CA1289618C - Photovoltaic solar cells in combination with single-ply roofing membranes - Google Patents
Photovoltaic solar cells in combination with single-ply roofing membranesInfo
- Publication number
- CA1289618C CA1289618C CA000583543A CA583543A CA1289618C CA 1289618 C CA1289618 C CA 1289618C CA 000583543 A CA000583543 A CA 000583543A CA 583543 A CA583543 A CA 583543A CA 1289618 C CA1289618 C CA 1289618C
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- Canada
- Prior art keywords
- membrane
- layer
- roofing
- cells
- flexible
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
- Y02B10/10—Photovoltaic [PV]
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
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- Photovoltaic Devices (AREA)
Abstract
Abstract of the Disclosure A combination form of flexible roofing material including a reinforced single-ply membrane base for being adhered to the roof substrate. On the base is laminated a structurally flexible layer of solar cells encapsulated and sealed in a flexible intermediate layer of solar radiation transparent plastic protected by a cover layer of weather-proof solar transparent plastic. The roofing is constructed for being manufactured in elongate sheets, rolled up for transport to the site and installed by conventional methods including sealing to adjacent sheets of similar single-ply membrane material which may or may not incorporate solar cells. This is continued until the roof covering is complete. Examples are given for reinforced plastic sheet, modified bituminous sheet, and elastomeric sheet roofing materials as well as for a wide variety of solar cells materials together with methods for fabricating these materials into the roofing system disclosed.
Description
~2~6~
General Statement of the Invention This invention relates to multi-functional roofing 6ystems which cvmbine a photovoltaic ~olar ~ollection eature with roofing ~7aterials ~hat have the pri~ary purpose of pr~viding environmental prote~tion to ~he ho8t ~tructure. ~he photovoltaic ~olar cells !a~ ~ployed herein described have the function of gel7erating electricity. This invention i8 primarily directed to an ~pplication which employs single-ply roofing material, although other types of roofing materials could be used if desired.
A layer of photovoltaic solar cells is laminated to a base of flexible roofing material, which roofing material is commonly termed a membrane. These solar cells, after lamination, are further encapsulated and sealed in a flexi-ble intermediate layer of solar radiation transparent plastic, which in turn is pr~tected by a cover layer of weather-proof solar radiation transparent plastic~ The size and shape of the solar cells, and the pattern in which they are laminated to the roofinq material base, is arranged in a manner which allows continued flexibility of the roofing material after the said lamination takes place.
The roofing material, in conjunction with the encapsulated solar cells, i5 applied to the roofs of building structures, generally by adhering it to the roof substructure, i.e., roof deck wood, concrete, corrugated steel, galvanized steel panels or any of the commonly used insulation boards that are positioned over roof decks.
The roofing mater;al ~s manufactured in elongated ~heets which is rolled up for transp~rt to the c~nstruction "~
, .
, , ' ~2~
site. ~nstallation is accomplished thr~ugh a variety of mechanical fastening devices, adhesives means, torchi~g or any other me~hods which are conventionally employed in the roofing industry. Adjacent sheet~ of roofing material are ~ommonly ~ealed together where they ~djoin. ~d~oln~ng .sheet~ ~ay or ~ay not incorpor~te sol~r ~ell~.
~ xamples o~ roofi~g ~aterials to ~ch solar c~ a~e or may be l~m~nated, ~nclude reinforcad ~lexibl~ thermo-plastic ~heet, modified bitum1nous ~heet, and vu~c~n~zed or . non-vulcanized elastomeric ~heet. Thi8 di~closure covers the inGorporation of a variety of solar cells into the above exampled classes of roofing materials, including their fabrication in the manufacturing plants and their installation into roofing syste~s as a whole.
Background and Summary of oof~n~ Systems ~ here are well over 500 roofing materials and ~ystems currently in use. The purpose of all of them is to prevent rain water from entering the building structure. The classical roofing materials, such as clay tiles~ cedar ~nd asphalt shingles, and metallic panels such as galvanized steel, copper and tin sheets, have all been and are being used successfully for sloping roQfs. The bituminous built-up roofing system conslsting of three or four layers of asphalt (hot melt or emulsion) in conjunction with layers of bitum~ns saturated or not saturated roofing ~elts, and a topping of protective gravel and sometimes coating was the common and almo~t the only choice for the construction o~
flat roofs during the past 10~ years.
However, technological ~dvances have brought about a .
: ., ~ ' ' ., ' ' ' :
6~
new generation of roofing materials consisting of single-ply roofing membranes. These membranes are basically classified into four major groups, as follows:
1. Modified Bitumens: ~re composite sheets con isting of bitu~en, mod~fiers ~APP, B~S) and/or reinforcement ~uch as pl~st~c film, polye&t~r mats~ fibergl~6s, elt ~r f~bric~. ~he ~sdifying - compounds lmpart flexibility and elasti~ity while improving cohes~ve strength and resi~tance to flow at high temperat~res. ~he reinforcement ~ay be laminated to one surface or embedded within the modified bitumen.
