AU2021102142A4 - Device for generating electricity - Google Patents

Abstract

The present disclosure provides a device for generating electricity. The device comprises a panel having an area that 5 is transparent for at least a portion of visible light and having a light receiving surface. The panel comprises at least one series of solar cells, each solar cell having opposite major surfaces having opposite electrical polarities, each solar cell overlapping another one of the solar cells and .0 being electrically connected in series. The at least one series of solar cells is positioned along and in the proximity of an edge of the panel, along the area that is transparent for at least a portion of visible light and substantially parallel the light receiving surface of the panel. .5 19 1/3 100 104 102 106 110---....- I I II I I _ 108 Figure 1 102 116 108 112 112 112 112 Figure 2 110 108 102 - Figure 3 17542342_1 (GHMatters) P111629.AU.2

Description

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Figure 3

17542342_1 (GHMatters) P111629.AU.2

Device for generating electricity

Field of the Invention

The present disclosure relates to a device for generating electricity and relates particularly, though not exclusively, to a panel, such as a panel for a window comprising solar cells.

.0 Background of the Invention

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

.5 Overheating of interior spaces, such as spaces that receive sunlight through such window panels, is a problem that may be overcome using 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 largely transmissive for visible light, but diverts a portion of incident infrared light to side portions of the panel where it is absorbed by solar cells to generate electricity.

It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country.

Summary of the Invention

The present invention provides in a first aspect a device for

generating electricity, the device comprising:

a panel having an area that is transparent for at least a

portion of visible light and having a light receiving surface;

and

at least one series of solar cells, each solar cell

having opposite major surfaces having opposite electrical

.0 polarities, each solar cell overlapping another one of the

solar cells therein and being electrically connected in

series;

wherein the at least one series of solar cells is

positioned along and in the proximity of an edge of the panel,

.5 along the area that is transparent for at least a portion of

visible light and substantially parallel the light receiving

surface of the panel.

The panel may be a panel of a window and the device may .0 further comprise a frame structure for supporting the panel.

In this embodiment the device may be provided in the form of a

window unit for a building, such as an insulated glass unit.

The solar cells of the series of solar cells are positioned in

an overlapping relationship or in a shingle-like arrangement,

which has advantages for window applications. In such

applications space is limited and solar cells should be as

small as possible. Embodiments of the present invention avoid

gaps between adjacent solar cells. Consequently, a conversion

efficiency per area can be increased. Further, there is no

need for top contacts or fingers which would otherwise reduce

an area of each solar cell available for receiving photons for

generating electricity.

The solar cells of the at least one series of solar cells may

have a front surface portion which is directly or indirectly

bonded to the panel in a manner such that an airgap between

the solar cells and the panel is avoided. An additional

adhesive may be used for the bonding. In one embodiment the

adhesive has a refractive index that at least approximates

that of the panel material, which may for example be glass or

a suitable polymeric material. Alternatively, the solar cells

may have an outer layer of a polymeric material, such as

.0 Polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA) or

another suitable material. The solar cells are in this

embodiment directly bonded to the panel. For example, if the

solar cells comprise a layer of PVB or EVA or another suitable

material, that material may be slightly softened and then

.5 adhered directly to the panel. As a gap between the panel and

the solar cells is avoided, light intensity losses of light

propagating from the panel into the solar cell are reduced.

The device may comprise a plurality of the series of solar .0 cells and which may be positioned around (and may surround)

the area that is transparent for at least a portion of visible

light. The plurality of the series of solar cells may be

positioned in the proximity of edges of the panel such that

the panel is largely transparent for at least a portion of

visible light and the area that is transparent for at least a

portion of visible light is a central area and at 5, 10, 15,

20, 50, 100 or even 500 x larger than an area of the panel at

which the series of the solar cells are positioned.

The at least one series of the solar cells typically is

positioned at a panel surface that is opposite the light

receiving surface such that light received by the light

receiving surface propagates through at least a portion of the

panel before reaching the at least one series of solar cells.

The panel may have four edges and at least one of the series

of solar cells may be positioned at each edge of the panel.

In one specific embodiment the at least one series of solar

cells comprises at least two series of solar cells which may

be positioned at adjacent edges of the panel and which may be

electrically connected in series or in parallel.

