WO2024156034A1

WO2024156034A1 - A window for a buildling or structure

Info

Publication number: WO2024156034A1
Application number: PCT/AU2024/050044
Authority: WO
Inventors: Douglas John Charles HUNT
Original assignee: Clearvue Technologies Ltd
Priority date: 2023-01-25
Filing date: 2024-01-25
Publication date: 2024-08-02

Abstract

The disclosure provides a window unit for a building or structure. The window unit has a first panel having a major surface and being at least largely transmissive for visible light, and a plurality of solar cells each having an active area and being positioned along and in proximity of one or more edges of the first panel. The plurality of solar cells may be located around a first area of the first panel in which the first panel is at least largely transmissive for visible light. A solar selective coating is located on or over the major surface of the first panel within a first projection area defined by a projection of the first area onto the major surface of the first panel in a direction parallel to a surface normal of the first panel. An area surrounding the first projection area may be at least largely free from the solar selective coating.

Description

A WINDOW FOR A BUILDLING OR STRUCTURE

Field

The present disclosure relates to a window for a building or structure and relates particularly to a window which generates electricity.

Background

Buildings such as office towers, high-rise housings and hotels use large amounts of exterior window panelling and/or facades which incorporate glass panelling.

Such glass panelling receives large amounts of sunlight, which results in heating of interior spaces requiring the use of air conditioners. A large amount of energy is globally used to operate air conditioners.

PCT international applications numbers PCT/AU2012/000778, PCT/AU2012/000787 and PCT/AU2014/000814 (owned by the present applicant) disclose a spectrally selective panel that may be used as a windowpane and that is transmissive for visible light, but has solar cell modules attached that absorb light, such as infrared and/or other re-emitted (internally wavelength-converted) radiation, to generate electricity.

One or more embodiments may provide further improvement.

Summary

A first aspect provides a window unit for a building or structure, the window unit comprising: a first panel having a major surface and being at least largely transmissive for visible light; a plurality of solar cells each having an active area and being positioned along and in proximity of one or more edges of the first panel, the plurality of solar cells being located around a first area of the first panel in which the first panel is at least largely transmissive for visible light; and a solar selective coating located on or over the major surface of the first panel within a first projection area defined by a projection of the first area onto the major surface of the first panel in a direction parallel to a surface normal of the first panel, wherein an area surrounding the first projection area is at least largely free from the solar selective coating.

In one specific embodiment the area surrounding the first projection area may be entirely free from the solar selective coating and surround the solar selective coating. The solar selective coating may be applied on or over the major surface of the first panel within the entire first projection area. The first projection area may be surrounded by a border area and the border area may be largely to entirely free from the solar selective coating.

The solar selective coating may be a low emissivity coating (“Low-E coating”), such as a coating that is at least largely transmissive for visible light, but blocks at least a portion of infrared light and/or ultraviolet light. The window unit may be incorporated into a building. By applying the Low-E coating to the major surface of the first panel within the first projection area, penetration of the infrared or ultraviolet light radiation into an interior space of the building can reduced. Further, in one or more embodiments, the solar selective coating is not applied at or over the area surrounding the first projection area and consequently is not applied over the solar cells. An embodiment may have the advantage that heating of interior spaces of a building can be reduced without reducing absorption of infrared or ultraviolet light by the solar cells and consequently without reducing an output of electricity of the solar cells.

The first projection area may include a coated area surrounded by a border area. The solar selective coating may be applied at or over the coated area and the border area within the first projection area may be at least partially or entirely free from the solar selective coating.

The border area may have a non-uniform width. The border area may have a uniform width. The border area may have a width in the rage of 0.1 -0.2, 0.2-0.5, 0.5-1 , 1-1.5, 1.5-2, 2-2.5, 2.5 - 3, 3-3.5, 3.5-4, 4-4.5 and 4.5-5 cm or more. The first projection area including the coated area and the border area may have a total extension ranging from a few centimetres to a few metres.

