U.S. patent application number 11/770699 was filed with the patent office on 2008-11-27 for flat roof tile with integrated photovoltaic module.
This patent application is currently assigned to LUMETA, INC.. Invention is credited to Timothy M. Davey, Brian J. Flaherty.
Application Number | 20080289272 11/770699 |
Document ID | / |
Family ID | 40071103 |
Filed Date | 2008-11-27 |
United States Patent
Application |
20080289272 |
Kind Code |
A1 |
Flaherty; Brian J. ; et
al. |
November 27, 2008 |
FLAT ROOF TILE WITH INTEGRATED PHOTOVOLTAIC MODULE
Abstract
A roofing module provides weather protection generates
electrical power. The module includes an injection molded base
having a size, a shape and an appearance of a conventional flat
concrete roofing tile with a top surface having a slate-like
striated texture. The base is made from lightweight plastic
material. The base includes a depressed portion in an upper
surface. A photovoltaic panel assembly is positioned in the
depressed portion with electrical conductors from the photovoltaic
panel passing through an opening in the depressed portion.
Inventors: |
Flaherty; Brian J.; (Alamo,
CA) ; Davey; Timothy M.; (Newport Beach, CA) |
Correspondence
Address: |
JERRY TURNER SEWELL
P.O. BOX 10999
NEWPORT BEACH
CA
92658-5015
US
|
Assignee: |
LUMETA, INC.
Irvine
CA
|
Family ID: |
40071103 |
Appl. No.: |
11/770699 |
Filed: |
June 28, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60940408 |
May 26, 2007 |
|
|
|
Current U.S.
Class: |
52/173.3 |
Current CPC
Class: |
Y02E 10/50 20130101;
Y02B 10/10 20130101; H02S 20/25 20141201 |
Class at
Publication: |
52/173.3 |
International
Class: |
E04D 13/18 20060101
E04D013/18 |
Claims
1. A roofing module that provides weather protection and that
generates electrical power, comprising: a base comprising a
generally rectangular injected molded plastic structure having the
size and appearance of a conventional concrete roofing tile,
including a striated upper surface; and a photovoltaic panel
assembly positioned in a depressed portion of the grooved upper
surface of the base, the photovoltaic panel assembly comprising a
photovoltaic panel installed in a panel support frame, the panel
support frame being removably installable in the depressed portion
of the base with at least a pair of electrical output conductors
that pass through the upper surface of the base.
2. The roofing module as defined in claim 1, wherein: the
photovoltaic panel includes an output module extending from a lower
surface, the output module enclosing electrical connections between
electrical output conductors on the photovoltaic panel and
weather-resistant electrical conductors, the that provides weather
protection and that generates electrical power; the panel support
frame includes at least one opening aligned with the output module
to receive the output module when the photovoltaic panel is
installed in the panel support frame; and the base includes an
opening aligned with the opening in the panel support frame to
receive an extended portion of the output module when the panel
support frame with the photovoltaic module is installed in the
base.
3. The roofing module as defined in claim 1, wherein the base
includes a plurality of notches formed along one boundary of the
depressed portion to allow water to drain from the depressed
portion.
4. The roofing module as defined in claim 1, wherein the base
includes a first interlocking groove at one edge and an
interlocking tab at an opposite edge, the interlocking tab
configured to engage the interlocking groove of an adjacent module
and also to engage an interlocking groove of a conventional
concrete roofing tile.
5. A method of constructing a roofing tile having an integrated
photovoltaic array, comprising: constructing a photovoltaic
assembly, comprising: installing a photovoltaic array in a frame
having a central depressed portion sized to receive the
photovoltaic array, the photovoltaic array including at least a
pair of electrical conductors; and securing the photovoltaic array
to the frame; and installing the photovoltaic assembly in a
injection molded base having a size, a shape and an appearance
selected to correspond to a size, a shape and an appearance of a
conventional concrete roofing tile with a slate-like striated upper
surface such that the base is interchangeable with the conventional
concrete roofing tile, comprising: positioning the photovoltaic
assembly in a depressed portion of an upper surface of the
injection molded base; passing the at least a pair of electrical
conductors through an opening in the upper surface of the injection
molded base; and securing the photovoltaic assembly to the
injection molded base.
