U.S. patent application number 10/577640 was filed with the patent office on 2007-10-04 for solar tiles.
This patent application is currently assigned to SOLAR CENTURY HOLDINGS LIMITED. Invention is credited to Martyn John Charles Berry, Daniel Gower Davies.
Application Number | 20070227583 10/577640 |
Document ID | / |
Family ID | 29725767 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070227583 |
Kind Code |
A1 |
Davies; Daniel Gower ; et
al. |
October 4, 2007 |
Solar Tiles
Abstract
The invention consists of a solar thermal tile. The tile
comprises a transparent portion for permitting the entry of
sunlight into a heating space below the tile, and a chassis formed
separately from the transparent portion on which the transparent
portion is mounted. The chassis has at least one protrusion for
forming an overlapping relationship with a neighbouring tile. The
chassis may be formed from plastic or sheet metal. The transparent
portion may be formed from a polycarbonate laminate.
Inventors: |
Davies; Daniel Gower; (Bath,
GB) ; Berry; Martyn John Charles; (London,
GB) |
Correspondence
Address: |
DAVID E. HUANG, ESQ.;BAINWOOD HUANG & ASSOCIATES LLC
2 CONNECTOR ROAD
SUITE 2A
WESTBOROUGH
MA
01581
US
|
Assignee: |
SOLAR CENTURY HOLDINGS
LIMITED
91-94 LOWER MARSH, WATERLOO
LONDON
GB
SE1 7AB
|
Family ID: |
29725767 |
Appl. No.: |
10/577640 |
Filed: |
October 29, 2004 |
PCT Filed: |
October 29, 2004 |
PCT NO: |
PCT/GB04/04590 |
371 Date: |
March 2, 2007 |
Current U.S.
Class: |
136/251 ;
126/569; 126/621 |
Current CPC
Class: |
F24S 20/69 20180501;
Y02E 10/40 20130101; Y02B 10/10 20130101; H02S 20/25 20141201; Y02E
10/50 20130101; F24S 2020/17 20180501; Y02B 10/20 20130101; Y02E
10/44 20130101 |
Class at
Publication: |
136/251 ;
126/569; 126/621 |
International
Class: |
F24J 2/00 20060101
F24J002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2003 |
GB |
0325509.8 |
Claims
1-20. (canceled)
21. A set of tiles, incorporating at least one conventional roof
tile, at least one solar thermal tile and at least one photovoltaic
tile, wherein the at least one solar thermal tile comprises a
chassis on which is mounted a transparent portion for permitting
the entry of sunlight into a heating space below the at least one
solar thermal tile, the chassis being formed separately from said
transparent portion, wherein the chassis comprises at least one
protrusion on at least one edge and at least one aperture, said
transparent portion being located to cover the at least one
aperture, said protrusion being adapted to form an overlapping
relationship with a second tile when correctly mounted adjacent
thereto, wherein the at least one solar thermal tile has a tile
width which is a multiple of the width of the at least one
conventional roof tile, and wherein the at least one photovoltaic
tile comprises a photovoltaic cell, a chassis which is
substantially identical in external appearance to that of the at
least one solar thermal tile and a photovoltaic laminate, said
photovoltaic laminate being mounted in substantially the same
position on the photovoltaic tile chassis as the transparent
portion on the solar thermal tile chassis.
22. The set of tiles of claim 21, wherein the chasses comprise a
non-transparent material.
23. The set of tiles of claim 22, wherein the non-transparent
material is a plastic.
24. The set of tiles of claims 22, wherein the chasses are moulded
components.
25. The set of tiles of claim 22, wherein the non-transparent
material is a metal.
26. The set of tiles of claim 25, wherein the chasses comprise
folded sheet metal.
27. The set of tiles of claim 21, wherein the transparent portion
has peripheral edges, and the solar thermal tile chassis is
arranged to support the transparent portion at said peripheral
edges.
28. The set of tiles of claim 21, wherein the transparent portion
comprises sheet material.
29. The set of tiles of claim 21, wherein the transparent portion
is formed from polycarbonate material.
