WO2019180560A1

WO2019180560A1 - Solar tile module and solar tile system

Info

Publication number: WO2019180560A1
Application number: PCT/IB2019/052116
Authority: WO
Inventors: Igor ŽÁČEK
Original assignee: Zacek Igor
Priority date: 2018-03-19
Filing date: 2019-03-15
Publication date: 2019-09-26

Abstract

Solar tile module intended mainly for tiling of building facades comprises at least two segments, at least one of them being the photovoltaic segment (1) and comprising a photovoltaic cell (14) and at least one of them being the cooling segment (2) for cooling of the photovoltaic segment (1), where at least a part of the cooling segment (2) area is made from a material with light reflectance value higher than that of the photovoltaic segment (1) surface, and the photovoltaic segment (1) is interconnected with the cooling segment (2) by a thermal conductor (3) and the photovoltaic segment (1) is equipped with an element (4) providing electrical connection to other photovoltaic segments (1). Solar tile system intended mainly for tiling of building facades containing the solar tile modules according to this invention, which solar tile modules are adapted for attachment directly to building facades without aeration gap, where the photovoltaic segments (1) are electrically interconnected, preferably by electrical conductor, and form photovoltaic array; the ratio of photovoltaic segments (1) to cooling segments (2) is from 0.5:1 to 1.5:1, more preferable from 0.75:1 to 1.25:1 and the most preferable is 1:1 and photovoltaic segments (1) are interconnected with the cooling segments (2) by thermal conductor (3).

Description

SOLAR TILE MODULE AND SOLAR TILE SYSTEM

Technical Field

[0001] The technical solution relates to solar tile module intended mainly for tiling of facades and solar tile system, and belongs to the area of energetics and building industry and belongs to so called Building integrated photovoltaics - BIPV.

Background Art

[0002] Recently, attention has turned to the use of renewable energy sources. This has brought about the effort to improve efficiency of generating so-called green energy without negative impact on environment, ideally near the points of consumption, which would cut down the losses from transmission and eliminate the dependence on centralized power stations situated at remote places away from the points of consumption.

[0003] Renewable energy sources that have been in use for longer time include solar energy. Solar thermal collectors allow for use of thermal potential of solar radiation and photovoltaic cells facilitate generation of electrical energy through large-scale solar power stations as well as smaller units placed near human settlements.

[0004] Recently, photovoltaic systems directly integrated into the shells of buildings have gained more attention. Besides their primary function, obtaining the solar energy, emphasis is also placed on aesthetic criteria, which opens the door to original and creative methods of incorporating the photovoltaic systems into buildings.

[0005] With increasing temperature of photovoltaic cells, their efficiency decreases. Therefore, it is necessary to ensure their effective cooling, which is, at present, usually provided by air flow at the rear part of the cell or use of a cooling medium.

[0006] Solutions utilizing air cooling generally require a special support system that ensures there is a gap between the building and the photovoltaic cell. Such cooling method seems to be insufficient mostly in smaller buildings where the height of the building does not provide sufficiently strong stack effect. Moreover, the very structure can impact the intended appearance of the building. Besides, the cooling that uses a medium requires presence of other layers within the photovoltaic system, which increases the complexity of the structure as well as demands on propelling and storage of the medium.

[0007] Some constructions completely omit the air gap on the rear side, which results in lower panel output caused by overheating as well as in a shorter service life. [0008] Patent document US 6061978 describes a device with aeration chamber between photovoltaic module and face of building where at least part of the chamber’ s outlet is located above the chamber’s inlet, thereby ensuring cooling air flow through the chamber.

[0009] Patent document CZ 305632 describes cooling of photovoltaic module using a layer containing conduit holes for cooling medium, which is located below the layer comprising the solar cells. The conduit holes are formed from series of hollow organic fibers with ends connected to an inlet or outlet collector and a layer of thermal conductive material is placed between the layers of solar cells and layers of hollow fibers.

[0010] Patent document GB 2504802 describes a method of photovoltaic cell cooling using water- supplied capillary fibers placed behind the cell, while water evaporates from the fibers during cooling.

