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EP-4736600-A1 - PARTIALLY FLEXIBLE PHOTOVOLTAIC LAMINAR PRODUCT AND MANUFACTURING METHOD THEREOF

EP4736600A1EP 4736600 A1EP4736600 A1EP 4736600A1EP-4736600-A1

Abstract

A method for making a partially flexible photovoltaic laminar product (1), comprising the steps of a) providing a substantially horizontal work (2); b) depositing on the surface (2) a first flexible base layer (3) made of fabric coated with a first polymer material; c) depositing on the first base layer (3) a second coupling substrate (5); d) depositing on the coupling substrate (5) at least one third photovoltaic layer (6) provided with at least one cell made of material with photovoltaic effect and electrical junctions wherein the opposite surfaces (6A, 6B) of the at least one third photovoltaic layer (6) are provided with respective coatings (7A, 7B) made of ethylene-vinyl acetate (EVA); e) depositing on the at least one third photovoltaic layer (6) at least one fourth protection layer (12) made of a second polymer material so as to obtain a sandwich structure (13); f) inserting the structure (13) into a treatment chamber (14) and g) maintaining in the chamber (14) controlled thermal (T) and barometric conditions (P) for a predetermined time (t) to carry out the thermoplastic melting and polymerisation of the layers (3, 5, 7A, 7B, 12) maintaining the at least one cell made of material with photovoltaic effect and the junctions unchanged. The coupling layer (5) is single and it is made of at least one first elastomeric material.

Inventors

  • DI MASSIMO, Roberto
  • SEGATO, STEFANO

Assignees

  • Naizil S.r.l.

Dates

Publication Date
20260506
Application Date
20240627

Claims (15)