30. The set of tiles of claim 21, each chassis further
incorporating a rear overlap surface, the rear overlap surface
being formed to support a third tile placed above the at least one
solar thermal tile and/or the at least one photovoltaic tile.
31. The set of tiles of claim 21, wherein the chassis of the
photovoltaic tile further comprises at least one hole to allow
airflow.
32. The set of tiles of claim 21, wherein said multiple is
four.
33. A building comprising a surface, the surface comprising a set
of tiles according to claim 21, the building further comprising a
fluid heating system mounted in a heating space behind one or more
solar thermal tiles.
Description
FIELD OF THE INVENTION
[0001] The invention relates generally to the field of solar tiles.
The invention more specifically relates to the provision of solar
heating in buildings using solar thermal tiles, and the provision
of electricity using solar photovoltaic tiles.
BACKGROUND OF THE INVENTION
[0002] The major source of power in the industrialized world is
fossil fuel combustion. The supply of fossil fuels is finite, and
furthermore, the burning of fossil fuels is believed to contribute
greatly to environmental pollution and global warming. Nuclear
power is also used for electricity generation but nuclear power
stations are potentially extremely dangerous if the reactors are
not closely monitored, and the fission process generates highly
dangerous waste. Consequently, a global need to develop new ways of
generating power has been recognized.
[0003] Therefore, so-called `renewable energy sources` have become
the focus of much attention. These renewable sources include wave,
wind and solar power. All of these sources of power are effectively
infinite. In some countries (such as the UK) the government
provides financial incentives to individuals and organizations that
use alternative energy sources, further increasing interest in
these technologies. Consumers who are `environmentally aware`
welcome products and services that do not negatively impact the
environment.
[0004] Domestic and industrial water heating consumes a large
amount of power. This is both expensive for the consumer, and, if
that energy is derived from fossil fuel combustion or nuclear
fission, environmentally damaging. Therefore, a means of water
heating powered by a free, alternative energy source is highly
desirable.
[0005] Solar energy is renewable and its generation causes no
environmental damage. Even in non-tropical climes, solar energy is
a significant source of power; a south facing roof on a building in
Britain receives about 1000 kWh/m.sup.2 per year. Solar energy may
be harnessed in solar thermal systems to heat water directly, or by
using photovoltaic cells to generate electricity.
[0006] Solar thermal systems typically use solar energy incident on
building surfaces to heat water. Existing solar thermal systems are
often difficult to integrate with roofs, either during construction
of the roof or as an addition to an existing roof. They may require
modification to the supporting structure of the roof, or they may
not be compatible with conventional roofing tiles. Conventional
solar thermal systems may be heavy, making them difficult, or even
hazardous, to install on roofs. In some cases, cranes may be
required to lift and position solar thermal systems.
[0007] Some conventional solar thermal systems take the form of
assemblies that are fixed on top of an existing roof. A typical
example is the MEGASUN.TM. solar hot water heater, available from
Helioakmi Ltd., Nea Zoi, Aspropyrgos, 19300, Attiki, Greece. The
MEGASUN heater consists of a water storage tank and a solar energy
collector on a support base. Water from the tank is circulated
through the solar energy collector, which transfers heat
accumulated from the sun to the water. The support base, which is
adjusted according to the angle of the roof, is screwed on top of
the roof. The storage tank and collector are then assembled on the
support base. Such specific installation procedures may necessitate
special staff training and tools.
[0008] Other known solar thermal systems consist of solar thermal
tiles that are designed to replace conventional tiles in the roof.
These tiles are transparent to solar radiation. The solar radiation
that passes through the tile heats a thermal collector in a space
under the tile, within the roof. The tile described in
International Patent Application WO-02/31415 comprises a one piece
transparent polycarbonate moulding. As the tiles are made of
polycarbonate, they are susceptible to damage. They are also
different in appearance to conventional tiles. Furthermore, it is
often desirable to integrate solar thermal tiles with photovoltaic
tiles in order to produce both hot water and electricity from solar
energy. A solar thermal tile as described in International Patent
Application WO-02/31415 would have a very different appearance to a
photovoltaic tile incorporating a photovoltaic laminate. This
causes aesthetic problems and results in a heterogenous overall
appearance when these tiles are incorporated into a building
surface.
