EP2008016A2

EP2008016A2 - Electrical power supply

Info

Publication number: EP2008016A2
Application number: EP07732209A
Authority: EP
Inventors: David Mayer
Original assignee: Power Pack Technology Holdings GmbH
Current assignee: Power Pack Technology Holdings GmbH
Priority date: 2006-03-30
Filing date: 2007-03-29
Publication date: 2008-12-31
Also published as: GB0606309D0; WO2007113498A2; WO2007113498A3

Abstract

Provision for electrical power supplies which combine solar power generation and turbine power generation are useful at remote locations. By combining two forms of power generation the problem with respect to inconsistency of supply are avoided. Furthermore optimizing solar panels, electrical power generation and in particular turbine configurations aid operational performance enabling a practical electrical power supply.

Description

Electrical Power Supply

The present invention relates to electrical power generation and more particularly but not exclusively to power generation for public lighting such as street lights and outside lighting used in public or open spaces utilising solar and/or wind turbines.

Electrical power generation is important in a wide range of industries and in particular where provision of cabled electrical power supply may be difficult. Thus, electrical power generation in a stand alone situation may be advantageous with respect to -public lighting, generating -electrical power for a radio frequency transmitter or repeater station, provision of fluid pumping apparatus in remote locations or simply to provide electrical power supply at a remote dwelling or otherwise.

It is known to generate electrical power through solar or photo voltaic panels or through use of wind turbines. A clear problem with solar panels is that during daylight hours electrical power is generated but at night time or on days when there is insufficient solar light incident upon the panels, it will be necessary to utilise stored electrical power generated previously. This may be inconvenient. Similarly, wind turbines generate electrical power when there is adequate wind but electrical power is not optimised or a reduced power capacity may only be possible when there are light winds. Such variability with respect to electrical power generation will at best be inconvenient and at worst render the electrical generation sources as too unreliable to be unacceptable. In any event, provision of large battery capacity to store electrical power from solar panels or excess power generation from wind turbines on windy days will add to costs and accommodation requirements. An example of where stand alone electrical power generation will be beneficial is with regard to provision of lighting in public places such as streets, car parks and paved areas and is important in order to improve safety, convenience and security. Traditionally, such lighting has been provided through street lamps supplied with electrical power taken from a mains electrical supply. The lighting itself has been provided through sodium discharge lamps which by their nature are difficult to switch on and off in order to conserve electrical power. Thus, more recently in order to provide more efficiency and conserve energy street lighting has been provided which incorporates solar panels or photovoltaic arrangements in order to generate electrical power of a DC nature. Wind turbines can also be used to generate electrical power but of an AC nature. The solar panels and wind turbines may be added separately typically to a pre-existing street lamp design and so are not necessarily aesthetically or technically optimised. It will also be understood that typically street lighting and public lighting is required during hours of darkness so that solar panels may not be the most convenient form of electrical power generator and will normally require a battery to store electrical charge generated by the solar panel during daylight hours. Wind turbines can produce electrical charge but, as indicated, generally of an alternating current type and at varying power levels dependent upon the prevalent wind circumstances.

In view of the above it will be understood that there is a requirement for stand alone electrical power generation in a number of situations.

In accordance with a first aspect of the present invention there is provided a lamp for public lighting, the lamp comprising an integral generator combination having a wind turbine and a solar panel, the generator combination having a regulator to provide a pre-determined electrical power value from the electrical power generated by the wind turbine and/or the solar panel, the regulator including a switch to provide electrical power directly to the lamp or to a battery or to both dependent upon a condition of the wind turbine or solar panel.

Generally, the generator combination is integrally formed as part of a housing for the lamp.

Possibly, the solar panel is secured above the wind turbine.

Advantageously, there is a lighting source secured below the wind turbine.

Possibly, the regulator is as defined below.

In accordance with a second aspect of the present invention incorporate a regulator for an electrical power generator, the regulator comprising a controller to provide a substantially consistent output voltage, the controller having an AC to DC converter to provide turbine DC voltage from a turbine generator, the controller coupled to a solar DC source from a photovoltaic arrangement the controller consolidating the turbine DC voltage and the solar DC voltage to produce a merged DC voltage as an output.

Typically, the AC to DC converter is arranged to provide a substantially consistent turbine DC voltage.

- Generally, the merged DC voltage is provided to a battery.

Possibly, the turbine generator has a speed adjustor. Potentially, the speed adjustor comprises a variable electrical resistance to at least one winding of the turbine generator. Generally, the speed adjustor defines a maximum speed for the turbine generator. Possibly, the controller is coupled to an electrical load such as a lamp. Advantageously, the electrical load comprises an LED array. Generally, the merged DC voltage is supplied to a lamp directly and/or via an accumulator or battery or capacitor. Typically, the output is switched by the controller dependent upon turbine generator and/or the photovoltaic arrangement operation.

Possibly, the controller includes an ambient light detector. Typically, the ambient light detector is a light dependent resistor. Generally, the light detector provides a signal controller and the controller adjusts the output when a predetermined ambient light condition is determined by the ambient light detector for a period of time.