The solar cells of the plurality of solar cells may be spaced apart from the first panel by a gap, such as a gap filled with a gas and may be held in position by a holder.

Alternatively, the plurality of solar cells may be attached to the first panel such that no air gap is formed between the solar cells and the first panel. The solar cells of the plurality of solar cells may for example be attached to the first panel using a suitable adhesive, such as ethylene-vinyl acetate (EVA) or another suitable material.

The first major surface of the first panel may face an outside of a building or structure to which the window may in use be applied and the first panel may comprise an opposite second major surface which in use faces towards an interior space of the building or structure. The solar cells of the plurality of solar cells typically face the second major surface directly. The solar selective coating may be applied to the first or second surface of the first panel.

The first panel may comprise a suitable glass or polymeric material. In one specific embodiment the first panel comprise ultra-clear low-iron glass.

In one embodiment the first panel comprises parallel first and second component panel portions which are laminated together. A luminescent material may be embedded in a sandwich layer positioned between the first and second component panel portions. The sandwich layer may comprise polyvinyl butyral (PVB). In one specific example the luminescent material is embedded in the PVB. The first and second panel portions may be laminated together using a sandwich layer including ethylene-vinyl acetate (EVA) or another suitable material. The plurality of solar cells, such as bifacial solar cells, may be sandwiched between the first and second component panel portions and may be embedded within the PVB material and may be arranged in an overlapping or “shingled” arrangement.

The window may further comprise a second panel which is parallel to the first panel and spaced apart from the first panel. A cavity may be formed between the first panel and the second panel. The second panel may be at least largely transmissive for visible light.

The window unit may comprise a further solar selective coating located on or over the major surface of the second panel within a third projection area defined by a projection of the first area onto the major surface of the second panel in a direction parallel to a surface normal of the second panel, and an area surrounding the third projection area may be at least largely free from the solar selective coating. In this embodiment the solar cells are typically bifacial solar cells.

The window may comprise a frame supporting the first panel, the second panel and the plurality of solar cells. The solar cells are typically silicon-based, but may alternatively include perovskite - based solar cell or solar cells that comprise CulnSes, CIGS or CIS, GaAs, CdS or CdTe.

The window may be arranged such that a central area of the window is transmissive for at least the majority of visible light is at least 5, 10, 15, 20, 50, 100 or even 500 x larger than an area of the first panel at which the plurality of solar cells are positioned.

The central area that is transmissive for at least the majority of visible light may be transmissive for at least 60%, 70%, 80%, 90% or even at least 95% of visible light incident of the receiving surface of the first panel at normal incidence.

Brief Description of the Drawings

Embodiments will now be described by way of example only with reference to the accompanying non-limiting figures, in which:

Figure 1 is a schematic front view of an embodiment of a window unit for a building or structure;

Figure 2a and Figure 2b are schematic cross-sectional representations of portions of an embodiment of the window for a building or structure;

Figure 3a and Figure 3b are schematic cross-sectional representations of portions of an embodiment of the window for a building or structure; and

Figure 4a Figure 4b is a schematic front view of an embodiment of a window unit.

Detailed Description of Embodiments

Referring initially to Figure 1 , there is shown a schematic top view of a window unit 100 in accordance with an embodiment of the present disclosure. The window unit 100 comprises a first panel 102 and four first series of solar cells 104 106, 108, 110 positioned at or in proximity of respective edges of the first panel 102. Further, four second series of solar cells 112, 114, 116 and 118 are also positioned along the edges of the first panel 102. The four first series of solar cells 104 106, 108, 110 and the four second series of solar cells 112, 114, 116 and 118 face a major surface of the first panel 102 panel and together are located or surround a central area 120 of the first panel 102. The central area 120 is at least largely transmissive for light. In an embodiment, the central area 120 is transmissive for at least 60%, 70%, 80%, 90% or even at least 95% of visible light incident of a receiving surface of the first panel 102 at normal incidence.