[0009] It is an object of the present invention to provide a
solution to the above problems.
[0010] According to the present invention there is provided a solar
thermal tile, the tile comprising a transparent portion for
permitting the entry of sunlight into a heating space below the
tile, the tile further comprising a chassis, formed separately from
the transparent portion, on which the transparent portion is
mounted, wherein the chassis comprises at least one protrusion on
at least one edge, the protrusion forming an overlapping
relationship with a second tile when correctly mounted adjacent
thereto. In the context of the present invention, a `chassis` is a
support structure. Preferably, the chassis surrounds at least part
of another component.
[0011] By providing a chassis, the transparent portion may be
supported and protected, facilitating ease of storage, handling and
fitting. Furthermore, the chassis may fulfil an aesthetic function.
A tile formed entirely of a transparent material, such as glass or
polycarbonate, would be less durable in comparison to the present
invention. A chassis protects the transparent material, thereby
allowing the tiles to be readily stacked for storage and
transport.
[0012] The protrusion facilitates a good fit between the tiles,
helping to maintain building accuracy, and further reinforces the
whole roof. By providing a protrusion on the chassis, not the
transparent material, the chassis bears any loads or impacts
inflicted on the building surface, thus preserving the transparent
material. In addition to forming an overlapping relationship, the
protrusion can be formed to interlock with the neighbouring tile,
further strengthening the overall strength of the set of fitted
tiles in the building surface. Furthermore, the overlapping
relationship formed between a tile according to the present
invention and a neighbouring tile helps ensure that the roof is
weatherproof.
[0013] The chassis is preferably made of non-transparent material.
By providing a chassis made of non-transparent material, materials
that are strong, easily formed and lightweight may be employed.
Such materials can provide the support and protection necessary for
the transparent portion. Thus, by combining a transparent portion
and a non-transparent chassis, the necessity for a transparent
portion for solar thermal heating is combined with the advantages
of non-transparent materials in terms of durability, ease of
manufacture, and ease of integration with existing conventional
roofing tiles. The non-transparent material may be metal. The metal
may be folded to form the chassis, giving a highly durable and
readily manufactured chassis. Alternatively, the non-transparent
material may be a plastic, with the concomitant advantage of
non-corrosion.
[0014] The invention further contemplates providing a set of tiles,
incorporating at least one solar thermal tile according to the
invention. A solar thermal tile according to the present invention
is readily integrated with conventional roofing tiles, and thus may
be provided as part of a set of tiles for installation in a
building surface. A building surface may be a roof or a wall.
[0015] The set of tiles preferably further comprises photovoltaic
tiles comprising photovoltaic cells. The photovoltaic tiles may
comprise a chassis. The chassis confers similar advantages when
provided in combination with a photovoltaic cell as it does when
provided in combination with a transparent portion of a solar
thermal tile. It would in some circumstances be desirable to
integrate solar thermal water heating tiles and photovoltaic tiles
in the same building surface, in order to heat water and generate
electricity on those building surfaces that receive the most
incident sunlight. By providing a building surface incorporating a
set of tiles comprising solar thermal tiles and photovoltaic tiles
according to an embodiment of the present invention, a durable and
aesthetically uniform building surface that supplies solar thermal
energy and solar electricity is obtained.
[0016] Further features and advantages of the invention will become
apparent from the following description of preferred embodiments of
the invention, given by way of example only, which is made with
reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates a solar thermal tile as an embodiment of
the present invention.
[0018] FIGS. 2a, 2b, and 2c illustrate right, left and front end
views of the solar thermal tile illustrated in FIG. 1.
[0019] FIG. 3 illustrates the underside of the solar thermal tile
illustrated in FIG. 1.
[0020] FIG. 4 illustrates an embodiment of the present invention,
incorporated into a building surface.
[0021] FIG. 5 illustrates the embodiment of the invention of FIG. 1
incorporated into a building surface.
