Patent Publication Number: US-2015059852-A1

Title: Flexible photovoltaic apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This utility application claims priority to Taiwan Application Serial Number 102216203, filed Aug. 29, 2013, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a flexible photovoltaic apparatus, and in particular, to the flexible photovoltaic apparatus which can be easily designed and integrated into daily necessities and has high flexibility. 
     2. Description of the Prior Art 
     Current flexible photovoltaic apparatus includes an amorphous silicon or micro-crystalline silicon (μ-Si) thin film photovoltaic device sealed between two layers of polytetrafluoroethylene (PTFE). However, the light-incident face of current amorphous silicon or micro-crystalline thin film photovoltaic device exhibits dark blue or dark black, and the PTFE layers are transparent. Therefore, the appearance of the amorphous silicon or micro-crystalline thin film photovoltaic device is unsightly, and that limits applications of current flexible photovoltaic apparatus and makes it difficult to design and integrate current flexible photovoltaic apparatus into daily necessities. 
     In addition, there is a huge space to improve the flexibility of current flexible photovoltaic apparatus to expand applications of the flexible photovoltaic apparatus. 
     SUMMARY OF THE INVENTION 
     Accordingly, one scope of the invention is to provide a flexible photovoltaic apparatus which can be easily designed and integrated into daily necessities and has high flexibility. 
     According to a preferred embodiment of the invention, a flexible photovoltaic apparatus includes a composite fabric structure, a thin film photovoltaic device and a protection layer. The thin film photovoltaic device is bonded on an upper surface of the composite fabric structure. The protection layer is transparent, and is bonded on the thin film photovoltaic device and the upper surface of the composite fabric structure such that two terminals of thin film photovoltaic device are exposed. The lower surface of the composite fabric structure serves as a decorative surface. 
     In one embodiment, composite fabric structure includes a base layer and a fabric layer. The base layer provides the upper surface. The fabric layer is bonded together with the base layer, and provides the lower surface. 
     In one embodiment, fabric layer can be a textile fabric layer, a natural leather layer or an artificial leather layer. 
     In one embodiment, the base layer can be formed of ethylene-tetra-fluoro-ethylene (ETFE), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), thermoplastic polyurethane (TPU), ethylene-vinyl acetate (EVA), polyurethane (PU), polyethylene terephthalate (PET) or other commercial synthetic resin. 
     In one embodiment, the protection layer can be formed of PTFE, PMMA, EVA or other commercial synthetic resin. 
     In one embodiment, thin film photovoltaic device can be an amorphous silicon thin film photovoltaic device, a microcrystalline silicon thin film photovoltaic device, a CdS thin film photovoltaic device, a CdTe thin film photovoltaic device, a CuInSe 2  thin film photovoltaic device, a Cu(In,Ga)Se 2  thin film photovoltaic device, a dye-sensitized thin film photovoltaic device, etc. 
     Distinguishable from the prior art, the flexible photovoltaic apparatus of the invention includes the fabric layer providing decorative effect which makes it easy to design and integrate the flexible photovoltaic apparatus of the invention into daily necessities. Moreover, the flexible photovoltaic apparatus of the invention has high flexibility. 
     The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE APPENDED DRAWINGS 
         FIG. 1  is a schematic diagram illustrating the top view of a flexible photovoltaic apparatus according to the first preferred embodiment of the invention. 
         FIG. 2  is a sectional view of the flexible photovoltaic apparatus shown in  FIG. 1  along line A-A. 
         FIG. 3  is a sectional view of a flexible photovoltaic apparatus according to the second preferred embodiment of the invention. 
         FIG. 4  is a sectional view of a flexible photovoltaic apparatus according to the third preferred embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1 and 2 ,  FIG. 1  is a schematic diagram illustrating the top view of a flexible photovoltaic apparatus  1  according to the first preferred embodiment of the invention.  FIG. 2  is a sectional view of the flexible photovoltaic apparatus  1  shown in  FIG. 1  along line A-A. 
     As shown in  FIG. 1  and  FIG. 2 , the flexible photovoltaic apparatus  1  according to the first preferred embodiment of the invention includes a composite fabric structure  10 , a thin film photovoltaic device  14  and a protection layer  16 . 
     The thin film photovoltaic device  14  is bonded on the upper surface  102  of the composite fabric structure  10 . The protection layer  16  is transparent and bonded on the thin film photovoltaic device  14  and the upper surface  102  of the composite fabric structure  10  such that two terminals ( 142  and  144 ) of the thin film photovoltaic device  14  are exposed, as shown in  FIG. 1 . The exposed two terminals ( 142  and  144 ) provide electrical connection in series with other thin film photovoltaic device  14 , or provide electrical connection with an external circuit. In particular, the lower surface  104  of the composite fabric structure  10  serves as a decorative surface. 
