LOW COST LINEAR CONCENTRATED HYBRID SOLAR ENERGY SYSTEM
FIELD OF THE INVENTION
The present invention relates to hybrid solar power systems for conversion of solar energy to electrical and thermal energy through use of photovoltaic array and working fluid heating.
DESCRIPTION OF THE RELATED ARTS
There are currently in use a wide variety of systems and methods for utilizing solar power as a source of energy. For example, photovoltaic systems are widely known for converting sunlight into electricity. Another common type of system is the solar trough. The solar trough is a type of solar thermal system where sunlight is concentrated by a curved reflector onto a pipe containing a working fluid that can be used for process heat or to produce electricity. Solar thermal electric power plants using solar trough technology are well known.
A variation of the solar trough technology is a photovoltaic concentrator system. The photovoltaic concentrator system uses sun-tracking mirrors that reflect light onto a receiver lined with photovoltaic solar cells. The mirrors concentrate the incident solar energy on the solar cells so that they are illuminated with approximately 20-100 times normal solar concentration. Such systems can convert at an efficiency of about 20%. The balance of the solar energy is converted into heat. However, the performance of the solar cells is degraded at excessively high temperatures. Accordingly, excess heat must be removed Typically, this is accomplished by means of a cooled heat exchanger attached to the photovoltaic solar cells. For example, the photovoltaic cells can be provided with an integrated passive heat sink to maintain the solar cells at a moderate temperature.
The conversion of solar energy to thermal or electrical energy through the use of systems such as photovoltaic arrays, passive absorbers of solar energy, solar furnaces, trough concentrating collectors with sun trackers is well established in the art.
U.S. Pat No. 4,315,163 describes a multi-power electrical system for supplying electrical energy to a house including a solar photovoltaic array, a battery charger and DC to AC inverter. U.S. Pat No. 4,147,157 describes an active solar energy system comprising an array of solar collectors for both generating power for a pump and for heating a fluid, a pumping device powered by the array to circulate the heated fluid and a storage tank to contain the heated fluid. Similarly, U.S. Pat No. 5,293,447 describes a system for heating water using solar energy comprising a photovoltaic array, a water heater and a controller. Systems have also been proposed for simultaneously converting solar energy to thermal and electrical. For example, U.S. Pat No. 4,392,008 describes a flat plated solar thermal collector below and in spaced conductive relationship to a plate-mounted array of photovoltaic cells. U.S. Pat No. 5,522,944 describes an apparatus with an array of photovoltaic cells and a plurality of interconnected heat collecting tubes disposed on the same plane with the array. Other systems attempting to optimize electrical energy conversion and provide conversion to thermal energy from solar energy have been proposed. For example, U.S. Pat No. 4,373,308 describes a solar cell array consisting of individually rotatable, elongated segments driven by a sun tracker and motor with a thermal solar collector supported beneath the solar cell array for utilization of solar energy received through a roof opening in a building. U.S. Pat No. 6,018,123 describes a solar cell module provided at the position of a heat collecting plate inside a heat collector in which hot air can be led into a house while maintaining the performance of solar cells.
S6630622 discloses an apparatus for converting solar energy to thermal and electrical energy including a photovoltaic grid for converting the concentrated solar energy into electrical energy mounted on a copper plate that provides even temperature dispersion across the plate and acts as a thermal radiator when the apparatus is used in the radiant cooling mode; and a plurality of interconnected heat transfer tubes located within the enclosure and disposed on the plane below the copper plate but conductively coupled to the copper plate for converting the solar energy to thermal energy in a fluid disposed within the heat transfer tubes. Fresnel lenses are affixed to the apparatus on mountings for concentrating the solar energy on to the photovoltaic grid and functioning as a passive solar tracker
UvS6994082 discloses a lightweight solar concentrator of the reflecting parabolic or trough type that is realized via a thin reflecting film, an inflatable structure! nousing and tensioned fibers. The reflector element itself is a thin, flexible reflecting sheet or film. The film is maintained in the parabolic trough shape by means of a plurality of identical tensioned fibers arranged to be parallel to the longitudinal axis of the parabola. Fiber ends are terminated in two identical spaced anchor plates, each containing a plurality of holes which lie on the desired parabolic contour. In a preferred embodiment, these fibers are arrayed in pairs with one fiber contacting the front side of the reflecting film and the other contacting the back side of the reflecting film; The reflective surface is thereby siidably captured between arrays of fibers which control the shape and position of the reflective film. Gas pressure in the inflatable housing generates fiber tension to achieve a truer parabolic shape.