[0011] Patent document WO 2009/018016 describes a system, an apparatus, and a method of regulating temperature of photovoltaic cell through direct contact of the cell with material changing its phase during operation, whilst transforming the liquid phase into gas upon absorption of heat from photovoltaic cell, thereby achieving its cooling.

[0012] Considering the potential utility value of BIPV in industry and growing demand for such technologies, it is desirable to use conversion of solar radiation to electrical and thermal energy while maintaining the aesthetic qualities of buildings. Therefore, technological solutions must be researched that would allow for placement of photovoltaic systems directly upon the support, while such placement would not be at the expense of energy efficient transformation. Instead, it is demanded that the technology provides a higher efficiency of the photovoltaic cells. At the same time, competition in the market should optimally introduce aesthetically appropriate solution and new possibilities of combining structural elements and photovoltaic cells.

Nature of Invention

[0013] The aforementioned shortcomings are, to a large extent, eliminated by the solar tile module intended mainly for tiling of facades according to this invention, based on the principle that it comprises at least two segments, at least one of them being the photovoltaic segment comprising a photovoltaic cell and at least one of them being the cooling segment intended to provide cooling of the photovoltaic segment. At least a part of the cooling segment area is made from a material with light reflectance value higher than that of the photovoltaic segment surface. The photovoltaic segment is interconnected with the cooling segment by a thermal conductor and the photovoltaic segment is equipped with an element providing electrical connection to other photovoltaic segments.

[0014] The photovoltaic segment comprises a photovoltaic cell allowing generation of electrical energy. The cooling segment serves as heat dissipation surface from the photovoltaic segment, i.e. it is a cooler to the photovoltaic segment. Surface of the cooling segment has higher light reflectance value than the surface of the photovoltaic segment (i.e. surface of the photovoltaic cell). Therefore, a major part of solar radiation is reflected from the surface of the cooling segment while only a minor part of solar radiation is absorbed by the cooling segment material. The opposite is true for the photovoltaic segment, where a major part of solar radiation is absorbed by the photovoltaic cell. For this reason, the cooling segment has lower temperature than the photovoltaic segment. Due to the photovoltaic and the cooling segments being interconnected by thermal conductor, heat is transferred from the warmer to the colder material, i.e. from the photovoltaic segment to the cooling segment, which prevents overheating of the photovoltaic cell, improves efficiency of electrical energy generation, and also increases service life of the photovoltaic cells. Heat is dispersed on the cooling segment so the cooling segment can continuously accept heat from the photovoltaic segment.

[0015] Solar tile module according to this invention can be split into two or more independent elements, which is preferable, mainly for manufacturing, technological reasons as well as for simpler and more variable application. Splitting of the solar tile module results in creation of two or more independent elements, one element being the photovoltaic element comprising the photovoltaic segment and another element being the cooling element comprising the cooling segment, and/or one element being the photovoltaic-cooling element comprising the photovoltaic segment as well as certain portion of the cooling segment and another element being the cooling element comprising the remaining portion of the cooling segment of the solar tile module.

[0016] The higher reflectance value of the cooling segment surface is provided by the graphic layer. Graphic layer represents at least 30 % of the cooling segment surface. Graphic layer can cover up to the whole cooling segment surface.

[0017] Based on choice of the graphic layer material, its coloration, light reflectance, i.e. absorption properties, and module surface represented by the graphic layer, the required cooling parameters of the photovoltaic cells can be set. Graphic layer can also satisfy design requirements and meet aesthetic criteria for module appearance as well as facade appearance, as graphic layer can be arranged into a diversity of shapes, colors, and patterns. It can be of one or multiple colors. The higher the light reflectance of the applied graphic layer, the higher is the efficiency of the module and the system.

[0018] Photovoltaic segment incorporates the following layers: covering layer, laminating sheet, photovoltaic cell, second laminating sheet, insulating sheet, thermal conductor, and supporting layer. These layers are arranged in the aforementioned order, below the covering layer. All layers are combined by lamination. Insulating sheet serves as electrical insulator.

[0019] A third laminating sheet may be placed behind the insulating sheet. Use of the third laminating sheet is preferable mainly due to providing more structural strength to the photovoltaic segment.