     In one embodiment, the composite fabric structure  10  includes a base layer  11  and a fabric layer  12 . The base layer  11  provides the upper surface  102 . The fabric layer  12  is bonded together with the base layer  11 . As shown in  FIG. 1 , the fabric layer  12  is bonded on the lower surface  112  of the base layer  11 . The fabric layer  12  also provides the lower surface  104  (decorative surface  104 ). 
     In one embodiment, the fabric layer  12  can be a textile fabric layer, a natural leather layer or an artificial leather layer. The textile fabric layer as the fabric layer  12  can be all kinds of textile fabrics, for example, woven fabric, warp knitting fabric, circular knitted fabric, velvet, non-woven fabric, etc. The decorative surface  104  of the fabric layer  12  can be applied by post-treatments, for example, printing, gluing, shaping, pollution preventing, fire resisting, fluffing, sanding, shearing, calendering, embossing, laminating, or other treatment. 
     As shown in  FIG. 2 , the flexible photovoltaic apparatus  1  of the invention also includes a sealing layer  13  (e.g., an EVA layer) and a sealing layer  15  (e.g., an EVA layer). The sealing layer  13  is boned between the base layer  11  and the thin film photovoltaic device  14 . The sealing layer  15  is bonded between the protection layer  16  and the thin film photovoltaic device  14 . In one embodiment, base layer  11 , the sealing layer  13 , the thin film photovoltaic device  14 , the sealing layer  15  and the protection layer  16  are bonded together by hot press. The sealing layer  13  and the sealing layer  15  seal the thin film photovoltaic device  14 . 
     In one embodiment, the base layer  11  can be formed of ETFE, PTFE, PMMA, TPU, EVA, PU, PET or other commercial synthetic resin. The base layer  11  must meet the requirements of various weathering properties to protect the thin film photovoltaic device  14 . 
     In one embodiment, thin film photovoltaic device  14  can be an amorphous silicon thin film photovoltaic device, a microcrystalline silicon (μ-Si) thin film photovoltaic device, a CdS thin film photovoltaic device, a CdTe thin film photovoltaic device, a CuInSe 2  (CIS) thin film photovoltaic device, a Cu(In,Ga)Se 2  (CIGS) thin film photovoltaic device, a dye-sensitized thin film photovoltaic device, etc. 
     In one embodiment, the protection layer  16  can be formed of PTFE, PMMA, EVA or other commercial synthetic resin. The protection layer  16  must meet the requirements of water vapor barrier, electrical insulation, dimensional stability, moist heat aging resistance, anti-ultraviolet, etc. 
     In one embodiment, the flexible photovoltaic apparatus  1  according to the first preferred embodiment of the invention has a thickness in a range of about from 0.05 mm to 5 mm. The flexible photovoltaic apparatus  1  according to the first preferred embodiment of the invention can be wound into a tubular article. The flexibility of the flexible photovoltaic apparatus  1  according to the first preferred embodiment of the invention is defined as a diameter of the tubular article which is about form 5 mm to 500 mm. 
     Referring to  FIG. 3 ,  FIG. 3  is a sectional view of a flexible photovoltaic apparatus  1  according to the second preferred embodiment of the invention. The components and devices in  FIG. 3  identical to those shown in  FIG. 2  are given the same numerical notations, and will be not described in detail herein. Hereinafter, only difference between the second preferred embodiment and the first preferred embodiment is described. 
     In the second preferred embodiment of the invention, the flexible photovoltaic apparatus  1  has no base layer  11 , the fabric layer  12  is directly bonded on the sealing layer  13  (e.g., EVA layer). The fabric layer  12  provides the decorative surface. 
     Similarly, the flexible photovoltaic apparatus  1  according to the second preferred embodiment of the invention has a thickness in a range of about from 0.05 mm to 5 mm. The flexible photovoltaic apparatus  1  according to the second preferred embodiment of the invention can be wound into a tubular article. The flexibility of the flexible photovoltaic apparatus  1  according to the second preferred embodiment of the invention is defined as a diameter of the tubular article which is about form 5 mm to 500 mm. 
     Referring to  FIG. 4 ,  FIG. 4  is a sectional view of a flexible photovoltaic apparatus  1  according to the third preferred embodiment of the invention. The components and devices in  FIG. 4  identical to those shown in  FIG. 2  are given the same numerical notations, and will be not described in detail herein. Hereinafter, only difference between the third preferred embodiment and the first preferred embodiment is described. 
     In the second preferred embodiment of the invention, the flexible photovoltaic apparatus  1  has no base layer  11 , another protection layer  16  is directly bonded on the sealing layer  13  (e.g., EVA layer). An interface layer  17  glues the protection layer  16  and the fabric layer  12 . The fabric layer  12  provides the decorative surface. 
     With above description of the flexible photovoltaic apparatus of the invention, it is clearly understood that the flexible photovoltaic apparatus of the invention provides decorative effect and has high flexibility. Therefore, the flexible photovoltaic apparatus of the invention can expand applications thereof, and can be easily designed and integrated into daily necessities. 
     With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.