Possibly, the controller determines battery condition. Advantageously, when the controller determines battery condition as full or fully charged then the controller is arranged to provide any merged DC voltage as an output directly to an electrical load. Typically, the electrical load comprises a lamp, or electrical resistance heater.

Possibly, the controller determines excess energy from the turbine generator and/or photovoltaic arrangement necessary to charge the battery. Typically, when the controller determines there is excess energy from the turbine generator and/or photovoltaic arrangement to charge the battery then only a proportion of that excess energy is provided directly as the output.

Generally, the LEDs are provided with an excess electrical current for an "on" time period and then are not powered for an "off' time period. Normally, the "on" time period is shorter than the "off' time period with a flicker frequency sufficient to provide a desired level of illumination. In accordance with a third aspect of the present invention there is provided a method of operating an electrical power generator as described above.

In accordance with a fourth aspect of the present invention there is provided a generator for electrical power generation, the generator comprising a plurality of electrical windings and a plurality of magnetic poles, parts of the electrical windings and the magnetic poles arranged to progressively overlap at an inclined angle relative to each other when rotated.

Generally, the electrical windings are arranged at an orientation angle relative to a respective radial projection about a centre of rotation for the generator. Typically, the orientation angle is about 35 - 45° and preferably about 37°.

Possibly, the electrical windings are provided in a stator housing and there is an armature or shaft which incorporates the magnetic poles and is arranged to rotate relative to the stator housing. Typically, the magnetic poles are provided as rare earth magnets. Possibly, the stator housing is formed from aluminium.

Typically, there is a gap between the electrical windings and magnetic poles which is less than substantially 0.5mm.

In accordance with a fifth aspect of the' present invention there is provided a turbine for a generator used in respect of electrical power generation, the turbine comprising a plurality of blades curved towards a centre boss, an outer part of at least one blade defining an aerofoil and an inner edge having a gap to the boss centre, the aerofoil arranged to associate with a peripheral wall having apertures to provide aerodynamic lift when subject to a fluid flow. Generally, each blade has an aerofoil at its outer edge.

Typically, the blade curvature has a radius substantially the same as the radius of the turbine.

Possibly, the gap is equal to the diameter of the centre boss.

Typically, the aerofoil has a leading surface to a rear surface in an aerofoil ratio of about 1 :1.5. Generally, the aerofoil ratio relates to the length of the leading surface from a peripheral edge of the outer part towards the central boss and the length of the rear surface from the peripheral edge towards the central boss.

Typically, the apertures have a width which is substantially half the length of the leading surface. Generally, the apertures have radiating guide vanes. Advantageously, the guide vanes are' at a vane angle less than 90° to the surface of the peripheral wall.

In accordance with a sixth aspect of the present invention there is provided a solar panel comprising a plurality of solar cells formed into a non rectangular shape, each solar cell located within the non rectangular shape having substantially the same area to provide substantial electrical impedance matching between each cell.

Generally, the non rectangular shape is a circle.^' Typically, the solar cells are provided with the same area by adjusting the cordal width of each cell.

Typically, each solar cell comprises photovoltaic elements to provide electrical power when exposed to light. In accordance with a seventh aspect of the present invention there is provided a method of forming solar panels having a non rectangular shape, the method comprising considering the non rectangular shape in order to define cell areas of substantially equal size in a base and fabricating the solar cells in the base having the cell areas of substantially equal size.

Typically, fabricating the solar cells involves using a linear orientated laser to form an electrical junction between solar cells. Typically, the laser generally is arranged to provide linear junctions in the base but by base movement relative to the laser the junctions are formed on a curve.

Typically, the non rectangular shape is a circle.

Embodiments of aspects of the present invention will now be described by way of example only with reference to the accompanying drawings in which:

Fig. 1 is a schematic diagram of a street light in accordance with aspects of the present invention;

Fig. 2 is a block diagram illustrating a controller function in accordance with aspects of the present invention;

Fig. 3 is a schematic illustration of part of a stator housing for a generator in accorάance with aspects of the present invention;

Fig. 4 is a schematic illustration of a rotor for a generator in accordance with aspects of the present invention;

Fig. 5 is a schematic illustration of a turbine arrangement in accordance with aspects of the present invention; Fig. 6 is a schematic illustration of a solar panel in accordance with aspects of the present invention; and,

Fig. 7 is a schematic illustration of a method of forming a solar panel in accordance with aspects of the present invention.

As indicated above, stand alone electrical power generation will allow more¹ convenient supply of electrical power and so improve the ease of provision of such amenities as street lighting. Furthermore, use of solar power and wind power has advantages with regard to reduced consumption of electrical power from mains electricity supply and may allow more extensive use of distributed electrical power generator systems. Furthermore, such street lighting or other users of electrical power- may be provided in locations where there is not ready access to mains electricity. By aspects of the present invention solar power generation is combined with wind power generation in order to provide in the example outlined below sustainable illumination by street lighting when required. However, as indicated there are other uses of a stand alone electrical power generator.