[0022] FIG. 6 illustrates a photovoltaic tile.
[0023] FIG. 7 illustrates the underside of the photovoltaic tile of
FIG. 6.
[0024] FIG. 8 illustrates an embodiment of the invention in
combination with a photovoltaic tile, in a building surface.
[0025] FIGS. 9 and 10 illustrate an embodiment of the invention
incorporated into a building.
[0026] FIG. 11 illustrates an alternative embodiment of the
invention, in combination with a conventional roofing tile.
DETAILED DESCRIPTION OF THE INVENTION
[0027] FIG. 1 illustrates a solar thermal tile 1 according to a
first embodiment of the invention. The transparent portion 2
consists of a polycarbonate sheet supported in the chassis 6.
Alternatively, the transparent portion may consist of toughened
glass. The transparent portion may be affixed to the chassis using
a sealant, and/or with tape, bolts, or screws. The chassis 6 is
formed of folded sheet metal. The chassis 6 comprises a supporting
bar 3 (shown in FIG. 2), a rear overlap section 8, a front end 10,
and left and right ends 12 and 14, respectively. In an embodiment,
the chassis 6 is formed in two parts, the first part consisting
substantially of rear overlap section 8, supporting bar 3 and
portions of the left end 12 and right end 14, the second part
consisting of the rest of the chassis, comprising front end 10, the
remainder of left and right ends 12 and 14, and the portion of the
chassis that surrounds transparent portion 2. It will be recognised
that the chassis could, however, be formed in one unitary part, or
it could be made of several individual parts.
[0028] The left end 12 has a first protrusion 16 which both
co-extends substantially with the left end 12 and protrudes
horizontally outwards from the left end 12. The right end 14 has a
similar, second protrusion 18. The first and second protrusions 16
and 18 form an overlapping relationship with another adjacent tile
placed alongside (along the horizontal axis). The adjacent tile may
be another solar thermal tile according to an embodiment of the
invention, or a conventional roofing tile, or a photovoltaic tile,
or another form of building surface.
[0029] In an embodiment, the chassis is formed of folded sheet
metal. The chassis may be formed from several individually formed
folded sheet metal sections, which are bonded together by welding
and/or riveting. The chassis may be powder-coated, galvanised,
painted, or plastic-coated in order to prevent corrosion. In a
specific embodiment, the chassis is formed from several sections of
folded steel, TIG (tungsten inert gas) welded and pop-riveted
together. The assembled chassis is powder coated.
[0030] FIG. 2a shows the right end (profile) view of the solar
thermal tile 1, showing right end 14. Second protrusion 18 can be
seen coextending along right end 14, and incorporates a downturned
edge which forms an overlapping relationship with a neighbouring
tile.
[0031] FIG. 2b shows the left end (profile) view of the solar
thermal tile 1, showing left end 12. The first protrusion 16
extends from the left end 12. First protrusion 16 incorporates an
upturned edge, and forms an overlapping relationship with a
neighbouring tile. The formation of the protrusion may be altered
according to the form of a neighbouring tile.
[0032] In another embodiment, the protrusion may be formed so as to
interlock with a neighbouring tile. For example, the edges could be
extended so as to make physical contact with a neighbouring
tile.
[0033] FIG. 2c shows the front view of the solar thermal tile 1.
The front end 10 and the supporting bar 3 can be seen. The first
and second protrusions 16 and 18 can be seen extending horizontally
from right and left ends 12 and 14, respectively. When two solar
thermal tiles 1 are placed correctly adjacent with respect to one
another, the first protrusion 16 of a first tile would form an
overlapping relationship with the second protrusion 18 of a second
tile. The overlapping relationship of the first and second
protrusions 16 and 18 forms a robust, accurate, space efficient and
weatherproof interconnection between the two tiles.
[0034] FIG. 3 shows a bottom view of the tile of FIGS. 1, 2a, 2b
and 2c. Right end 14 and front end 10 are indicated for the
purposes of orientation. The underside of chassis 6 incorporates
apertures 30, 31, 32 and 33. The apertures transmit solar radiation
that has passed through the transparent portion 2 (shown in FIG. 1)
from the tile to the heating space below the tile.