.0 In one embodiment adjacent ones of the at least two series of

the solar cells may be oriented at an angle relative to each

other (such as an angle in the range of 80 - 100 degrees or

substantially 90 degrees) and may face the light receiving

surface. At least one solar cell of the at least two series

.5 of solar cells may overlap with, and may be electrically

series connected to, at least one solar cell of an adjacent

one of the at least two series of solar cells whereby the at

least two series of solar cells are electrically series

connected. Alternatively, at least one solar cell of the at .0 least two series of solar cells may overlap with, and may be

electrically insulated from, at least one solar cell of an

adjacent one of the at least two series of solar cells and the

at least two series of solar cells may be electrically

connected in parallel.

In one specific example a solar cell positioned at an end of

one of the at least two series of solar cells overlap a solar

cell of the adjacent one of the at least two series of solar

cells in a manner such that the adjacent series of solar cells

form an angle, such as an angle of substantially 90 degrees.

In one specific embodiment the panel has a substantially right

angle and has a generally rectangular shape. Adjacent series

of solar cells may be positioned at adjacent edges of the panel such that the adjacent series of solar cells form a substantially right angle. In this embodiment a solar cell positioned at an end of adjacent series of solar cell may form an overlapping relationship with a side surface of a solar cell positioned at an end of the adjacent series of solar cells.

In one embodiment adjacent ones of the at least two series of

the solar cells are substantially parallel to each other and

.0 face the light receiving surface. At least one solar cell of

the at least two series of solar cells may overlap with and

may or may not be electrically series connected to, at least

one solar cell of an adjacent one of the at least two series

of solar cells. Further, a first and a second series of the

.5 solar cells may be positioned immediately adjacent (and

substantially parallel to) each other and all or at least most

of the solar cells of the first series may overlap with

respective solar cells of the second series. At least some or

all of the solar cells of the first series may be electrically .0 isolated or may be electrically connected with the respective

solar cells of the second series. In one specific embodiment

the solar cells of the first series are electrically connected

with respective ones of the solar cells of the second series

and the solar cells of the second series are electrically

series connected. Alternatively, the first and second series

of solar cells may be electrically insulated from each other

and the solar cells or the first series may be series

connected and the solar cells of the second series may be

electrically series connected.

The solar cells of the first and second series may be inclined

in the same manner and direction. Alternatively, the solar

cells of the first and second series may be inclined in a

opposite manner and direction. Further, the solar cells of the first and second series may be inclined by the same or different angles relative to a surface normal of the receiving surface.

The panel may be a first panel and the device may comprise a

second panel that may be positioned substantially parallel the

first panel in a manner such that light received by the light

receiving surface of the first panel initially propagates

through the first panel before being received by the second

.0 panel. The second panel may also have an area that is

transparent for at least a portion of visible light.

Each solar cell may have a rear surface portion that is

directly or indirectly bonded to the second panel whereby each

.5 solar cell of the first series and/or second series may be

directly or indirectly bonded to both the first and the second

panels and each solar cell is sandwiched between the first and

second panels. In this embodiment both the front and also the

rear surfaces of the device are surfaces of the first or .0 second panel (which may be glass panels), which has the

advantage of protecting the solar cells and also has the

advantage of providing reliable (vacuum) sealing surfaces for

window application.

The at least one series of solar cells may be at least one

series of first solar cells and the device may further

comprise at least one series of second solar cells positioned

at the second panel. Each second solar cell may have opposite

major surfaces having opposite electrical polarities, each

second solar cell may overlap with another one of the second

solar cells and may or may not be electrically connected in

series, wherein the at least one series of second solar cells

is positioned along and in the proximity of an edge of the second panel and facing the light receiving surface of the first panel.

The second solar cells may be bonded to the second panel, such

as directly bonded, in a manner such that an airgap between

the second solar cells and the second panel is avoided.

The second panel may have four edges and may comprise at least

one of the series of second solar cells positioned at each

.0 edge of the second panel.

In one specific embodiment the at least one series of solar

second cells comprises a plurality of series of second solar

cells which are oriented at adjacent edges of the second

.5 panel. The series of the second solar cells may be oriented at

an angle relative to each other (such as an angle in the range

of 80 - 100 degrees or substantially 90 degrees). At least

one solar cell of one of the series of second solar cells may

overlap with at least one solar cell of an adjacent series. In .0 one specific example a solar cell positioned at an end of one

of the series of second solar cells and may overlap with a

solar cell of an adjacent series of second solar cells in a

manner such that the adjacent series of solar cells form an

angle. The overlapping solar cells at the ends of the adjacent

series of second solar cells may be electrically connected to

each other whereby the adjacent series of solar cells are

electrically series connected. Alternatively, the overlapping

solar cells at the ends of the adjacent series of second solar

cells may be electrically insulated from each other and the

adjacent series of solar cells may be electrically connected

in parallel.