  1. 1. A method of making a partially flexible photovoltaic laminar product (1), comprising the following steps: a) providing a substantially horizontal work surface (2); b) depositing on said work surface (2) a first flexible base layer (3) made of fabric coated with a first polymer material; c) depositing on said first base layer (3) a second coupling substrate (5); d) depositing on said second coupling substrate (5) at least one third photovoltaic layer (6) provided with at least one cell made of material with photovoltaic effect and with electrical junctions, the opposite surfaces (6A, 6B) of said at least one third photovoltaic layer (6) being provided with respective coatings (7A, 7B) made of ethylene-vinyl acetate (EVA); e) depositing on said at least one third photovoltaic layer (6) at least one fourth protection layer (12) made of a second polymer material so as to obtain a sandwich structure (13); f) inserting said sandwich structure (13) into a treatment chamber (14); g) maintaining thermal (T) and barometric conditions (P) in said chamber (14) controlled for a predetermined time (t) to carry out the thermoplastic melting and polymerisation of said first layer (3), of said second substrate (5), of said coatings (7A, 7B) and of said fourth layer (12) maintaining said at least one cell made of material with photovoltaic effect and said junctions unchanged; characterised in that said coupling layer (5) is single and it is made of at least one first elastomeric material, and in that said first base layer (3) is subjected to a step h) of lateral trimming to obtain an edge seam (16) provided with joining means for joining to a structure on which there is applied said laminar product (1) or to at least one further laminar product (1).
  2. 2. Method as claimed in claim 1 , characterised in that said joining means are selected from the group comprising welding or seam of a folded or extruded section and they form a protection member of said base layer (3) adapted to increase the half-life of said sandwich structure (13) avoiding a step of lacquering said base layer (3).
  3. 3. Method as claimed in claim 1 , characterised in that said controlled thermal conditions (T) provide for maintaining a substantially even temperature comprised between 140°C e 165°C and preferably close to 150°C in said treatment chamber (14).
  4. 4. Method as claimed in claim 1 , characterised in that said controlled barometric conditions (P) provide for maintaining a degree of vacuum that is variable with time and comprised between 0.3 bar and 1 bar in said treatment chamber (14).
  5. 5. Method as claimed in claim 1 , characterised in that said predetermined time (t) is comprised between 900s and 1200s and preferably close to 1100s.
  6. 6. Method as claimed in claim 1 , characterised in that said work surface (2) has an upper surface (2A) subjected to suction in order to retain the sandwich structure (13) during the deposition of said superimposed layers and so as to mutually couple said layers eliminating any air inclusions between the various layers and forming a unitary flexible photovoltaic laminar product (1).
  7. 7. Method as claimed in claim 1 , characterised in that said first polymer material of said first base layer (3) is selected from the group comprising polyvinyl chloride (PVC), plasticised polyvinyl chloride, thermoplastic polyurethane (TPU), acrylic resins, silicone elastomers, polytetrafluoroethylene (PTFE) polymers, ethylene tetrafluoroethylene (ETFE).
  8. 8. Method as claimed in claim 1 , characterised in that there is provided a step i) of coupling a plurality of laminar strips (10) made of conductive flexible material to said at least one third photovoltaic layer (6) to connect said electrical junctions to a junction box (11 ) for connecting one or more cells made of material with photovoltaic effect of said at least one third photovoltaic layer (6).
  9. 9. Method as claimed in claim 1 , characterised in that during said step g) of maintaining thermal (T) and barometric conditions (P), there is provided the positioning on said sandwich structure (13) of a plate (15) having a lower face (15B) designed to come into contact with said fourth protection layer (12), said lower face (15B) having a plurality of evenly distributed recesses adapted to form corresponding lenticular faces on said fourth protection layer (12).
  10. 10. Method as claimed in claim 1 , characterised in that said first (3), second (5), at least one third (6) and fourth layer (12) are subjected to tensioning during said steps b), c), d) and e) of deposition on said work surface (2).
  11. 11 . Method as claimed in claim 1 , characterised in that said deposition steps b) and c) are adapted to obtain a first sandwich and said deposition steps d) and e) are adapted to obtain a second sandwich, before said step f) of insertion there being provided a step j) of laminating said second sandwich with controlled thermal (T) and barometric conditions (P) for a predetermined time (t), a step k) of trimming the peripheral edge of said second laminated sandwich and a step I) of coupling said first sandwich with said second laminated and trimmed sandwich.
  12. 12. A partially flexible photovoltaic laminar product (1) obtainable with the method according to one or more of the preceding claims, comprising a first flexible base layer (3) made of fabric coated with a first polymer material, a second coupling substrate (5), at least one third photovoltaic layer (6) provided with at least one cell made of material with photovoltaic effect and electrical junctions wherein the opposite surfaces (6A, 6B) of said at least one third photovoltaic layer (6) are provided with respective coatings (7A, 7B) made of ethylene-vinyl acetate (EVA) and at least one fourth protective layer (12); characterised in that said coupling layer (5) is single and it is made of a first elastomeric material and in that said first base layer (3) has an edge seam (16) provided with joining means for joining to a structure on which there is applied said laminar product (1) or at least one further laminar product (1).
  13. 13. Product as claimed in claim 12, characterised in that said joining means comprise a welding or a seam of a folded or extruded section defining a protection member of said base layer (3) adapted to increase the half-life of said sandwich structure (13) avoiding a step of lacquering said base layer (3).
  14. 14. Product as claimed in claim 12, characterised in that said material with photovoltaic effect is selected from the group comprising monocrystalline silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, gallium phosphide, indium phosphide, cadmium telluride, copper indium gallium selenide (CIGS), tin sulphide, zinc sulphide, organic perovskite, inorganic perovskite, photovoltaic polymers, dye-sensitized solar cells (DSSC) and quantic points.
  15. 15. Product as claimed in claim 12, characterised in that said first base layer (3) has dimensions greater than those of the other layers superimposed thereon, said at least one fourth layer (12) having dimensions greater than those of said second substrate (5) and at least one third layer (6) so as to almost completely cover said first base layer (3) and create a frame (17) around said at least one third photovoltaic layer (6) to allow the coupling of said laminar product (1) with other photovoltaic laminar products of the same type, or to a structure on which said laminar product (1) is applied.