General Statement of the Invention This invention relates to multi-functional roofing 6ystems which cvmbine a photovoltaic ~olar ~ollection eature with roofing ~7aterials ~hat have the pri~ary purpose of pr~viding environmental prote~tion to ~he ho8t ~tructure. ~he photovoltaic ~olar cells !a~ ~ployed herein described have the function of gel7erating electricity. This invention i8 primarily directed to an ~pplication which employs single-ply roofing material, although other types of roofing materials could be used if desired.
A layer of photovoltaic solar cells is laminated to a base of flexible roofing material, which roofing material is commonly termed a membrane. These solar cells, after lamination, are further encapsulated and sealed in a flexi-ble intermediate layer of solar radiation transparent plastic, which in turn is pr~tected by a cover layer of weather-proof solar radiation transparent plastic~ The size and shape of the solar cells, and the pattern in which they are laminated to the roofinq material base, is arranged in a manner which allows continued flexibility of the roofing material after the said lamination takes place.
The roofing material, in conjunction with the encapsulated solar cells, i5 applied to the roofs of building structures, generally by adhering it to the roof substructure, i.e., roof deck wood, concrete, corrugated steel, galvanized steel panels or any of the commonly used insulation boards that are positioned over roof decks.
The roofing mater;al ~s manufactured in elongated ~heets which is rolled up for transp~rt to the c~nstruction "~
, .
, , ' ~2~
site. ~nstallation is accomplished thr~ugh a variety of mechanical fastening devices, adhesives means, torchi~g or any other me~hods which are conventionally employed in the roofing industry. Adjacent sheet~ of roofing material are ~ommonly ~ealed together where they ~djoin. ~d~oln~ng .sheet~ ~ay or ~ay not incorpor~te sol~r ~ell~.
~ xamples o~ roofi~g ~aterials to ~ch solar c~ a~e or may be l~m~nated, ~nclude reinforcad ~lexibl~ thermo-plastic ~heet, modified bitum1nous ~heet, and vu~c~n~zed or . non-vulcanized elastomeric ~heet. Thi8 di~closure covers the inGorporation of a variety of solar cells into the above exampled classes of roofing materials, including their fabrication in the manufacturing plants and their installation into roofing syste~s as a whole.
Background and Summary of oof~n~ Systems ~ here are well over 500 roofing materials and ~ystems currently in use. The purpose of all of them is to prevent rain water from entering the building structure. The classical roofing materials, such as clay tiles~ cedar ~nd asphalt shingles, and metallic panels such as galvanized steel, copper and tin sheets, have all been and are being used successfully for sloping roQfs. The bituminous built-up roofing system conslsting of three or four layers of asphalt (hot melt or emulsion) in conjunction with layers of bitum~ns saturated or not saturated roofing ~elts, and a topping of protective gravel and sometimes coating was the common and almo~t the only choice for the construction o~
flat roofs during the past 10~ years.
However, technological ~dvances have brought about a .
: ., ~ ' ' ., ' ' ' :
6~
new generation of roofing materials consisting of single-ply roofing membranes. These membranes are basically classified into four major groups, as follows:
1. Modified Bitumens: ~re composite sheets con isting of bitu~en, mod~fiers ~APP, B~S) and/or reinforcement ~uch as pl~st~c film, polye&t~r mats~ fibergl~6s, elt ~r f~bric~. ~he ~sdifying - compounds lmpart flexibility and elasti~ity while improving cohes~ve strength and resi~tance to flow at high temperat~res. ~he reinforcement ~ay be laminated to one surface or embedded within the modified bitumen.
2. Thermoplastlcs (PVC, ethylene interpolymer): are similar to non-vulcanized elastomers in that there is no cross-linking of ~he molecules. They can be repeatedly softened when heated and hardened when cooled. PVC membranes may be welded together with heat or solvents and will develop bond strengths which equal or surpass the strength of the base material.
3. Vulcanized Elastomers (EPDM, Neoprene~, also referred to as thermosets: are the chemical cross lin~age of polymers (chains of molecules) which occurs during the manufacturing process. A
distinguishing characteristic is that it can only be bonded to itsel~ during installation by use of an adhesive because once cured, nsw molecular linkages cannot be formed.
distinguishing characteristic is that it can only be bonded to itsel~ during installation by use of an adhesive because once cured, nsw molecular linkages cannot be formed.
4. Non-Vulcanized Elastomers (chlorinated polyethylene, chlorosulfonated polyethylene, ':
~2~
polyisobutylene, acrylonitrite b~tadiene polymer) are manufactured without any cross-linking between chalns of polymer molecules. Although exposure to the elements may naturally cure ~ome of these polymers during the~r l~fetlmet ~11;non-vulcanized elastomers can be heat weldea during . initial installation.