The window unit 100 also comprises a frame structure 115 which is positioned behind the first series of solar cells 104 106, 108, 110. The frame structure 115 is shown generally in Figure 1 and in some embodiments may be positioned within a perimeter or circumference of the first panel 102. In an embodiment, the window unit 100 comprises a second panel (not shown) which is oriented parallel to the first panel 102 and in use exposed to an inner space of the building or structure to which the window unit 100 is mounted.

In an embodiment, the first panel 102 is transmissive for at least 90% of incident visible light. The first series solar cells 104 106, 108, 110 and the second series of solar cells 112, 114, 116 and 118 are positioned at an edge region of the first panel 102 such that only at the edge region of the first panel 102 the transmission of incident light is obstructed by the solar cells. In an embodiment, the window unit 100 is arranged such that a central area 120 is transmissive for at least the majority of visible light and is at least 5, 10, 15, 20, 50, 100 or even 500 x larger than an area of the first panel 102 at which the plurality of solar cells are positioned (e.g. the first series solar cells 104 106, 108, 110 and/or the second series of solar cells 112, 114, 116 and 118).

A low emission coating in the form of low emissivity coating, referred herein as Low-E coating 122, is positioned on the first panel 102 in first projection area of the of the first panel 102 which is in the form a central area 120. The central area 120 is surrounded by the first series of solar cells 104, 106, 108 and 110 and second series of solar cells 112, 114, 116 and 118. The Low-E coating 122 blocks a portion of infrared light and/or ultraviolet light. In an embodiment, the Low-E coating 122 coats the entire central area 120. No Low-E coating 122 is positioned on the first panel 102 at areas at which the solar cells are positioned as is described in more detail with reference to Figure 4a and Figure 4b.

The window unit 100 may for example be incorporated into a building. By applying the Low-E coating 122 at or over the central area 120 of the first panel 102, penetration of the infrared or ultraviolet light radiation into an interior space of the building can reduced. Further, the Low-E coating 122 is not applied over an area at which solar cells are positioned. An embodiment may have the advantage that heating of interior spaces of a building may be reduced without reducing light absorption of infrared or ultraviolet light by solar cells and consequently without reducing an output of electricity of the solar cells. Referring now to Figure 2a, components of the window unit 100 are described in further detail. Like features are given like reference numerals.

The first panel 102 has a first major surface 210 which is exposed to a space that is outside of the window unit 100 and which is the surface at which the window receives direct sunlight light when the window is incorporated to the building or structure. The first panel 102 comprises in this embodiment ultra-clear low-iron glass. However, the first panel 102 can be formed from other forms of glass.

Figure 2a further shows the Low-E coating 122 which is in this embodiment applied to the first major surface of the first panel 102.

In window unit 100 or window unit 100a the Low-E coating 122 is arranged to have a high reflectivity for wavelengths between 300 nm to approximately 420 nm, and also for approximately 750 to approximately 1000 nm. In a variation of the described embodiment and as shown in Figure 2b with reference to window unit 100a, the Low-E coating 122 may for example be positioned on an inside surface (i.e. second major surface 211) of the first panel 102. The second major surface 211 in use faces towards an interior space of a building or structure. All other features of window unit 100 and window unit 100a are otherwise the same.

In an embodiment, the first panel 102 comprises first panel portion 204 and second panel portion 206 which are laminated together using a polyvinyl butyral (PVB) layer 208. The first panel portion 204 and second panel portion 206 are parallel to one another.

In an embodiment, the PVB layer 208 includes luminescent material. The luminescent material in the PVB layer 208 absorbs incoming light and emits fluorescence radiation in random directions. A portion of the emitted fluorescence radiation is directed within the first panel 102 by total internal reflection towards an edge region of the first panel 102 where a portion of the light can be absorbed by the solar cells (such as solar cells of the series 108, 116) for generation of electricity.