It will be understood that solar power generation will occur during daylight hours when typically street lighting is not required and therefore solar power generation by its nature requires a battery to store electrical energy generated during those daylight hours for use at night. Wind power by its nature is dependent upon the prevailing wind conditions or other fluid flow such as within a stream or river for a water mill. These conditions will vary and therefore the electrical power generation from the driven turbine will vary. In such circumstances solar power and turbine power generation systems are not ideally suited to provide consistent electrical power generation. Thus, as indicated, a battery will generally be utilised as a store or buffer within which the sustainable period of operation can be assured. Nevertheless, solar and wind power provide two potential sources of power generation so extending the periods of potential on-line supply directly to public lighting or otherwise.

Aspects of the present invention provide an integration of a solar panel and a turbine generator, typically in the form of a wind turbine electrical power generator. It will be understood that solar panels comprise photovoltaic arrangements which convert sunlight into electrical power. Turbines generally utilise a fluid flow such as wind to turn a turbine which is secured through a shaft to an electrical power generator in the form of electrical windings and magnets which through electromagnetic effects generate, electrical power.

Fig. 1 provides a schematic illustration of a street light arrangement 1 as an example of an electrical power using device which may utilise an electrical power generator in accordance with aspects of the present invention. Thus, the arrangement 1 comprises a pole or stanchion 2 which presents a lamp housing 3 in which a lamp 4 is provided in order to provide illumination. A solar panel 5 is secured on an upper surface of the housing 3 and a turbine generator located within the housing 3. Typically, the turbine generator is formed with a peripheral wall within which apertures 6 are provided to achieve turbine operation as described later in accordance with aspects of the present invention. Integration of the solar panel 5 and the turbine within a common housing 3 ensures that there are two sources of electrical power generation which can be utilised in order to power the lamp 4 or other power using devices in other applications. As will be described later with regard to aspects of the present invention these two sources of electrical power generation will be merged by an appropriate processor acting as a controller or regulator in order to appropriately power the lamp 4. Normally a rechargeable battery will be provided to act as a stable buffer for electrical power to ensure the lamp 4 or other power users in other applications continue to operate when required, for at least a period of time without further input from the solar panel 5 or turbine generator. As indicated above, the solar panel will generally produce a DC solar voltage whilst a fluid turbine such as that using the wind will generally produce an AC voltage. In such circumstances a regulator is required in order to 5 match and merge these electrical power generation sources. This regulator provides control with respect to energy generation input, and energy output to the lamp. The regulator as indicated acts as a controller with regard to electrical power inputs from the solar panel and turbine as energy sources as well as monitoring battery charging and electrical power output to the

I O illumination lamp 4 (Fig. 1) which is typically in the form of light emitting diodes (LEDs) in an array. The controller also acts to switch on and off the electrical power output to the LEDs for best sustained illumination effect and also, as indicated below, in order to provide a maximum speed limit for the turbine generator.

15

Typical street light operation is outlined below, but it will be understood that electrical power can be generated for a number of uses, such as pumping or heating of water supplies.

0 As the ambient light levels increase or decrease, an LDR (light dependant resistor) is triggered and the output power supply to the lamp is switched off and on respectively. The regulator controller only allows this operation if the ambient light level change is constant for a period of time. This is to prevent the un-intentional operation from spurious light sources, for 5 example a car headlight or a cloud temporarily obscuring the sun.

. When the circuit is in the "off' mode and the battery is fully charged, any excess energy from the input sources (solar panel or turbine generator) may be "dumped" through the output to the lamp. If this condition arises in the 0 "on" mode the output from the battery is reduced or disconnected and the excess energy is sent directly as the output to the lamp. This method is used to prevent excess use of the battery in order to prolong its life and to make full use of the ambient energy from the turbine or possibly the solar panel available.

The output is arranged into three parallel branches or phases where each can typically drive up to eight LEDs. The LEDs can be driven at electrical currents above their normal operating limits for short periods of time. As LEDs reduce in efficiency with temperature rises from a constant current, the output is arranged as a square wave of around 80 Hertz, with the addition that the "on" period is slightly less than the "off' period. The human eye cannot see this "flicker" but the LED benefits from a cooling "off' period between electrical pulses and remains more efficient as a result. As the pulse electrical current value is higher than the normal LED current the average light level remains constant. It will also be understood that banks of LEDs may be phased to ensure at least one bank is operationally powered and illuminated at all times during an "on" mode.

The regulator, as indicated above, acts in order to control the various input electrical power generating sources in order to achieve as far as possible a consistent generated direct electrical current output. In the example street lamp this output will be to the LEDs of the lamp or illumination arrangement. As indicated above, solar power will generally only be generated during daylight hours in appropriate conditions so inherently this power source will typically be utilised in order to charge the battery. However, there may be periods when the battery is fully charged or the electrical power generated by the solar panel is greater than that necessary for battery charging during which time output from the solar panel will be dumped effectively as a load presented through the lamp causing illumination of the LEDs when ambient light conditions, that is to say it is daylight, do not necessitate illumination or another load may be provided such as a heating element. It will also be appreciated it may be possible to store the electrical power in some other way such as by lifting a dead weight against an appropriate mechanical system in order to store electrical power generated and then when that power is required the weight released in order to drive the system and therefore generate power for utilisation with respect to illumination 5 of the lamp. Electrical power may also be "dumped" through an electrical resistance heater or water heater or pump for a well etc.