See Roofinq Maqa~ine, Single Ply Systems ~ndex, April r 1986/ pp~ 17-42 ~D & H Publication~ Inc.
l~ Al1 types of single-ply roofing membranes are applied , in one of four ways:
-~' 1. Fully adhered to the substrate 2. Loosely laid and ballasted 3. Mechanically fastened 4. Used under insulation board as a protected membrane system.
Typical rolls of these membranes have a width as large as lO feet and a length cut and rolled of between 30 or lOO
~- feet, ~uring app1ication they are usua11y lapped two to five inches in the machine direction,and ~p to six inches ,, :
at the end of the rolls to form a waterproof seam at the overlap. Joining is accomplished by one of the following techniques:
l. Heat, with propane torch or hot air gun (by hand, semi automatic, or self-propelled welding . machlnes) 2. Adhesives, as with ~olvent, emulsion or solvent based adhesives, doub1e-sided adhesive tapes, or pre-appl~ed adhesSve with removable Felease paper : : 5 .
, ~ , . . ~ , .
3. ~ltrasonic, microwave, or heat-pressure techniques.
Back~round Relating to Solar Eneryy The value ~f 801~r ~nergy ~llecti~n for ~upplementlng or ~ven replaclng ~onY~n~ionally fueled ~ystem6 for generating ele~ri~$y ha~ ~e~ n~ efitabl~hed. However, until recently, ~ost D~ the ~tovoltaic based ~ystems have not been cost ef~ec~ive, and ~eca~se of this, they w~re not suitable for large-scale commercial application where another source of electric pDwe~ was available. Th~
primary cost factors related to: 1) the cost of manufacturing photovoltai~ cells~ and 2~ the cost of installins a~d m~intaining the ~y~tem. Beca~se of the traditionally low efficie~cy of the cells, ~ery larqe array.s of cells were reg~ired in order to generate usable levels of power. .These l~rge arrays mos~ often required heavy steel structures to suppoxt ~heir weight and to cope with the usually high wind loads ~reate~ by the array. These structures usually require su~stantial amounts of maintenance to k~ep them operati~nal.
Recent technological ad~ances, though, have brought about substantial increases in solar cell efficiency, while simultaneously ~ramat~cally r~d~ring their cost. See "Special Report on Photovolt~ic Cells", Kenneth ~weibel, Chemical and Engineeri~y News, July 7, 1986, pages 34-48.
These new cells, employed in con~unction with a roofing .system that totally ellmlnates any need for a spccial support structure for the cell array, opens broad commercial applications for photovoltaic power generation.
With this invention, it is literally pos~ible to create an ' ' . ~' , : '' '' ' : , electric power generatlng plant by little more than simply unrolling it on a roof. While systems have been proposed for incorporating solar cells lnto shingle constructions ,(see ~or example U.S. Patent 4,040,867 issued to Fores~ieri, et al. ), no proposals have been found that are similar to ths-invention disclosed herein. The unique.ness here is that it is possible to generate many thou~ands of watts ~f power without the necessity of makïng n~unerous electrical interconnections, which could involve hundred6 or more man hours at the job site. This invention makes use of arrays of thousands of solar cells, which are interconnected at the manufacturing facility. After manufacture, the arrays are tested at the factory prior to shipment to the job site. Thus, once the array arrives at the job site, there i5 little more to do except to roll it out, seam the lap joints, fasten it down, and plug it into the structure's electrical system. The need for highly trained technical, personnel at the job site is obviated because of the simplicity of the installation process. The work at the site is primarily performed. by roofers, as opposed to elactronics specialists.
Most certainly this invention is multi-functional, because not only does it generate power, it serves a primary function of protecting the h,ost structure from the elements. Besides this invention, no other known ~ystems consist of y,ery large pre-fabricated photovoltalc cell arrays encapsulated in a single-ply roofing membrane which provides environmental protection on~even a totally flat roof.
' .
~2~
polyisobutylene, acrylonitrite b~tadiene polymer) are manufactured without any cross-linking between chalns of polymer molecules. Although exposure to the elements may naturally cure ~ome of these polymers during the~r l~fetlmet ~11;non-vulcanized elastomers can be heat weldea during . initial installation.
See Roofinq Maqa~ine, Single Ply Systems ~ndex, April r 1986/ pp~ 17-42 ~D & H Publication~ Inc.
l~ Al1 types of single-ply roofing membranes are applied , in one of four ways:
-~' 1. Fully adhered to the substrate 2. Loosely laid and ballasted 3. Mechanically fastened 4. Used under insulation board as a protected membrane system.
Typical rolls of these membranes have a width as large as lO feet and a length cut and rolled of between 30 or lOO
~- feet, ~uring app1ication they are usua11y lapped two to five inches in the machine direction,and ~p to six inches ,, :
at the end of the rolls to form a waterproof seam at the overlap. Joining is accomplished by one of the following techniques:
l. Heat, with propane torch or hot air gun (by hand, semi automatic, or self-propelled welding . machlnes) 2. Adhesives, as with ~olvent, emulsion or solvent based adhesives, doub1e-sided adhesive tapes, or pre-appl~ed adhesSve with removable Felease paper : : 5 .