[0035] FIG. 4 illustrates the incorporation of a tile into a
building surface according to an embodiment of the invention. FIG.
4 shows a profile view of solar thermal tile 1 incorporated into a
roof, between conventional tiles 20 and 22, the roof having an apex
24. The solar thermal tile 1 is supported on a first batten 34A by
the supporting bar 3. The solar thermal tile 1 is further supported
by overlapping with conventional tile 22. The first and second
battens 34A and 34B are horizontal wooden battens, as found in many
conventional roofs. The chassis 6 and supporting bar 3 are provided
with holes, in order to secure the tile to the batten with screws
or bolts.
[0036] Beneath solar thermal tile 1 is a heating space 35. The
heating space 35 is enclosed within container 39 to prevent
convective heat loss. Container 39 is supported between battens 34A
and 34B. The heating space 35 includes a heating surface 36. The
heating surface 36 is made up of two sheets of conductive material,
such as a metal. The heating surface may be treated in a number of
ways, in order to maximise its absorption in the solar spectrum
while minimising its heat emission characteristics in the infra-red
region of the spectrum. In this embodiment, heating surface 36 is
painted black for maximum absorption. The heating surface 36 is in
conductive communication with a pipe 37, which contains water. The
pipe 37 is made of a thermally conductive material, such as copper.
Container 39 comprises a layer of insulation 38. The container 39
is ideally airtight, in order to prevent loss of heat by
convention, and to maintain a heated air environment around the
heating surface 36 and the pipe 37.
[0037] In this embodiment of the invention, sunlight passes through
transparent portion 2 of solar thermal tile 1, then through
apertures 30, 31, 32 and 33 (shown in FIG. 3), to heating space 35.
In heating space 35, the sunlight is absorbed by heating surface
36. Heating surface 36 conducts heat energy to pipe 37, where the
heat energy is absorbed by the water within the pipe. The heated
water is then pumped away actively or passively, for domestic use.
Insulating layer 38 ensures that the temperature of heating space
35 is maximised by preventing loss of heat energy. Loss of heat
energy by convection is further minimised by the insulative blanket
of still air around heating surface 36 and pipe 37. The transparent
portion 2 may be double glazed (i.e. include more than one
transparent sheet), to further reduce heat loss.
[0038] The rear overlap section 8 of the chassis of solar thermal
tile 1 is formed to accommodate another tile in the vertical axis.
When solar thermal tile 1 is incorporated into a building surface
such as a roof, tiles placed above solar thermal tile 1 overlay the
rear overlap section 8. The conventional roofing tile 20 overlaps
the solar thermal tile 1 at the rear overlap section 8, while the
solar thermal tile 1 itself overlaps conventional roofing tile 22.
Rain will flow away from the roof apex 24 down the tiles, and due
to the arrangement of the overlapping of the conventional tile 20,
solar thermal tile 1 and conventional tile 22, will be prevented
from leaking through the roof.
[0039] FIG. 5 illustrates solar thermal tile 1 integrated into a
building surface 60. Dashed lines indicate features that would not
be visible, such as protrusions or the edges of tiles that are
concealed by other overlapping tiles. Solar thermal tile 1 is shown
to scale with the building surface 60, which consists of three
horizontal rows of overlapping tiles.
[0040] The building surface 60 may form part of a roof, or a wall.
The building surface 60 includes conventional tiles 50-59 and solar
thermal tile 1. Dashed lines indicate features that are, in
practice, hidden from view behind other features. Protrusions 16
and 18 form overlapping relationships with cooperating formations
on neighbouring conventional tiles 54 and 55 at edges 62 and 64. It
can be seen that, in the vertical axis, the edges of conventional
tiles 50-53 overlap solar thermal tile 1, and solar thermal tile 1
overlaps part of conventional tiles 56, 57, 58 and 59, in order to
create a waterproof, sloping building surface of uniform
appearance. Solar thermal tile 1 is equivalent in width to four
conventional tiles, and in length is equivalent to one conventional
tile, in order to fit into the building surface without the need
for specially sized surrounding tiles.