Description
RELATED APPLICATIONS
[0001] The present application claims the benefit of priority under
35 U.S.C. .sctn.119(e) to U.S. Provisional Application No.
60/940,408, filed on May 26, 2007.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to solar panels for generating
electrical energy and more particularly relates to solar modules
integrated into a flat roof tile.
[0004] 2. Description of the Related Art
[0005] Conventional solar panels for generating electrical power
for residences are flat and are placed on a portion of the roof
that faces the sun during midday. Originally, the solar panels were
mounted over existing roofing materials (e.g., shingles) and formed
a generally unaesthetic addition to a home. In some areas, the
solar panels were not permitted because of the unattractive
appearance. Recently developed solar panels are constructed in
sizes and shapes that can be mounted directly to the underlying
roof structure as replacements for flat roofing materials (e.g.,
flat concrete tiles) such that the solar panels provide the dual
purpose of generating electrical power in response to sunlight and
of providing protection from moisture intrusion while integrating
in an aesthetically pleasing way with the roof system.
SUMMARY OF THE INVENTION
[0006] The roofing tile with integrated modular solar panel
described herein and illustrated in the attached drawings enables
the electricity-generating solar panel to be included in a seamless
application with a conventional roofing tile because the solar
panel is advantageously embodied in a shape and size of a
conventional flat tile. As discussed herein, the size and shape of
the solar panel tile may be adapted to the size and shape of tiles
from a number of different manufacturers. The size and shape of the
solar panel tile enables the same roofing mechanic who installs the
conventional roofing tiles to install the solar panel tile without
any special tools or fasteners. In particular, the solar panel
tiles interlock with or overlap with adjacent conventional tiles
when installed in the same course. The adjacent tiles may be solar
panel tiles or conventional roofing tiles. The solar panel tiles
have aesthetic features that match the aesthetic features of the
conventional tiles.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Certain aspects in accordance with embodiments of the
present invention are described below in connection with the
accompanying drawing figures in which:
[0008] FIG. 1 illustrates a top perspective view of a first
embodiment of a solar panel tile;
[0009] FIG. 2 illustrates a bottom perspective view of the solar
panel tile of FIG. 1;
[0010] FIG. 3 illustrates an exploded perspective view of the solar
panel tile of FIG. 1 looking at the top in the direction of FIG. 1
showing the base tile, the panel frame and the solar panel;
[0011] FIG. 4 illustrates an exploded perspective view of the solar
panel tile of FIG. 1 similar to the view of FIG. 3 but with the
solar panel tile rotated to show the lower edge;
[0012] FIG. 5 illustrates an exploded perspective view of the solar
panel tile of FIG. 1 looking at the bottom in the direction of FIG.
2;
[0013] FIG. 6 illustrates a cross-sectional elevation view of the
solar panel taken along the line 6-6 in the exploded view of FIG.
3;
[0014] FIG. 7 illustrates a cross-sectional elevation view taken
along the lines 7-7 in FIG. 1;
[0015] FIG. 8 illustrates a perspective view of an embodiment of a
photovoltaic panel advantageously incorporated into the solar panel
tile of FIGS. 1-7;
[0016] FIG. 9 illustrates an enlarged cross-sectional view of the
photovoltaic panel of FIG. 8 taken along the lines 9-9 in FIG. 8;
and
[0017] FIG. 10 illustrates an exploded perspective view of the
photovoltaic panel of FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIGS. 1-7 illustrate an embodiment of a flat solar panel
tile 100 suitable for mass production using injection molding
techniques. The solar panel tile 100 comprises a tile base 102 and
a solar panel assembly 104. The solar panel assembly comprises a
solar panel support frame 106 and a photovoltaic panel (solar cell
array) 108.
[0019] The tile base 102 is sized and shaped to conform to the size
and shape of a conventional flat concrete tile configured to
simulate the aesthetic appearance of a slate tile. In particular,
the tile base has a plurality of striations (e.g., closely spaced
grooves and ridges) formed on an exposed top surface 112 that are
similar to the grooves on a concrete tile so that the top surface
provides a "slate-like" appearance when viewed from a distance. An
opposing bottom surface 114 (FIG. 2) of the tile base is formed as
a plurality of strengthening ribs 116. Preferably, the tile base
comprises injected molded plastic.