[0020] The cooling segment incorporates the following layers: covering layer, colored graphic layer, laminating sheet or alternatively, the laminating sheet may be replaced by adhesive, thermal conductor, and supporting layer. The cooling segment serves as heat dissipation surface.

[0021] Preferably, a thermal conducting material is used as supporting layer. This material must be sufficiently strong to act as supporting layer but must also be thermally conductive to serve as thermal conductor. Such material can be metal sheet, for instance, which is sufficiently strong and thermally conductive at the same time. If the used supporting layer is made of material that does not comply with the requirement of thermal conductivity, thermal conductor must be used in the module structure.

[0022] Preferably, the supporting layer carries an attached distance element, which may be a brick or other porous material. Such distance element will create space for electrical cables that are used to electrically connect the photovoltaic cells. This is preferable mainly due to simplified application of modules onto building facades.

[0023] The surface of photovoltaic segment and/or cooling segment preferably bears a covering layer made of light-transparent material. Preferably, such light-transparent material is glass. Covering layer protects the module against effects of weather and pollution. Preferably, the graphic layer is located on the bottom side of the covering layer.

[0024] In a preferable embodiment, the graphic layer is made of ceramic color, preferably ceramic printing on glass. Such color can be applied to the covering glass using the ceramic in glass printing technique, in which the pigments of the ceramic dye are applied onto the glass, they are left to dry out and then, subjected to high temperature, become part of the glass.

[0025] The covering layer of the photovoltaic segment can be superposed by an anti-reflection layer that prevents undesired light reflection, increasing the amount of absorbed solar radiation. [0026] Solar tile system intended mainly for tiling of building facades containing the solar tile modules according to this technological solution, where the solar tile modules are adapted for attachment to building facades, that is directly onto the facade base without aeration gap, where the photovoltaic segments are electrically interconnected, preferably by electrical conductor, and form photovoltaic array; the number of photovoltaic and cooling segments within the solar tile system should be approximately equivalent in order to achieve sufficient cooling effect and increased output of the photovoltaic cells. Preferable ratio of photovoltaic segments to cooling segments is from 0.5: 1 to 1.5: 1, more preferable from 0.75: 1 to 1.25: 1 and the most preferable is 1: 1.

[0027] If is preferable if the photovoltaic segments and the cooling segments are arranged in alternating positions.

[0028] Depending on the aesthetic intention, the solar tile modules can be of various sizes and shapes provided that thermal connection is ensured as well as appropriate ratio between the surface area of the photovoltaic segments and the graphic layer on the cooling segments.

[0029] The cooling and the photovoltaic segments form photovoltaic array that can cover, either completely or partially, a building facade or roof or other devices and installations used by people. As continuous cover, the photovoltaic array also provides thermal and acoustic insulation of buildings as well as building protection against weather effects.

[0030] The solar tile system described herein represents an efficient yet highly aesthetic solution of generating energy from solar radiation. Possible combinations of different shapes, sizes, and arrangements of individual modules as well as the variable design of the graphic layer open the door for creative approach to the visual aspects of buildings, following specific requirements. Cooling of photovoltaic cells using adjacent colder segments with higher reflectance of material provides higher efficiency of electrical energy generation from solar radiation at lower initial costs of the photovoltaic cells themselves. The structure of the solar tile module and of the system built from the modules also reduces the cost of complex cooling systems and structures necessary for forming the aeration gap as well as the overall construction costs associated with e.g. plastering, thermal and acoustic insulation, since application of the solar tile system replaces the aforementioned structural elements.

Description of Figures

[0031] Fig. 1 represents a front view of the solar tile module.

Fig. 2 represents a front view of the photovoltaic-cooling element of the solar tile module. Fig. 3 represents a back view of the photovoltaic-cooling element.

Fig. 4 schematically represents photovoltaic part of the solar tile module in cross section. Detail “A” is represented in more detail in a side view on Fig. 8.

Fig. 5 represents a front view of the cooling element of the solar tile module.

Fig. 6 represents a back view of the cooling element of the solar tile module.

Fig. 7 schematically represents the cooling element of the solar tile module in cross section. Detail“A” is represented in more detail in a side view on Fig. 8.