[0041] FIG. 6 shows a photovoltaic tile 90 according to an
embodiment of the invention. Photovoltaic tile 90 incorporates a
chassis 92, a photovoltaic laminate 94, and protrusions 96 and 98.
The photovoltaic laminate 94 is made up of a protective layers and
photovoltaic cells (not shown) and generates electricity from
incident solar light. The tile may also include a rectifier (not
shown) to convert the direct current output of the photovoltaic
cells to alternating current.
[0042] The chassis 92 is formed of folded sheet metal and includes
a front end 91 and a rear overlay section 95. In this embodiment of
the invention, chassis 92 is similar in appearance and construction
to chassis 6 of FIG. 1. In this way, a homogenous and uniform
appearance will be achieved when photovoltaic tile 90 and solar
thermal tile 1 are incorporated into the same building surface. The
provision of a chassis confers similar advantages for a
photovoltaic tile as for a solar thermal tile, such as lightness,
durability, mechanical strength, ease of handling and fitment, ease
of manufacture, and ease of integration with existing conventional
roofing tiles. Note, however, that front end 91 includes
ventilation holes, to allow airflow into the tile and prevent
overheating of the photovoltaic cells within the tile. The
ventilation holes are not present in the solar thermal tile
chassis.
[0043] FIG. 7 shows the underside of photovoltaic tile 90, showing
apertures 110, 111, 112, and 113. Front end 91 is shown for the
purposes of orientation. Photovoltaic cells within chassis 92 are
connected to power outlet 115. Power outlet 115 is connected to
power lines 116 and 118. Power lines 116 and 118 end in plugs 120
and 122, respectively. Plugs 120 and 122 may be connected to an
electrical network, in order to supply electricity to the network,
or to a neighbouring photovoltaic cell, in order to provide an
array of photovoltaic tiles, the array being connected as a whole
to an electrical network.
[0044] FIG. 8 shows an embodiment of the invention in combination
with photovoltaic tile 90. Building surface 70 comprises three
horizontal rows of tiles and incorporates a solar thermal tile 1
according to an embodiment of the present invention, and the
photovoltaic tile 90. As in FIG. 5, dashed lines indicate features
that would not be visible in practice, such as the edges of tiles
and protrusions that are underneath other tiles. The first and
second protrusions 16 and 18 of solar thermal tile 1 form
overlapping relationships with neighbouring conventional tiles 101
and 102 respectively. Protrusions 96 and 98 of photovoltaic tile 90
form overlapping relationships with neighbouring conventional tiles
103 and 104. It can be seen that solar thermal tile 1 and
photovoltaic tile 90 are overlapped by conventional building tiles
above them, and solar thermal tile 1 and photovoltaic tile 90
themselves overlap a layer of conventional tiles below them.
Building surface 70 provides both solar thermal water heating and
solar-generated electricity, which is desirable to
`environmentally-aware` consumers.
[0045] FIG. 9 shows an embodiment of the invention, incorporated
into a surface of a building. Building 140 has a roof 142, the roof
including conventional tiles in area 144, an area of solar thermal
tiles 200 comprising solar thermal tiles according to an embodiment
of the present invention, and an area of photovoltaic tiles 202
comprising photovoltaic tiles according to the present invention.
Building 140 has a plumbing system (shown in FIG. 10) that allows
the solar thermal system to add heat to the domestic hot water
system in the building.
[0046] With respect to the placing of the area of solar thermal
tiles 200 and the area of photovoltaic tiles 202 on building 140,
non-tracking (stationary) solar thermal and photovoltaic systems on
buildings in the northern hemisphere should be placed on a surface
that faces true south. The systems should be placed at an angle
equal to the latitude of the geographical area of the building, in
order to ensure maximum incident sunlight. The surface should not
be shaded. The building may include a battery system (not shown) to
store the electricity produced by photovoltaic tiles.