[0020] In the following description, "top" and "bottom" are used to
designate the two opposing surfaces 112, 114 with respect to the
"thickness" of the solar panel tile 100; "upper" and "lower" and
"height" refer to the aspects of the tile with respect to a
vertical direction along the slope of a roof (not shown) when a
solar panel tile is oriented in a typical roof installation; and
"left" and "right" and "width" refer to aspects of the tile with
respect to a horizontal direction across the roof.
[0021] The top surface 112 of the tile base 102 has a horizontal
width of approximately 34.6 inches and has a height of
approximately 17 inches. In the illustrated embodiment, the tile
base has an overall thickness from the top surface to the bottom
surface 114 of approximately 1.25 inches. In general, the plastic
is molded to have a structural thickness of approximately 0.125
inches in most locations; however, the plastic may be thicker in
some portions of the structure and thinner in other portions of the
structure in accordance with the mold characteristics.
[0022] The solar panel tile 100 is positioned in FIG. 1 with an
upper edge 120 of the tile base 102 located toward the lower left
in the drawing and with a lower edge 122 located toward the upper
right in the drawing. The tile base is configured to be positioned
on a roof in a horizontal rank with the upper edge of the tile base
positioned beneath a lower edge of a tile in a next higher rank
such that the tiles in higher ranks overlap tiles in the next lower
rank in a conventional manner. The top surface of the tile base
includes a plurality of holes 124 (e.g., 6 holes) formed
approximately 1.8 inches from upper edge and extending through the
thickness of the tile base. Each hole has a diameter of
approximately 0.078 inch. When the solar panel tile is installed on
a roof, a fastener may be driven through the holes to secure the
tile to the roof. The holes are covered by an overlapping portion
of a tile in a higher rank on the roof.
[0023] The top surface 112 of the tile base 102 has a left edge 130
shown at the lower right for the orientation of the tile base in
FIG. 1. The tile base includes a lower interlocking tab 132 that
extends outwardly from the left edge by approximately 1 inch. An
interlocking groove 134 is formed in the tab parallel to the left
edge.
[0024] The top surface 112 of the tile base 102 has a right edge
140 shown at the upper left in the orientation of the tile base in
FIG. 1. An interlocking tongue 142 extends downwardly below the top
surface proximate to the right edge. The tongue is sized and
positioned so that the tongue engages the interlocking groove 134
when the right edge of the tile base is placed adjacent to the left
edge of a tile in the same horizontal rank. Thus, two horizontally
adjacent tiles are interlocked. In addition, any water draining
into the space between the left and right edges of adjacent tiles
is drained by the groove to the top surface of a tile in the next
lower rank.
[0025] As shown in FIGS. 3 and 4, the top surface 112 of the tile
base 102 has a recessed portion 150. The recessed portion has a
generally rectangular shape having a width from left to right of
approximately 32.3 inches. The recessed portion has a height in the
direction from the upper edge of the tile base toward the lower
edge of the base tile of approximately 12.4 inches. The boundaries
of the recessed portion are defined by four perimeter walls. An
upper boundary wall 152 is offset from the upper edge 120 of the
tile base by approximately 4.2 inches. A lower boundary wall 154 is
offset from the lower edge 122 of the tile base by approximately
0.5 inch. A left boundary wall 156 is offset from the left edge 130
of the base tile by approximately 1 inch. A right boundary wall 158
is offset from the right edge 140 of the tile base by approximately
1.3 inches. The recessed portion has bottom surface 160 at a depth
from the top surface of approximately 0.55 inch.
[0026] As further shown in FIGS. 2, 3 and 4, the recessed portion
150 includes a generally rectangular cutout 170. The cutout passes
through the tile base 102 from the bottom surface 160 of the
recessed portion to the bottom surface 114 of the tile base. The
ribs 116 of on the bottom surface of the tile base are removed in
the area encompassed by the cutout. In the illustrated embodiment,
the cutout has a width in the direction from the left boundary
towards the right boundary of approximately 4-4.25 inches, and has
a length in the direction from the upper boundary of the recess to
the lower boundary of the recess of approximately 2.5-2.75 inches.
