WO2014060415A1

WO2014060415A1 - Icpvs - an integrated concentration photovoltaics system, an installation comprising the same and a field installment method for the same

Info

Publication number: WO2014060415A1
Application number: PCT/EP2013/071532
Authority: WO
Inventors: Ricard PARDELL VILELLA
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-10-15
Filing date: 2013-10-15
Publication date: 2014-04-24
Anticipated expiration: 2015-04-15

Abstract

The present invention relates to an integrated CPV system (ICPVS), which can be manufactured and tested as a single unit and rapidly deployed on the field without requiring skilled personnel. The integrated CPV system comprises a top assembly and a bottom assembly, wherein the bottom assembly provides for the fixing of the system to the ground, whereas the top assembly comprises a particular support structure for CPV systems. Furthermore, the present invention relates to an installation comprising a plurality of such integrated CPV systems, and to a field installment method for installing said integrated CPV systems.

Description

ICPVS - AN INTEGRATED CONCENTRATION PHQTQVQLTAICS SYSTEM.

AN INSTALLATION COMPRISING THE SAME AND A FIELD INSTALLMENT METHOD FOR THE SAME

TECHNICAL FIELD

[0§1] The present invention relates generally to Concentration Photovoltaic (CPV ) systems and in particular, to an integrated CPV system ( ICPVS ), which can be manufactured and tested as a single unit and rapidly deployed on the field without requiring skilled personnel.

BACKGROUND OF THE INVENTION

[§02] For the commonly deployed high concentration CPV systems, it is mandatory that concentrators are aligned with respect to the sun within a certain optical acceptance angle characteristic to those modules. Therefore, the optical system has some tolerance to trackin deviation. Each CPV technology has an acceptance angle inherent to its design dependent on the concentration ratio and the optical design of the concentration system.

[003] Concentrators are basically composed of a photovoltaic cell onto which solar radiation is concentrated by an optical system. The concentrators are usually integrated into modules, each module comprising a group of concentrators arranged in an array pattern. CPV systems comprise multiple CPV modules mounted on top of a solar tracking structure.

[004] In order for the system to work properly it is necessary that all the modules, and therefore all the concentrators within each module are kept within the design acceptance angle.

[005] Usually, the design of the CPV module has been isolated from the design of the solar tracker, so that each of these critical components is manufactured independently, often by different companies, and system integrati n is done at the latest stage of the value chain: on the field. In this de-integrated approach, system installation basically consists in first erecting the solar tracker structure on the field, and then mounting individual CPV modules on top of that tracking structure.

[006] However, the problem is that field conditions can be very variable, and also the skills of personnel involved in field system integration. This results in multiple disadvantages which can increase the installation costs and reduce the quality and reliability of the integrated system. For example, such systems usually need field alignment of structural elements in order to assure tracking structure co-planarity or individual alignment of mounted modules in order to assure module co-planarity on top of a non co-planar structure. Additional ly, such systems also suffer from tracking structure deformation and unexpected deflections due to assembly or component variability on the field. Moreover, there is a need of integration of multiple tracking components, l ike sensors, motors, drives and a control system, which introduces multiple potential failure points and increases the requirement of skilled manpower on the field.

[007] These systems suffer also the problem of a slow commissioning process as each CPV system must be integrated and tested on the field, which also brings high maintenance costs due to incidences derived from field integration. Many CPV trackers use a fine tuning solar sensor, which is field mounted to the tracking structure. However, the field alignment and calibration of this device is a common source of problems such as installation and maintenance incidences. The fact that modules are field mounted on top of the tracking structures also implies a certain degree of structural redundancy between them.

[008] Besides these problems and disadvantages, this de-integrated deployment approach has been widely adopted by the CPV industry. As a consequence, the systems have been usually built the larger the better, as under this approach there are obvious economies of scale if the number of trackers per MW is minimized, both on the installation and operation phases.

[009] Therefore, a need has been identified to overcome some or all of the problems and disadvantages of the prior art and to provide an integrated concentration photovoltaic system ICPVS, which can be manufactured and tested as a single unit, and which can be rapidly deployed on the field. Furthermore, there is a need of a system with optimized logistics allowing a very efficient transportation from the assembly line to the destination installation site. Finally, there is the need for a very fast to deploy foundation and interconnection system having a low environmental impact, and which could be eventually easy to dismantle.

SUMMARY

[0010] It is therefore an object of the present invention to provide solutions to some or all the above mentioned problems. In accordance with one or more embodiments and corresponding disclosure thereof, various aspects are described in connection with an integrated concentration photovoltaic system ICPVS.