Fig. 8 schematically represents a side view of the connection of the thermal conductors of the photovoltaic segment and cooling segment of the solar tile module.

Fig. 9 represents heat distribution from the photovoltaic segment to the cooling segment of the solar tile module.

Fig. 10 schematically represents heat distribution between the photovoltaic segments and the cooling segments within the solar tile module.

Fig. 11 schematically represents the solar tile module in cross section. Detail“A” is represented in more detail in a side view on Fig. 8.

Fig. 12 schematically represents the photovoltaic segment of the solar tile module in cross section with thermal conductor in the form of metal strip.

Fig. 13 schematically represents the cooling segment of the solar tile module in cross section with thermal conductor in the form of metal strip.

Fig. 14 represents a side view of the photovoltaic segment of the solar tile module with thermal conductor in the form of metal strip.

Fig. 15 represents a back view of the cooling segment of the solar tile module with thermal conductor in the form of metal strip.

Fig. 16 schematically represents a back view of the connection of the photovoltaic segment and cooling segment of the solar tile module with thermal conductor in the form of metal strip.

Examples of Embodiments

[0032] The invention is further disclosed in more detail by means of following non-limiting examples of embodiments.

Example 1

[0033] Fig. 1, Fig. 2 and Fig. 11 represent the solar tile module according to the present invention. It comprises the photovoltaic segment J_and the cooling segment 2. The photovoltaic segment 1 comprises a photovoltaic cell 14. The cooling segment 2 is intended to provide cooling of the photovoltaic segment J_. At least part of the cooling segment 2 area is made from a material with light reflectance value higher than that of the surface of the crystalline silicon (c-Si)-based photovoltaic segment’s 14 for generation of electrical energy, and the photovoltaic segment J_ is interconnected with the cooling segment 2 by a thermal conductor 3. The photovoltaic segment J_ is equipped with an element 4 providing electrical connection to other photovoltaic segment 2. The electric cable connection of the photovoltaic segments in the solar tile system is provided by the element ^providing electrical connection.

[0034] Material with higher reflectance value forming at least part of the cooling segment 2 surface is a graphic layer 12.

[0035] The photovoltaic segment 1 of the solar tile module incorporates the following layers: covering layer JT, laminating sheet J_3, photovoltaic cell 14, second laminating sheet 15, insulating sheet J_6, third laminating sheet 17 and metal sheet, which is thermal conductor 3 and supporting layer JjJ at the same time. These layers are arranged in the aforementioned order, below the covering layer JT, where all layers are combined by lamination. A distance element 5, in this example of embodiment being a brick, is attached to the supporting layer J_8 by adhesive 19.

[0036] The cooling segment 2 of the solar tile module incorporates the following layers: covering layer JT , colored graphic layer 12, which serves as heat dissipation surface, laminating sheet 13, which may be replaced by adhesive. It further incorporates metal sheet, which is thermal conductor 3 and supporting layer JjJ at the same time. These layers are arranged in the aforementioned order, below the covering layer JT, where all layers are combined by lamination. A distance element 5 is attached to the supporting layer JjJ by adhesive 19.

[0037] The colored graphic layer 12 is made of ceramic color and the arrangement of the colored graphic layer 12 of the cooling segment 2 is adapted to the required aesthetic appearance of the facade. The graphic layer 12 is of one color.

[0038] The covering layer JT of the cooling segment 2 and the covering layer of the photovoltaic segment J_ are made of glass. The covering layer JT and the colored graphic layer 12 of the cooling segment 2 are made of glass with printing. The graphic layer 12 is made of ceramic color, which is applied to the bottom side of the covering layer JT using the ceramic in-glass printing technique.

[0039] The graphic layer 12 of the cooling segment 2 forms more than 50 % of the cooling segment 2 surface. [0040] The photovoltaic cell 14 absorbs solar radiation, where a part of this radiation is used to generate electrical energy and the remaining part constitutes lost heat, which is transferred from the photovoltaic cell 14 to the cooling segment 2 of the photovoltaic tile module with graphic layer 12 that serves as a heat dissipation surface.

Example 2

[0041] Identical with the example of embodiment 1, except that the third laminating sheet T7 is not used.