The cutout is offset from the right boundary wall 158 of the recess
by approximately 0.5-0.75 inch. The cutout is positioned
approximately midway between the upper boundary wall 152 and the
lower boundary wall 154. The cutout may also be located elsewhere
in the recess in accordance with the positioning of electrical
connectors (discussed below) on the photovoltaic panel 108.
[0027] As further illustrated in FIGS. 3 and 4, the cutout 170 is
surrounded by a perimeter ridge 172 that has a thickness of
approximately 0.1 inch and that is raised above the bottom surface
160 of the recessed portion 150 by approximately 0.25 inch. Any
water that may collect on the bottom surface of the recessed
portion is blocked from flowing into the cutout by the perimeter
ridge. The lower boundary wall 154 of the recessed portion includes
a plurality (e.g., 3) of slots 174 that pass through the upper
surface 112 of the tile base 102 to permit any such water to drain
onto the top surface of a tile in the next lower rank of tiles or
to drain from the roof if the tile is in the lowest rank.
[0028] As shown in FIG. 3, the lower boundary wall 154 of the
recessed portion 150 further includes a plurality of rectangular
openings 180 (e.g., 3 openings) having widths of approximately 1
inch and having heights of approximately 0.375 inch. As shown in
FIG. 4, the upper boundary 152 includes a plurality (e.g., 3) of
generally circular openings 182 having diameters of approximately
0.156 inch.
[0029] The recessed portion 150 of the tile base 102 is sized and
shaped to receive the solar panel support frame 106. The support
frame comprises an injection molded plastic material with an upper
outer wall 202, a lower outer wall 204, a left outer wall 206 and a
right outer wall 208 that conform to the upper boundary wall 152,
the lower boundary wall 154, the left boundary wall 156 and the
right boundary wall 158 of the recessed portion. Each outer wall of
the support frame has a height of approximately 0.5 inch, which is
slightly less than the depth of the recessed portion so that when
the support frame is positioned within the recessed portion, the
top of each outer wall is generally flush with or slightly below
the upper surface 112 of the tile base 102. The rectangular outer
dimensions of the support frame are slightly smaller than the
rectangular dimensions of the recessed portion of the tile base so
that the support frame fits easily in the recessed portion with
little room for movement in any direction.
[0030] The support frame 106 includes a plurality of generally
rectangular protrusions 210 (e.g., 3 protrusions) extending from
the lower outer wall 204. The protrusions are positioned to be
aligned with and inserted into the rectangular openings 180 in the
lower boundary wall 154 of the recessed portion 150 of the tile
base 102. The support frame further includes a plurality of
circular openings 212 (e.g., 3 openings) extending partially
through the upper outer wall 202 below the level of the recessed
portion. When the support frame is inserted into the recessed
portion of the tile base, the circular openings in the support
frame are aligned with the circular openings 182 in the upper
boundary wall 152 of the recessed portion. As shown in FIG. 2 and
in FIG. 6, a fastener (e.g., a screw) 214 is inserted through the
aligned holes to secure the support frame to the tile base.
[0031] The support frame 106 has a recessed middle portion 220 that
has a depth of approximately 0.1875 inch to a lower surface 222 of
the recessed middle portion. Each outer wall of the support frame
106 has a thickness of approximately 0.25 inch. The recessed middle
portion of the support frame has a vertical length in the direction
from the inside of the lower outer wall 204 to the inside of the
upper outer wall 202 of approximately 12.31 inches and has a
horizontal width in the direction from the inside of the left outer
wall 206 to the inside of the right outer wall 208 of approximately
31.7 inches.
[0032] In the illustrated embodiment, the lower surface 222 of the
recessed middle portion 220 of the support frame 106 has a
plurality of openings 230 (e.g., 19 openings) formed therein to
reduce the mass of the support frame, which also reduces the
quantity of plastic needed to manufacture the support frame.