[0011] One embodiment of the present invention provides an integrated concentration photovoltaic system ICPVS.

[0012] Another embodiment of the present invention provides an installation comprising said integrated concentration photovoltaic system ICPVS.

[0013] Yet another embodiment of the present invention provides a field installation method.

[0014] Further aspects of the present invention provide methods and devices that implement various aspects, embodiments and features, and are implemented by various means.

BRIEF DESCRIPTION OF THE DRAWING(S)

[0015] The features and advantages of the present invention become more apparent from the detailed description set forth below when taken in conjunction with the drawings in which l ike reference characters identi y corresponding elements in the different drawings. Corresponding elements may also be referenced using different characters.

[0016] FIG. 1 shows an example integrated CPV system ICPVS according to the present invention.

[0017] FIG. 2 shows an exploded view of the ICPVS of Fig. 1 .

[0018] FIG. 3 shows the inner support structure of the ICPVS of Fig. 1.

[0019] FIG. 4 shows a more detailed view of the implementation of the connection means joinin the inner support structure with the CPV super-modules. [0020] FIGs. 5 and 6 show a more detailed view of means for joining two CPV super- modules to form an ICPVS of FIG. 1 .

[0021] FIG. 7 shows a rear view of the ICPVS of Fig. 1 .

[0022] FIG. 8 shows a cross-sectional view of the ICPVS of the invention.

[0023] FIG. 9 is a general overview of an example ICPVS system installation according to the present inventi n.

[0024] FIGs. 10 to 15 show individual steps of an example field installment method for the ICPVS system of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0025] FIG. 1 shows a frontal view of an integrated concentration photovoltaic system ICPVS of the invention. The ICPVS comprises a top assembly 8 and a bottom assembly 9. The ICPVS further comprises a foundation post 11, which is to be driven into the ground, and which supports on its top the bottom assembly 9. The ICPVS further comprises super- modules containing a plurality of CPV modules, or concentrators, each. Such super-modules are part of the top assembly 8. Most efficient optical concentration systems for the super-modules are based on refractive optics havin an F- number of 1 or higher (being the F number the focal length to aperture ratio of the optical system. Therefore, there is a significant distance between the front side and the back side of each CPV super-module, the distance being proportional to the concentration ratio, the cell size and the optical F-number. This design allows the incorporation, i.e. the integration, of a structural support element (not shown) in the interior of the top assembly for supporting the CPV super-modules. Furthermore, the top assembly 8 is detachably assembled onto the bottom assembly 9 by fixing means, such as bolts (not shown). Hence, top assembly 8 and bottom assembly 9 may be assembled together either at the manufacturing site or at the site where the ICPVS is to be installed.

[0026] FIG. 2 shows the ICPVS in more detail using an exploded view of the afore- described ICPVS comprising said top assembly 8, said bottom assembly 9 and said foundation post 11. As described before, FIG. 2 also shows that the three elements of top assembly 8, bottom assembly 9 and foundation post I I may be detachably assembled one onto another. Hence, it is possible to use the ICPVS as a single unit. wherein top and bottom assembly 8, 9 are attached one onto another, or the ICPVS may be used as two separate units, i.e. top assembly 8 and bottom assembly 9 are not attached one onto another, but are used individual ly.

[0027] Using top and bottom assembly 8, 9 individually, i.e. separated from each other, allows a faster deployment on the installation field improving the logistics thereof. Hence, the top assembly 8, herein a support structure is integrated within the super- modules, may be tested, for example for field al ignment and/or calibration, as a single unit at the manufacturing site while the bottom assembly 9 can already be shi ped to the installation site. Therefore, no skilled personnel may be required in the field other than the construction workers. Hence, installation costs and logistics may be reduced, while the quality and reliability of the ICPVS is increased compared to conventional systems. Due to the increased qual ity and reliabi lity of the ICPVS, maintenance costs may be reduced.