Example 3

[0042] Identical with the example of embodiment 1, except that the supporting layer l_8 is made of thermally non-conductive material, therefore the solar tile module comprises a separate thermal conductor 3.

Example 4

[0043] Solar tile module according to the present invention comprises the photovoltaic segment 1 and the cooling segment 2. The photovoltaic segment l_ comprises the photovoltaic cell 14. The photovoltaic cell 14 is the SunPower® C60 type. The cooling segment 2 is intended to provide cooling of the photovoltaic segment 1.

[0044] Solar tile module is split into two independent elements, that is the photovoltaic element (Fig. 4) comprising the photovoltaic segment 1 and the cooling element (Fig. 5, 6, 7) comprising the cooling segment 2. Both elements are provided with a thermal conductor. The thermal conductor 3 with a width of 0.5 cm is placed on each side of both elements.

[0045] The layer arrangement of the respective segments is further identical with the example of embodiment 1.

Example 5

[0046] Solar tile module according to the present invention comprises the photovoltaic segment

1 and the cooling segment 2. The photovoltaic segment 1 comprises the photovoltaic cell 14. The cooling segment 2 is intended to provide cooling of the photovoltaic segment 1.

[0047] Solar tile module is split into two independent elements, that is the photovoltaic-cooling element comprising the photovoltaic segment 1 as well as certain portion of the cooling segment

2 and the cooling element comprising the remaining portion of the cooling segment 2 of the solar tile module. Fig. 2 and 9 represent a front view and Fig 9 represents a back view of the photovoltaic-cooling element. The edges of both elements are equipped with thermal conductor in the split area. The graphic layer 12 forms 100 % of the cooling segment surface.

[0048] The layer arrangement of the respective segments is further identical with the example of embodiment 1.

Example 6

[0049] Solar tile module according to the present invention is split into two independent elements, that is the photovoltaic element (Fig. 12, 14 and 16) comprising the photovoltaic segment 1 and the cooling element (Fig. 13, 15 and 16) comprising the cooling segment 2. The photovoltaic segment structure is identical with the example of embodiment 1, except that the third laminating sheet F7 is not used, the thermal conductor 3 is a metal strip placed as shown in Fig. 12, 14 and 16 and the element 4_providing electrical connection with other photovoltaic segments is Junktion Box. The metal strip performs at the same time the function of supporting layer 18.

[0050] The cooling segment 2 is made of glass with printing, which is the covering layer JT at the same time, and colored graphic layer 12. The thermal conductor 3, which is metal strip, is attached to the bottom side of the cooling segment 2 by adhesive or lamination. The metal strip performs at the same time the function of supporting layer 18.

Example 7

[0051] Fig. 10 represents solar tile system according to this invention. To create the system as facade tiling, the solar tile modules are split into two independent elements according to the example of embodiment 5. The split is into the photovoltaic -cooling element comprising the photovoltaic segment 1 as well as portion of the cooling segment 2 and the cooling element comprising the remaining portion of the cooling segment 2 of the solar tile module. Solar tile modules are attached to the building facades by adhesive or bonding cement, directly onto the facade base without aeration gap. The photovoltaic cells 14 are electrically interconnected, that is by electrical conductor 4, and form photovoltaic array. The photovoltaic cells are connected by the element 4 providing electrical connection to the electrical energy accumulator eventually other device for electrical energy take-off. Ratio of photovoltaic-cooling segment to cooling elements is 1: 1. The photovoltaic-cooling elements are interconnected with the cooling elements by thermal conductors 3. Fig. 10 represents the heat flow from photovoltaic segments 1 to the cooling segments 2 of the system.

[0052] The photovoltaic segments 1 and the cooling segments 2 are arranged in alternating positions.

Example 8

[0053] Solar tile system described in the example of embodiment 7, except that the ratio of photovoltaic-cooling segment to cooling elements is from 0.75:1 to 1.25:1.

Example 9

[0054] Solar tile system described in the example of embodiment 7, except that the ratio of the photovoltaic-cooling segment to cooling elements if from 0.5:1 to 1.5:1.