It will be understood that typically the widest variation in electrical power generation will be with regard to the turbine generator. This is due to

I O the generator being dependent upon fluid flow conditions such as the prevailing wind conditions which may vary considerably. In such circumstances as indicated above,, generally the electrical current generated by the turbine generator will be utilised in order to charge the battery but when that battery is fully charged or there is excess electrical energy generated by

15 the turbine generator this will be directed to the lamp or the other load demand such as a fluid pump or radio transmitter, in order to create illumination with the electrical supply presented from the battery similarly reduced or eliminated dependent upon the value of the excess current provided by the turbine generator. 0

Switching between conditions where the merged electrical current acts as an output in order to charge the battery or to power the lamp directly or to be effectively dumped will be controlled by a controller. The battery acts as a guarantee of a minimum period of illumination or other requirement capacity 5 for alternative power generator applications and will be specified accordingly.

Fig. 2 provides a schematic illustration in the form of a flow diagram with regard to a controller function provided by the regulator. Thus, as can be seen electrical power is provided by a solar generator ^"20 or a wind turbine 0 generator 21 through a charge pumping device 22. This charge pumping device 22 is connected to a regulator 23 and a controller 24. The regulator 23 distributes electrical power to a battery 25 and a pulse width modulator 26 under the control of the controller 24. In such circumstances a controller 24 monitors through the charge pump device 22 the electrical power provided by the generators 20, 21. Dependent upon the electrical power values, the^' regulator 23 is configured to provide power to the battery 25 and/or the pulse width modulator 26 in order to provide electrical power to LEDs 27 in banks to achieve illumination. The regulator 23 is also connected to a clamp device 28 to stabilise the regulator 23 and also potentially acts as a dump for excess electrical power if required.

As indicated above in the illustrative example, the controller 24 is also connected to a light level control 29 and a light level sensor 30. The control 29 and the sensor 30 act to ensure that power is only provided to the LEDs for illumination of the LEDs 27 when required, that is to say during periods of darkness. As outlined typically, the light level control 29 will be arranged to ensure that a trigger light level for illumination as determined by the sensor 30, must occur for a fixed period of time before power is provided for illumination so avoiding transients such as car headlights switching off illumination. In other applications alternative switches may be provided dependent upon demand so with an electric pump power may be provided when needed to fill a reservoir tank or when pumping is required. Thus, the present stand alone generator can meet that demand directly or via a battery.

Generally, the controller 24 and, where provided, the light level control 29 or other switching will be provided in a micro processor 19 accommodated within an appropriate housing.

The battery 25 acts as a store for electrical power produced typically during the daylight hours by the solar panel as well as the wind turbine 21. As outlined above, generally the solar panel 20 will not provide electrical power during periods of darkness, but the wind generator 21 will continue to provide electrical power dependent upon prevailing conditions. In such circumstances the battery 25 will be charged during daylight periods typically at least by the solar panel 20 assuming there is adequate sunlight so that the battery 25 will be able to provide electrical power for illumination of the LEDs 27 or other demands with other applications. The wind power generator 21 may continue to provide electrical power during periods of darkness and this may charge the battery 25 or potentially directly provide power to the LEDs 27 or other demand.

As outlined above, generally the pulse width modulator 26 will be arranged to provide power to the LEDs such that there iβ an "on" time period and an "off¹ time period with the LEDs driven marginally above the normal •electrical current during the "on" time periods. The "on" time periods as defined by the modulator 26 will tend to be shorter than the "off' time periods to allow cooling of the LEDs.

Fig. 2 is a block diagram illustrating the relationship for control and regulation of electrical power generation in accordance with aspects of the present invention. It will be understood that the particular devices utilised in order to create the processors as outlined in the block diagram will be dependent upon availability and durability in service.

Aspects of the present invention utilise a generator driven by a turbine in order to generate electrical power. As it is impossible to extract more energy from the wind or other fluid flow than the turbine size will allow a generator in accordance with aspects of the present invention is designed with low "cogging" characteristics. In order to maintain power output levels and to keep wear to a minimum a three phase, brushless, AC design is adopted. Figs. 3 and 4 illustrate aspects of a design in accordance with the present invention which consists of an aluminum stator- casing 30, in which the generator coils 31 are mounted, and a central armature or shaft 40 upon which rare earth magnets 41 as magnetic poles are mounted. The shaft 40 is driven by a turbine (not shown). A roller bearing is used on each end of the shaft 40 to support it in a casing and to allow rotation. In order to reduce any cogging effects the windings 31 are orientated at an orientation angle typically in the order of 37° from the vertical but possibly in the range 35° to 45° and the magnets are polarized in the direction of rotation in segments to create a ' number of magnetic poles around the circumference of the shaft 40. A critical consideration is the air gap between the magnets 41 and winding 31 when assembled. Typically, it must not exceed 0.5 millimeters but this will^' depend upon the particular structure and size of the generator.