, ~ , . . ~ , .
3. ~ltrasonic, microwave, or heat-pressure techniques.
Back~round Relating to Solar Eneryy The value ~f 801~r ~nergy ~llecti~n for ~upplementlng or ~ven replaclng ~onY~n~ionally fueled ~ystem6 for generating ele~ri~$y ha~ ~e~ n~ efitabl~hed. However, until recently, ~ost D~ the ~tovoltaic based ~ystems have not been cost ef~ec~ive, and ~eca~se of this, they w~re not suitable for large-scale commercial application where another source of electric pDwe~ was available. Th~
primary cost factors related to: 1) the cost of manufacturing photovoltai~ cells~ and 2~ the cost of installins a~d m~intaining the ~y~tem. Beca~se of the traditionally low efficie~cy of the cells, ~ery larqe array.s of cells were reg~ired in order to generate usable levels of power. .These l~rge arrays mos~ often required heavy steel structures to suppoxt ~heir weight and to cope with the usually high wind loads ~reate~ by the array. These structures usually require su~stantial amounts of maintenance to k~ep them operati~nal.
Recent technological ad~ances, though, have brought about substantial increases in solar cell efficiency, while simultaneously ~ramat~cally r~d~ring their cost. See "Special Report on Photovolt~ic Cells", Kenneth ~weibel, Chemical and Engineeri~y News, July 7, 1986, pages 34-48.
These new cells, employed in con~unction with a roofing .system that totally ellmlnates any need for a spccial support structure for the cell array, opens broad commercial applications for photovoltaic power generation.
With this invention, it is literally pos~ible to create an ' ' . ~' , : '' '' ' : , electric power generatlng plant by little more than simply unrolling it on a roof. While systems have been proposed for incorporating solar cells lnto shingle constructions ,(see ~or example U.S. Patent 4,040,867 issued to Fores~ieri, et al. ), no proposals have been found that are similar to ths-invention disclosed herein. The unique.ness here is that it is possible to generate many thou~ands of watts ~f power without the necessity of makïng n~unerous electrical interconnections, which could involve hundred6 or more man hours at the job site. This invention makes use of arrays of thousands of solar cells, which are interconnected at the manufacturing facility. After manufacture, the arrays are tested at the factory prior to shipment to the job site. Thus, once the array arrives at the job site, there i5 little more to do except to roll it out, seam the lap joints, fasten it down, and plug it into the structure's electrical system. The need for highly trained technical, personnel at the job site is obviated because of the simplicity of the installation process. The work at the site is primarily performed. by roofers, as opposed to elactronics specialists.
Most certainly this invention is multi-functional, because not only does it generate power, it serves a primary function of protecting the h,ost structure from the elements. Besides this invention, no other known ~ystems consist of y,ery large pre-fabricated photovoltalc cell arrays encapsulated in a single-ply roofing membrane which provides environmental protection on~even a totally flat roof.
' .
5~nshi~e has been the most destructive factor in respect to the service life of roofing materials, and substantial effort and expense has been directed towards the development of protection from ~olar radiation. With this invention, the tradit~onal enemy of roofing ~y~tems has been converted ~nto a benefici~l and ge~rou~ ally.
Summary of the Invention and ~
This invention consists of the lamination or bonding of photovoltaic solar cells to a flexible roofing membrane. After lamination, these solar cells aLe encapsulated in a transparent potting material, and further protected by a transparent plastic overlay. The solar cells are electrically interconnected into arrays in order to generate electrical power which possesses the desired voltage and current characteristics.
The roofin~ membrane, as well as providing a base to which the solàr cells are laminated, also provides environmental protection to the str~cture where it is installed. Thus, this invention represents a new and improved roofing system which incorporates in a single unit both the functions of protecting the host structure from the elements, and a solar collection system d~rectly usable as electricity with no cost and with minimum maintenance expenditure.
The primary objects of the invention are as follows:
1. ~o provide environmental protection to the ~tructure where ~t is installed;
2. To collect solar energy a~d convert it into electrical power wlth the desired - ., . ~ -~ ' ' ' ' 5 ~,Y3~36~8 characteristics;
3~ To generate usable electrical power, when installed on a typical residential and commercial structure~ in a ma~nitud~ of thousands and millions of wa~ts~ respectively, ~ince the amo~nt of electriclty g~nerat~d i~ di2ectly p~oport~onal to the~roof surface area.
4. To bs install~d on roof~ of ~ny type ~onfiguration, i.e., gradual 810pe, sharp pitch, flat, or in any combination thereof ~ .
. To remain flexi~le after manufacture, includin~
encapsuIation of the solar cells, so that it is capable of being rolled up for transport, and being unrolled at the constr~ction site;
Summary of the Invention and ~
This invention consists of the lamination or bonding of photovoltaic solar cells to a flexible roofing membrane. After lamination, these solar cells aLe encapsulated in a transparent potting material, and further protected by a transparent plastic overlay. The solar cells are electrically interconnected into arrays in order to generate electrical power which possesses the desired voltage and current characteristics.
