and liquids, such as rain water, sewer water, treated sewer effluent, or sea water.

An embodiment of the invention provides pressure chambers and turbines for powering sewer pumping stations and storm water pumping stations. Such a pumping station, often in an isolated location, suffers from power failures by séparation from a power grid network during a storm, which can lead to local flooding. The failure is causée! by damage to power fines by objects, such as tree branches, being afiected by high winds. Such storms are often associated with lightning events, which may be used by the pressure ehambers in combination with the turbine to provide electricity to power the pumping station.

A further embodiment provides a pressure chamber and turbine arrangement opérable to supply power loeally to a télécommunications system. The embodiment will provide un-interrupted cellular service to the télécommunications system should grid-supplied power be interrupted during a thunder storm.

One embodiment of the invention provides a turbine powered by an aforementioned pressure vessel and a sewage storage tank. The sewage storage tank generates gas from waste décomposition which is used to power the turbine. The gas produced by the sewage storage tank is largely méthane. The turbine is either driven by the pressure of the methane gas, or by the energy released when the methane gas is combusted. Another embodiment of the invention provides ultrasonic agitation to the sewage in the sewer storage tank to increase methane production, thus încrcasing the efficiency of the sewage tank and turbine energy system.

A hydraulie aecumulator may bc used to store pressure produced by an aforementioned energy storage device or pressure vessel. A hydraulie aecumulator is an energy storage device comprising a pressure storage réservoir in which a non-compressible hydraulie fluid is held under pressure by an extemal source such as a spring, a raiscd weight, or a compressed gas. If the energy storage device is used to store energy of a pressurised fluid, the stored pressure may bc later released at a controlled rate to maximise the efficiency of a turbine coupled to the hydraulie aecumulator. The hydraulie aecumulator may be inserted between a pressure vessel and a turbine to regulate the pressure supplied to a turbine.

Any aforementioned turbine may be a micro-turbine. Micro-turbines are smaller than conventional turbines, with a smaller power output than a conventîonal turbine. The microturbine is cheaper to install and run, and can be installed in a domestic résidence. The small size and power output mean that multiple micro-turbines may be used in parallel. The hydraulie aecumulator is opérable to store pressure to supply to a micro-turbine. The combination of a pressure aecumulator and a micro-turbine allow a large amount of pressure to be stored and later released slowly and intermittently to power the micro-turbine.

Claims (10)

1. Claims:

   1. A System, comprising a plurality of power generating devices, the devices having:

   a pressure chamber, and a conductor for receiving a lightning strike; wherein the conductor passes through the pressure chamber;

   the pressure chamber is a réservoir for a fluid; and the fluid is pressurised when a conductor receives a lightning strike;

   the System further comprising a turbine in fluid communication with the power generating devices; wherein the System is arranged such that pressurised fluid flows from the power generating devices to the turbine.
2. 2. A System according to claim 1, wherein at least one of the pressure chambers comprises a valve between the pressure chamber and the turbine, arranged to selectively release pressure from the pressure chamber.
3. 3. A System according to any preccding claim, further comprising a hydraulic accumulator between the turbine and the pressure chambers of the power generating devices, arranged to store pressure produced by the power generating devices, and further arranged to release stored pressure to the turbine.
4. 4. A System according to any prcceding claim, wherein the conductors comprise a section of increased electrical résistance within the pressure chambers.
5. 5. A System according to any prcceding claim wherein one or more of the power generating devices further comprises pressurising means to pressurise its respective pressure chamber.
6. 6. A System according to any preceding claim, wherein one or more of the pressure chambers has a first wall and a second wall surrounding the first wall, and wherein the conductor at least parlially surrounds the first wall of the pressure chamber.
7. 7. A method of generating power comprising conducting lightning strikes through one or more electrically insulated pressurised chambers; and channclling fluid heated by the energy of the lîglitning strike from the pressuriscd chambers to a turbine; wherein the fluid is displaced by expansion of heated fluid.
8. 8. A method of generating power according to claim 7, wherein the lightning strike is conducted through the pressure chamber by an electrically conducting structure; and the method further comprises:

   selectively channclling fluid from the pressurised chambers to the turbine through pressure rclease valves.
9. 9. A method according to claim 7 or claim 8, further comprising storing pressure generating in the pressure chambers in a hydrauhe accumulator, and selectively releasing the stored pressure to the turbine.
10. 10. A method of generating electrical power according to claim 8 or claim 9 further comprising pressurising fluid within the pressurised chamber prior to a lightning strike.