Fig. 3 provides a schematic illustration of the relationship between the electrical windings 31 (one shown) and the magnets 41 (shown in broken line) of a generator in accordance with aspects of the present invention. As can be seen the windings 31 and the magnets 41 are arranged to progressively overlap at an inclined angle relative to each other when rotated. As indicated above, generally the electrical windings are oriented at an orientation angle in the order of 37° to a vertical or radial projection from the centre of rotation for the generator, that is to say the shaft 40. In such circumstances, there is a smoother more progressive transfer between magnetic pole-to-pole interactions with the coils compared to previously abrupt .change overs. Thus, at low speeds the "cogging" effects of abrupt change overs is reduced leading to improved electrical power generation.

In accordance with further aspects of the present invention there is provided a turbine which in the example integral street light housing 3 depicted in Fig. 1 acts to drive a shaft which in turn will drive the generator for electrical power generation possibly controlled as described above with regard to Fig. 2 and using a generator as shown in Figs. 3 and 4. The turbine will generally be secured upon a vertical axis and allowed to rotate when subject to fluid flows such as wind. However, it will be understood that turbines are used in a whole range of electric power generator arrangements and a turbine in accordance with aspects of the present invention can be used in most of such arrangements.

The blades of the turbine are of a curved design where typically the first quarter of the length is of an aerofoil shape. The remainder of the curve of the blade is of constant chord. The blade curves inward from the perimeter of the turbine toward a centre point of rotation. The centre point is a location boss which has a diameter equal to the gap between the boss and an inner end edge of the blade. The major radius of the blade is equal to the radius of the turbine. The aerofoil shape is of a one point five to one ratio where the surface edge of the leading edge is one point five times the length of the leading edge. An odd number of blades are preferable to aid balancing of the unit as a whole.

The turbine will generally be located within a peripheral wall with apertures in order that the lift effects of the aerofoils of the respective turbine blades can be utilised to achieve a desired level of operational efficiency. The apertures will be dimensioned for correspondence with the turbine dimensions.

Fig. 5 illustrates schematically a turbine 50 and a turbine arrangement 51 in accordance with aspects of the present invention. Thus, as outlined above, the turbine 50 generally comprises a platform upon which blades 52 are presented relative to a central boss 53 which acts as a hub upon which the turbine 50 rotates. About the turbine 50 in the arrangement 51 is a peripheral wall housing 54 in which there are apertures through which fluid, that is to say wind, moves to encounter the blades 52 of the turbine 50. Either side of these apertures vanes 55 are provided to guide the fluid flow, that is to say the wind, towards the blades 52 as required. The purpose of the vanes 55 in association with the apertures is to provide some guiding as indicated such that the arrangement 51 is less dependent upon fluid flow or wind source direction.

As outlined above, component and feature configuration and orientation within the turbine 50 are important. Thus, the central boss 53 has a diameter C which is the equivalent of the gap D between an inner edge 56 of each blade 52 and the boss 53. The blades 52 have a radius which is substantially the same as the radius of the platform upon which the turbine 50 presents the blades 52. In accordance with aspects of the present invention an outer edge portion 57 of the blades 52 defines an aerofoil. This aerofoil is arranged such that the width or length A of a lead side 57 is in a ratio of 1 :1.5 times the length of a rear or trailing side 58 of the aerofoil defined by the end edge portion 57 of the blade 52. In such circumstances the aerofoil generates lift to facilitate rotation of the turbine 50 about the hub created by the central boss 53.

Generally, the length of the leading surface is given by the value A and the apertures in the housing wall 54 are spaced and sized such that the width of two apertures is given by the value B. The values A and B are substantially equal so that each aperture is roughly half the value A so that the aerofoil created in the end edge portion 58 during rotation always spans at least two apertures.

In use it will be understood that the turbine 50 will rotate in the direction given by arrowhead X when subject to a fluid flow such as wind. In such circumstances for illustration purposes wind will flow in the direction of arrowheads Y through the turbine. It should be appreciated that arrowheads Y are depicted in the stationary situation but in reality the turbine 50 will rotate. In any event, the fluid flow Y will act upon the aerofoil created at the end edge portion 57 of the blades 52 in order to create lift which will facilitate rotation of the turbine 65 at relatively low fluid flow rates. In, such circumstances a shaft secured to the central hub 53 will rotate in order to generate electrical power by an appropriate generator mechanism which may be as described above with regard to Figs. 3 and 4.

Previously solar panels as indicated have been used in order to generate electrical power which is then utilised in creating illumination through a lamp or provides a power source for other demands. Conventional solar panels have a regular rectangular shape in order to ensure consistent solar cell size for impedance matching and also for convenience in terms of creating junctions between the cells utilising a laser process.

Solar cells are traditionally of rectangular design. This is due to impedance issues created when cells of differing resistances are used on the same plate.

It will be understood that a circular solar cell would be convenient for use within an integrated street lamp or other applications as this will typically be the circular cross sectional shape of the turbine and generator combinations. A rectangular solar panel will either be limited in area and therefore waste space within the circular envelope defined by the turbine arrangement or arranged to extend beyond the circular profile. As indicated above, traditionally solar panels in the form of photovoltaic solar cells have been generally rectangular for ease of defining cell areas and impedance matching between the cells in a panel. It will be understood that it is necessary for the impedance and therefore the electrical resistance in each cell to be substantially the same otherwise the cell will be unbalanced with respect to the electrical charge developed in each cell across the panel and therefore electrical potential gradients created with electrical inefficiencies.

