US20120291766A1

US20120291766A1 - Solar energy collection apparatus

Info

Publication number: US20120291766A1
Application number: US13/574,407
Authority: US
Inventors: John Varga
Original assignee: Carding Specialists Canada Ltd
Current assignee: Carding Specialists Canada Ltd
Priority date: 2010-01-22
Filing date: 2011-01-21
Publication date: 2012-11-22
Also published as: CN102792103A; WO2011089437A3; GB201001012D0; WO2011089437A2

Abstract

Solar energy concentrating apparatus having an array of lenses to receive and concentrate the solar radiation towards a plurality of stationary targets. The lenses are supported on a moveable structure to enable the lenses to move laterally in the east-west and north-south directions. Each lens of the array is also configured to rotate about an axis extending in the north-south direction. Drive means is coupled to a plurality of lateral and rotational movements mechanisms to orientate the lenses towards the target as the sun moves throughout the day and year.

Description

The present invention relates to solar energy collection apparatus and more particularly, to a concentrating type collector that uses a lens to concentrate the solar rays.
Solar energy collection devices are well established and may be categorised according to two types. Non-concentrating collectors receive the solar radiation directly, as parallel rays of radiation. Such devices typically comprise a solar panel, or array of photovoltaic cells that may be heated and configured to transmit and store the solar radiation.
A further type of solar collector is referred to as a concentrating type which reflects or refracts the radiation using lenses or minor assemblies so as to concentrate the rays onto a target as a more focused solar footprint.
WO 2009/134208 discloses a solar energy collector that utilises a lens to focus the solar radiation and is mounted via a cradle with a plurality of solar cells fixed to the cradle base to receive the light from the lens.
WO 2009/125334 discloses a solar energy generating device having a fixed orientation concentrator, in the form of a Fresnel lens of the new focus and linear solar collector mounted parallel to the focal point of the lens and configured to move in any direction perpendicular to the linear focus in order to attempt to obviate the need for additional orientating mechanisms for the lens.
WO 2005/057092 discloses a solar energy collection system in which a lens is used to focus the solar radiation onto a receiving body to convert the radiation into electrical and/or heat energy. A pivoting structure is provided to enable rotation of the target in the east/west direction in order to track the concentrated radiation transmitted through the lens.
US 2009/0272425 discloses a concentrating solar receiver that utilises a Fresnel lens to both reflect and refract solar radiation to a thermal cycle engine that coverts the solar energy to mechanical energy which in turn is converted to electrical energy. Movement of the solar receiver is controlled by a sun tracking sensor and actuation provided by a vertical and horizontal drive motor.
WO 2009/002168 discloses an array of rotatably mounted lenses for concentrating solar radiation onto collectors that are coupled to a heat transfer liquid. The liquid, when heated by the solar radiation may be guided through a heat exchanger to generate steam for electricity generation. The array of lenses is configured to rotate about two perpendicular axes to track the position of the sun throughout the day.
However, there is a continued need for apparatus that will efficiently harness the solar radiation throughout the day and year whilst being of a design sufficiently robust to withstand weathering by the elements whilst maximising the use of the incident radiation.
Accordingly, the inventors provide solar energy concentrating and support apparatus configured to harness and concentrate solar energy suitable for use in regions that frequently experience an abundance of sunlight and are exposed environments. The apparatus is also configured to withstand weathering by the elements without loss of energy conversion efficiency.
According to a first aspect of the present invention there is provided solar energy concentrating apparatus comprising: an array of lenses to receive and to concentrate solar radiation towards a plurality of targets; at least one lens support structure to moveably mount each lens of the array to receive the solar radiation; a first lateral movement mechanism to move the lenses in a first lateral direction relative to the targets; a second lateral movement mechanism to move the lenses in a second lateral direction relative to the targets; a third lateral movement mechanism to move the lenses in a direction up and down relative to the targets; a first rotational movement mechanism to rotate the lenses about a first axis extending substantially in the second lateral direction; and at least one drive means to drive the lens movement mechanisms.
Preferably, the apparatus further comprises a second rotational movement mechanism to rotate each lens about a second axis extending in the first lateral direction. The axes of rotation of the in the second rotational direction is substantially perpendicular to the axes of rotation of a lens in the first rotational direction.
Optionally, the lens support structure comprises a primary support having a circumferential or peripheral ring type frame to mount the lens, a support shaft extending centrally through the lens and support cables extending from the central shaft to the outer ring frame. Additionally, the lens support structure may further comprise a secondary support to mount the primary support, the secondary support comprising cables extending around the primary support. Preferably, the cables of the primary and secondary support are pre-stressed such that when placed under tension the cables are resistant to twisting, elongate extension and distortion due to incident mechanical forces.
Preferably, the array of lenses is arranged in rows of lenses to form a grid network of lenses with rows in the first lateral direction and rows in the second lateral direction.
Preferably, each lens of the array comprises a plurality of Fresnel lenses extending in at least two substantially parallel planes, one above the other so as to provide an air flow gap between the planes of the lenses. Additionally the lenses may be constructed from individual sections of Fresnel lenses according to a staggered or multi-planar configuration to provide airflow vents or ducts through the assembled lens to minimise the perpendicular force component of the incident wind when installed and in use. Fins or other air flow directing elements may also be attached to the lens to assist with deflecting or channelling air. Such fins may also be attached to other components of the apparatus.
Preferably, the first lateral movement mechanism comprises cables extending in the first (east-west) direction and pulley wheels and/or spools and stanchions positioned at the end of each row of lenses in the first (east-west) direction, the stanchions coupled to one of the cables in the east-west direction such that when the drive means is actuated the stanchions pivot in the east-west direction and the lenses move laterally in the first (east-west) direction. Also preferred is that the second lateral movement mechanism comprises cables extending in the second (north-south) direction and pulley wheels and/or spools and stanchions positioned at the end of each row of lenses in the second (north-south) direction, the stanchions coupled to one of the cables in the second (north-south) direction such that when the drive means is actuated the stanchions pivot in the second (north-south) direction and the lenses move laterally in the second (north-south) direction. Also preferred is that the third lateral movement mechanism comprises cables and pulley wheels and/or spools. Also preferred is that the first rotational movement mechanism comprises cables and pulley wheels and/or spools.
The present apparatus is configured to orientate the lenses continuously towards the stationary targets or target such that the focal point of the lenses and the concentrated solar radiation is always directed to the same region. This avoids consideration of means to move the targets to receive the concentrated solar radiation. Also, the size of the target bodies may be minimised to reduce the footprint of the apparatus by always concentrating the solar radiation to the same region via movement of the lenses in the three lateral coordinates (x, y and z) and one or two rotational axis.
Preferably, the second rotational movement mechanism comprises cables extending substantially in the second (north-south) direction and pulley wheels and/or spools.