US5058565 discloses a solar concentrator device. The device includes a solar concentrating panel having a longitudinal axis and defining a parabolic surface having a focal line substantially parallel to its longitudinal axis. The parabolic surface terminates in opposed longitudinal side edges. A mechanism is provided for rotating the panel about its longitudinal axis. Finally, an arrangement provides
torsional support for the panel and includes a frame structure aligned obliquely to the longitudinal axis and extending between the opposed longitudinal side edges of the parabolic surface.
US6653551 discloses a stationary solar photovoltaic array module design, which constitutes four steps of optical concentrations of photovoltaic electric power generation systems. A compound parabolic concentrator (CPC) is mounted under a first and second optical concentrating fresnel lenses that concentrates the intensity of sunlight. Then the focused sunlight is further concentrated twenty limes by the third optical concentrator CPC. The high mirror quality of CPC allows 98% of the reflected rays to be focused at the bottom of the CPC. At this point, the intensified sunlight is homogenized as it passes through a fourth optical concentrator glass lens, which with anti-reflection coating on the top of the glass lens' surface, incident on the multi-junction solar cell accomplish the fourth optica! concentration for the photovoltaic electric energy conversion
However, there is an unmet need in the art for improvements to optimiize systems that convert solar energy to both thermal and electrical energy efficiently.
BRIEF SUMMARY OF THE INVENTION
The invention concerns a system for generating electric power from solar energy. The invention makes use of a solar parabolic trough reflector with single axis tracking concentrating sunlight onto a hybrid solar PV/solar thermal receiver at the axis of the trough. The receptor consists of a linear solar PV array at the point of focus where it experiences insulation of 40x suns, mounted onto a heat sink structure that incorporates solar thermal collectors to either side of the point of focus, at which they experience insulation of 10-20x suns. The integrated heat sink also provides the necessary cooling for the PV ceils mounted in the linear solar PV array. The trough itself is manufactured from injection moulded HOPE, coated in an adhesive mirror surface, in order to minimize cost and weight, whilst maintaining overall system efficiency. Tracking is provided by a single azimuth
slew drive, controlled by a PLC, ensuring that the reflector tracks the sun consistently through the day.
Each Low Cost Linear Concentrated Hybrid Solar Energy System (LCLCHSES) assembly consist of two key components; a reflective parabolic tracking mirror panel and hybrid solar PV/solar thermal receivers at the focal point of the parabolic reflector. In addition each LCLCHSES assembly will require tracking, control, power off take and thermal fluid circulation systems. Multiple LCLCHSES assemblies in a standard length of 4.2 meters will be mechanically coupled using features built into the mirror design to form arrays of up to 20m in length with adjacent units sharing mounting and tracking hardware. Multiple columns will be installed side by side to create solar PV fields to the required size.
According to one of the embodiments, the invention uses an injection moulded HOPE or plastic structure for the parabolic reflector in order to reduce cost and weight compared to conventional metal structures, whilst retaining structural rigidity. Further, a film reflective coating is used to provide the mirrored surface, rather than a conventional mirror, to reduce cost and weight whilst retaining reflective efficiency.
According to another embodiment, the system is having an integrated extruded structure for thermal energy receivers and heat sink and whereas the solar PV/solar thermal receiver device includes a photovoltaic array and thermal energy receivers mounted on heat sink which forms part of a cooling system for the photovoltaic array.
In yet another embodiment, solar thermal receivers are set to either side of the solar PV receiver, thus displaced sideways from the focal point of the parabolic reflector, to take advantage of the intense heat at either side of the point of focus to provide thermal energy outputs in addition to the electrical output from the
solar PV receiver, increasing total energy capture efficiency. Thermal fluid flows through the solar thermal receiver and the heat sink structure on which the solar PV receivers are mounted to provide cooling to the PV cells so as to avoid overheating.