[0028] FIG. 3 shows the ICPVS of FIG. 1 without the super-modules. That is, FIG. 3 shows the interior supporting structure of the top assembly 8 that provides support from within and is integrated into the super-modules. Said interior supporting structure is here shown as attached onto the bottom assembly 9 on top of the foundation post 1 1 . Said interior supporting structure comprises a horizontal support means 2, for example a tube, and a central vertical structural part 3, for example a box. In FIG. 3, the CPV super modules are configured to allow the horizontal tube 2 penetrating and passing through the interior of them (not shown). Preferably, the horizontal tube 2 passes partially through the super modules. As a consequence, this tube 2 acts as a main structural supporting element and also as an elevation pivoting point. Hence, by using the horizontal tube 2 as a main structural supporting element, the ICPVS takes advantage of the empty space inside each super-module 1 and vertical structural elements thereof can rely on the tube 2 itself as main supporting point. Therefore, this design avoids any structural redundancy in the integrated CPV system. This means that the manufacture of the integrated CPV system benefits from this simpl ified design, in that it may be carried out faster and in more economic ways.

[0029] Moreover, the super modules and the supporting structure can be manufactured at the same manufacturing site, so that the integration of these two parts may be carried out as the last step of a manufacturing process resulting in an improved commissioning. [0030] Furthermore, the horizontal tube 2 and the central structural box 3 form together a cross assembly, wherein the tube 2 and the box 3 are orthogonally arranged. Tube 2 and box 3 are arranged in such a way that the cross assembly is located approximately in the center of the top assembly 8. Regarding the central structural box 3, it is preferred that said box 3 is having a rectangular section, as wind forces parallel to the horizontal tube 2 will always be lower than those normal to it. As a consequence, the distance between two super-modules 1 of an ICPVS can be minimized.

[0031] In a preferred aspect of this invention, the horizontal tube 2 may be perforated to allow for at least power and signal cables pass through it (not shown). The horizontal tube 2 and the structural central box 3 may thus be communicated. Furthermore, the perforation of tube 2 may allow also for the communication of the air masses of the two super- modules 1, the horizontal tube 2 and the central box 3. A single passive vent or an active blowing system may be installed inside the structural central box 3, having the advantage of reducing the number of components involved in the internal air management, thus reducing the system cost, the probability of failure and simplifying the maintenance operations.

[0032] Due to the above structural design of the interior basic supporting structure, the two super-modules of each ICPVS rotate in elevation pivoting about horizontal tube 2. In a preferred aspect of this invention, each super-module rotates about tube 2 on polymeric maintenance-free bearings 4. This is shown in more detail in FIG. 4. The horizontal bearings 4 are mounted inside each super-module, which has only one side perforated to allow the penetration of the horizontal tube 2. This perforation may be protected using o-ring seals 5, so that the ensemble of the two super-modules and the inside of the horizontal tube 2 are protected from the environment.

[0033] Therefore, maintenance costs may be reduced or even eliminated for these parts of the ICPVS. The polymeric maintenance-free bearings may have a long zero maintenance duration, i.e. a duration during which substantially no maintenance is required, which may last 25 years.

[0034] As has been described before, the ICPVS of FIG. 1 comprises two super- modules in the top assembly 8. These super-modules are assembled between them by coupling means 7, for example two union brackets 7 a, 7b (the latter thereof not shown in FIG. 1). The arrangement of the union bracket 7a with the two super-modules is shown in more detail in FIG. 5, depicting the front side of the top assembly 8, whereas FIG. 6 illustrates the arrangement of the two super-modules with the union bracket 7b in the back side of the top assembly 8. Said bracket 7a may further comprise a hole 7c, which allows it to be bolted to the central box 3 in order to secure the ICPVS system during transportation. In general, bracket 7b is located over the tube 2. whereas bracket 7a is located below the tube 2. Both brackets mechanical ly l ink the two super-modules and increase the overall stiffness.

[0035] FIG. 7 illustrates a rear view of the ICPVS of FIG. 1. As shown here, the ICPVS may further comprise at the back side of the top assembly 8 a screw or bolt actuator 6, which is used as an elevation drive. One of the elevation actuator's extremes, i.e. a first end, is attached to central box 3. The other elevation actuator's extreme, i.e. a second end, is attached to top union bracket 7b.

[0036] In a further preferred aspect of this invention, the ICPVS comprises additionally a central electrical and communication connection means 10, for example a mast as illustrated in FIG. 8. Said FIG. 8 depicts a cross-sectional view of an example ICPVS of FIG. 1. The central connection mast 10 is guided through the bottom 9 and top assembly 8 of the ICPVS until it exits in the upper part of the top assembly 8, between the two super-modules 1 . In particular, this mast 10 is attached to the fixed part of the bottom assembly 9, solidary to the ground, and passes through the horizontal tube 2 and central structural box 3. In other words, mast 10 is attached to the part of the bottom, assembly 9, which is fixed to the foundation post 1 1 and, thus, united to the ground. The mast 10 exits in the upper part of the top assembly 8 exceeding the height of the super-modules 1 when those are moved in vertical position. Hence, the central connection mast 10 allows for an aerial cable 14 electrical and communications connection without interfering with the super-modules of the top assembly 8. Such an aerial cable 14 for electrical and communication connecti n is advantageous over a terrestrial one, because laying terrestrial cables require additional field work and materials. Therefore, installment of the ICPVS installation of the invention minimizes material and installment time costs and requires additional ly no civil works other than just cleaning and flattening the installati n field.