The present apparatus may comprise any suitable means to provide lateral actuation of the lenses in the x, y and z coordinates and rotational movement in the two axes, as will be appreciated by those skilled in the art. Accordingly, the drive for the movement mechanisms may also comprise standard components including electric, electromagnetic, solar or other fuel driven motors. Where the present invention is implemented with cables the drive means for the first, second and third lateral movement mechanisms and the first and second rotational movement mechanisms may comprise a motorised winch, pulley wheel or spool to shorten and lengthen each of the respective cables. Reference within this specification to ‘cable’ includes all manner of relatively thin member including specifically a cord, flex, lead, wire, chain, rope and the like. Preferably, the cables comprise wound steel cables including specifically stainless steel cables that may be coated to improve resistance to weathering and corrosion.
As will be appreciated, any support structure may be used to suspend the lenses above the ground and the respective targets. Such suspension systems may comprise entirely rigid structures including for example interconnected steel girders to form a three dimensional frame structure. Alternatively or in addition, the lens support structure may comprise a catenary or other moveable suspension mechanism.
Preferably, the lens support structure comprises a crane block mounted between the lenses in the second (north-south) direction, the crane block being connected to the cables of the first, second and third lateral movement mechanisms to translate movement imparted by the drive means to move the lenses of the array. The crane block may comprise one or a plurality of motors to drive one or a plurality of pulley wheels or spools to drive indirectly rotation of the lens about at least one axis. Preferably, the crane block is connected to the support structure and in particular the secondary support structure that mounts the primary support structure via at least one shaft, each lens configured to rotate about each respective shaft in the first (east-west) direction.
According to a second aspect of the present invention there is provided a method of concentrating solar radiation comprising: receiving and concentrating solar radiation towards of a plurality of targets using an array of lenses; supporting the array of lenses using a moveable support structure; moving the array of lenses in a first lateral direction relative to the targets using a first lateral movement mechanism; moving the array of lenses in a second lateral direction relative to the targets using a second lateral movement mechanism; moving the lenses in a direction up and down relative to the targets using a third lateral movement mechanism; rotating the lenses about a first axis extending substantially in the second lateral direction using a first rotational movement mechanism; and driving the movement mechanisms to move the lenses in the lateral and rotational directions.
According to a third aspect of the present invention there is provided solar energy collection apparatus comprising: solar energy concentrating apparatus as described herein; a conduit network to contain a gas phase working fluid and allow the fluid to flow in contact with the targets such that the working fluid is heated by the targets.
Preferably, the collection apparatus further comprises a heat storage device connected in fluid communication to the targets by the conduit network to receive the heated working fluid, the storage device comprising a heat storage material to store the heat energy received from the working fluid. Optionally, the conduit network comprises metal, ceramic and/or clay based piping. Optionally, the material of the storage device comprises a natural mineral such as stone or rock. Alternatively the storage material may comprise a synthetic aggregate such as concrete and the like.
According to the fourth aspect of the present invention there is provided apparatus for converting solar energy to electrical energy comprising: solar energy concentrating apparatus as described herein; solar energy collection apparatus as described herein; a heat exchanger connected in fluid communication with the conduit network to receive the heated working fluid and to transfer the received heat energy; a turbine coupled to a heat exchanger; an electric generator coupled to the turbine to generate electricity.
According to a fifth aspect of the present invention there is provided a method of supplying electricity generated by the apparatus as described herein to an electricity network and to a method of delivering the electricity via the network to a plurality of users.
According to a sixth aspect of the present invention there is provided solar energy concentrating apparatus having a lens support structure comprising: an annular or polygonal frame configured to surround a concentrating lens at an outer perimeter region of the lens; a plurality of radial spokes mounted at the frame and extending from the frame to a mount positioned substantially centrally relative to the annular frame and the radial spokes.
According to a seventh aspect of the present invention there is provided solar energy concentrating apparatus having a support frame to mount a concentrating lens, the lens comprising: at least one first lens plate extending in a first plane; at least one second lens plate extending in a second plane, the second lens plate being spatially separated from the first lens plate in a direction perpendicular to the planes to provide a gap between the first and second lens plates.
According to an eighth aspect of the present invention there is provided solar energy concentrating apparatus to support a concentrating lens, the apparatus comprising: a plurality of elongate support members comprising one or a plurality of cables extending between a first mount and a second mount; wherein a separation distance between the members in a direction perpendicular to the direction between the first and second mounts increases away from each of the first and second mounts to reach a maximum separation region: wherein a concentrating lens mounted substantially at the maximum separation region and is suspended between the first and second mounts by the support members.
According to a ninth aspect of the present invention there is provided solar energy concentrating apparatus to mount at least one concentrating lens to direct concentrated solar radiation from the lens onto a target, the apparatus comprising: a moveable stanchion mounted at a first end by a pivoting or moveable joint to allow a second end of the stanchion to move laterally in x, y and z coordinates relative to the first end; at least one lens connecting member extending between a region towards the second end of the stanchion and a region close to or at lens such that movement of the second end of the stanchion is translated to provide a corresponding movement of the lens.
According to a tenth aspect of the present invention there is provided solar energy concentrating apparatus to move at least one concentrating lens to direct the concentrated solar radiation from the lens onto a target, the apparatus comprising: a suspension system configured to suspend at least one lens above the ground, at least part of the suspension system extending above the lens relative to the ground; a crane mechanism positioned so as to raise and lower the lens relative to the suspension system.
According to an eleventh aspect of the present invention there is provided solar energy concentrating apparatus to move at least one concentrating lens to direct concentrated solar radiation from the lens onto a target, the apparatus comprising: a lens support structure to mount a lens moveably relative to a target; a first elongate track mounted above the ground and extending in a first direction; a second elongate track mounted above the ground and extending in a second direction transverse or perpendicular to the first direction; wherein the lens, via the support structure, is capable of movement laterally in the first direction along the first track and in the second direction along the second track such that movement of the lens along the first and second tracks is configured to orientate the lens to direct concentrated solar radiation from the lens onto the target.
According to a twelfth aspect of the present invention there is provided solar energy concentrating apparatus to move at least one concentrating lens to direct concentrated solar radiation from the lens to a target, the apparatus comprising: a suspension system configured to suspend at least one lens above the ground; the suspension system comprising: a plurality of columns upstanding from the ground; a beam or catenary system mounted upon the columns and capable of suspending the lens above the ground.