In Fig. 6 a circular solar panel 60 is divided into a number of segments 61 across a base plate. The impedance issue is approached by adjusting the cordal width 62 of each cell segment 61. Thus, matching the area of each segment 61 of the panel. Therefore the outer segments 61f, 61a will be wider than the inner segments 61d, 61e, 61b, 61c, but the areas will remain constant. One issue is the creation of junctions on a curve. As the laser process traditionally used is linear, it therefore follows that it is not compatible to curves. This is resolved by using the linear laser equipment, but the plate is not fixed but is rotated and moved relative to the laser.

As indicated above, it is necessary for each of the cell segments 16 to have the same size and area for impedance matching but also the cell segments 61 need to be coupled together in order to utilise the photovoltaic arrangement effects within the cells 61 to provide electrical power. In such circumstances a positive electrical connection rail 63 is provided along with negative rails 64. It will be appreciated in such circumstances the panel 60 effectively has two photovoltaic arrangements in respective halves defined between the positive rail 63 and the negative rail 64. Each cell segment 61 within these halves will then contribute through its photovoltaic arrangements to electrical power generation for transmission to a battery as described above. Operation of photovoltaic arrangement is well known and it is by considering the non rectangular shape of the panel 60 in accordance with aspects of the present invention which allows a more convenient circular cross section to be provided for integration with a wind turbine which by its nature will generally be circular in profile.

Although a circular cross section has been defined as a non rectangular shape it will also be understood that other non rectangular shapes such as triangles, oval and polygon shapes could be provided assuming that the necessary cell areas can be defined for equivalence in terms of electrical impedance. Non rectangular shapes are achievable in accordance with aspects of the present invention due to a method and process step with regard to the laser. Previously, lasers have been used in order to create the electrical junctions between the photovoltaic arrangements in solar cells and panels. A base material within which the photovoltaic solar cells are formed is normally accurately and robustly located and the laser moved relative to that base. The laser in such circumstances is an essentially linear device creating axial and perpendicular orientation junctions. By aspects of the present invention junctions can be created upon curves by securely locating the laser and then accurately manipulating the base within which the photovoltaic cells are formed as well as the junctions between those cells.

Fig. 7 is a schematic illustration of a method for forming a non rectangular solar cell or panel in accordance with aspects of the present invention. Thus, a laser 70 which is typically utilised to create linear junctions by movement relative to a stable presentation of a base material 71 within which photovoltaic solar cells 72 are formed is presented to the base 71 upon a displaceable mounting 73. Thus, a conventional and convenient laser 71 which is set up to create linear junctions for rectangular solar panels can be utilised in order to create junctions to the cells 72 with a Gurved aspect.

It will be appreciated that the laser 70 must be accurately utilised in order that its beam acts upon the base 71 to consistently and accurately create junctions for the cells 72. In such circumstances previously as indicated the base 71 was securely located and fixed as a constant to enable the laser 70 to achieve the necessary junctions. The laser 70 in such circumstances can be accurately programmed in order to create the necessary junctions without reference to spatial displacements which will alter the necessary calculations in order to achieve the desired junctions for an operational solar panel. By aspects of the present invention the laser 70 is still configured to consistently produce the same junction as would be expected if the base 71 was fixed but as the base is moved and rotated it will be understood that curved junctions are created rather than linear junctions as expected with a linear process for the laser 70. 5

In the above circumstances once the desired non rectangular shape for the solar cell is determined and therefore the necessary cell segments drawn such that they have the same area it will be understood that the laser 70 will be fixed above the base 71 and the mounting 73 manipulated such that the I O laser 70 will create the junctions necessary between the cell segments defined for the non rectangular solar panel.

In terms of manufacturing a solar panel of a non rectangular shape it will be understood that the shape is first determined in order to create or

15 identify segments having an equal area for impedance and then the base shape presented to an appropriate device in order to create photovoltaic arrangements. Typically, these will be printed or otherwise formed in the base and a laser device as described above utilised in order to create electrical junctions between the formed photovoltaic solar cells having substantially the

20_. same area in the cell segments defined for the non rectangular shape. By this method the laser is fixed whilst the base is moved.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it 25 should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

1. A lamp for public lighting, the lamp comprising an integral generator combination having a wind turbine and a solar panel, the generator combination having a regulator to provide a pre-determined electrical power value from the electrical power generated by the wind turbine and/or the solar panel, the regulator including a switch to provide electrical power directly to the lamp or to a battery or to both dependent upon a condition of the wind turbine or solar panel.

2. A lamp as claimed in claim 1 wherein the generator combination is integrally formed as part of a housing for the lamp.