Sixteen of the openings are formed in a pattern of rectangular
openings with the sides having longer lengths parallel to the left
outer wall 206 and the right outer wall 208 and with sides having
shorter lengths parallel to the upper outer wall 202 and the lower
outer wall 204. Although illustrated as rectangular openings, the
openings may be configured in other shapes. Three of the openings
proximate the right outer wall are positioned with the respective
longer sides parallel to the upper outer wall and the lower outer
wall. One of the three openings is designated as a connector module
opening 232. The connector module opening aligned with and has
approximately the same dimensions as the outer dimensions of the
perimeter ridge 172 surrounding the cutout 170 in the recessed
portion 150 of the tile base 102. The size and position of the
connector module opening are also selected to match the position of
the positioning of electrical connectors (discussed below) on the
photovoltaic panel 108. As illustrated in the bottom view in FIG.
5, the rectangular openings are surrounded by a plurality of ribs
234 extending horizontally and vertically across the support frame
to provide a structurally stable frame.
[0033] The recessed middle portion 220 of the support frame 106 is
sized to receive the photovoltaic (solar cell array) panel 108. The
photovoltaic panel has a generally rectangular surface having a
horizontal width of approximately 31.65 inches, a vertical height
of approximately 11.75 inches and a thickness of approximately
0.1875 inch between an upper surface 304 and a lower surface 306.
The photovoltaic panel may have a conventional construction
comprising a plurality of cells connected in a selected
series-parallel combination to produce a desired output voltage
when solar energy is incident on the upper surface of the
photovoltaic panel. In a particularly preferred embodiment, the
photovoltaic panel is constructed in the manner described in FIGS.
8, 9 and 10, described below. The photovoltaic panel is secured in
the support frame by a suitable weather-resistant adhesive, such
as, for example, silicon adhesive.
[0034] The lower surface 306 of the photovoltaic panel 108 includes
an output module (junction box) 310, which is adhered to the lower
surface after the photovoltaic panel is constructed in the manner
described in FIGS. 8, 9 and 10. In particular, first and second
sturdy weather-resistant, external electrical conductors 312, 314
are electrically connected to the relatively fragile electrical
conductors (not shown) that provide the electrical output of the
cells in the photovoltaic panel.
[0035] After the electrical interconnections are completed and
tested, the output module (junction box) 310 is adhered to the
lower surface 306 of the photovoltaic panel 108 in a conventional
manner using epoxy sealant (see FIG. 6). The output module provides
electrical insulation over the electrical connections and that also
provides strain relief so that handling of the external electrical
conductors 312, 314 during installation of the flat solar tile 100
does not break the electrical connections or break the fragile
electrical conductors of the photovoltaic panel 108. Preferably,
the output module is formed using a mold (not shown) so that the
output module has predetermined dimensions (e.g., rectangular) that
fit within the cutout 170 in the tile base 102 and that pass
through the opening 232 in the support frame 106. For example, in
the illustrated embodiment, the output module has a horizontal
length of approximately 4.2-4.4 inches, a vertical width of
approximately 2.6-2.7 inches and a thickness of approximately 0.3
inch.
[0036] When the photovoltaic panel 108 is inserted in the support
frame 106 and the support panel is inserted in the tile base 102,
the output module fits within the aligned opening 232 in the
support frame and the cutout 170 in the tile base. The external
conductors 312, 314 extend below the tile base. As illustrated in
FIG. 5, the tile base includes a plurality of rib notches 320
formed in selected ones of the ribs 116 proximate the upper edge
120. The rib notches are sized to receive the external conductors.
One of the external conductors (e.g., the first conductor 312) is
routed through a first set of the rib notches and through a first
edge notch 322 in the upper edge 120 of the tile base proximate the
left edge 130. The other external conductor (e.g., the second
conductor 314) is routed through a second set of the rib notches
and through a second edge notch 324 in the upper edge proximate the
right edge 140.
[0037] A selected length of the first conductor 312 extends beyond
the first edge notch 322 and is terminated in a first weather
resistant connector 330 having a first mating polarity (e.g.,
female). A selected length of the second conductor 314 extends
beyond the second edge notch 324 and is terminated in a second
weather resistant connector 332 having a second mating polarity
(e.g., male). When a plurality of the solar tiles 100 are
positioned in a horizontal rank on a roof, the photovoltaic panels
108 in adjacent solar tiles are electrically connected in series by
plugging the male connector from one tile into the female connector
of the adjacent tile. The tile at each end of a horizontal rank of
tiles is connected to a respective cable connected to a control
system (not shown) in a central location that receives the
electrical outputs from the strings and provides a system power
output in a conventional manner.