In yet another embodiment, a lightweight aluminum tubular structure at the centre of rotation of the parabolic trough in order to provide a point of connection for the single axis tracking system, the mounting point for the hybrid solar array, to allow interconnection to adjoining assemblies and to provide longitudinal rigidity for the overall assembly.
In yet another embodiment, a single axis tracking system to improve efficiency compared to a fixed panel array, utilizing a single azimuth slewing drive connected to the aluminum tubular structure at the centre of rotation of the parabolic trough.
In yet another embodiment, a concentrated linear PV cell array based on Laser Grooved Buried Contact (LGBC) PV cells capable of providing up to 40X concentration and average efficiency of 18.5%, mounted in an integrated solar PV receiver assembly.
In yet another embodiment, integrated connectors are used to assemble individual solar system assemblies of 4.2 meters in length into combined arrays of up to 25.2m in length controlled by using a single slewing drive and PLC.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Figure 1: General arrangement: shows overall configuration of the LCLCHSES as deployed
, Figure 2: Hybrid receiver: shows the configuration of the hybrid receiver Assembly, with the solar PV receiver assembly top centre, with solar thermal receivers to each side and an integral heat sink/chassis assembly to the base and centre.
Figure 3: Hybrid receiver - PV detail: shows solar PV receivers mounted along the hybrid receiver chassis, with bus bar connectors and heat sink and with solar thermal receivers mounted to either side
Figure 4: Solar thermal receiver: shows detail of the solar thermal receivers, with absorber channels and heat transfer channels incorporated in to the form of the extrusion, with associated end caps and connectors
Figure 5: Mirror assembly: shows arrangement of HOPE moulded mirror chassis incorporating longitudinal and transverse frames, single axis rotation drive axle and supporting a bonded film mirror surface
Figure 6: Tracking assembly: shows mounting arrangements for the single axis electric slewing drive and bearing assembly, which together allow the mirror assemblies to track the path of the sun in a single azimuth tracking arrangement.
, Figure 7: Pylon and bearing detail: shows the means of mounting each end of a mirror assembly and supporting it whilst allowing it to rotate as directed by the single axis tracking arrangement as described above. Also shows the means of mounting a series of individual LCLGHSES assemblies so as to form an array of the required length whilst allowing single axis rotation of the entire array and allowing for some amount of misalignment over rough ground
DETAILED DESCRIPTION OF THE INVENTION
Low Cost Linear Concentrated Hybrid Solar Energy System (LCLCHSES) comprises of a parabolic trough reflector with single axis tracking, concentrating sunlight onto a hybrid solar PV/solar thermal receiver at the axis of the trough. The hybrid receiver consists of a linear solar PV receiver at the point of focus where it experiences insolation equivalent to 40-50x suns, mounted onto a heat sink structure that incorporates solar thermal receivers to either side of the line of focus, at which location they experience insulation equivalent to 10-20x suns. The heat sink also provides the necessary cooling for the PV cells mounted in the solar PV receiver. The trough itself is manufactured from injection moulded HOPE, onto which is bonded a mirror film surface, this combination minimizing both cost and weight, whilst maintaining overall system efficiency. Tracking is provided by a single axis electrical azimuth slewing drive, controlled by a PLC (programmable logic controller), ensuring that the reflector tracks the sun consistently throughout the day.
Now referring to figurel and figure2, the mirror assembly (1) consists of a parabolic reflector (2) to reflect incident radiation from the sun and is configured such that the chosen angle of incidence, the centre of curvature and the radius of the mirror surface result in an equivalent radiation of 40-50 suns at the focal line of the mirror (3).