3. A lamp as claimed in claim 1 or claim 2 wherein the solar panel is secured above the wind turbine.

4. A lamp as claimed in any of claims 1 , 2 or 3 wherein the lighting source is secured below the wind turbine.

5. A lamp as claimed in any preceding claim wherein the regulator comprises a controller to provide a substantially consistent output voltage, the controller having an AC to DC converter to provide turbine DC voltage from a turbine generator, the controller coupled to a solar DC source from a photovoltaic arrangement the controller consolidating the turbine DC voltage and the solar DC voltage to produce a merged DC voltage as an output.

6. A lamp as claimed in claim 5 wherein -the AC to DC converter is arranged to provide a substantially consistent turbine DC voltage.

7. A lamp as claimed in claim 5 or claim 6 wherein the merged DC voltage is provided to a battery.

8. A lamp as claimed in any preceding claim wherein the turbine generator has a speed adjuster.

9. A lamp as claimed in claim 8 wherein the speed adjustor comprises a variable electrical resistance to at least one winding of the turbine generator.

10. A lamp as claimed in claim 8 or claim 9 wherein the speed adjustor defines a maximum speed for the turbine generator.

11. A lamp as claimed in claim 5 and any claim dependent thereon wherein the controller is coupled to an electrical load such as the lamp.

12. A lamp as claimed in claim 11 wherein the electrical load comprises an LED array.

13. A lamp as claimed in claim 5 and in any claim dependent thereon wherein the merged DC voltage is supplied to the lamp directly and/or via an accumulator or battery or capacitor.

14. A lamp as claimed in claim 5 and in any claim dependent thereon wherein the output is switched by the controller dependent upon turbine generator and/or the photovoltaic arrangement operation.

15. A lamp as claimed in claim 5 and in any claim dependent thereon wherein the controller includes an ambient light detector.

16. A lamp as claimed in claim 15 wherein the ambient light detector is a light dependent resistor.

17. A lamp as claimed in claim 15 or claim 16 wherein the light detector provides a signal controller and the signal controller adjusts the output when a predetermined ambient light condition is determined by the ambient light detector for a period of time.

18. A lamp as claimed in claim 5 or in any claim dependent thereon wherein the controller determines battery condition.

19. A lamp as claimed in claim 18 wherein^' when the controller determines a battery condition as full or fully charged then the controller is arranged to provide any merged DC voltage as an output directly to an electrical load.

20. A lamp as claimed in claim 19 wherein the electrical load comprises a lamp, or electrical resistance heater.

21. A lamp as claimed in claim 5 or in any claim dependent thereon wherein the controller determines excess energy from the turbine generator and/or photovoltaic arrangement necessary to charge the battery.

22. A lamp as claimed in claim 21 wherein when the controller determines there is excess energy from the turbine generator and/photovoltaic arrangement to charge the battery then only a proportion of that excess energy is provided directly as the output.

23. A lamp as claimed in claim 12 and any claim dependent thereon wherein the LEDs are provided with an excess electrical current for an "on" time period and then are not powered for an "off¹ time period.

24. A lamp as claimed in claim 23 wherein the "on" time period is shorter than the "off" time period with a flicker frequency sufficient to provide a desired level of illumination.

25. A lamp for public lighting substantially as hereinbefore described with reference to the accompanying drawings.

26. A regulator for an electrical power generator, the regulator comprising a controller to provide a substantially consistent output voltage, the controller having an AC to DC converter to provide turbine DC voltage from a turbine generator, the controller coupled to a solar DC source from a photovoltaic arrangement the controller consolidating the turbine DC voltage and the solar DC voltage to produce a merged DC voltage as an output.

27. A regulator as claimed in claim 26 wherein the AC to DC converter is arranged to provide a substantially consistent turbine DC voltage.

28. A regulator as claimed in claim 26 or in claim 27 wherein the merged DC voltage is provided to a battery.

29. A regulator as claimed in any of claims 26 to 28 wherein the turbine generator has a speed adjustor.

30. A regulator as claimed in claim 29 wherein the speed adjustor comprises a variable electrical resistance to at least one winding of the turbine generator.

31. A regulator as claimed in claim 29 or claim 30 wherein the speed adjustor defines a maximum speed for the turbine generator.

32. A regulator as claimed in any of claims 26 to 31 wherein the controller is coupled to an electrical load.

33. A regulator as claimed in claim 32 wherein the electrical load comprises an LED array.

34. A regulator as claimed in any of claims 26 to 33 wherein the merged DC voltage is supplied to a lamp directly and/or via an accumulator or battery of capacitor.

35. A regulator as claimed in any of claims 26 to 34 wherein the output is switched by the controller dependent upon turbine generator and/or the photovoltaic arrangement operation.

36. A regulator as claimed in any of claims 26 to 35 wherein the controller includes an ambient light detector.

37. A regulator as claimed in claim 36 wherein the ambient light detector is a light dependent resistor.

38. A regulator as claim 36 or claim 37 wherein the light detector provides a signal controller and the controller adjusts the output when a predetermined ambient light condition is determined by the ambient light detector for a period of time.

39. A regulator as claimed in any of claims 26 to 38 wherein the controller determines battery condition.

40. A regulator as claimed in claim 39 wherein when the controller determines battery condition as full or fully charged then the controller is arranged top provide any merged DC voltage as an output directly to an electrical load.