Figure 2a also shows the second panel 202 of the window unit 100. The second panel 202 is parallel and spaced from the first panel 102 to define a cavity therebetween. The second panel is at least largely transmissive for visible light. The second panel 202 may have a similar transmissivity to the first panel 102. The second panel 202 is shown in Figure 2a and Figure 2b as being a single pane of glass but in other embodiments the second panel 202 can be formed from a laminated structure. Although not shown in Figure 2a and Figure 2b, the second panel 202 may also include a Low-E coating.

In the embodiments shown in Figure 2a and Figure 2b, the solar cells of the first series (104, 106, 108 and 110) and second series (112, 114, 116 and 118) are spaced apart from the first panel 102. The solar cells of the second series 112, 114, 116 and 118 are positioned parallel to the first major surface 210 of the first panel 102. The solar cells of the first series 104, 106, 108 and 110 are positioned at an inclined orientation relative to the first major surface 210 of the first panel 102.

A projection of the Low-E coating 122 in a direction parallel to a surface normal of the Low-E coating 122 does not overlap with the first series of solar cell (104, 106, 108 and 110) and second series of solar cells (112, 114, 116 and 118). In this embodiment the Low-E coating is not applied within an area 225 surrounding the Low-E coating and which has an outer boundary defined by a projection of the solar cells into the plane of the low-E coating 122 parallel to a surface normal of the Low-E coating 122. Accordingly, the window unit 100a and window unit 100a has a border area 226 that surrounds or is adjacent to the Low-E coating 122. This border area 226 may be largely or entirely free from the Low-E coating 122 or may be completely free from the Low-E coating 122. As the Low-E coating 122 does not extend into the area 225, it is enabled that not only infrared and ultraviolet light which reaches the window unit at normal incidence can reach the solar cells without passing through the Low-E coating 122, but also infrared and ultraviolet light incident at relatively large angular range will not be absorbed but the Low-E coating 122 and can reach the solar cells. Dependent on design parameters of the window unit the area 225 may have a width ranging from a few millimetres to a few centimetres. In an embodiment, the border area 226 extends from an edge 232 of the first panel 102 to an edge 230 of the Low-E coating 122. In an embodiment, a width W of the border area 226 ranges from >40 mm to <120 mm. In an embodiment, the width W of the border area 226 ranges from 0.1 -0.2, 0.2-0.5, 0.5-1 , 1-1 .5, 1 .5-2, 2-2.5, 2.5 - 3, 3-3.5, 3.5-4, 4-4.5 and 4.5-5 cm or more.

In an embodiment, the border area 226 has a total extension ranging from a few 10 centimetres to a few metres. The extension of the border area 226 extends around a perimeter of the first panel 102. Alternative, the extension of the border area 226 can extend along one side of the first panel 102. A layer of butyl 220 or similar sealant is applied at a recess between edge portions of the first panel 102, the second panel 202 and the spacer 200 to form a primary seal of the window unit 100 or window unit 100b.

A person skilled in the art will appreciate that in alternative embodiments the solar cells of the first series 104, 106, 108 and 110 may be inclined by another suitable angle. Further, the solar cells of the second series 112, 114, 116 and 118 may alternatively be positioned at an inclined angle relative to the first major surface 210 of the first panel 102 or may be parallel to the first major surface 210 of the first panel 102. In another alternative embodiment the window unit 100 or window unit 100a may not comprise the solar cells of the first series 104, 106, 108 and 110.

