Patent Publication Number: US-2011067747-A1

Title: Photovoltaic device and power module

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to power generation devices, and more particularly, to a concentrated photovoltaic module. 
     2. Description of Related Art 
     In conjunction with the rapid residential, commercial and industrial development, fossil fuels are gradually running out, and greenhouse gas emissions are becoming a global concern. Hence, providing a stable energy supply is becoming a global challenge. Compared with conventional coal-fired, gas-fired or nuclear power generation, solar cells directly convert solar energy into electricity through the photoelectric effect without generating any greenhouse gases or pollutants such as carbon dioxide, nitrogen oxides and sulfur oxides. Moreover, solar cells are helpful to reduce human beings&#39; dependence on fossil fuels and provide safe, self-contained power sources. 
     Referring to  FIG. 4 , a conventional concentrated photovoltaic module  9  at least comprises a hollow-shaped receiving unit  90 , a lens  91  disposed on the receiving unit  90 , and a solar cell assembly  92  disposed at the bottom of the receiving unit  90  and corresponding in position to the lens  91 . When the sun is shining thereon, the lens  91  focuses the sunlight on the solar cell assembly  92 , thereby outputting electric energy. 
     The receiving unit  90  of the conventional concentrated photovoltaic module  9  is hermetically sealed to prevent foreign bodies or dust from entering the receiving unit  90 . However, water vapor left behind in the receiving unit  90  during the assembly process ends up being confined in the receiving unit  90 , and can thereby compromise the photoelectric conversion otherwise enabled by the solar cell assembly  92 , thereby reducing the conversion efficiency and shortening the service life of the concentrated photovoltaic module. 
     Therefore, it is imperative to overcome this drawback of the prior art, that is, the failure to prevent water vapor from compromising photoelectric conversion. 
     SUMMARY OF THE INVENTION 
     To overcome the above drawback, the present invention provides a concentrated photovoltaic module, which comprises: a carrier formed of a plurality of rods connected with each other, the rods defining a plurality of side areas, a top area and a bottom area of the carrier; a plurality of side plates covering the side areas, respectively, and coupled to the carrier, the side plates having a plurality of openings; and a light-collecting unit comprising a lens assembly disposed above the carrier and a solar cell assembly disposed below the carrier and corresponding in position to the lens assembly, a receiving space being defined and formed by the light-collecting unit and the side plates such that sunlight is focused on the solar cell assembly by means of the lens assembly and air is discharged from the receiving space through the openings of the side plates. Preferably, the solar cell assembly is further provided with a plurality of through holes. 
     Preferably, the side areas, the top area, and the bottom area of the carrier are of a rectangular shape. 
     According to an embodiment, the lens assembly has a plurality of concave portions and the corresponding rods have a plurality of protruding portions for engaging with the concave portions. Alternatively, the lens assembly has a plurality of protruding portions and the corresponding rods have a plurality of concave portions for engaging with the protruding portions. 
     The rods are extruded aluminum rods, and the side plates are made of plastic. 
     Each of the openings has at least a bend, and the bend has a sag for preventing incoming dust from reaching the receiving space. Since the side plates are made of plastic, the total weight of the concentrated photovoltaic module can be reduced and the bend-equipped openings can be easily formed. Each of the openings has a dust collector, and each of the openings is covered with a filtering member. 
     The concentrated photovoltaic module is further provided with a plurality of through holes, wherein each of the through holes has at least a bend, and the bend has a sag for preventing incoming dust from reaching the receiving space. Each of the through holes has a dust collector. 
     Each of the through holes is covered with a filtering member. 
     The photovoltaic module further comprises a heat-dissipating member disposed below the solar cell assembly. 
     According to the present invention, water vapor is discharged from the receiving space through the openings of the side plates or the through holes of the solar cell assembly to thereby prevent the photoelectric conversion taking place in the solar cell assembly from being adversely affected by the water vapor otherwise present in the receiving space, thereby reducing the possibility of damage to the solar cell assembly and prolonging the service life of the concentrated photovoltaic module. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIGS. 1A and 1B  are a perspective diagram and an exploded diagram of a concentrated photovoltaic module of the present invention, respectively; 
         FIGS. 2A and 2B  are partial exploded diagrams showing rods and a light-collecting unit of the concentrated photovoltaic module of  FIGS. 1A ,  1 B; 
         FIGS. 3A ,  3 B and  3 C are partial sectional diagrams of the concentrated photovoltaic module according to different embodiments of the present invention; and 
         FIG. 4  is an exploded diagram showing a conventional concentrated photovoltaic module. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following specific embodiments are provided to illustrate the disclosure of the present invention. These and other advantages and effects will be apparent to those skilled in the art after reading the disclosure of this specification. 