Listing of the reference signs:

[0055]

1 - Photovoltaic segment

11 - Covering layer

12 - Graphic layer

13 - Laminating sheet

14 - Photovoltaic cell

15 - Second laminating sheet

16 - Insulating sheet

17 - Third laminating sheet

18 - Supporting layer

19 - Adhesive

2 - Cooling segment

3 - Thermal conductor

4 - Element providing electrical connection

5 - Distance element

Claims

1. Solar tile module intended mainly for tiling of building facades, characterized in that it comprises at least two segments, at least one of them being the photovoltaic segment (1) comprising a photovoltaic cell (14) and at least one of them being the cooling segment (2) intended to provide cooling of the photovoltaic segment (1), where at least a part of the cooling segment (2) area is made from a material with light reflectance value higher than that of the photovoltaic segment (1) surface and the photovoltaic segment (1) is interconnected with the cooling segment (2) by a thermal conductor (3) and the photovoltaic segment (1) is equipped with an element (4) providing electrical connection to other photovoltaic segments (1).

2. Solar tile module according to claim 1, characterized in that it is split into at least two independent elements, that is the photovoltaic element comprising the photovoltaic segment (1) and the cooling element comprising the cooling segment (2) and/or the photovoltaic-cooling element comprising the photovoltaic segment (1) as well as portion of the cooling segment (2) and the cooling element comprising the remaining portion of the cooling segment (2).

3. Solar tile module according to any of claims 1 and 2, characterized in that the material with higher reflectance value, forming at least part of the cooling segment (2) surface, is a graphic layer (12), where the graphic layer (12) is of one or multiple colors.

4. Solar tile module according to any of claims 1 to 3, characterized in that the photovoltaic segment (1) incorporates the following layers: covering layer (11), laminating sheet (13), photovoltaic cell (14), second laminating sheet (15), insulating sheet (16), thermal conductor (3), and supporting layer (18), where these layers are arranged in the aforementioned order, below the covering layer (11) and all layers are combined by lamination.

5. Solar tile module to the claim 4, characterized in that a third laminating sheet (17) is placed behind the insulating sheet.

6. Solar tile module according to any of claims 4 to 6, characterized in that the cooling segment (2) incorporates the following layers: covering layer (11), colored graphic layer (12), laminating sheet (13) or adhesive, thermal conductor (3), supporting layer (18), where these layers are arranged in the aforementioned order, below the covering layer (11).

7. Solar tile module according to claims 4 to 6, characterized in that the thermal conductor (3) and the supporting layer (18) are made of one layer, that is the supporting layer (18) thermally conductive, made of thermally conductive material.

8. Solar tile module according to claims 3 to 7, characterized in that the supporting layer (18) carries an attached distance element (19), which may be a brick or other porous material.

9. Solar tile module according to any of claims 3 to 8, characterized in that the graphic layer (12) of the cooling segment (2) represents at least 30 % of the cooling segment (2) surface.

10. Solar tile module according to any of claims 4 to 9, characterized in that the covering layer (11) is made of light-transparent material, preferably of glass.

11. Solar tile module according to claim 10, characterized in that the covering layer (11) and colored graphic layer (12) of the cooling segment (2) are made of glass with printing.

12. Solar tile module according to any of claims 6 to 11, characterized in that the colored graphic layer (12) is made of ceramic color.

13. Solar tile module according to any of claims 4 to 12, characterized in that the covering layer (11) of the photovoltaic segment (1) is superposed by an anti-reflection layer.

14. Solar tile system intended mainly for tiling of building facades containing the solar tile modules according to any of claims 1 to 13, characterized in that the solar tile modules are adapted for attachment directly to building facades without aeration gap, where the photovoltaic segments (1) are electrically interconnected, preferably by electrical conductor, and form photovoltaic array; the ratio of photovoltaic segments (1) to cooling segments (2) is from 0.5:1 to 1.5:1, more preferable from 0.75:1 to 1.25:1 and the most preferable is 1:1 and photovoltaic segments (1) are interconnected with the cooling segments (2) by a thermal conductor (3).

15. Solar tile system according claim 14, characterized in that the photovoltaic segments (1) and cooling segments (2) of solar tile modules are arranged in alternating positions.