The mirror assembly (1) consists of a HOPE structural chassis (4) with longitudinal and transverse sub frames to provide the required torsional stiffness. The mirror surface consists of a bonded film mirror (5) applied to the front surface of the mirror assembly. The mirror assembly is designed to optimize optical and reflective efficiency whilst minimizing weight and cost. At the focal line of the mirror (3), mounted on four supporting arms (6), is a hybrid solar receiver assembly (7) incorporating a solar PV receiver (8) at the point of maximum incident solar radiation, to generate electricity, and two solar thermal receivers (9) to either side of the point of maximum solar radiation, to extract thermal
energy. The two solar thermal receivers, together with the heat sink assembly (10) that provides cooling for the solar PV receiver (8), form an integral unit, providing a mounting chassis for the solar PV receiver (8) and lending the whole structural rigidity, as well as providing points of connection to the supporting arms (6). The mirror assembly (1) is rotated about its axis of rotation by means of an eiectrically driven single axis tracking assembly (11) that is programmed to slowly rotate the array so as to accurately follow the sun's path during the day. In so doing, the energy collection efficiency of the system is greatly improved over that of a non-tracking system. The motor in the single axis tracking assembly and its point of attachment to the central axle will be of sufficient power and physical strength to allow up to 6 mirror assemblies formed into a single array to be controlled by a single tracking assembly. The tracking assembly (11) is controlled by a remotely mounted central controller (12) that, with the aid of a solar position algorithm, electronically directs the tracking assembly to precisely position the parabolic mirror assembly for maximum solar capture. The central controller (12) can also stow the mirror assembly when a preset wind speed is reached. The central controller is connected to the tracking assembly (11) by means of a USB network connection.
The supporting pylons (13) and their associated means of bearing the load of the mirror assemblies are designed to provide unhindered rotation of the mirror assembly around its axis of rotation through a total of 240 degrees, whilst allowing for some misalignment (due to possible unevenness of the ground on which the arrays are located or poor installation). Array connectors (14 and 44) allow for mechanical interconnection of up to 6 mirror assemblies each of up to 4,2 meters in length to form a single mirror array of up to 25.2 meters in length (although the effective length of the mirrors themselves is just 24 meters due to tne space taken by supporting structures and the tracking drives).
An electrical connection (15) runs from one end of the solar PV receiver (8) in an
armoured cable of a suitable specification along one of the two end supporting arms (6) to a junction box (16) mounted on a supporting pylon (13). Connections to the solar PV receiver (8) are made by way of locking multi pin quick connectors. Junction boxes (16) for each individual assembly in the array are interconnected, with a single electrical output to an inverter and power control unit.
A thermal fluid pipe (17) carries cold thermal liquid into the solar thermal receiver (9) by means of a connector, with the pipe running along one of the end supporting arms (4) and then down to the main cold thermal liquid supply pipe (18) running in close proximity to the unit. Another thermal liquid pipe (19) carries heated thermal liquid from the solar thermal receiver (9) by means of a connector, with the pipe running along the one of the two supporting arms (6) and then down to main thermal liquid return pipe (20) running in close proximity to the unit. Connections to the solar thermal receiver (9) are made by way of locking connectors. Both thermal liquid pipes consist of flexible armoured hoses. Thermal liquid is circulated in both the cold and hot sides of the system by a single circulating pump (20). The pump is controlled by a system controller (21) that monitors flow rate, outlet temperature and inlet temperature. In the event that the return temperature fails below a given set point, the flow rate is reduced. If it increases above the set point, the flow rate is increased. If it exceeds the set point by a preset amount, a bypass valve is opened and additional cool thermal liquid is added to the circuit.
Referring to' diagrams 2, 3 and 4, the hybrid solar receiver assembly (7) consists of a centrally mounted solar PV receiver (8), bonded to the integrated Chassis/Heat sink assembly (10) using thermally conducting adhesive (22) Extensions to the integrated Chassis/Heat sink assembly (10) form the two solar thermal receivers (9) to either side of the solar PV receiver (8).
The solar PV receiver (8) consists of a receiver mounting (23) onto which is mounted a medium concentration solar PV cell (24) suitable for 40-50 suns concentration, together with ancillary components and connectors as described later. A number of receivers, each providing an electrical output from the PV cell mounted on it, are connected by means of an electrical bus bar (25) surface mounted lengthwise along the hybrid solar receiver assembly (7). The solar PV receivers are mounted onto the heat sink (10) as described above, in order to remove excess heat from the solar PV cells (24). Excess heat would otherwise reduce efficiency and cell longevity.