     Referring to  FIGS. 1A and 1B , a concentrated photovoltaic module according to the present invention comprises: a carrier  1  formed from a plurality of rods  10  connected to each other, a plurality of side plates  2  coupled to the carrier  1 , and at least one light-collecting unit  3  comprising a lens assembly  30  and a solar cell assembly  31  and connected to the carrier  1 . 
     The rods  10  of the carrier  1  define a plurality of side areas  10   c  to be covered by the side plates  2 , a top area  10   a  to be covered by the lens assembly  30 , and a bottom area  10   b  to be covered by the solar cell assembly  31 . The rods are made of aluminum or an alloy thereof. The surface of the rods  10  is subjected to sandblasting, anodizing or electrodeposition coating. 
     The side plates  2  are coupled to the rods  10  to thereby cover the side areas  10   c , respectively. The side plates  2  are further formed with a plurality of openings  20  which penetrate the side plates  2 . In addition, the side plates  2  are made of plastic, and are adhered to, screwed to, or engaged with the rods  10  so as to be fixed in position to the carrier  1 . In the present embodiment, the side plates  2  made of plastic weigh less than the carrier  1  made of aluminum, thereby reducing the total weight of the photovoltaic module. 
     In the present embodiment, the carrier  1  is configured to carry two said light-collecting units  3 , by being topped with two said lens assemblies  30  covering the top area  10   a  and bottomed with two said solar cell assemblies  31  covering the bottom area  10   b  and corresponding in position to the lens assemblies  30 , respectively. Thus, a receiving space S is defined and formed by the carrier  1 , the light-collecting units  3  and the side plates  2 . Sunlight is focused on the solar cell assemblies  31  by means of the lens assemblies  30 . Air enters and exits the receiving space S via the openings  20 . 
     In the present embodiment, the carrier  1  is a hexahedron, as the side areas  10   c , the top area  10   a , and the bottom area  10   b  are of a rectangular shape. The rods  10  form an upper frame  1   a  for carrying the lens assemblies  30  and a lower frame  1   b  for carrying the solar cell assemblies  31 . The lens assemblies  30  cover the top area  10   a , and the solar cell assemblies  31  cover the bottom area  10   b . Four said side plates  2  provided between the upper frame  1   a  and the lower frame  1   b  are configured to cover the four adjacent side areas  10   c , respectively. Hence, the lens assemblies  30 , the solar cell assemblies  31 , and the side plates  2  together define a hermetically sealed receiving space S. In other embodiments, the carrier  1  can be of other shapes. 
     In the present embodiment, the openings  20  are formed in the side plates  2  to penetrate the side plates  2 , and thus water vapor can be discharged from the receiving space S. Since water vapor can be discharged from the receiving space S through the openings  20 , photoelectric conversion taking place in the solar cell assembly  31  is unlikely to be adversely affected by the water vapor otherwise present in the receiving space S, thereby reducing the possibility of damaging the solar cell assembly. 
       FIG. 2A  shows a way of connecting two rods  10 ,  10 ′ together. In the present embodiment, two said rods  10 ,  10 ′ are aluminum extruded rods. Two said rods  10 ,  10 ′ are adjacent and perpendicular to each other, and are each provided with a plurality of slots  100 ,  100 ′ extending inward from the surface of each of two said rods  10 ,  10 ′. A nut  11  is disposed in one of the slots  100  of the rod  10 , while a fixing member  12  having a penetrating hole  120  is disposed in one of the slots  100 ′ of the rod  10 ′. A bolt  13  is passed through the penetrating hole  120  of the fixing member  12  to engage with the nut  11 , thereby fastening together two said rods  10 ,  10 ′ that are adjacent and perpendicular to each other. It should be noted that various ways of fastening two said rods  10 ,  10 ′ together exist and are well known in the art, and the above-described disclosure refers to one of the conventional ways of fastening. 