A specific implementation of the present invention will now be described, by way of example only, and with reference to the accompanying drawings in which:

FIG. 1 is a side elevation view of a lens support structure configured to support a lens used to concentrate solar radiation onto a target according to a specific implementation;

FIG. 2 is a cross section through A-A of FIG. 1;

FIG. 3 is a side elevation view of the support structure of FIG. 1 with the lens rotated through 90°;

FIG. 4 is perspective view of a lens comprising a plurality of Fresnel lenses supported by a cabled structure according to a specific implementation of the present invention;

FIG. 5 is a plan view of the lens and support structure of FIG. 4;

FIG. 6 is the cross section through A-A of FIG. 5;

FIG. 7 is a side elevation view of a support cable mounting bracket;

FIG. 8 is a perspective view of a cable securing mechanism for the cables of FIG. 7;

FIG. 9 is a further plan view of the lens support structure of FIG. 5;

FIG. 10 is a plan view of a region of the lens support structure of FIG. 9;

FIG. 11 is a side elevation view of a section of the lens through A-A of FIG. 12;

FIG. 12 is a plan view of a section of the lens support structure of FIG. 9;

FIG. 13 is a more detailed plan view of a region of the lens of FIG. 12;

FIG. 14 is a perspective view of a lens plate mounting bracket of FIG. 13;

FIG. 15 is a side elevation view of a lens plate mounted between two mounting brackets of FIG. 14;

FIG. 16 illustrates a perspective view of the axial support rod of FIG. 5 that provides annual rotational movement of the lens assembly;

FIG. 17 is a further side elevation view of the lens support structure of FIG. 1;

FIG. 18 is a cross sectional side elevation view through the lens and axial support rods of FIG. 16;

FIG. 19 is a perspective view of the lens and rotatable pulleys to provide axial rotation of the lens about two axis corresponding to annual and diurnal rotational movement;

FIG. 20 is a schematic plan view of two lenses interconnected by pulleys and belts configured to provide annual angular movement of the lens;

FIG. 21 is a side elevation view of the assembly of FIG. 20;

FIG. 22 is a further side elevation view of four lens assemblies coupled together for cooperative rotation about the support rods of FIG. 18 to provide annual movement;

FIG. 23 is a side elevation view of the lens support structure of FIG. 1 further illustrating the biaxial rotational movement of the lens within the support structure;

FIG. 24 illustrates a plurality of lenses and support structures coupled together to provide simultaneous rotational motion about axis 107 of FIG. 1 corresponding to diurnal movement;

FIG. 25 illustrates a grid network of rows of lenses and support structures illustrating both axes of rotation corresponding to both annual and diurnal movement;

FIG. 26 illustrates an end elevation view of a plurality of lens support structures of FIG. 1 configured to move in the vertical plane via pulleys, belts and winches;

FIG. 27 is a further end elevation view of the lens support structure of FIG. 1 mounted within an A-frame support, which in turn is mounted upon a diurnal rail which in turn is mounted upon a perpendicular extending annual rail;

FIG. 28 is a side elevation view of the lens support structure and rails of FIG. 27;

FIG. 29 is a perspective of the lens support structures and diurnal and annual rails of FIGS. 27 and 28;

FIG. 30 is a plan cross section view of the crane block illustrated in FIG. 26 and mounted between each lens support structure of FIG. 1;

FIG. 31 illustrates schematically a plurality of lenses mounted upon movable stanchions for movement in the east-west direction;

FIG. 32 is a schematic illustration of an array of lenses mounted according to a grid configuration, with each lens moveable in both the east-west and north-south directions;

FIG. 33 is an end elevation view of the lens support structure of FIG. 27 in which the lenses are moveable via the stanchions of FIG. 31;

FIG. 34 is a side elevation view of the lens movement apparatus of FIG. 33;

FIG. 35 is a schematic perspective view of a plurality of lens support structures of FIG. 1 suspended from a cable system supported by vertical columns;

FIG. 36 is a schematic side elevation view of a further embodiment of the lens suspension apparatus of FIG. 35;

FIG. 37A is a plan view of the lens suspensions system of FIG. 36;

FIG. 37B is a plan view of a section of the lens suspension system of FIG. 37A;

FIG. 38 is an end elevation view of the lens support and suspension system;

FIG. 39 is a further end elevation view of the suspension system of FIG. 38;

FIG. 40 is a schematic side elevation view of a further embodiment of the lens suspension system of FIG. 36;

FIG. 41 is a schematic plan view of a further lens suspension system of FIG. 37;

FIG. 42 is a schematic side elevation view of a further embodiment of the lens suspension system of FIG. 36;

FIG. 43 illustrates schematically an end elevation view of a further lens suspension system of FIG. 39; and

FIG. 44 illustrates schematically components of a heat energy transfer and storage apparatus coupled to heat exchanger and electricity generator according to a specific embodiment of the present invention.