[0047] FIG. 10 shows part of the plumbing system of building 140
shown in FIG. 9. FIG. 10 illustrates a portion of the inside
surface of the roof 142 where the area of solar thermal tiles 200
and the area of photovoltaic tiles 202 meet. The roof 142 is of a
known type, consisting of a timber framework overlaid with tiles,
and incorporates vertical joists 150 and horizontal battens 160 on
which all tiles are placed and to which all tiles are secured.
[0048] Solar thermal tile 146 according to an embodiment of the
invention and photovoltaic tile 148 according to an embodiment of
the invention are shown. Solar thermal tile 146 and photovoltaic
tile 148 are secured to the batten 162 by supporting bars 152 and
154, respectively. Photovoltaic tile 148 includes apertures 156,
157 and 158, and electricity generated by the photovoltaic cells
within the photovoltaic tile 148 is provided to an electrical
network via electrical cable 164. Solar thermal tile 146 has a
heating space 166. In an embodiment of the invention the heating
space 166 is arranged similarly to the heating space 35, as shown
in FIG. 4. Cold water is pumped into heating space 166 via inlet
pipe 168 and out via outlet pipe 170. In this way, the plumbing
system of the building is connected to the fluid heating system of
the tile.
[0049] FIG. 11 illustrates an alternative embodiment of the
invention, in combination with a conventional tile. The `Galloway`
tile (available from Russell Roof Tiles, Wellington Road,
Burton-on-Trent, Staffs DE14 2AW, UK) is an example of a
conventional tile. A cross section is shown. A solar thermal tile
180 according to an embodiment of the invention has a protrusion
182. The conventional tile 186 has a corrugated edge 188. It can be
seen that, in addition to forming an overlapping relationship in
accordance with the invention, the protrusion 182 and corrugated
edges 188 of the protrusions can form a firm, robust interlock.
Alteration of the dimensions of the protrusion 182 and corrugated
edge 188 will allow physical contact, further strengthening the
interconnection between solar thermal tile 180 and conventional
tile 186.
[0050] It will be understood that various modifications may be made
to the invention. In an embodiment of the invention, the heating
space may contain a heat collecting assembly. In an embodiment,
this assembly may take the form of an array of tubes containing a
heating medium. The tubes of the assembly may be formed of a metal
such as copper, which is cheaply and freely available, easily
worked into complex tubular shapes, and is highly conductive.
[0051] The heating medium may be a liquid such as water, which may
be used directly for domestic hot water applications, or oil, in
which case the heat would need to be transferred from the oil to
water.
[0052] The shape of the protrusion may be altered. For example, the
protrusion may be corrugated to match the corrugation of a
neighbouring conventional roof tile.
[0053] In an embodiment where the heat collecting assembly contains
a liquid heating medium, the assembly is arranged to be in fluid
communication with the outside of the tile, so that heating medium
may be pumped in and out of the tile. In an alternative embodiment
of the invention, the heat collecting assembly may take the form of
a grid made up of solid metal wire, in conductive communication
with the outside of the tile. The space occupied by the heating
assembly may be lined with a reflective material, such as metal
foil, in order to reflect radiation from the heat collecting
assembly back towards it. Alternatively, thermal insulation such as
rock wool or fibreglass may be used in the heating space.
[0054] Due to the temperature difference between the heating space
and the air outside the building surface, condensation may form in
the heating space. The chassis may incorporate air holes to prevent
the accumulation of moisture within the tile.
[0055] A tile according to the present invention may be used in a
wide variety of climates and may be adapted for differing
environments. For example, in coastal regions the chassis may be
made of anodised aluminium, to prevent corrosion caused by humidity
and salt water. The chassis may be made with an inwardly reflective
coating, in order to prevent any heat loss from the heating
space.
[0056] The transparent portion may be a sheet made of
polycarbonate, or alternative materials such as laminated glass.
Glass and steel have similar thermal expansion characteristics. An
advantage of such a combination is that, in high temperatures, the
structure of the tile as a whole will not be compromised as the
transparent portion and the chassis will expand at approximately
the same rate.
[0057] An embodiment of the invention may be implemented in a
variety of locations. An embodiment of the invention may be
implemented in both permanent and temporary buildings, during or
after construction.
* * * * *