The top surfaces of the solar thermal receivers (9) are grooved, with the internal surfaces of the grooves being covered in a reflective coating (26). The angles of the grooves are cut so as to create an optical funnel to concentrate incident solar radiation onto the non reflective heat absorbing coating surfaces (27) at the bottom of the grooves. The same non reflective heat absorbing coating is also used on the top surface of the grooved area and on the outward facing side of the solar thermal receiver. The heat generated by the absorption of the incident solar radiation is itself absorbed by the heat transfer fluid flowing through the heat transfer ducts (23) underneath the grooved area. Use of non reflective heat absorbing coatings (27) on all surfaces expect the internal surfaces of the grooves (24) maximizes heat retention and absorption by the heat transfer fluid.
The two solar thermal receivers (9) and the heat sink (10) are an integrated unit to be formed from a single metal extrusion (28). Within the extrusion are multiplicities of heat transfer ducts (23) that carry the thermal liquid along the length of the solar thermal receivers (9) and the heat sink (10) and back again, thus increasing dwell time within the system in order to maximize heat absorption and also allowing entry and exit of the heat transfer fluid at the same end. Arrangements will be made for the connection of inflow and outflow lines to the main thermal fluid circulation system by way of flexible armoured hoses and
watertight locking connectors attached to an end cap/connector block (29) at one end of the solar thermal receiver (9). At the other end of the receiver will be a sealed end cap fitting (30) that closes off the heat transfer ducts in pairs and which allows the heat transfer fluid to return to the end of the receiver at which it originally entered.
Referring to Diagram 5: The parabolic mirror assembly (1) consists of a single piece injection moulded structure (31) into which are incorporated transverse frames (32) and longitudinal frames (33) in order to give the mirror the necessary torsional rigidity. The structure will be manufactured using a molding into which High Density Polyethylene (HDPE) or a suitable recycled equivalent is injected under pressure. As a lack of stiffness would degrade the optical efficiency of the mirror, and therefore the overall energy conversion efficiency of the system, and as a single molding of the size proposed may not be able provide sufficient stiffness, a series of smaller moldings may be utilized, these moldings being combined into a single rigid assembly by through bolting.
The parabolic mirror assembly (1) will be coated using a bonded mirror film surface (2) to achieve a target optical efficiency in excess of 77%. The mirror film material will be ReflecTech Mirror Film. This will be bonded directly onto the HDPE injection moulded structure.
A single axis rotation drive axle (34) consisting of a hollow aluminum tube will pass through holes cut in the transverse frames, so as to place the tube in the intended axis of rotation of the mirror assembly (1). Physical connection between the mirror assembly (1) and the single axis rotation drive axle (34) will be by way of bearing plates (35) mechanically attached to the axle and the transverse frames of the mirror assembly by way of a number of through bolts (36).
Referring to diagram 6: As outlined previously, the mirror assembly (1) is rotated about its axis of rotation by means of an electrically driven single axis tracking assembly (11) consisting of a suitably specified electronically driven slewing drive (37) with zero backlash and self locking, capable of tracking accuracy of +/-1 mrad with a range of travel of -60 degrees to +180 degrees. The electric motor for the slewing drive shall be weatherproof. Motor drive and motor control will be by way of 120 or 240 volt AC single phase connection.
The electronically driven slewing drive (37) shall be connected to the single axis rotation by means of a. thrust plate (38). The thrust plate shall be connected to Doth the electronically driven slewing drive and the single axis rotation axle by means of through bolting as shown (39). The electronically driven slewing drive (37) shall be load bearing. The electronically driven slewing drive (37) shall have sufficient torque so as to be able to control up to 6 individual mirror assemblies in an array of up to 25.2 meters in length at wind speeds of up to 130km/h.
The electronically driven slewing drive (37) shall be controlled by a remotely mounted central controller (12) that can, with the aid of a solar position algorithm, electronically direct the tracking assembly to precisely position the parabolic mirror assembly for maximum solar capture. The central controller (12) can also stow the mirror assembly when a preset wind speed is reached. The central controller is connected to the tracking assembly (11) by means of a USB network connection. The electrically driven single axis tracking assembly (11) shall be rigidly mounted on to the top of a supporting pylon (13). Each pylon (13) shall be properly mounted on a secure concrete foundation using a minimum of 4 bolts. so as to give the structure the necessary stability and rigidity in all expected weather conditions.