Referring to FIGS. 1 to 4, a lens 106 is mounted within a primary support 111 which in turn is mounted within a secondary support 100. Primary support comprises an elongate shaft 109 extending perpendicular and through the centre of lens 106. A plurality of cables 110, that are preferably tensioned or pre-stressed, extend between shaft 109 and regions of first side 403 of lens 106 and a second side 404.
The primary support 111 is mounted within secondary support 100 that also comprises a plurality of tensioned, pre-stressed cables 102 that extend radially outward from common point A to extend over two annular rings or polygonal frame 108 that extend around primary support 111. Cables 102 extend over each rigid polygonal or annular frame 108 and then converge to a second common point A aligned axially with the first common point A. Primary support 111 is mounted at secondary support 100 via a rotatable shaft 400 with one end of shaft 400 rotatably connected to the lens 106 and a second end 401 rigidly connected to secondary support 100. Accordingly, lens 106 is cable of rotation about axis 103. Shaft 400 and lens 106 are held in position via suitable cables 104 as described further with reference to FIGS. 16 to 18. Lens 106 is also configured for rotation about axis 107 extending between common cable points A, as described with reference to FIGS. 23 to 25.
Cables 102 and 110 may comprise separate cables or may comprise respective single cables that are wound around the respective frames and mounts to create the seemingly multi-cable construction.
Referring to FIG. 3, a crane block 300 is positioned at the common points A between each primary 111 and secondary 100 support structure that are coupled end to end as illustrated in FIG. 29. The crane block 300 and accordingly lens support structures 111 and 100 are suspended in a vertical direction by suspension cables 301 discussed further referring to FIG. 26.
FIGS. 5 to 15 illustrate components and construction of the lens 106. The primary lens support 111 comprises a hollow annular tube 500 divided into circumferential or perimeter sections that are secured together by conventional means such as bolts, screws, welding or other frictional contact to form a wheel structure having an outer frame 500. Cable spokes 507 extend from the circumferential support 500 to a common central mounting region 510. Each tensioned, pre-stressed cable 507 is secured at support 500 via a mounting bracket 501 that encapsulates support 500. A plurality of mounting brackets 501 extend circumferentially around support 500 to mount each of the plurality of cable spokes 507. When orientated in the substantially horizontal plane as illustrated in FIG. 1, the weight of lens 106 and the structural rigidity of the lens assembly is supported, in part, by the transverse cables 110 that also extend between mount bracket 501 and the shaft 109 (central mount 510) aligned perpendicular or transverse to the general plane of the lens 106.
According to the present embodiment, a plurality of circumferentially extending tie cables 509 extend between each of the spoke cables 507 and are mounted upon respective plate mounts 508 positioned radially from centre 109 to the outer circumferential support 500. According to further specific embodiments, the lens support structure comprising outer frame 500, central mount 510 and radial spokes 507 does not comprise the connecting tie cables 509.
Referring to FIG. 5, a shaft mount 505 is positioned at two diametrically opposed regions of circumferential mount 500 to receive and house one end of a respective shaft 400. The inboard end of shaft 400 is mounted within a bearing assembly 503 having suitable bearings 503 to enable the lens assembly 106 to rotate axially about shaft 400. Shaft 400 is mounted at end 401 via mount 502 secured to annular rings 108 as described further referring to FIG. 16.
Referring to FIG. 8, each cable 507, 509, 110 maybe anchored in position via a male 800 and female 801 lock assembly to secure each cable 507, 509, 110 when placed under tensile load as required to impart structural rigidity to the lens assembly 106.
FIGS. 9 to 15 further illustrate the securement of lens plates within the lens assembly 106. A plurality of lens plates 506 are assembled to form a Fresnel lens and are mounted between spoke cables 507 and tie cables 509. The lens plates 506 are secured in position between four respective plate mounts 508.
Referring to FIG. 10, according to one embodiment a notch 1001 may be provided within each lens plate 506 to abut against an outer region of plate mount 508. Alternatively, suitable mounting pins, screws, bolts, rivets or ties 1000 may be used to rigidly connect each lens plate 506 in position relative to cables 507 and 509. Suitable deformable spacers 900 may be positioned at the outermost region between lens plates 506 and circumferential support 500, referring to FIG. 9, to avoid damage or unwanted movement to lens plates 506.
Referring for FIG. 13, similar deformable or resiliently compressible buffers 1300 may be positioned between opposed mating edges 1301 of lens plates 506 again to avoid damage due to any unintentional movement of the lens assembly components.
Referring to FIGS. 11 and 14, the lens plates 506 are staggered according to an alternating sequence above and below tie cables 509 so as to create an air or wind flow gap between planes A and B aligned parallel to each plate 506. Accordingly, the lens assembly 106 via vent spacings A-B is configured to withstand wind forces perpendicular and transverse to the plane of lens plate 506 when installed in use above ground level. According to the embodiment of FIGS. 11, 14 and 15, each plate mount 508 is formed as a frame comprising opposed sidewalls 1401, 1405 separated at each respective end by opposed upper 1402 and lower 1403 end plates. A notch or recess 1400 is formed in each sidewall 1404, 1406 extending from face 1406 and similarly a second notch or recess 1404 is also formed in each sidewall 1401, 1405 from the opposed opposite face 1405. Notches 1400 are formed in a lower half of plate 508 and notches 1404 are formed in an upper half of plate 508. The notches 1400 and 1404 are aligned and sized to accommodate the edge regions of lens plates 506 to secure them in position to extend from each plate mount 508 from a first side 1406 and second side 1405 spaced apart in the vertical direction. Transverse shaft cables 110 extend from upper plate 1402 and lower plate 1403 but are positioned off centre with respect to central vertical plane 1407. As illustrated in FIG. 15, when tension is applied to shaft cables 110, each plate 508 twists 1500 such that each lens plate 506 is braced against each respective notch 1404, 1404 to hold the plates 506 in position.
Referring to FIG. 16, each shaft 400 extending diametrically from circumferential support 500 provides rotational connection between the primary support 111 and secondary support 100. Each shaft 400 forms a connection between the circumferential support 500 and the two rigid frames 108 via side shaft cables 104 and 1600. In particular, four cables 104 extend in the same plane and are secured to the lens end of the shaft 1601 from a region of each annular ring 108. Additionally, a further four cables 1600 also extend from regions of each annular ring 108 towards outboard second end 1602 of shaft 400 furthest from lens assembly 106. Each cable 104 and 1600 may be pre-tensioned or stressed so that when assembled under tensile load, the cable assembly as illustrated in FIG. 16 is configured to resist bending or twisting forces. FIG. 17 further illustrates the housing of the primary support 111 within the secondary support 100 that mounts the lens assembly 106 via shaft 400 using four elongate cables (formed as separate cables or from a single cable that is wound back on itself) that extend from the polygonal or circumferential support frames 108 and converge to each end mount A as shown in FIG. 1.
FIG. 18 further illustrates a further embodiment of the lens support structure 100 and 111 that does not comprise the two polygonal or annual support frames 108. As described earlier, frames 108 are configured to neutralise or balance the compressive forces that are created and directed inwardly by cables 102 towards the lens 106. Without the frames 108, and in order to withstand the compressive forces imparted by cables 102, 1904 that extend over and about primary support 111, thrust bearings 1800 are accommodated within bearing assembly 503. Additionally, by imparting the required tensile load to each cable 102, 1904 any compressive forces exerted upon lens assembly 106 can be equilibrated or minimised. The cables 102 are separated and supported by a rigid frame section 1800, being effectively a section of larger frame 108.