Figure 3a illustrates components of a window unit 300 in accordance with another embodiment of the present disclosure. Window unit 300 is similar to window unit 100 and like components are given like reference numerals. The window unit 300 comprises a first panel 102a and a second panel 202 which are spaced apart by a spacer 200. The first panel 102a comprises component panel portions 204 and 206 which are laminated together using a polyvinyl butyral (PVB) layer 208. Sandwiched between the first panel portion 204 and the second panel portion 206 and embedded in the PVB layer are a series of solar cells 302. In an embodiment the solar series of solar cells 302 comprise bifacial solar cells having opposite active areas. In an embodiment, the solar cells 302 are positioned in an overlapping “shingled” relationship. The window unit 300 is arranged such that, when the window unit is positioned within a building or structure, the solar cells 302 can receive sunlight incident through the first panel portion 204. Further, the solar cells 302 can receive light from an interior of the building or structure directed through the second panel portion 206 and the second panel 202.

The window unit 300 comprises a Low-E coating 122 positioned on an exterior surface (i.e. first major surface 210) of the first panel 102a. Similar to window unit 100, a projection of the Low-E coating 122 in a direction parallel to a surface normal of the Low-E coating 122 does not overlap with the solar cells 302. In this embodiment there is an area 225 surrounding the Low-E coating 122 and positioned between the Low-E coating 122 and a projection of the solar cells into the plane of the Low-E coating 122, which enables that the solar cells 302 receive infrared and ultraviolet light incident at a relatively wide angular range without the incident light being filtered by the Low-E coating 122. Similar to window unit 100, in window unit 300 the border area 226 extends from an edge 232 of the first panel 102a to an edge 230 of the Low-E coating 122. The width W of the border area 226 is similar or the same as for window unit 100.

In an embodiment the window unit 300 also comprises a further solar selective coating in the form of second Low-E coating 304 positioned at an inner surface of the second panel 202. A projection of the second Low-E coating 304 in a direction parallel to the surface normal of the second Low-E coating 304 does not overlap with the solar cells 302. In this embodiment there is a narrow area 227 which surrounds the second Low-E coating 304 and is positioned between the second Low-E coating 304 and a projection of the solar cells 302 into the plane of the second Low-E coating 304, which enables that the solar cells 302 receive infrared and ultraviolet light incident at a relatively wide angular range without the incident light being filtered by the second Low-E coating 304. In an embodiment, the narrow area 227 is similar to area 225. The second Low-E coating 304 may have any suitable optical properties. However, in an embodiment the second Low-E coating 304 has the same optical properties (and is formed in the same manner) as the Low-E coating 122 described above. The second Low-E coating 304 may have a similar width W to the Low-E coating 122.

Figure 3b shows another embodiment of a window unit 300a. Window unit 300a is the same as window unit 300 and like references are used to describe like features. The main difference between window unit 300 and window unit 300a is that in window unit 300a the Low-E coating 122 is on a second major surface 211 of the first panel 102a. Accordingly, in window unit 300a the Low-E coating 122 faces a cavity formed between the first panel 102a and the second panel 202.

In an embodiment, the second panel 202 is a laminate structure similar to the first panel 102a such that each of the first panel 102a and the second panel 202 have a solar cell sandwiched within the laminate structure (not shown). The solar cell sandwiched within the laminate structure may be a bifacial solar cell.

In an embodiment, the first panel 102 of window unit 100 and/or 100a takes the form of first panel 102a from window unit 300. In such an embodiment, solar cell 116 is omitted and replaced by solar cell 302 laminated within the first panel 102a.

As described above, the border area 226 extends around the central area 120 and thus Low-E coating 122. However, the border area 226 can have a uniform of non-uniform width. Referring the Figure 4a, in an embodiment the border area 226 has a uniform width where a width w1 extending from a top edge 412 of the central area 120 to an edge 410 of the window unit 100a is the same as a width w2 extending from a side edge 414 of the central area 120 to a side edge 416 of the window unit 100a. Accordingly, in an embodiment, w1=w2. However, w1 is not always the same as w2 and the border area 226 can have a non-unfirm width. For example, with reference to Figure 4b, w1 >w2 in window unit 100b. An advantage of having w1>w2 is that a larger area suitable to placement of solar cells can be utilised in e.g. top and bottom regions of a window unit where a user is less likely to notice a reduced field of vision. However, in an embodiment w2>w1 such that side regions of the window unit have larger area suitable to placement of solar cells. In an embodiment, w1 =w2 for two adjacent sides (e.g. top side and left side) of a window unit but a width w3=w4 for other two adjacent sides (e.g. bottom side and right side) of the window unit. For example w1 ,w2 > w3,w4.