Referring to Diagram7; the load bearing surface for the mirror assemblies (1) is formed by a pair of self aligning bearings (40) mounted onto a bearing mounting
plate (41) which is itself secured to the pylon (13) by way of the pylon top plate (42). Selection of a properly specified self aligning ball bearing assembly will allow for misalignment.of up to 3 degrees. It is important that the interaction between the self aligning bearings and the single axis rotation axle (43) shall minimize any lateral movement of the mirror assemblies. Individual mirror assemblies (1) can be formed into Mirror Arrays by way of Array connectors (44). The Array Connectors consist of an opposing pair of splines at either end of each individual single axis rotation axle. In order to reduce friction, the bearing surfaces of the splines shall be Delryn coated.
LCLCHSES shall find its application in, utility scale installations, off grid distributed power installations and commercial and industrial installations in developing countries: The benefits of LCLCHSES to end users will come from enhanced energy avaifability at a reduced cost through the use of innovative design to provide solar energy at low cost by Integrating solar PV and solar thermal in a hybrid system to maximize total energy collection and conversion efficiency, reducing assembled system weight significantly, thus reducing costs associated with tracking and control systems, allowing easier handling and installation, and reducing roof top loadings, ability to manufacture using recycled materials where possible, for instance in the reflector assembly, ability to optimize for local manufacture, providing ease of installation and minimizing life time costs through low ongoing maintenance requirements.
in as much as the present invention is subject to many variations, modifications and changes in detail, it is intended that all subject matter discussed above or shown in the accompanying drawings be interpreted as illustrative only and not be taken in a limiting sense.

We Claim:
1. A low cost linear concentrated hybrid solar system comprising of a parabolic trough reflector with single axis tracking, concentrating sunlight on to PV/solar thermal receivers at the axis of the trough and the said hybrid receiver consists of a linear solar PV receiver at the point of focus and solar thermal receivers to either side of the point of focus, mounted onto a heat sink structure, the said heat sink also providing the necessary cooling for the PV cells mounted in the linear solar PV receiver wherein the trough itself is manufactured from injection moulded HOPE or plastic, onto which is bonded a mirror film surface, in order to minimize cost and weight, whilst improving overall system efficiency.
2. The solar system as claimed in claim 1 wherein the system is having an integral extruded unit for the solar thermal receivers, together with the heat sink assembly that provides cooling and mounting for the solar PV receiver.
3 The solar system as claimed in claim [1] wherein the hybrid solar PV solar thermal receiver device lies at the axis of the parabolic trough and the receiver consists of a linear solar PV receiver at the point of focus where it experiences insolation of 40x suns and two linear solar thermal receivers, one mounted to either side of the linear solar PV receiver, at which location they experience insolation of 10-20x suns.
4. The solar system as claimed in claim [1] wherein the said iineai solar PV/solar receiver assembly consists of the two solar thermal receivers mounted on a heat sink that also provides the necessary cooling for the PV cells as well as providing the physical structure for the hybrid solar system.
5. The solar system as claimed in claim [1] wherein hybrid solar PV/solar thermal receiver device will incorporate a linear concentrated solar PV receiver
assembly at the focus point of the reflector and consisting of a linearly arranged series of Laser Grooved Burled Contact (LGBC) medium concentration PV cells optimized for 40-50x suns, each mounted onto a receiver board, with the necessary connections and bypass diodes to form a PV receiver assembly whereas each receiver assembly will measure 100mm x 100mm, taking into account necessary separation between cells and each array will incorporate up to 40 receiver assemblies.
6. The solar system as claimed in claim [1] wherein each hybrid solar PV/solar thermal receivers are grooved and coated in a non reflective heat absorbing coating, mounted to either side of the central linear concentrated PV receiver and thermal fluid flowing through aluminum extruded multiple channels having connectors provided at each end to allow the ingress and egress of thermal fluid.
7. The solar system as claimed in claim [6] wherein grooves cut Into the surface of the solar thermal receivers form mini light tunnels to focus Incoming sunlight onto the non reflecting heat absorbing coating at the base of each
groove.
8. The solar system as claimed in claim [1] wherein each PV/thermal receiver assembly will be mounted using thermally conductive adhesive onto a structural heat sink that runs along the line of focus of the parabolic reflector so as to dissipate heat from the PV cells and their associated receiver assemblies and the said heat sink also provides a mounting point for the two solar thermal receivers.