Referring to FIG. 19, lens assembly 106 is capable of rotation about axis 103 as bearing assembly 503 rotates about shaft 400. This angular rotation 1905 enables lens assembly 106 to track the position of the sun according to its annual movement. Lens 106 is also configured to rotate 1906 about axis 107 to follow the diurnal movement of the sun. According to the specific embodiment, the annual rotational movement 1905 is provided by pulley 1900 mounted at lens 106 and driven by pulley belt 1901. The diurnal movement 1906 is provided by pulley 1902 mounted at each end of the secondary support 100 (illustrated in FIGS. 1 and 3), with rotation of pulley 1902 provided by belt 1903.
FIGS. 20 to 22 further illustrate the mechanism for imparting rotation of lens 106 about shaft 400 to provide annular tracking movement of the sun. The collective rotational movement of each lens 106 is achieved by coupling the annual rotational pulleys 1900. Accordingly, a plurality of lenses 106 may be connected in series and rotatably adjusted coincidentally via a common drive motor (not shown) mounted at crane block 300 and configured to drive driving pulley 2009 detailed further referring to FIG. 30. Each lens comprises a single 1900 or dual pulley 2001 to receive driving belts 1901, 2000, 2003 that interconnect neighbouring lenses within a row of lenses to provide simultaneous or ‘ganged’ rotation about axis 103. According to the specific embodiment, only one drive pulley 2009 is required for each row of lenses with other pulleys 2009 within the row providing stabilisation of the intermediate belts 2000, 2003. However, according to further embodiments suitable drive motors may be provided at each crane block 300 to drive each pulley 2009.
A region 2008 of each lens is ‘cut-away’ or is devoid of lens plates 506 and support 500 such that the body of lens 106 does not interfere or contact the drive belts 2000, 2003, 1901 when each lens 106 is rotated 1905 about axis 103 as illustrated in FIG. 19. As perimeter frame 500 is continuous, belts 1901, 2000, 2003 extend above or below the perimeter section 500 so as to effectively extend through the lens and frame assembly as illustrated in FIGS. 20 and 21. Accordingly, each lens 106 is capable of achieving a minimum angle of inclination relative to the horizontal that corresponds to approximately 8°. Rotation beyond this lower limit would provide unwanted contact between frame 500 and belts 1901, 2000, 2003. According to further embodiments, each region 2010 of frame 500 that is orientated immediately above or below the belts 1901, 2000, 2003, is smooth, profiled or in some other way configured to withstand contact with the drive belts such that lens 106 may be rotated to the horizontal position and capable of rotation through 180° and not through approximately 50° (according to the embodiments of FIGS. 20 to 21).
FIG. 21 is a side elevation view through A-A of FIG. 20. Via rotation of drive pulley 2009 each lens pulley 1900, 2001 is rotated to impart rotation 1905 of lens 106 to track annual movement.
FIGS. 23 and 24 illustrate the mechanism for providing diurnal rotational movement 1906 of lens 106 via rotational pulleys 1902 positioned at each end of the secondary support 100. Each pulley 1902 is mounted at shaft 2301 between crane block 300 and a cable frame plate 2300 corresponding to positions A of FIG. 1. Plate 2300 is of a sufficient diameter to avoid unwanted twisting of the secondary support 100 as the assembly 100 is rotated 1906 about axis 107.
FIGS. 24 and 25 illustrate an array and network of interconnected lenses 106 and assemblies 111, 100, arranged in rows, where each lens 106 is configured for biaxial rotation 1905 and 1906. As illustrated, rotation 1906 occurs in the north-south axis to provide diurnal tracking of the sun's movement during the day whilst rotation 1905 occurs in the east-west axis and is optional to provide optimum annual tracking motion of the sun throughout the year.
FIG. 26 illustrates the apparatus configured to displace the lenses 106 and primary and second supports 111, 100 in the vertical plane 2604. Each secondary support 100 is mounted at respective crane blocks 300 as illustrated in FIG. 3. Each crane block 300 comprises pulleys 2603 to received drive belt 301. Belt 301 also extends around crane pulleys 2602 that are affixed or suspended in position from a suitable gantry or suspension catenary as illustrated further in FIGS. 27 to 29 and 35 to 43. Drive belt 301 is terminated towards its respective ends by a suitable winch or drive spool 2600, being for example a conventional cable tensioner having a motor and drive pulley. Accordingly, as one or both winches 2600 are actuated, belt 301 is affectively shortened between winch end points 2600 to raise crane block 300 in the vertical direction 2604 and accordingly displace lens 106 vertically upward. A reverse operation of winch 2600 accordingly lowers lens 106 in direction 2604. To avoid unbalanced vertical displacement of each lens 106, each crane block 300 is independently driven by a respective winch 2600 or winch pair. According to further specific embodiments, a series of lens 106 and assemblies A, B, C and D may be raised and lowered vertically via a common drive belt 301 extending around each crane and/or pulleys 2602. According to a yet further embodiment, the movement cables associated with assemblies A, B, C and D may be interfaced with common winches 2600 such that each row of assemblies A, B, C and D are acted upon by only one or two winches 2600.
FIGS. 27 to 29 illustrate a specific embodiment for suspending lens assembly 106 and for enabling lateral displacement in the north-south and east-west axes. Lens assembly 106 and primary and secondary supports 111, 100 are mounted within two opposed A-frames 2707. The crane pulleys 2602 are mounted at crane mount 2700 at the apex of frame 2707. The A-frame 2707 also comprises feet extensions 2701 positioned at each lower leg, with each foot comprising a pair of rollers 2702 to sit upon and roll over the surface of an elongate diurnal track or rail 2703 extending in the east-west direction. The diurnal rail 2703 is in turn mounted upon an annual track or rail 2705 via similar feet and roller assemblies 2704 located at the bottom of each A-frame 2701, 2702. The annual rail 2705 is in turn mounted above the ground 2601 via support stanchions 2706. Cables 2800 extend from the upper and lower regions of diurnal track 2703 so as to move the track laterally relative to the annual track 2705. Cables 2800 are connected to suitable drive means (not shown) to shorten and lengthen cables 2800 and provide the movement of track 2703.
FIG. 29 provides a schematic perspective view of the secondary supports 100 and configured for east-west and north-south lateral movement via rails 2703 and 2705. FIG. 29 further illustrates the apparatus for enabling vertical movement of the secondary assemblies 100 via the respective belts 301 as described with reference to FIG. 26.
FIG. 30 illustrates the cross sectional plan view of the crane block 300 and end region of secondary support 100. Each crane block pulley 2603 is mounted upon axle 3006 that is in turn mounted at crane block housing 3004. The vertical displacement belt 301 extends around pulleys 2603 to provide the vertical movement 2604. As illustrated, belt 301 passes around the outside of A-frame 2707 according to the embodiment of FIGS. 27 to 29.
According to the further embodiment described with reference to FIGS. 35 to 43 the crane block assembly of FIG. 30 is the same however the A-frame 2707 is not required. As illustrated, crane block 300 comprises a means to mount vertical movement pulleys 2603, the diurnal rotational pulley 1902 and the annual rotational pulley 2009 that is mounted upon axial 3005 which is in turn mounted at crane block 300 via arm 3000. A motor (not shown) is also mounted at crane block 3000 and configured to drive rotation of pulley 2009 via rotation of axel 3005. Accordingly, this motor (not shown) drives annual rotation of the lens 106 about axis 103. Additionally, the same or an additional motor (not shown) mounted at crane block 300 is configured to drive rotation of pulley 1902 which in turn drives rotation of lens 106 in the diurnal axis of rotation 1906.
Crane block 300 also provides a means to mount a lateral displacement cable 3007. Crane blocks 300, positioned at end or terminating positions of a series (row) of interconnected lens supports 100, also mount a lateral displacement cable 3201 extending in the north-south axis as illustrated in FIG. 32. Crane block 300 therefore provides a hub for connection to the various mechanisms for providing lateral east-west (x) and north-south (y) movement; diurnal rotation about axis 103; annual rotation about axis 107 and vertical displacement (z) 2603 perpendicular to the x and y movement planes.
