Photovoltaic element

Patent metadata

Field	Value
Publication number	US-12278300-B2
Application number	US-202017641867-A
Country	US
Kind code	B2
Filing date	Sep 18, 2020
Priority date	Sep 19, 2019
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

The invention relates to a photovoltaic module comprising (a) a front layer ( 1 ) arranged on the sunlight facing side of the photovoltaic module, wherein the front layer ( 1 ) comprises a first polypropylene composition, comprising a polypropylene, wherein the transmission of the front layer for light in the wavelength range of 350 nm to 1200 nm is on average at least 65% as compared to a situation without the front layer as determined according to ASTM D1003-13, (b) a sealing layer ( 2,4 ) which at least partly encapsulates a plurality of photovoltaic cells ( 3 ), wherein the sealing layer ( 2, 4 ) comprises a polyolefin elastomer composition comprising an ethylene-α-olefin copolymer and (c) a back layer ( 5 ), wherein the back layer ( 5 ) comprises a first reinforced polypropylene layer comprising a second polypropylene composition comprising a polypropylene and optionally a reinforcing filler, wherein the sealing layer is arranged between the front layer and the back layer.

First claim

The invention claimed is:

1. A photovoltaic module comprising
(a) a front layer arranged on the sunlight facing side of the photovoltaic module wherein the front layer comprises at least 95 weight percent of a first polypropylene composition based on total weight of the front layer, wherein the first polypropylene composition comprises at least 95 weight percent of a random copolymer of propylene and a comonomer wherein the comonomer is ethylene or an alpha olefin of 4 to 12 carbon atoms, provided that if the comonomer is ethylene the ethylene is present in amounts of no greater than 7 weight percent based on total weight of the random copolymer, wherein the transmission of the front layer for light in the wavelength range of 350 nm to 1200 nm as determined according to ASTM D1003-13, is on average at least 65% as compared to a situation without the front layer,
(b) a sealing layer which at least partly encapsulates a plurality of photovoltaic cells by having a first portion of the sealing layer above the plurality of photovoltaic cells and a second portion of the sealing layer below the plurality of photovoltaic cells where each of the first portion and the second portion of the sealing layer are a monolayer,
wherein the scaling layer comprises a polyolefin elastomer composition comprising an ethylene-alpha-olefin copolymer wherein the amount of alpha olefin is less than 40 weight percent based on weight of the ethylene-alpha-olefin copolymer and wherein the sealing layer is characterized by a transmission of the sealing layer for light in the wavelength range of 350 nm to 1200 nm as determined according to ASTM D1003-13, is on average at least 65% as compared to a situation without the sealing layer, and
(c) a back layer, wherein the back layer comprises a first polypropylene layer comprising a second polypropylene composition comprising a polypropylene, wherein (i) the second polypropylene composition comprises a reinforcing filler, and/or (ii) the back layer further comprises a second polypropylene layer adjacent to the first polypropylene layer and a third polypropylene layer adjacent to the second polypropylene layer on a side opposite from the first polypropylene layer, wherein the second polypropylene layer is a polypropylene foam or a polypropylene honeycomb structure and wherein the back layer has a flexural stiffness in at least one direction of at least 5 Nm, wherein the flexural stiffness is measured according to ASTM D790M (Three point bending with span of 40 cm) and/or a flexural stiffness to weight/m 2 ratio of at least 1.5 Nm 3 /kg, wherein the flexural stiffness is the lowest flexural stiffness the back layer and wherein the flexural stiffness is measured according to ASTM D790M (Three point bending with span of 40 cm) and wherein the weight/m 2 is the weight (in kg) per square meter of the back layer,
wherein the first portion of the sealing layer is arranged between and in direct contact with the front layer and the plurality of photovoltaic cells and the second portion of the sealing layer is arranged between and in direct contact with the back layer and the plurality of photovoltaic cells.

2. The photovoltaic module according to claim 1 , wherein the first polypropylene composition further comprises a mixture of light stabilizing additives, said mixture of light stabilizing additives comprising:
i) a high molecular weight hindered tertiary amine light stabilizer having a weight average molecular weight (measured by ASTM D6474-12) of at least 1600 g/mol;
ii) a low molecular weight hindered secondary amine light stabilizer (s-LM-HALS) having a weight average molecular weight (measured by ASTM D6474-12) of below 1000 g/mol,
iii) an ultraviolet synergist, and
iv) an ultraviolet absorber, and c) a mixture of antioxidant additives, said mixture of antioxidant additives comprising
i) a phenolic antioxidant and
ii) a phosphite additive.