In one specific embodiment the second panel has a

substantially right angle and a generally rectangular shape.

At least two of series of second solar cells may be positioned

at adjacent edges of the second panel such that adjacent

series form a substantially right angle. In this embodiment a

second solar cell positioned at an end of one of the series of

second solar cells may overlap with a side surface of a second

solar cell positioned at an end of an adjacent series of

second solar cells.

The second panel may further comprise a diffractive element

.0 and/or luminescent material in order to facilitate redirection

of incident infrared light to edges of the second panel.

Further, the device may comprise at least one series of third

solar cells that is positioned at at least one edge surface of

.5 the second panel and oriented substantially perpendicular to a

major surface of the second panel whereby the at least one

series of third solar cells is positioned substantially

perpendicular to the series of first solar cell at the first

panel and the series of second solar cells at the second .0 panel. The series of third solar cells is positioned to

receive at least a portion light redirected by the diffractive

element and/or the luminescent material. The deflection of

infrared radiation by the diffractive element has the further

advantage that transmission of infrared radiation into

buildings (when the panel is used as a window pane) can be

reduced, which consequently reduces overheating of spaces

within the building and can reduce costs for air conditioning.

The solar cells may be silicon-based solar cells, but may

alternatively also be based on any other suitable material,

such CIGS or CIS, GaAs, CdS or CdTe.

In one specific embodiment the solar cells of the series of

first solar cells and the series of second solar cells are silicon-based and the solar cells of the series of third solar cells are CIS- or CIGS-based.

The invention will be more fully understood from the following

description of specific embodiments of the invention. The

description is provided with reference to the accompanying

drawings.

Brief Description of the Drawings .0

Figure 1 is a schematic top view of a device for generating

electricity in accordance with an embodiment of the present

invention;

.5 Figure 2 is a schematic cross-sectional representation of a

component of the device for generating electricity in

accordance with an embodiment of the present invention;

Figure 3 is a schematic top view of a portion of the device for generating electricity shown in Figure 1; and

Figures 4 and 5 are schematic cross-sectional representations

of a portion of the device in accordance with an embodiment of

the present invention.

Detailed Description of Embodiments

Referring initially to Figure 1, there is shown a schematic

top view of a device for generating electricity 100 in

accordance with an embodiment of the present invention. The

device 100 comprises a panel 102 and in this embodiment four

series of solar cells 104 106, 108,110 are positioned at

respective edges of the panel 102. The four series of solar cells 104 106, 108,110 face a light receiving surface of the panel and together surround an area of the panel that is at least largely transmissive for light. The panel 102 may for example form a panel of a window of a building or another structure and the four series of solar cells 104 106, 108,110 may be positioned at a frame structure that supports the panel

102 and one or more other panels to for a window unit.

The panel 102 may have any shape, but in one specific

.0 embodiment is rectangular and may be square. The panel 102 may

be formed from suitable glass or polymeric materials.

Figure 2 shows a cross-sectional representation of a portion

of the panel 102 and a portion of the series of solar cells

.5 108. The solar cells 112 of the series of solar cells 108 and

arranged in an overlapping relationship and electrically

coupled using a conductive adhesive 116. The solar cells 112,

have opposite major surfaces and which have different

polarities and are oriented such that only surfaces of the .0 same polarities face the panel 102. The conductive adhesive

116 couples a back face of one of the solar cells 112 with a

front face of an adjacent solar cell 112. Consequently, the

solar cells of the series of solar cells are electrically

series connected.

The solar cells 112 are adhered directly to the panel 102. In

this example the solar cells 112 comprise outer ETA layers.

Prior to adhering the solar cells 112 to the panel 102, the

ETA is slightly softened (by the careful application of heat)

and then the solar cells 112 are pressed against the panel

102. Once the softened ETA has hardened again, the solar cells

are adhered to the panel 102.

Figure 2 is a schematic representation only. A person skilled

in the art will understand that the solar cells 112 relatively

long compares to their thickness and consequently the solar

cells 112 are substantially parallel the panel 102 even though

they are arranged in an overlapping (shingled) relationship.