       FIG. 2B  is a partial exploded diagram of the light-collecting unit  30 . The lens assembly  30  has a Fresnel lens  300  and a plurality of protruding portions  301  capable of being inserted into the slots  100  for the lens assembly  30  to be positioned on the rods  10 . In other embodiments, the lens assembly  30  may have concave portions, wherein the rods  10  have corresponding protruding portions for engaging with the concave portions. Moreover, the lens assembly  30  and the rods  10  can be assembled by adhering the lens assembly  30  to the rods  10 , rather than inserting the protruding portions  301  into the slots  100 . Referring to  FIGS. 1B and 2B , the Fresnel lens  300  can be directly integrated with a piece of glass instead of being connected with a piece of glass through a frame  302  as shown in  FIG. 2B . The lens assembly  30  can have a different structure and still serve the same purpose as disclosed in the present invention; hence, the lens assembly  30  is not herein described in detail. 
     The solar cell assembly  31  comprises: a plate member  310  disposed on the carrier  1  and having a plurality of through holes  310   a ; a plurality of insulating substrates  311  disposed on the plate member  310 ; a plurality of light gathering members  312  disposed on the insulating substrates  311 , respectively; a plurality of solar cells  313  disposed inside the light gathering members  312  on the insulating substrates  311 , respectively; and a plurality of heat-dissipating members  314  disposed below the solar cells  313 , respectively. Light beams leaving the lens assembly  30  are focused on the solar cells  313  by means of the light gathering members  312 . It should be noted that the light-collecting unit  3  of the present invention may come in different forms and dimensions as disclosed in the prior art and is not regarded as an essential technical feature of the present invention; hence, the light-collecting unit  3  is not herein described in detail. 
     The through holes  310   a  of the solar cell assembly  31  are configured for removal of air such that photoelectric conversion taking place in the solar cell assembly  31  is unlikely to be adversely affected by water vapor, thereby efficiently reducing the risk of damage occurring to the solar cell assembly  31 . 
       FIGS. 3A ,  3 B and  3 C show the concentrated photovoltaic module according to different embodiments of the present invention. Referring to  FIG. 3A , in this embodiment, each of the openings  20  has at least a bend, and the bend has a sag  200  for holding dust P, thereby preventing entry of the dust P into the receiving space S which might otherwise adversely affect the internal cleanness of the concentrated photovoltaic module. In other embodiments, each of the openings  20  has a dust collector made of an adhesive, for example, such that the dust P can be attached thereto. Referring to  FIG. 3B , each of the openings  20  can be covered with a filtering member  4 , such as a nano-mesh, for preventing relatively large particles of the dust P from entering the openings  20  and the receiving space S, while relatively small particles of the dust P stop at the sag  200  and stay therein. Thus, the aforesaid dustproof effect is enhanced by the dual dustproof mechanisms. 
     Referring to  FIG. 3C , each of the through holes  310   a  has at least a bend, and the bend has a sag  3100  for holding the dust P, thereby preventing the dust P from entering the receiving space S where it might otherwise adversely affect the internal cleanness of the photovoltaic module. In other embodiments, each of the through holes  310   a  has a dust collector made of an adhesive, for example, such that the dust P can be attached thereto. Each of the through holes  310   a  is covered with a filtering member  4  for enhancing the dustproof effect. The above-described filtering member is merely an example and thus can be replaced with filtering members of other types. 
     According to the present invention, the openings of the side plates or the through holes of the solar cell assembly are configured for removal of moisture. As a result, water vapor is discharged from the receiving space through the openings of the side plates or the openings of the solar cell assembly to thereby prevent the photoelectric conversion taking place in the solar cell assembly from being adversely affected by the water vapor otherwise present in the receiving space, thereby reducing the possibility of damage being caused to the solar cell assembly and prolonging the service life of the concentrated photovoltaic module. 
     The above-described descriptions of the detailed embodiments are intended to illustrate the preferred implementation of the present invention but are not intended to limit the scope of the present invention. Accordingly, persons skilled in the art can make many modifications and variations to the embodiments and yet still fall within the scope of present invention as defined by the appended claims.