5 41. A regulator as claimed in claim 40 wherein the electrical load comprises a lamp, or electrical resistance heater.

42. A regulator as claimed in any of claims 26 to 41 wherein the controller determines excess energy from the turbine generator and/or

) 0 photovoltaic arrangement necessary to charge the battery.

43. A regulator as claimed in claim 42 wherein when the controller determines there is excess energy from the turbine generator and/or photovoltaic arrangement to charge the battery then only a proportion of that

I 5 excess energy is provided directly as the output.

44. A regulator as claimed in claim 33 and any claim dependent thereon wherein the LEDs are provided with an excess electrical current for an "on" time period and then are not powered for an "off' time period. 0

45. A regulator as claimed in claim 44 wherein the "on" time period is shorter than the "off time period with a flicker frequency sufficient to provide a desired level of illumination.

5 46. A regulator for an electrical power generator substantially as hereinbefore described with reference to the accompanying drawings.

47. A method of operating an electrical power generator using a regulator as claimed in any of claims 26 to 46. 0

48. A generator for electrical power generation, the generator comprising a plurality of electrical windings and a plurality of magnetic poles, parts of the electrical windings and the magnetic poles are arranged to progressively overlap at an inclined angle relative to each other when rotated.

49. A generator as claimed in claim 48 wherein the electrical windings are arranged at an orientation angle relative to a respective radial projection about a centre of rotation for the generator.

50. A generator as claimed in claim 49 wherein the orientation angle is about 35 - 45°.

51. A generator as claimed in claim 50 wherein the orientation angle is preferably about 37°.

52. A generator as claimed in any of claims 48 to 51 wherein the electrical windings are provided in a stator housing and there is an armature or shaft which incorporates the magnetic poles and is arranged to rotate relative to the stator housing.

53. A generator as claimed in any of claims 48 to 52 wherein the magnetic poles are provided as rare earth magnets.

54. A generator as claimed in claim 52 and in .any claim dependent thereon wherein the stator housing is formed from aluminium.

55. A generator as claimed in any of claims 48 to 54 wherein there is a gap between the electrical windings and magnetic poles which is less than substantially 0.5mm.

56. A generator for electrical power generation substantively as hereinbefore described with reference to the accompanying drawings.

57. A turbine for a generator used in respect of electrical power generation, the turbine comprising a plurality of blades curved towards a centre boss, an outer part of at least one blade defining an aerofoil and an inner edge having a gap to the boss centre, the aerofoil arranged to associate with a peripheral wall having apertures to proved aerodynamic lift when subject to a fluid flow.

58. A turbine as claimed in claim 57 wherein each blade has an aerofoil at its outer edge.

59. A turbine as claimed in claim 57 or claim 58 wherein the blade curvature has a radius substantially the same as the radius of the turbine.

60. A turbine as claimed in any of claims 57 to 59 wherein the gap is equal to the diameter of the centre boss.

61. A turbine as claimed in any of claims 57 to 60 wherein the aerofoil has a leading surface to a rear surface in an aerofoil ratio of about 1 :1.5.

62. A turbine as claimed in claim 61 wherein the aerofoil ratio relates to the length of the leading surface from a peripheral edge of the outer part towards the central boss and the length of the rear surface from the peripheral edge towards the central boss.

63. A turbine as claimed in any of claims 57 to 62 wherein the apertures have a width which is substantially half the length of the leading surface.

64. A turbine as claimed in any of claims^" 57 to 63 wherein the apertures have radiating guide vanes.

65. A turbine as claimed in any of claims 57 to 64 wherein the guide vanes are at a vane angle less than 90° to the surface of the peripheral wall.

66. A turbine for a generator used in respect of electrical power generation substantially as hereinbefore described with reference to the accompanying drawings.

67. A solar panel comprising a plurality of solar cells formed into a non rectangular shape, each solar cell is located within the non rectangular shape having substantially the same area to provide substantial electrical impedance matching between each cell.

68. A panel as claimed in claim 67 wherein the non rectangular shape is a circle.

69. A panel as claimed in claim 67 or in claim 68 wherein the solar cells are provided with the same area by adjusting the.cordal width of each cell.

70. A panel as claimed in any of claims 67 to 69 wherein each solar cell comprises photovoltaic elements to provide electrical power when exposed to light.

71. A solar panel substantially as hereinbefore described with reference to the accompanying drawings.

72. A method of forming solar panels having a non rectangular shape, the method comprising considering the non rectangular shape in order to define cell areas of substantially equal size in a base and fabricating the solar cells in the base having the cell areas of substantiaHy equal size.

73. A method as claimed in claim 72 wherein fabricating the solar cells involves using a linear orientated laser to form an electrical junction between solar cells.

74. A method as claimed in claim 72 or in claim 73 wherein the laser generally is arranged to provide linear junctions in the base but by base movement relative to the laser the junctions are formed on a curve.

75. A method as claimed in any of claims 72 to 74 wherein the non rectangular shape is circle.

76. A method of forming solar panels substantially as hereinbefore described with reference to the accompanying drawings.

77. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.