Description

PARTIALLY FLEXIBLE PHOTOVOLTAIC LAMINAR PRODUCT AND MANUFACTURING METHOD THEREOF DESCRIPTION Field of the invention [001] The present invention generally relates to the technical field of photovoltaic laminar products and it particularly relates to a method for making a partially flexible photovoltaic laminar product. [002] The invention also relates to a partially flexible photovoltaic laminar product. Background art [003] Photovoltaic devices adapted to directly convert light energy into electricity by using a surface layer made of semiconductor material have been known long since. [004] These photovoltaic devices are generally divided into two different types having a semiconductor material based on crystalline silicon or amorphous silicon respectively. [005] The use of crystalline silicon allows to obtain rigid photovoltaic modules applicable to the flat surfaces of a building, while the use of amorphous silicon allows to obtain thin and flexible photovoltaic films applicable to the non-flat surfaces present on the roofing systems of spaces and compartments. [006] Generally, there are provided one or more surface layers adapted to coat the semiconductor material in order to allow it to be used on different types of roofing and to protect them from bad weather while maintaining their characteristics intact over time. [007] However, the coupling of the semiconductor material to flexible surfaces is carried out by using specific binding agents and it provides for particularly long manufacturing times. [008] In order to at least partially overcome such drawbacks, there have been developed methods for making photovoltaic laminar products, which provide for joining a plurality of hot-welded flexible photovoltaic films. [009] Document WO2011/095304 discloses a flexible photovoltaic laminar product adapted to obtain a roll-up roof comprising a series of photovoltaic films each enclosed in a series of flexible strips made of plastic material. [0010] The strips are made of ethylene tetrafluoroethylene (ETFE) and each of them is joined to the subsequent strip by means of ultrasonic welding to obtain a continuous surface cover. [0011] A first drawback of such solution lies in the fact that the manufacturing method is laborious and difficult, with the resulting increase in manufacturing times and costs. [0012] A further drawback of such solution lies in the fact that the cover has a series of opaque strips interspersed with a series of inactive spaces and devoid of semiconductor material, with the resulting decrease in the active surface and therefore in the total amount of energy collected and converted . [0013] Another drawback of such solution lies in the fact that the presence of non-active spaces makes the roofing surface semi-transparent and not fully shading. [0014] A further drawback of such solution lies in the fact that there arises the need to use a dedicated system for obtaining the photovoltaic roofing laminar product. [0015] In order to at least partially overcome such drawbacks, there have been developed methods for making a flexible photovoltaic laminar product by directly coupling a photovoltaic cell on a flexible base layer made of coated fabric. [0016] Document EP2773826 discloses a method for coupling at least one photovoltaic cell to a coated fabric by interposing a pressure-sensitive adhesive layer. [0017] Furthermore, the method provides for obtaining a seam or a thermal welding along an inactive and perimeter area of the photovoltaic cell in order to obtain a layer of air between the module and the base layer. [0018] However, this type of adhesion or anchoring has a reduced half-life and requires frequent maintenance or replacement. [0019] A further drawback common to the solutions described above lies in the fact that the various surfaces do not adhere completely but by partial coupling along the periphery of the photovoltaic module, which therefore is not completely integrated with the base layer. [0020] Document IT20183834 discloses a method for making a flexible photovoltaic laminar product. Technical problem [0021] In the light of the prior art, the technical problem addressed by the present invention is to integrate at least one cell made of material with photovoltaic effect in a base layer in a homogeneous and durable manner. Summary of the invention [0022] The object of the present invention is to solve the aforementioned problem by providing a method for making an at least partially flexible photovoltaic laminar product which is highly efficient and cost-effective. [0023] A particular object of the present invention is to provide a method of the type described above that allows to obtain a unitary photovoltaic laminar product. [0024] A further particular object of the present invention is to provide is to provide a method of the type described above that allows to full integrate a photovoltaic module in flexible base layer. [0025] Another object of the invention is to provide a m