The person skilled in the art will appreciate embodiments of the present disclosure may take many different forms. For example, the solar cells may be provided in any suitable arrangement oriented along edges of the first panel 102. Further, the Low- coating may have any suitable properties and may alternatively be applied to an inner surface of the panel 102.

Any discussion of the background art throughout this specification should in no way be considered as an admission that such background art is prior art, nor that such background art is widely known or forms part of the common general knowledge in the field in Australia or worldwide.

In the claims that follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word “include” or variations such as “includes” or “including” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments.

Claims

1 . A window unit for a building or structure, the window unit comprising: a first panel having a major surface and being at least largely transmissive for visible light; a plurality of solar cells each having an active area and being positioned along and in proximity of one or more edges of the first panel, the plurality of solar cells being located around a first area of the first panel in which the first panel is at least largely transmissive for visible light; and a solar selective coating located on or over the major surface of the first panel within a first projection area defined by a projection of the first area onto the major surface of the first panel in a direction parallel to a surface normal of the first panel, wherein an area surrounding the first projection area is at least largely free from the solar selective coating.

2. The window unit of claim 1 wherein a border area surrounding the first projection area is entirely free from the solar selective coating and wherein the solar selective coating is coating the entire first projection area.

3. The window unit of claim 1 wherein the first projection area is surrounded by a border area and wherein the border area is largely to entirely free from the solar selective coating.

4. The window unit of claim 3 wherein the border area has a uniform width.

5. The window unit of claim 3, wherein the border area has a non-uniform width.

6. The window unit of any one of claims 3 to 5 wherein the border area has a width in a range of 0.1 -0.2, 0.2-0.5, 0.5-1 , 1 -1 .5, 1 .5-2, 2-2.5, 2.5 - 3, 3-3.5, 3.5-4, 4-4.5 and 4.5-5 cm or more.

7. The window unit of any one of claims 3 to 5 wherein the first projection area includes the coated area and the border area has a total extension ranging from a few 10 centimetres to a few metres.

8. The window unit of any one of the preceding claims wherein the solar selective coating is a low emissivity coating (“Low-E coating”), which is at least largely transmissive for visible light, but blocks at least a portion of infrared light and/or ultraviolet light.

9. The window unit of any one of the preceding claims wherein the first major surface the first panel faces an outside of a building or structure into which the window is use incorporated and wherein the first panel comprises a second major surface which in use faces towards an interior space of the building or structure, wherein the solar cells of the plurality of solar cells face the second major surface directly and wherein the solar selective coating is applied to the first or second major surface of the first panel.

10. The window unit of any one of the preceding claims comprising a second panel which is parallel to the first panel and spaced apart from the first panel, the second panel being at least largely transmissive for visible light.

11 . The window unit of claim 9 comprising a further solar selective coating located on or over a major surface of the second panel within a third projection area defined by a projection of the first area onto the major surface of the second panel in a direction parallel to a surface normal of the second panel, and an area surrounding the third projection area is at least largely free from the solar selective coating.

12. The window unit of any one of the preceding claims wherein the window unit is arranged such that a central area of the window is transmissive for at least the majority of visible light and is at least 5, 10, 15, 20, 50, 100 or even 500 x larger than an area of the first panel at which the plurality of solar cells are positioned.

13. The window unit of claim 11 wherein a central area that is transmissive for at least the majority of visible light is transmissive for at least 60%, 70%, 80%, 90% or even at least 95% of visible light incident of a receiving surface of the first panel at normal incidence.