[§037] With respect to the bottom assembly 9 of the ICPVS of the invention, said assembly 9 comprises a higher rotating part and a fixed lower part (not shown). The lower part will be fixed to the foundation post 1 1 , for example by bolting. In particular, the bottom assembly contains an azimuth drive (not shown). In a preferred aspect of this invention, this part also comprises polymeric m a i n ten ance-free hearings. The azimuth mechanism comp ses a wheel, to which a chain or belt is attached or fastened (not shown). This chain or belt may be actuated by a sprocket or pulley driven by an azimuth motor. All power and control cables are driven down from the top assembly 8 to the bottom assembly 9, where the power and control electronics of the system are placed for better accessibility (not shown). Hence, almost all cables run through the inner part of the ICPVS. Therefore, no cable is visible except the one connected to the elevation actuator 6.

[0038] Hence, maintenance costs may be reduced, since almost all cables are protected from environmental influences. Furthermore, it is not necessary to lay the power and control cables at the instal lation site, since the top assembly already provides them. Instead, the power and control cables only have to be connected accordingly, which reduces installment time and costs.

[0039] FIG. 9 depicts a general view of an ICPVS installation comprising a plurality of the integrated concentration photovoltaics system ICPVS of the present invention. Each ICPVS comprises a top assembly 8 detachably mounted on a bottom assembly 9, wherein the bottom assembly 9 is fixed to the ground 12 by means of a foundation post 1 1 . While the bottom assembly 8 comprises two super-modules containing a plurality of CPV modules, the bottom assembly 9 comprises an azimuth drive (not shown), and a central connection mast 10, which aerially connects the different ICPVS systems by means of an aerial cable 14 for electrical and communications connection. The ICPVS installation can then be connected to a final pole 13, from which underground cables 15 can provide electrical and communication connections to a field bus. Hence, this ICPVS installation is very fast to depl y on the field, can be easi ly interconnected, and involves a low environmental impact. The installation of the invention may even be easily and quickly dismantled if need would be.

[0040] The afore-described ICPVS installation may be instal led in the field as described in the following. FIGs. 10 to 14 show different stages of a field instal lment of the ICPVS of the inventi n. According to FIG. 10, field installment comprises first driving the posts 11 , preferably made of steel, into the ground 12. These posts 1 1 may be I I beams, square tubes or any other suitable profile, which is able to w ithstand not only tilting and radial forces but also torque. Hence, the ICPVS installation may have a solid and stable ground structure providing for a longer l ife-time of the whole installation. An alternative is to use round steer tubes to which several plates had been welded l ike wings. In the drawings of FIGs. 10 to 14 square tubes are shown as an exam le. These posts 11 can be very efficiently installed using mechanized post-driving machines 16 designed for road guard-rail installation.

[0041] According to FIG. 11, once the posts 11 have been driven into the ground, bottom assembl ies 9 may be transported by trucks and bolted on top of posts 11 through attachment plates. In one preferred aspect of this invention, the bottom assemblies 9 are transported by small trucks because of the si/e of said assemblies 9.

[0042] According to FIGs. 12 and 13, the top assemblies 8 may then be shipped on trucks to the field, where they may be picked by cranes and bolted to previously installed bottom assemblies 9. In one aspect of this invention, the transport of the top assemblies 8 is carried out by large trucks. The central cross design of the inner support structure allows the top assemblies 8 to be transported by bolting its bottom part to the truck trailer platform and to be hoisted from the top of central box 3. In this preferred aspect, top and bottom assemblies 8, 9 are used as two separate units which are not united until their installment on the field. This approach provides for optimized logistics, fast commissionin and a very efficient transport of the individual assemblies 8 and 9 from the assembling line at the manufacturing site to the destination installation site. Moreover, the assemblies 8 and 9 when separated may be installed or dismantled on field more quickly. Not desired to be bound to any theory, it is estimated that this approach allows the installment of 1 MW of solar power per day using a small field team of, for example, just 10 people.