Turning now to Figure 3, there is shown a schematic

representation of a corner region of the of the device shown

in Figure 1. Figure 3 shows a portion of the panel 102 and a

.0 portion of adjacent series of solar cells 108, 110. In this

embodiment the series of the solar cells 108, 110 form a right

angle and an end surface of a solar cell positioned at end of

the series 110 of solar cells overlaps with a side portion of

a solar cell positioned at an end of the other series 108 of

.5 solar cells. The overlapping portions of the solar cells are

electrically series connected using a conductive adhesive 116

in the same manner as illustrated above with reference to

Figure 2. In a variation of the described embodiment the

overlapping portions of the solar cells at the ends of the .0 series 108, 110 are electrically insulated from each other and

the series of solar cells 108, 110 are electrically parallel

connected.

Turning now to Figure 4, there is shown a cross-sectional view

of a portion of a window unit in accordance with an embodiment

of the present invention. The window unit 400 comprises the

panel 102 with the series of (shingled) solar first cells 104,

106, 108 and 110, which are encapsulated by a layer of ETA

109. The panel 102 has a light receiving surface 103. In this

embodiment the panel 102 is a first panel and the window unit

400 also comprises a second panel 402, which is positioned

parallel, and spaced apart from, the first panel 102. The

second panel 402 has series of solar cells 404 directly

adhered to it in the same manner as illustrated above for the first panel 102 and with reference to Figures 1, 2 and 3. In this embodiment the panels 102 and 402 are rectangular and each comprise four series of solar cells that are adhered at edge portions of the panels 102, 404 and positioned as illustrated in Figure 1. The series of solar cells comprise overlapping (shingled) solar cells as illustrated in Figure 2 and corners are formed in a manner as illustrated above in

Figure 3 for the first panel 102.

.0 The window unit 400 also comprises a frame structure 405 that

is arranged to hold the panels 102 and 402 and the series of

solar cells in position.

The panels 102 and 404 comprise in this embodiment respective

.5 panes of glass that are each largely transmissive for visible

light. In an embodiment, the glass panes that form the panels

102 and 404 are formed of low iron ultra-clear glass pane,

with the panel 404 additionally having a low-E coating.

In the embodiment shown in Figure 4 the panel 404 is a

laminate structure having three sub-panes 404a, 404b and 404c.

The sub-pane 404a is formed of low iron ultra-clear glass

having a thickness of 4 mm, and second and third panes 404b

and 404c are each formed from ultra-clear glass having a

thickness of 4 mm. The sub-panes 404a, 404b and 404c mate with

each other to form a stack of the sub-panes substantially

parallel to one another. Disbursed between panes 404a and 404b

is an interlayer 410 of polyvinyl butyral (PVB). A PVB

interlayer 412 is also located between sub-pane 404b and 404c,

but PVB interlayer 412 also includes a light scattering

element. In this embodiment the light scattering element

comprises a luminescent scattering powder embedded in the PVB,

which also includes an epoxy that provides adhesion. The panel

404 also includes a diffraction grating that is arranged to facilitate redirection of light towards edge region of the panel 404 (i.e. towards the frame 20) and guiding of the light by total internal reflection.

It should be appreciated that the panel 404 could have any

number of panes with any number of interlayers. In some

embodiments the panel 404 may comprise a single piece of

optically transmissive material such as glass.

.0 The panel 404 has an edge 411 that has a plane which is

transverse to the light receiving surface 103. In the

embodiment of Figure 2, the angle between the edge 411 and the

light receiving surface 103 is 90°.

.5 The window unit 400 also has series of third solar cells 414.

The series of third solar cells 414 face the edge 411 and a

cavity between the first panel 102 and the second panel 404.

The series of third solar cells 414 substantially surround the

second panel 404 and are positioned to receive light that is redirected by the scattering material and/or the diffractive

element (not shown) to the edges 416 of the second panel 404.

Further, the series of third solar cells 414 also receives

light at an area which faces the cavity between the first

panel 102 and the second panel 404.

Figure 5 shows a device for generating electricity in

accordance with a further embodiment of the present invention.

Figure 5 shows the device 500 having a first panel 502 and a

second panel 504. The first and second panels 502, 504 are

transmissive for at least 70% of incident visible light

(limited by the transmissivity of the panel material, such as

glass). The device 500 comprises the above-described series of

solar cells 104 106, 108, 110 (only the series 104 is shown in

Figure 5) positioned at respective edges of the panels 502,

504.