[0038] As discussed above, the photovoltaic panel 108 may be a
conventional photovoltaic panel configured to have the dimensions
described above. In preferred embodiments, the photovoltaic panel
is constructed in accordance with a laminated photovoltaic panel
600 illustrated in FIGS. 8, 9 and 10. The photovoltaic panel 600 is
configured as a generally rectangular panel, which is sized and
shaped to fit in the depressed central portion 220 of the support
frame 106.
[0039] As illustrated in FIGS. 8, 9 and 10, a laminated
photovoltaic panel 600 is configured as a generally rectangular
panel, which is sized and shaped to fit in the depressed central
portion 220 of the support frame 106. In the illustrated
embodiment, the panel 600 has dimensions of approximately and has a
thickness of less than approximately 0.2 inch to fit within the
depth of the depressed central portion.
[0040] The panel 600 has a transparent upper protective layer 610
that faces upward and is exposed to the sun. A middle layer 620 is
positioned beneath the upper protective layer 610. The middle layer
620 comprises a plurality of photovoltaic cells 622 that are
electrically interconnected. The middle layer 620 rests on a rigid
lower layer 630. The middle layer 620 is secured to the rigid lower
layer 630 by a lower adhesive layer 640. The middle layer 620 is
secured to the upper protective layer 610 by an upper adhesive
layer 650.
[0041] The upper protective layer 610 provides impact protection as
well as weather protection to the panel 600. The upper protective
layer 610 advantageously comprises DuPont.TM. Teflon.RTM.
fluorinated ethylene propylene (FEP) resin, which is formed into a
film layer of suitable thickness (e.g., approximately 0.1 inch).
Thus, the photovoltaic cells 622 in the middle layer 620 are
exposed to direct sunlight without being exposed to moisture and
other climatic conditions and without being exposed to direct
impact by feet, falling objects, and debris.
[0042] In the illustrated embodiment, the rigid lower layer 630
comprises fiber reinforced plastic (FRP). For example, the FRP
layer advantageously comprises a polyester resin with embedded
stranded glass fibers. In one advantageous embodiment, the FRP
layer has a thickness of approximately 0.079 inch. The rigid lower
layer of FRP provides an advantageous combination of light weight,
rigidity, very low permeability and flatness
[0043] Preferably, the lower adhesive layer 640 is provided as a
thin film that is positioned on the upper surface of the rigid
lower layer 630. The array of photovoltaic cells 622 in the middle
layer 620 is then positioned on the lower adhesive layer 640. In
the illustrated embodiment, the lower adhesive layer 640
advantageously comprises a transparent adhesive, such as, for
example, ethylene-vinyl-acetate (EVA). EVA is a transparent,
heat-activated adhesive that is particularly suitable for securing
the cells. Other suitable adhesives, such as, for example,
polyvinylbuterol (PVB), or other pottant materials, can be
substituted for the EVA. before positioning the photovoltaic cells
640 on the lower adhesive layer 640.
[0044] After positioning the array of photovoltaic cells 622 on the
lower adhesive layer 640, the upper transparent adhesive layer 650
is placed over the middle layer 620 so that the photovoltaic cells
622 are sandwiched between the two transparent adhesive layers. The
upper adhesive layer 650 should match the physical characteristics
of the lower adhesive layer 640. In the illustrated embodiment,
both the upper adhesive layer 650 and the lower adhesive layer 640
comprise EVA, but other suitable transparent adhesives can be
substituted for the EVA. The transparent upper protective layer 610
is then positioned over the upper transparent adhesive layer 650 to
complete the laminated structure shown in an enlarged partial cross
section in FIG. 9.
[0045] The EVA material and the use of the EVA material to bind the
layers of a laminated photovoltaic cell are described, for example,
in U.S. Pat. No. 4,499,658 to Lewis. In addition to acting as a
binder to secure the photovoltaic cells 622 between the upper
protective layer 610 and the lower rigid layer 630, the upper EVA
layer 650 and the lower EVA layer 640 also act as a cushion between
the two outer layers.