The roofin~ membrane, as well as providing a base to which the solàr cells are laminated, also provides environmental protection to the str~cture where it is installed. Thus, this invention represents a new and improved roofing system which incorporates in a single unit both the functions of protecting the host structure from the elements, and a solar collection system d~rectly usable as electricity with no cost and with minimum maintenance expenditure.
The primary objects of the invention are as follows:
1. ~o provide environmental protection to the ~tructure where ~t is installed;
2. To collect solar energy a~d convert it into electrical power wlth the desired - ., . ~ -~ ' ' ' ' 5 ~,Y3~36~8 characteristics;
3~ To generate usable electrical power, when installed on a typical residential and commercial structure~ in a ma~nitud~ of thousands and millions of wa~ts~ respectively, ~ince the amo~nt of electriclty g~nerat~d i~ di2ectly p~oport~onal to the~roof surface area.
4. To bs install~d on roof~ of ~ny type ~onfiguration, i.e., gradual 810pe, sharp pitch, flat, or in any combination thereof ~ .
. To remain flexi~le after manufacture, includin~
encapsuIation of the solar cells, so that it is capable of being rolled up for transport, and being unrolled at the constr~ction site;
6. To have all the critical electrical interconnections to the solar cells be performed at the factory under controlled conditions, as : opposed to being performed at the construction site;
7. To enable installation at the construction site by ~elatively unskilled personnel;
8. ~o require little or no maintenance after the system i6 installed.
.
. Brief Descri ~ of the Drawin~
FIGURE 1 is a plan view showing a single-ply solar collection roo~ing cons~ructed in accordance with the present invention.
, : -.. . .
~213~6~3 FIGURE 2 is a cross-sectional view taken along the lines of 2-2 of FIGURE 1.
FI~URE 3 is a cross-sectional view taken along the lines ~f 3-3 of FIG~RE 1.
FIGURE 4 is a gr~ph depicting the voltage, ~u~rent Dnd power output of ~ typi~l solar sell rGofing of ~IGUR~ ~
, Detailed DescriDtion of the Preferred ~mbodiments Referring now to FIGURES 1 and 2, the roofing of the present invention is shown in detail and generally includes three layers, 10, 12, and 14. Layer 10 is a base layer and consists of a single-ply membrane roofing material made of a composite of layers of thermo plastic, elastomeric, or modified bituminous roofin~ membrane together with fiber reinforcing. The central layer 12 includes a plurality of solar collection cells 16 and is laid over the base layer 10. The solar collection cells can be a plurality of discrete cells or a distributed system made by electroplating and are encapsulated and sealed in a plastic pottant material for protection and support, Layer 1~
consists of a protective cover which is laid over the layer 12 and consists of a transparent, weatherproof plastic.
The layers are fused together to form a unitary structure.
Each of these layers has to serve a number of functions, a~ will be e~plained and is therefore, made of a specifically and specially selected material to achieve all of the properties needed to cooperate with the other layers as well to form a unitary and flexible structure while encapsulating the photovoltaic cells.
A range of materials suitable for each of the layers , ' - ' . ' : : ' ; . :
, ~ .. : . , ~Z~ 8 will now be described after which examples will be given with particular reference to preferred materials of construction of the individual layers. Examples will al~o be given of composite constructions together with a description of the ~ethods ~f makiny ~uch constructions.
In e~ch ~Ase it i~ important th~t the ~aterial5 be ~elected for c~operation 60 that they can be laminated together into a permanent composite ~nd unitary roofing material which will be resistant to the elements and to delamination.
T~e following are definitions of the abbreviations used ~erein:
PVC is polyvinylchloride, a thermoplastic base material;
PVF is polyvinylfl~oride, and is a thermoplastic c~ver material;
PVF2 is polyvinylidene fluoride, a thermoplastic cover la~yer material;
EPDM is ethyl propylene diene (monomer) terpolymer, and serves either as an elastomeric base material or pottant;
EVA is ethylene vinyl acetate, a pottant; and EPR is ethylene-propylene rubber.
Si is a silicon base material of a crystalline type used for photovoltaic cells;
a-Si is amorphous silicon, a solar cell material, as are CuInSe2 is cuprous indium diselenide;
GaAs is gallium arsenide;
CdTe is cadmium telluride;
HgZnTe is mercury-zinc telluride; and CdS is cadmium sulfide.
In accordance with the present invention, the reinforced single-ply membrane can be any of the standard flexible single-ply roofing materials currently receiving widespread use. In general there are three broad classes of such materials which are ~uitable for applic~tion of the present invention~ all of which include ~ome form of reinforcement in the form of f~br~u~ mater~al ~nc~rp~r~ted into the ~tructure. These single-ply roofing materials are generally known as thermoplastic roofing membranes~
elastomeric roofing membranes, and reinforced modified bituminous roofing membranes. They may or may not be reinforced.