3. The photovoltaic module according to claim 1 , wherein the ethylene-alpha-olefin copolymer in the polyolefin elastomer composition is crosslinked.

4. The photovoltaic module according to claim 1 , wherein the random copolymer is a propylene-ethylene copolymer having
i) a molecular weight distribution (MWD) of at least 5.0 and at most 10.0, wherein MWD is calculated by dividing the weight average molecular weight Mw by the number average molecular weight Mn and wherein Mw and Mn are measured according to ASTM D6474-12 and/or
ii) a melt flow rate in the range from 0.50 to 7.0 dg/min as determined using IS01133: 2011, at 2.16 kg and 230° C.

5. The photovoltaic module according to claim 1 , wherein the alpha-olefin in the ethylene-alpha-olefin copolymer is a linear, branched or a cyclic alpha-olefin having 3 to 20 carbon atoms and/or wherein the ethylene-alpha-olefin copolymer has a density of from 0.860 g/cm 3 to 0.905 g/cm 3 .

6. The photovoltaic module according to claim 1 , wherein the back layer comprises the second polypropylene layer and the third polypropylene layer, and the first and third polypropylene layer are in direct contact with the second polypropylene layer.

7. The photovoltaic module according to claim 1 , wherein the back layer consists of the first, second and third polypropylene layer.

8. The photovoltaic module according to claim 1 , wherein the polypropylene in the second polypropylene composition is a heterophasic propylene copolymer.

9. The photovoltaic module according to claim 1 , wherein the module consists of the front layer the sealing layer, the photovoltaic cells and the back layer.

10. The photovoltaic module according to claim 1 , wherein each of the front layer, the sealing layer and the back layer comprises at least 95 wt % polyolefins based on the total polymer in said layer.

11. A process for the preparation of the photovoltaic module of claim 1 , comprising the sequential steps of:
(a) providing the front layer, the sealing layer comprising the plurality of photovoltaic cells and the back layer
(b) assembling the front layer, the sealing layer and the back layer such that the front layer and the back layer are in contact with the sealing layer to form an assembly;
(c) heating the assembly such that at least part of the sealing layer melts;
(d) while heating, pressing the assembly to obtain a laminated assembly and
(e) cooling the laminated assembly to obtain the photovoltaic module.

12. A structure comprising the photovoltaic module of claim 1 on a roof or on a facade.

13. The photovoltaic module of claim 2 characterized by one or more of the following
the high molecular weight hindered tertiary amine light stabilizer comprises 1, 3, 5-triazine-2, 4, 6-triamine or N,N″-[1,2-ethanediylbis [[[4,6-bis [butyl (1,2,2,6,6-pentamethyl-4-piperidinyl) amino]-1,3,5-triazine-2-yl]imino]-3, 1-propanediyl]]-bis [N′,N″-dibutyl-Isr,N″-bis(1,2,2,6,6-pentamethyl-4-piperidinyl);
the low molecular weight hindered secondary amine light stabilizer comprises a mixture of esters of 2, 2, 6, 6-tetra-methyl-4-piperidinol and one or more fatty acids;
the ultraviolet synergist comprises an n-alkyl-3,5-dialkylated 4-hydroxybenzoate;
the ultraviolet absorber comprises 2-(2′-5 hydroxy-3′-t-butyl-5′-methylphenyl)-5-chlorobenzotriazole;
the phenolic antioxidant comprises tetrakis[methylene-3 (3,5′-di-t-butyl-4-hydroxyphenyl) propionate] methane or 1,3,5-tris (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)-isocyanurate;
the phosphite additive comprises tris (2,4-di-t-butylphenyl) phosphite;
the mixture of antioxidant additives includes calcium stearate.

14. The photovoltaic module of claim 4 wherein the random copolymer in the first polypropylene composition is

Assignees

• Sabic Global Technologies Bv

Inventors

• Van Den Heuvel Huibert Johan
• Bercx Rick Robert Emilie
• Van Giesen Roland
• Venderbosch Robert Walter
• Steenbakkers-Menting Henrica Norberta Alberta Maria
• Van Der Ven Maud
• Yaneva Petya Dochkova

Classifications

• H10F19/85

  Protective back sheets · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• Y02B10/10

  Photovoltaic [PV] · CPC title

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F19/804 Primary

  Materials of encapsulations · CPC title