[0043] According to FIG. 14, grid connection is done using an aerial cable 14 running through the top of each central connection mast 1 0, thereby completing the installation, which is shown in one way of exam le in FIG. 15. The individual systems are normally interconnected in the north-south direction, makin strings of several systems which are connected to at least one final pole 13 from which underground cables 1 5 can be connected to a field bus to provide electrical and communication connections (see FIG. 1). This aerial connection system minimizes material and installment time costs com ared to an underground solution. It further requires no civil works other than just cleaning and flattening the field. The installment process of the invention minimizes the usage of skilled personnel on the field and allows industrialized, fast, repeatable and error free installment and commissioning tasks. [0044] It is to be understood by the skilled person in the art that the various embodiments, realizations, and aspects of the invention have been so drafted with the aim of disclosing the invention in a concise manner. This does not mean that the intention is to limit the scope of the disclosure to the precise combination of embodiments, realizations, and aspects as drafted. On the other hand, the intention is that the different features of the inventive concepts described may be readily understood to be combinable as would be derived from a clear and objective reading of the disclosure by one of ordinary skil l in the art.

[0045] Those skilled in the art should appreciate that the foregoing discussion of one or more embodiments does not l imit the present invention, nor do the accompanying figures. Rather, the present invention is limited only by the following claims.

Claims

1. An integrated concentration photovoltaic system ICPVS comprising: a top assembly comprising two super modules, each comprising a plurality of

CPV concentrators; both super modules being attached together making up a single structure pivoting in elevation on a horizontal support tube, this horizontal tube being fixed to a vertical structural element, both configuring a cross shape arrangement, wherein both super-modules are perforated on one side allowing the penetration of the horizontal tube; and

a bottom assembly supporting the top assembly and allowing its azimuth rotation, being the lower part thereof fixed to the ground and the upper part thereof attached to the top assembly.

2. The system of claim 1, wherein said perforation of the two super- modules is protected by o-ring seals;

3. The system of claim 2, wherein each super module comprises polymeric maintenance-free horizontal bearings allowing rotation about the horizontal tube.

4. The system of claim 2, wherein the vertical structural element has a rectangular section.

5. The system of claim 2, wherein the horizontal tube is perforated, being the inside of the horizontal tube in communication with the inside of the vertical structural element and to the inside of each of the two super-modules, allowing for unified air management and at least power and signal cables to run horizontally through the tube and downwards through the vertical structural element, enabling electrical and communication connection thereof.

6. The system of claim 2, further comprising two union brackets configured to assemble the two super- modules, wherein one of the brackets comprises a hole configured to attach both super-modules to the central structural box during transportation.

7. The system of claim 2, further comprising a central connection mast attached to the fixed part of the bottom assembly, and thus being solidary to the ground, wherein said central connection mast passes vertically through the interior of the vertical structural element and the horizontal tube and protrudes in the upper part of the top assembly, configured for aerial electrical and communication connection of a plural ity of ICPVS systems.

8. The system of claim 2, wherein the bottom assembly is configured to be detachably connectable to the top assembly.

9. The system of claim 8, wherein the bottom assembly comprises:

a higher rotating part driven by an azimuth mechanism; and

a fi ed lower part configured to be fi ed to a foundation post.

10. The system of claim 9, wherein the bottom assembly further comprises the power and control electronics of the ICPVS system.

1 1 . The system of claim 10, further comprisin dri vin posts, which are selected from the group comprising I I beams, square tubes or round tubes.

12. The system of claim 2, further comprising a screw or bolt actuator.

13. The system of claim 2, wherein the plural ity of CPV concentrators of the two super modules is a plurality of optical concentration systems arranged in an array system.

14. An installati n comprising a plurality of the integrated concentrati n photovoltaics system ICPVS according to claim 1 .

15. The installation of claim 14 comprising at least one aerial cable running through the top of each central connection mast for allowing grid connection of the individual integrated concentration photovoltaics system ICPVS. wherein the grid connection comprises a final pole configured to connect the whole grid to the exterior.

16. An ICPVS field installment method, the method comprising the steps of: driving a plurality of foundation posts into the ground;

attaching one bottom assembly on top of each foundation post; and

attaching one top assembly according to claim 1 on each bottom assembly to form an installation comprising a plural ity of integrated concentration photovoltaics system ICPVS. The method of claim 16, comprising further the steps of:

connecting each top assembl y by at least one aerial cable to form a grid connection, wherein said grid connection comprises a final pole configured to connect the whole grid to the exterior.