One example of thermoplastic single-ply roofing membrane is a flexible PVC mate~ial having upper and lower layers 10a, and 10b honding fiber reinforcement 11 between them into a sandwich. The lower layer 10a is PVC filled with carbon black while the upper layer 10b is usually colored grey to reflect heat or possibly light blue, also to reflect heat and for aesthetic appearance. The reinforcing fibers 11 are commonly fiberglass and may be woven or non-woven. ~he reinforcing fibers provide the dimensional stability over a wide range of temperatures.
An example of such a membrane is that sold under the brand name Sucoflex (TM), available from PMS/Sucoflex of Torrance, California. Another example of a thermoplastic membrane is that sold under the brand name Rhenofol-C
available from Barra Corporation of America, West Caldwell, New Jersey.
An example o~ an elastomeric membrane in layer 10 is EDPM reinforced membrane sold under the name Hydroseal, available from American Hydrotech Inc. of Chicago, - .
, ' ' . ,' .
Illinois .
An example of a suitable modified bituminous material is the reinforced sheet, sold under the mark Tri-Ply-4 ~vailable from Tri-Ply Inc., of Madison He~ght~, Michigan 48071. For more examples see p~ge 19.
~ he selection of ro¢fing mater~ls for u~e ln a ~ven 6ituation i8 a complex subject ~ut is the ~;ame ~or the base layer 10 of the present invention ~s for roofing in general. A summary of the essential considerations and o the properties of thermoplastic, elastomeric and modified bituminous single-ply membranes is set forth in the paper by H. O. Laaly and o. Dutt entitled Single-Ply Roofing Membranes, Canadian Buildin~ Digest, CB~ 235 issued on February 1985, and a paper presented by H. ~. Laaly entitled "A Basis for Selecting Roo~ing Membranes", presented at the Second }nternational Symposium on Roofiny Technology, 1985, organized by NRCA, NBS, RILEM, ~ibrary of Congress catalog card 85-072090 ISBN 0-934-80900-3. The breadth of the possible selections of single-ply roofing membranes can be obtained from the Roofing Materials Guide, published semi-annually by National Roofing Contractors Association and the documents cited therein particularly:
~. ANSI/RMA IPR-3, 1985, 2. ASTM Standard for Vulcanized Rubber Sheets used in Single-Ply RooPing Membranes, and 3. ASTM D443~~85 Standard Specifications for Poly ~Vinyl Chloride~ Sheet Roofing. A large number of photovoltaic cell materials are available ~nd suitable for use in the present invention. These - include both those materials which are themselves flexible or, if rigid, can be subdivided and or~anized in a seqmented way so that they can be incorporated in a multi-layer construction of materials as disclosed herein which is, at least, sequentially ~lexible and, after manufacture~ can be bent between segm~nts ~o ~s to be rolled up for transport w~thout damage to the cell~
b Crystalline silicon solar cells ~ ~n example'of a suita,ble rigid material and will be disclosed in ,example I
herein. These cells are,typically q50 to 500 microns thick.
other suitable materials include amosphous siIicon or CulnSe2. The latter is 4 to 5 microns thick, it is fle~ible, and it can be electroplated on certain types of the materials disclosed. Additional materials include GaAs, CdTe and HgZnTe and the cascade constructions CdTe/CdS and CuInSe2/CdS. A d$sc~ssi~n of solar cell technology and these materials is given in the referenced arti~le by K. Zweibel in Chemical & Engineerinq News, July 7, 1986, pages 34-~8. In general, the selection of the above materials is made on the basis of cost and efficiency and ~t is not critical in the present invention which o~
the foregoing materials is incorporated subject to the constructional constraints for flexibility.
The cells are interconnected by conductors in a known' manner to produce suitable voltage and current. In the example shown, if of 4 rows, the conductors connect elements of each row in series, with the inner rows (22, ., shown) being connectQd to the outer rows by the ~us bars 24, 26 at one end, and with the other ends terminating in .
:
. - .
.. . :
36~B
parallel connection bus bars 28, 30 which serves to supply pl~s and minus polarities, as indicated.
The solar cells 16 are laid ~t in a suitable pattern and are encapsulated in pottant 12 which provides p~rmanent fixation of cells in specific positi~n5, but 8110ws ~ome Alight ~isplacemen~ ~f e~ch ~ell ~hile prov~ng each ~ell with cushioned support. The pottant serves to encapsulate the cells and seal them from the effects of the elements, p~rticularly moisture and environmental pollutants. In general, the pottant should possess good structural properties at both high summer temperature extremes and cold winter temperature extremes to accommodate expansion and contraction of the cell and adjacent material in the composite roofing membrane without allowiny delamination of any of the layers. Thus~ it is desirable that the pottant match the thermal coefficient of expansion of the adjacent materials over a wide range. In addition, the pottant has to be transparent so that it doesn't absorb solar radiation in a significant amount. Examples of suitable pottants include EVA, and the elastomeric pottants EPDM and poly~rethane (clear cast, solvent dispersed).