FIGS. 31 and 32 further illustrate the components to provide lateral east-west and north-south translational motion of the lenses 106 and assemblies 111, 100. Each lens assembly 106 is coupled in the east-west direction by lateral displacement cables 3007 that extend from each crane block 300 mounted between each secondary support 100. Cable 3007 terminates at a region of a winch assembly 3102 that comprises a suitable motor and spool 3103. Cable 3007 from a terminal crane block 300 passes over a curved surface 3101 of stanchion 3100 to be received at winch 3102 which is in turn mounted at the ground via mount 3104. Actuation of spool 3103 provides pivoting movement 3105 about pivot point 3106 (being a universal, ball or knuckle joint) mounted at the ground 2601. Accordingly, lenses 106 are configured to move laterally in the east-west direction in response to actuation of the winch assembly 3102. Similarly, a north-south lateral displacement cable 3201 extends from a terminal crane block 300 and is supported by pivotally mounted stanchion 3200 configured to pivot 3203 to provide the lateral north-south lateral movement of the lenses 106 as described with reference to FIG. 31 (in the east-west direction).
As will be appreciated, each winch assembly 3102 may be controlled electronically so as to automate diurnal and annular lateral movement of the lenses 106 specific to a particular geographical location and the relative sun motion to ensure that the solar radiation 3107 concentrated by each lens 106 is focused towards each respective stationary target 3100 and that the intensity of the radiation incident at target 3100 is not diminished or any reduction minimised by appropriate lens movement. The present apparatus is configured to orientate the lenses continuously throughout the day and year to concentrate and focus the solar radiation towards a single region (target 3100). That is, the focal position of the lenses does not change in the lateral east-west and north-south direction, nor does it change in the vertical direction. Accordingly, the target area may be relatively small and no consideration needs to be given to coordinated movement of the target in response to movement of the lenses and/or sun position.
As will be appreciated, the present apparatus is configured for manual and automated electronic control of the various drive components so as to provide computer and electronic control and actuation of the lateral east-west, north-south displacement; the vertical displacement 2604 and the annular and diurnal rotational movement of each lens assembly 106. Individual electronic control may be provided for each type of lateral and rotational drive means. Alternatively, a common electronic control may be provided to regulate all mechanical components. Moreover, actuation sensors (not shown) may also be provided and positioned at regions of the apparatus to monitor the imparted motion to the various components. Such movement sensing may then be coupled to the electronic control to provide diagnostic assessment, performance monitoring and automatic correction in the event of any undesired movement. For example, auto-correction via the electronic control may be required to compensate for unwanted movement due to wind forces incident at the apparatus. In addition to motion sensors, the apparatus may further comprise thermal, humidity, wind speed, air pressure, UV and other solar radiation sensors (not shown) to provide data to the electronic control which may then initiate instruction and control of the mechanical components in response. In particular, diode sensors (for example, four sensors) may be positioned at the region of the target to determine if the concentrated solar radiation form the lens is appropriately directed towards the target for optimum performance and to receive the maximum amount of solar radiation. As will be appreciated, the electronic control is network-configured to provide geographically remote monitoring, control and information/data exchange. The drive motors required to drive translational (horizontal and vertical) and rotational movement may be powered by suitable photovoltaic cells and/or conventional electrical motors.
FIGS. 33 and 34 illustrate the lateral displacement of the lens assemblies 106 according to the embodiment of FIGS. 27 to 29 in which the lenses 106 are mounted within respective A-frames 2707. As illustrated, each lens 306 is configured to move over an imaginary section of a sphere surface 3300 corresponding to the motion path of stanchion 3100 that also pivot over imaginary sphere surface 3105. This motion is achieved via coordinated control of the various translational and rotational movements of the apparatus in the x, y and z coordinates.
Accordingly, each lens 106 is capable of movement through approximately 140° (diurnal rotation) in order to track the daily movement of the sun. A second diurnal (translational) motion in an east-west direction along diurnal beam 2703 further compensates for the movement of the sun during the day to ensure a maximum concentration of solar radiation 3107 at stationary target 3100. Vertical movement of the lens 106 is also required during this diurnal translation and rotational motion and this is achieved via cable 301 and associated cranes or winches 2600 described with reference to FIG. 26.
A first annual (translational) movement of lenses 106 occurs via annual rail 2705. A second annual (rotational) motion optionally also occurs via rotation of each lens 106 about pivot axis 103. This rotation is provided through approximately 50° and corresponds to the latitude alignment of the lens when initially installed at a particular geographical location. An alternative arrangement may simply involve an initial manual angular adjustment of each lens 106 so as to correctly align for the geographical latitude when the apparatus is initially installed. According to this further embodiment, the focal position of the lenses may be adjusted manually or automatically to compensate for the annual solar motion to ensure sufficient concentrated solar radiation 3107 is incident at targets 3100. However, and as will be appreciated, rotation of the lens about two axis is beneficial to minimise the force component perpendicular to the plane of the lens created by the incident wind. The second rotational motion therefore may be optionally employed to minimise the force on the apparatus due to the wind and reduce any possible damage or unwanted movement of the apparatus.
The present lens and supporting structure assembly is specifically designed to withstand wind forces generated from wind speeds of up to approximately 20 mph. The use of cables is particularly advantageous as, when placed under tension and according to the present structural arrangement, provide a very robust lens support assembly whilst minimising the surface area against which the wind force is incident. Therefore, a reasonable proportion of the wind may pass through the lens assembly as described referring to FIG. 11 such that the lens itself and not its support structure provide the largest resistance to the wind. Accordingly, the mechanical stress imparted to the entire assembly from the wind is minimised. The use of high strength cables is also economically attractive as this requires less metal to create the lens support structure with regard to conventional more cumbersome apparatus.
To compensate for thermal expansion when exposed to large temperature variation, that will be experienced when the present apparatus is positioned for use in a hot daytime but cold night time environment, such as a desert and the like, all or most cables used in the present apparatus are tensioned or pre-stressed, to for example, 138 MPa, found to maintain the required tension for an approximate 60° C. temperature change.
According to a specific implementation, each lens 106 comprising the plurality of individual Fresnel lenses 506 is assembled according to conventional construction methods. Each lens 106 may be 7 to 10 metres in diameter. Such a lens 106 is configured for use with a target 3100 with a 30 cm to 50 cm diameter target window where, for example, the target comprises a 60 cm diameter pipe (not shown) to accommodate a heat transfer fluid forming part of a network or system associated with a heat store, turbine and/or heat exchanger as described with reference to International patent application no. PCT/GB2010/050536, which is hereby incorporated by reference. This is however summarised with reference to FIG. 44.