9. The solar system as claimed in claim [1] wherein the two solar thermal receivers and the heat sink are an integrated unit to be formed from a single .metal extrusion (28) having multiplicities of heat transfer ducts (23) that carry the
heat transfer liquid along the length of the solar thermal receivers and the heat sink .
10. The solar system as claimed in claim [1] wherein each heat sink comprises of an aluminum or light material extrusion containing multiple channels through which thermal fluid is able to flow and connectors are provided at each end to allow the ingress and egress of thermal fluid.
11. The solar system as claimed in claim [1] wherein the parabolic mirror assembly is in single piece injection moulded element using HOPE or recycled plastics, through which runs a single alloy tube at centre of the axis of rotation, mechanically bonded to the sub structure, providing both the mechanical pivot in conjunction with the support frames at each end of the array and the means of controlling elevation in conjunction with the single axis tracking system.
12. The solar system as claimed in claim [1] wherein the tracking system is provided by a single axis electrical azimuth slewing drive, controlled by a programmable logic controller (PLC), ensuring that the reflector tracks the sun consistently throughout the day.
13. The solar system as claimed in claim [1] wherein mirror assemblies of 4.2m in length and combined in arrays of up to 25.2m in length will be provided with single axis tracking using a single azimuth slewing drive connected to the aluminum tubular structure at the centre of rotation of the parabolic trough.
14. The solar system as claimed in claim [1] wherein each solar array will be served by a small thermal fluid circulating pump with associated pipe work so as to circulate thermal fluid through the heat sink and solar thermal receivers.
15. The solar system as claimed in claim [1] wherein fluid flow rate through the system will be determined automatically by the PLC and temperature sensors in the PV receiver assemblies thereby maintaining a near constant temperature within the receiver assemblies.
16. The solar system as claimed in claim [1] wherein each array (or senes of arrays) will be controlled by a PLC (programmable logic controller) responsible for ensuring that the reflector tracks the sun consistently throughout the day, for maintaining temperatures in the PV cells by regulating thermal fluid flows, and for protecting the assembly in extreme climatic conditions (heat, wind).
17. The solar system as claimed in claim [1] wherein each array will be mounted on variable length adjustable height pylons incorporating self aligning beanngs to enable the arrays to be mounted on rough or uneven ground or rooftops whilst avoiding unnecessary friction due to misalignment.
18. A method for manufacturing low cost linear concentrated hybrid solar system wherein an integrated parabolic mirror assembly, consists of an injection molded HOPE structure for the parabolic mirror and an adhesive mirror coating in conjunction with the HOPE structure to create a low cost, lightweight, low maintenance assembly.
19. A method for manufacturing solar system wherein an integrated injection molded HOPE or plastic structure for a photovoltaic array, PV/Thermal receivers and heat sink, which incorporates solar thermal receivers to either side of the line of focus and the said heat sink also provides the necessary cooling for the PV cells mounted in the linear solar PV array, is formed.
20. A method of manufacturing solar system as claimed in claim [18] wherein integrated photovoltaic array, PV/Thermal receptors and heat sink provides for an integrated mounting and energy collection structure.
21. A method of joining individual solar assemblies into a rigid array using interlocking connectors at the end of each individual assembly, allowing multiple assemblies to be connected together as a single array and controlled by using just one single axis tracking device wherein adjustable height pylons and self aligning bearings enable arrays to be mounted on rough or uneven ground or rooftops whilst avoiding unnecessary friction due to misalignment.
22. A method as claimed in claim 20 wherein individual assemblies may be interlocked through the connectors at the end of each individual assembly, allowing multiple assemblies to be connected together and controlled using just one single axis tracking device to control arrays of up to 25.2m in length.
23. The method as claimed in claim 17 and 18 wherein injection molded HOPE can be lightweight and cheap to produce, whilst offering sufficient structural rigidity, provided that individual assembly may not exceed a maximum of around 4.2m in length and 1.6m in breadth.
24. The method as claimed in claim 17 wherein the adhesive mirror coating applied to the injection moulded HOPE structure to provide a parabolic reflector is capable of delivering 40-50x suns at the focal point.
25. The hybrid solar system and method of manufacturing thereof substantially as herein described with reference to the accompanying drawings.