The solar cells 104 106, 108, 110 each have light receiving

surface portions facing the panel 502 and adhered to the panel

502 such that no air gap is present between the solar cells

104, 106, 108, 110 and the panel 502. Further, the solar cells

104, 106, 108, 110 each have a rear surface portions facing

the panel 504 and adhered to the panel 504. In this example

.0 the solar cells 104, 106, 108, 110 comprise outer polyvinyl

butyral (PVB) or ethylene-vinyl acetate (EVA) layers at the

front surfaces. A sheet of excluded-volume-branched-polymers

(EVB) or Ethylene tetrafluoroethylene (ETFE) is placed between

the panels 502 and 504 such that the sheet is also positioned

.5 between the rear surfaces of the solar cells 104, 106, 108,

110 and panel 504. Prior to adhering the solar cells 104, 106,

108, 110 to the panels 502, 504 (and the panels 502, 504 to

each other) the PVB, ETA, EVB or ETFE is slightly softened (by

the careful application of heat) and then the panel 502, 504

are pressed together such that the solar cells 104, 106, 108,

110 are positioned between the panels 502, 504. Once the

softened PVB, ETA, EVB or ETFE has hardened again, the solar

cells are sandwiched between, and adhered to, the panels 502,

504 without the need of an additional adhesive whereby a

laminated structure is formed. The panels 502, 504 protect the

solar cells 104, 106, 108, 110 and also provide reliable

sealing surfaces at both front and rear sides of the device,

which is advantageous for window applications.

In the present embodiment, the series of first and second

solar cells 104, 106, 108, 110, 408 may be silicon-based solar

cells, but can alternatively also be based on any other

suitable material such CdS, CdTe, GaAs, CIS or CIGS. The

series of third solar cells 414 may be CIS or CIGS-based, but

14 175423411 (GHMatters) P111629.AU.2 may alternatively also be based on any other suitable material such SI, CdS, CdTe, or GaAs.

Whilst a number of specific embodiments have been described,

it should be appreciated that the disclosed unit 400 maybe

embodied in many other forms. For example, the unit 400 may

not necessarily be rectangular, but may alternatively have any

other suitable shape (such as for example round or rounded).

Further, the panel 404 may comprise any suitable number of

.0 sub-panels. Further, the window unit may comprise a third

panel such that a triple glazing unit is formed.

Any discussion of the background art throughout this

specification should in no way be considered as an admission

.5 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.

Further, a person skilled in the art will appreciate that .0 modifications of the described embodiments are possible. For

example, the solar cells within each series may not

necessarily be series connected. The device may also comprise

adjacent and substantially parallel series of solar cells. The

adjacent and substantially parallel series of solar cells may

overlap such that each solar cell of a first series overlaps

with a (or a respective) solar cell an immediate adjacent and

substantially parallel series of the solar cells. The solar

cells of a first series may be electrically series connected

or alternatively may be electrically isolated from each other

and electrically connected with the respective solar cells of

a second series. For example, the solar cells of the first

series may be electrically connected with respective ones of

the solar cells of the second series and the solar cells of

the second series are electrically series connected. The solar cells of the first and second series may be inclined in the same manner and direction. Alternatively, the solar cells of the first and second series may be inclined in a opposite manner and direction. Further, the solar cells of the first and second series may be inclined by the same or different angles relative to a surface normal of the receiving surface.

Claims (4)

Claims

1. A device for generating electricity, the device comprising: a panel having an area that is transparent for at least a portion of visible light and having a light receiving surface; and at least one series of solar cells, each solar cell having opposite major surfaces having opposite electrical .0 polarities, each solar cell overlapping another one of the solar cells therein and being electrically connected in series; wherein the at least one series of solar cells is positioned along and in the proximity of an edge of the .5 panel, along the area that is transparent for at least a portion of visible light and substantially parallel the light receiving surface of the panel.

2. The device of claim 1 wherein the device is provided in '0 the form of a window unit for a building and wherein the solar cells of the series of solar cells are positioned in an overlapping relationship or in a shingle-like arrangement.

3. The device of claim 1 or 2 wherein solar cells of the at least one series of solar cells are bonded to the panel in a manner such that an airgap between the solar cells and the panel is avoided.

4. The device of any one of the preceding claims comprising at least two series of solar cells positioned along adjacent edges of the panel and wherein adjacent ones of the at least two series of the solar cells are oriented at an angle relative to each other and substantially parallel to the light receiving surface of the panel and wherein the at least one solar cell of the at least two series of solar cells overlaps with at least one solar cell of an adjacent one of the at least two series of solar cells and are electrically connected whereby the at least two series of solar cells are electrically series connected, and wherein the at least one solar cell of the at least two series of solar cells overlaps with, and is electrically insulated from, at least one solar cell of an adjacent one of the at

.0 least two series of solar cells and the at least two series

of solar cells are electrically connected in parallel.

.5