FIGS. 35 to 43 illustrate an alternative to the A-frame 2707 suspension system described in FIGS. 27 to 29. According to the further embodiment, the lens assemblies 106 and support structures 111, 100 are suspended from a catenary 1501, 1502 which, in turn, is suspended upon columns 3500 extending vertically upward from the ground 2601. As with the previous embodiment, each crane block 300 positioned between secondary supports 100 provides the suspension coupling for the vertically extending cable 300 that is in turn connected to an upper crane 3503 being for example a drive motor and spool. FIG. 35 illustrates schematically the mechanism for lateral movement via displacement cables 3007 in the east-west direction and cables 3201 extending in the north-south direction, with each respective cable being associated with a respective pivoting stanchion 3100, 3200 and acted upon by at least one winch or driven cable winding mechanism 3102.
FIG. 36 illustrates further embodiments of the suspension system of FIG. 35 in which each lens assembly 106 is suspended from a girder 3600 which is in turn supported by the vertical columns 3500. The girder 3600 may be held in position by cabling 3602 connected to a respective winch 3102 mounted at the same plane (at a similar height) to girder 3600. Alternatively, positional anchorage may be provided by cabling 3602 attached to the ground 2601 and also coupled or acted upon by a cable tensioner, tightener or winch 3102. According to the embodiment of FIG. 36, the lenses 106 may be suspended between adjacent columns 3500 in the annual (north-south) direction. Alternatively and referring to FIG. 41, the lenses 106 may be suspended in-line with the columns 3500 via an overhead girder 4100 or catenary 3501 as illustrated in FIGS. 35 and 40. If suspended by a catenary 3501, an intermediate thrust girder 4000 may extend between upper regions of columns 3500 to prevent columns 3500 collapsing inwardly due to weight of assemblies 106 and supports 111, 100. Alternatively and with reference to FIG. 42, the thrust girder 4000 may be omitted and positional securement of columns 3500 provided by tensioning cables 3602 extending from the upper region of each column 3500 and anchored at the ground 2601 where tension is created and maintained by tensioning device 3102.
Referring to FIGS. 36 and 39, vertical displacement of the array of lenses 106 is provided by respective cranes 3503 mounted at uppermost girder 3600 or catenary 3501. Each crane 3503 is coupled to neighbouring cranes of the same row via interconnecting coupling cable 3601. Accordingly, a common drive mechanism may be used to drive vertical displacement of each lens 106 within the assembly. Alternatively, each crane 3503 may comprise separate drive components.
Referring to FIG. 38, to enable the required lateral displacement of lenses 106 each column 3500 is configured to pivot from position B to position C in the diurnal direction (east to west). The pivoting movement of columns 3500 is required in order to reduce the footprint area of the array of lenses at a particular geographical location. The alternative to the embodiment illustrated in FIG. 38 would be to increase the lateral space in the east-west direction between columns 3500. As indicated however, this would increase the footprint size of the apparatus which may be undesirable. Depending upon the suspension position of the lenses with respect to columns 3500 in the annual direction (north-south) columns 3500 may also be required to pivot in this annual direction to avoid contact of the lens components 300, 100 with the columns 3500.
Additionally, to reduce the loading forces at regions of the apparatus when the columns 3500 are pivoted from position B to position C, crane 3503 may be configured to displace laterally from position A to position B coincidentally. FIG. 43 illustrates a possible mechanism to achieve this lateral displacement 4301 as columns 3500 pivot 4302 to an inclined position 4303. In particular, crane 3503 may be suspended at a catenary 3502 which, in turn, is suspended by spools or pulleys 4300 which are driven by appropriately positioned motors or winches (not shown).
This lateral movement of crane 3501 ensures suspension cable 301 remains vertical or near vertical during diurnal movement of the lens 106 to track the position of the sun 3800 and ensure solar radiation 3107 is continuously focused towards target 3100 during daylight hours.
Referring to FIGS. 37A and 37B, columns 3500 via cables 3007 and 3201 are configured to move laterally in directions A-A and B-B. As illustrated, crane block 300 is of a sufficient width such that cables 3007 extend either side of columns 3500. Accordingly, crane block 300 may be sized to provide the required clearance between columns 3500 and cables 3007. Via stanchions 3100, movement laterally in the direction A-A of both the columns 3500 and crane blocks 300 is synchronised so as to ensure that cables 3007 do not touch columns 3500. Columns 3500 are also configured to pivot in the direction B-B. However, the lateral movement in the B-B direction is not synchronised to the motion of the crane blocks 300. That is, the crane blocks 300 are not always central between the columns 3500 according to the present embodiment.
As will be appreciated, the lens assemblies 106 and associated components 111, 100 and 300 may be suspended or supported by any suitable mechanism capable of enabling each lens 106 to move laterally in the east-west (x) and north-south (y) directions, a perpendicular vertical (z) direction and diurnal rotation through 140° and annual rotation through approximately 50°. The support and suspension system must also be configured to allow the through-flow of air in order to withstand wind sheer forces incident on the apparatus.
Suitable mechanical actuation apparatus for the lens assemblies 106 may comprise rack and pinion mechanisms, chains, belts, cables, actuation rams (including pneumatic, hydraulic and other fluid operated rams and pistons), servo controlled mechanisms, concertina assemblies, telescopic actuators, rail and wheel assemblies, catenaries and suspension cable systems, magnetic and electromagnetic rotational and translational movement components and the like.
Referring to FIG. 44, the present lens actuation apparatus is configured for use with apparatus and methods to collect and transfer solar energy for power generation. Such power generation apparatus utilising solar radiation 3107 as an energy source may comprise a gas (or liquid) phase heat transfer medium that flows in contact with the target or plurality of targets 3100. The target or plurality of targets 3100 form part of a heat transfer network 4400 which is coupled to, for example, a heat energy storage device 4401, a heat exchanger 4402 and/or turbine 4404 to provide on-demand supply of electricity both during and optionally between solar energy collection periods. The conduit network 4400 contains the gas phase working fluid and allows the fluid to flow in contact with the targets 3100 such that the working fluid is heated by the targets 3100 as it flows past.
The heat storage device 4401 is connected in fluid communication with the targets 3100 by the conduit network 4400 which is configured to receive the heated working fluid. The storage device 4401 comprises a heat storage material 4406 (optionally stone or a natural mineral but also including synthetic aggregate) to store the heat energy received from the working fluid. Typically, each target 3100 comprises a heat transfer body positioned in the flow path of the working fluid as it flows through the target 3100. Thermal insulation (not shown) is also provided around the targets 3100 and fluid network 4400, and heat store 4401, to ensure minimum energy loss through conduction. Suitable valves 4408 and working fluid circulation fans 4407 control the flow of the working fluid around the network 4400. The working fluid heated by lenses 106 is coupled to the working fluid within the heat exchanger network 4403 which is in turn fed to the turbine 4404. An electricity generator 4405 is then coupled and powered by turbine 4404. According to further embodiments, an intermediate heat exchanger may be positioned between conduit network 4400 and heat store 4401 such that the working fluid within heat store 4401 is different to that that flows through each target 3100. Additionally, an embodiment of the present invention may not comprise the heat store 4401 and may simply comprise a plurality of heat exchangers 4402 in fluid communication with a working fluid that flows through, around or in thermal contact with targets 3100.
The present apparatus is suitable to create a grid network or array of moveable lenses 106 positioned above respective targets 3100 and installed at geographical locations with high solar radiation and available land space. The present apparatus is typically ground mounted. However, further embodiments may comprise additional floatation devices or water submerged pylons and support structures to enable the present apparatus to be geographically located over water and in particular the sea.