Additional elastomeric pottants include ethylmethyl acry}ate and poly-n-butyl-acrylate.
of the above mentioned materials, EVA is most suitable, having a favorable melting/softening temperature of about 140C and is capable o~ encapsulating and bonding the solar cell layex into the structure without air bubbles to foxm a consolidated bubble-free structure.
The material of cover layer 14 is selected primarily to provide for durability upon exposure to the elementsO
lS
.
In general, the cover has to be flexi~le and transparent, being over 90~ transmissive to ~olar radiation and also does not absorb ~olar radiation. By durable is meant that it ic capable of resistiag the elements for 20 to 30 years.
~his ~mplies that ~t must ~e highly weatherp~o~f, ~olsture-proof, ~mpact resi tant, rea50nably thi~ ~Md u~able in the automated f~brication proced~res for ~s~embly of the combination roofing.
Examples of such mater~als include ~ealar, a PVF, which is very dirt resistant, has exrellent weather resistance properties and is impervious to mvisture.
Another ~aterial includes Kynar t a poly-vinylidene fl~oride havin/ low dirt affinity and also excell~ent ~eather resistance. These materials typically h~ve a melting point in excess of ~00C, and are s~rong eno~gh that they need not be made thick, but can ~e for~ed as ~n independent coating layer and placed ov~r the inte~mediate layer 12 of potting.
Additional ~aterials slaitable for the cover layer 14 incl~de the flexible plexiglasses DR-61K and V-811 from Rohn ~ Haas.
Example I
A base layer 10 was formed of flexible single-ply roofing membrane PVC sold under the trade designation Sucoflex by PMS/Sucoflex of Torrance, California. ~his ~embrane is a fused sandwich of carbon black filled PVC as a base layer with a grey PVC cover layer between which is disposed a non-woven fi~erglass reinforcing layer. The intermediate layer 12 is EVA: the cover layer 14 is PVF
r* T~ rk~ 16 ' '' ~ ', .' " ~ ' . ' ~, ~' '' . , .~
(Tedlar). Layers 10, 12, and 14 will be fused together to form a unitary mem~rane~ The solar cell construction is shown in particular in ~IGVRES 1 and 2 and consist of a plural i ty of crystalline E;ilicon cells which are arranged in ~n ordered array h~in~ rs~ws 22a, 22b, 22c, and columns 23a, 23b, 23c with spa~es 32~ 34 acros~ th~ width of the structure ~o tha~ it c~n ~e ~l~xed ~n the ~paces.
~dd~tionally, the Bpac~s ~se provided with a depression grooves 32a, 32b which further facilitates bending ~see FIGURES 2 and 3). For practical reasons the pottant layer can comprise two individual layers between which is laid the photovoltaic solar cell construction after which the cover layer is placed on tDp. The EVA plastic has a lower thermoplastic softening pDint than either the base layer or the cover layer so that it will soften/melt and adhere to these layers and form a l~mination with them with suitable processing. Typically processing incudes an autoclave heating of the assembled elements to a temperature above the softening point, i.e. slightly above 140C for EVA or a period of about 30 minutes so that full bonding and lamination between the layers can take place. The lamination can be vacuum deb~l~ed prior to autoclaving to assure the elimination of bubbles.
In one example of this construction, the thicknesses of the layers were as ~ollows: PVC base layer 10, 47 mil;
EVA layer 12, 10 mil ~ach; photovoltaic cell, 450 to 500 microns; and cover laye2 14~ 4 mils. A continuous run of roofing material of the type given in this example could be made to an arbitrary length in the ~ame manner as is done in the continuous web manufscture of nylon sheet.
, : ; , .
Example II
., fhl'n ,~, 3his film photovoltaic c~lls are formed on a flexible ....
substrate, e.g. metal foil, and then laminated onto a flexible PVC base l~yer. The cells are ~elected from one of the materials a-Si, CdTe/CdS, and CuInSe2/CdS.
The following i~ an ~vailability table for exemplar roof~ng ~embr~ne~ of each class of ~ateria'ls suitable for use in the present invention.