[0046] The photovoltaic cells 622 are electrically interconnected
in a series-parallel configuration in a conventional manner to
provide a suitable output voltage. For example, in the illustrated
embodiment, 12 photovoltaic cells 622 are arranged in 2 rows of 6
cells each. The photovoltaic panel 600 is illustrated with two flat
ribbon electrical conductors 660, 662 extending from right side of
the middle layer 620. The two conductors 660, 662 are electrically
connected to the external conductors 312, 314 within the connector
module 310 shown in FIGS. 1-7. In the illustrated embodiment, the
two electrical conductors 660, 662 are bent and are passed through
openings (not shown) in the rigid lower layer 630. Thus, the free
ends of the two conductors 660, 662 are exposed beneath the rigid
lower layer 630 for interconnection to the external conductors 312,
314 within the connector module 310, as described above.
[0047] The upper protective layer 610, the middle layer 620, the
lower layer 660, and the two adhesive layers 640 and 650 are
stacked in the order shown in FIGS. 9 and 10 and are aligned to
form the sandwich structure shown in FIGS. 8 and 9. The free end of
each of the two panel output conductors 660, 662 are covered with a
temporary covering (e.g., a cloth tube, or the like) during the
lamination process. The structure is permanently laminated in a
known manner using heat and pressure. In one advantageous
embodiment, the structure is laminated in a vacuum laminator in the
manner described, for example, in US Patent Application Publication
No. 2005/0178248 A1 to Laaly et al. In particular, the structure is
first subjected to a vacuum to remove any trapped gas bubbles in
the EVA adhesives. The structure is then subjected to high pressure
to force the layers together as tightly as practical. The structure
is then heated to a suitable temperature (e.g., approximately
160.degree. C.) to cure the adhesives in the layers 640 and 650 and
thereby permanently bond the adjacent layers. During the high
temperature portion of the process, a portion of the upper layer
610 softens sufficiently to form a coating that surrounds the outer
edges of the other layers, thus forming a moisture-resistant
coating around the entire structure. In the illustrated embodiment,
the upper layer 610 and the two transparent adhesive layers 640,
650 secure the panel output conductors 660, 662 to the top of the
middle layer 620. Preferably, the panel output conductors 660, 662
extend from the bottom of the middle layer 620 and pass through one
or more openings (not shown) in the rigid lower layer 630. The
opening through the bottom layer 630 is sealed during the
lamination process. In an alternative embodiment, the panel output
conductors 660, 662 are connected to the photovoltaic cells 622 on
the middle layer 620 after the lamination process is completed
using known interconnection techniques.
[0048] The laminated structure is held at the high temperature for
a sufficient time to cure the upper transparent adhesive layer 650
and the lower transparent adhesive layer 640 and to cause the two
transparent adhesive layers to adhere together to become a combined
layer that completely encapsulates the photovoltaic cells 622. The
high temperature also causes the upper transparent layer 610 to
soften and flow to provide the protective upper coating described
above. The laminated structure is then allowed to cool to ambient
temperature.
[0049] After the lamination process is completed, the two panel
ribbon conductors 660, 662 are connected to the two external
conductors 312, 314, as discussed above. The connections between
the conductors and a portion of the conductors are connected within
the output module 310, as further discussed above. The panel is
secured to the panel support frame 106, and the panel support frame
is secured to the tile base 102 to complete the assembly of the
complete flat solar tile 100.
[0050] In accordance with the embodiments disclosed herein, an
aesthetically flat solar tile 100 combines the weather protection
features and appearance of a conventional flat concrete "slate"
tile with the electrical energy generating capabilities of a solar
cell sandwich. The flat solar tile is easily installed with flat
concrete tiles to include electrical energy generation capability
on newly constructed roofs and can replace concrete tiles to add
electrical energy generation capability to existing roofs.
[0051] The present invention is disclosed herein in terms of a
preferred embodiment thereof, which provides a photovoltaic panel
integrated into a flat solar tile having the appearance of a
concrete "slate" tile, as defined in the appended claims. Various
changes, modifications, and alterations in the teachings of the
present invention may be contemplated by those skilled in the art
without departing from the intended spirit and scope of the
appended claims. It is intended that the present invention
encompass such changes and modifications.
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