Claims

1. Solar energy concentrating apparatus comprising:

an array of lenses to receive and to concentrate solar radiation towards a plurality of targets;

at least one lens support structure to moveably mount each lens of the array to receive the solar radiation;

a first lateral movement mechanism to move the lenses in a first lateral direction relative to the targets;

a second lateral movement mechanism to move the lenses in a second lateral direction relative to the targets;

a third lateral movement mechanism to move the lenses in a direction up and down relative to the targets;

a first rotational movement mechanism to rotate the lenses about a first axis extending substantially in the second lateral direction; and

at least one drive means to drive the lens movement mechanisms.

2. The apparatus of claim 1 further comprising a second rotational movement mechanism to rotate each lens about a second axis extending in the first lateral direction.

3. The apparatus as claimed in claim 1 wherein the lens support structure comprises a primary support having a circumferential ring to mount to the lens, a support shaft extending centrally through the lens and support cables extending from the central shaft to the circumferential ring.

4. The apparatus as claimed in claim 3 wherein the lens support structure comprises a secondary support to mount the primary support, the secondary support comprising cables extending around the primary support.

5. The apparatus as claimed in claim 1 wherein the array of lenses is arranged in rows of lenses to form a grid network of lenses with rows in the first lateral direction and rows in the second lateral direction.

6. The apparatus as claimed in claim 1 wherein each lens of the array comprises a plurality of Fresnel lenses extending in at least two substantially parallel planes, one above the other so as to provide an air flow gap between the planes of the lenses.

7. The apparatus as claimed in claim 5 wherein the first lateral movement mechanism comprises cables extending in the first lateral direction and pulley wheels and/or spools and stanchions positioned at the end of each row of lenses in the first lateral direction, the stanchions coupled to one of the cables in the first lateral direction such that when the drive means is actuated the stanchions pivot in the first lateral direction and the lenses move laterally in the first lateral direction.

8. The apparatus as claimed in claim 5 wherein the second lateral movement mechanism comprises cables extending in the second lateral direction and pulley wheels and/or spools and stanchions positioned at the end of each row of lenses in the second lateral direction, the stanchions coupled to one of the cables in the second lateral direction such that when the drive means is actuated the stanchions pivot in the second lateral direction and the lenses move laterally in the second lateral direction.

9. The apparatus as claimed in claim 5 wherein the third lateral movement mechanism comprises cables and pulley wheels and/or spools.

10. The apparatus as claimed in claim 5 wherein the first rotational movement mechanism comprises cables and pulley wheels and/or spools.

11. The apparatus as claimed in claim 7 wherein the drive means for the first, second and third lateral movement mechanisms comprise a motorised winch, pulley wheel or spool to shorten and lengthen each of the respective cables.

12. The apparatus as claimed in claim 2 wherein the second rotational movement mechanism comprises cables extending substantially in the second lateral direction and pulley wheels and/or spools.

13. The apparatus as claimed in claim 12 wherein the drive for the first and second rotational movement mechanisms comprise at least one motor and a drive shaft coupled to at least one of the pulley wheels and/or spools to drive movement of the cables and impart rotational movement to the lens via at least one of the pulley wheels or spools.

14. The apparatus as claimed in claim 1 wherein the lens support structure comprises support columns extending upwardly from the ground and a catenary suspended from the columns, the array of lenses being suspended from the catenary.

15. The apparatus as claimed in claim 7 wherein the support structure comprises a crane block mounted between the lenses in the second lateral direction, the crane block being connected to the cables of the first, second and third lateral movement mechanisms to translate movement imparted by the drive means to move the lenses of the array.

16. The apparatus as claimed in claim 15 wherein the crane block comprises means to mount at least one pulley wheel.

17. The crane block as claimed in claim 15, when dependent on claim 4 wherein the crane block is connected to the secondary support structure.

18. The apparatus as claimed in claim 4 wherein the secondary support structure is coupled to the primary support structure via a shaft, each lens configured to rotate about each respective shaft in the first lateral direction.

19. A method of concentrating solar radiation comprising:

receiving and concentrating solar radiation towards of a plurality of targets using an array of lenses;

supporting the array of lenses using a moveable support structure;

moving the array of lenses in a first lateral direction relative to the targets using a first lateral movement mechanism;

moving the array of lenses in a second lateral direction relative to the targets using a second lateral movement mechanism;

moving the lenses in a direction up and down relative to the targets using a third lateral movement mechanism;

rotating the lenses about a first axis extending substantially in the second lateral direction using a first rotational movement mechanism; and

driving the movement mechanisms to move the lenses in the lateral and rotational directions.

20. Solar energy collection apparatus comprising:

solar energy concentrating apparatus as claimed in claim 1;

a conduit network to contain a gas phase working fluid and allow the fluid to flow in contact with the targets such that the working fluid is heated by the targets.

21. The collection apparatus as claimed in claim 20 further comprising a heat storage device connected in fluid communication to the targets by the conduit network to receive the heated working fluid, the storage device comprising a heat storage material to store the heat energy received from the working fluid.

22. The collection apparatus as claimed in claim 20 wherein the conduit network comprises metal, ceramic and/or clay based piping.

23. Apparatus for converting solar energy to electrical energy comprising:

solar energy collection apparatus as claimed in claim 20;

a heat exchanger connected in fluid communication with the conduit network to receive the heated working fluid and to transfer the received heat energy;

a turbine coupled to a heat exchanger; and

an electric generator coupled to the turbine to generate electricity.

24. Solar energy concentrating apparatus having a lens support structure comprising:

an annular or polygonal frame configured to surround a concentrating lens at an outer perimeter region of the lens;

a plurality of radial spokes mounted at the frame and extending from the frame to a mount positioned substantially centrally relative to the annular frame and the radial spokes.

25. Solar energy concentrating apparatus having a support frame to mount a concentrating lens, the lens comprising:

at least one first lens plate extending in a first plane;

at least one second lens plate extending in a second plane, the second lens plate being spatially separated from the first lens plate in a direction perpendicular to the planes to provide a gap between the first and second lens plates.

26. Solar energy concentrating apparatus to support a concentrating lens, the apparatus comprising:

a plurality of elongate support members comprising one or a plurality of cables extending between a first mount and a second mount;

wherein a separation distance between the members in a direction perpendicular to the direction between the first and second mounts increases away from each of the first and second mounts to reach a maximum separation region;

wherein a concentrating lens mounted substantially at the maximum separation region and is suspended between the first and second mounts by the support members.

27. Solar energy concentrating apparatus to mount at least one concentrating lens to direct concentrated solar radiation from the lens onto a target, the apparatus comprising:

a moveable stanchion mounted at a first end by a pivoting or moveable joint to allow a second end of the stanchion to move laterally in x, y and z coordinates relative to the first end;

at least one lens connecting member extending between a region towards the second end of the stanchion and a region close to or at lens such that movement of the second end of the stanchion is translated to provide a corresponding movement of the lens.

28. Solar energy concentrating apparatus to move at least one concentrating lens to direct the concentrated solar radiation from the lens onto a target, the apparatus comprising:

a suspension system configured to suspend at least one lens above the ground, at least part of the suspension system extending above the lens relative to the ground;

a crane mechanism positioned so as to raise and lower the lens relative to the suspension system.

29. Solar energy concentrating apparatus to move at least one concentrating lens to direct concentrated solar radiation from the lens onto a target, the apparatus comprising:

a lens support structure to mount a lens moveably relative to a target;

a first elongate track mounted above the ground and extending in a first direction;

a second elongate track mounted above the ground and extending in a second direction transverse or perpendicular to the first direction;

wherein the lens, via the support structure, is capable of movement laterally in the first direction along the first track and in the second direction along the second track such that movement of the lens along the first and second tracks is configured to orientate the lens to direct concentrated solar radiation from the lens onto the target.

30. Solar energy concentrating apparatus to move at least one concentrating lens to direct concentrated solar radiation from the lens to a target, the apparatus comprising:

a suspension system configured to suspend at least one lens above the ground;

the suspension system comprising:

a plurality of columns upstanding from the ground;

a beam or catenary system mounted upon the columns and capable of suspending the lens above the ground.