Figure 4 fihows a current/voltage plot for a roofing constructed in accordance with the invention based on the following particulars:
Irradiation (insolation) lOQ milliwatt/cm2 - Temperature 20C
Voltage, at open circuit 11.47 volts Current, at short circuit ~98 amp -Voltage at max power 8.69 volts ~2~
EXAMPLES FOR SINGLE-PLY ROOFING MEMBRANES
:
A. MOD~FIED ~ITUMENOUS
_ 1) Barrett Company Product ~ame:
901 Washington St. RAM 20D0-Ca~iphalte Wilmington, DE 19801 2) Flex-Shield International Product æhme:
P.O. Box 1790 Flex 8hield Maxk 686 West Commerce ailbert, AZ 85284 3) Villas Roofing Systems Product Name:
Riverbridge Industrial Centra Villaplast Front and Lloyd Streets Villaflex Chester, PA 19013 _ _ B. THERMOPLASTIC
1) Duro-Last Roofing Product Name:
Duro-Last Copolymer 2) Alkor Company Prcduct Name:
1 Blue Hill Plaza Alkorplex PVC
Pearl River, NY 10965 3) Sarnafil, Inc. Product Name:
100 Dan Road Sarnafil PVC
Canton, MA 02021 C ELASTOMERIC (Rubber and Rubber-like) 1) Carlisle Syntec Systems Product Name:
P.O. Box 7000 Surseal MARS ~EPDM) Carlisle, PA 17013 - vulcanized 2) Diversitech General Product Name:
Building Systems Division Genseal P.o. Box 875 - vulcanized Toledo, OH 93696-0875 3) Goodyear Tire L Rubber Co. Product Name:
1144 East Market Street Versigard Akron, OH_ 99316 _ -_vuleanized D. NON-VULCANIZED ELASTOMERS
1) Dunlop Construction Product Name:
Toronto, Canada Dunseal (CSPE) - non-vulcanized 2) ~ond Cote System Product Name:
West Point, Georgia Bond Grey 35 (NBP) - non-vulcanized - acrylonitrite butadiene polymer 3) J. P. Stevens Product Name:
Easthampton, Massachusetts Hi-Tuff (CSPE) ~y
.
. Brief Descri ~ of the Drawin~
FIGURE 1 is a plan view showing a single-ply solar collection roo~ing cons~ructed in accordance with the present invention.
, : -.. . .
~213~6~3 FIGURE 2 is a cross-sectional view taken along the lines of 2-2 of FIGURE 1.
FI~URE 3 is a cross-sectional view taken along the lines ~f 3-3 of FIG~RE 1.
FIGURE 4 is a gr~ph depicting the voltage, ~u~rent Dnd power output of ~ typi~l solar sell rGofing of ~IGUR~ ~
, Detailed DescriDtion of the Preferred ~mbodiments Referring now to FIGURES 1 and 2, the roofing of the present invention is shown in detail and generally includes three layers, 10, 12, and 14. Layer 10 is a base layer and consists of a single-ply membrane roofing material made of a composite of layers of thermo plastic, elastomeric, or modified bituminous roofin~ membrane together with fiber reinforcing. The central layer 12 includes a plurality of solar collection cells 16 and is laid over the base layer 10. The solar collection cells can be a plurality of discrete cells or a distributed system made by electroplating and are encapsulated and sealed in a plastic pottant material for protection and support, Layer 1~
consists of a protective cover which is laid over the layer 12 and consists of a transparent, weatherproof plastic.
The layers are fused together to form a unitary structure.
Each of these layers has to serve a number of functions, a~ will be e~plained and is therefore, made of a specifically and specially selected material to achieve all of the properties needed to cooperate with the other layers as well to form a unitary and flexible structure while encapsulating the photovoltaic cells.
A range of materials suitable for each of the layers , ' - ' . ' : : ' ; . :
, ~ .. : . , ~Z~ 8 will now be described after which examples will be given with particular reference to preferred materials of construction of the individual layers. Examples will al~o be given of composite constructions together with a description of the ~ethods ~f makiny ~uch constructions.
In e~ch ~Ase it i~ important th~t the ~aterial5 be ~elected for c~operation 60 that they can be laminated together into a permanent composite ~nd unitary roofing material which will be resistant to the elements and to delamination.
T~e following are definitions of the abbreviations used ~erein:
PVC is polyvinylchloride, a thermoplastic base material;
PVF is polyvinylfl~oride, and is a thermoplastic c~ver material;
PVF2 is polyvinylidene fluoride, a thermoplastic cover la~yer material;
EPDM is ethyl propylene diene (monomer) terpolymer, and serves either as an elastomeric base material or pottant;
EVA is ethylene vinyl acetate, a pottant; and EPR is ethylene-propylene rubber.
Si is a silicon base material of a crystalline type used for photovoltaic cells;
a-Si is amorphous silicon, a solar cell material, as are CuInSe2 is cuprous indium diselenide;
GaAs is gallium arsenide;
CdTe is cadmium telluride;
HgZnTe is mercury-zinc telluride; and CdS is cadmium sulfide.
In accordance with the present invention, the reinforced single-ply membrane can be any of the standard flexible single-ply roofing materials currently receiving widespread use. In general there are three broad classes of such materials which are ~uitable for applic~tion of the present invention~ all of which include ~ome form of reinforcement in the form of f~br~u~ mater~al ~nc~rp~r~ted into the ~tructure. These single-ply roofing materials are generally known as thermoplastic roofing membranes~
elastomeric roofing membranes, and reinforced modified bituminous roofing membranes. They may or may not be reinforced.
One example of thermoplastic single-ply roofing membrane is a flexible PVC mate~ial having upper and lower layers 10a, and 10b honding fiber reinforcement 11 between them into a sandwich. The lower layer 10a is PVC filled with carbon black while the upper layer 10b is usually colored grey to reflect heat or possibly light blue, also to reflect heat and for aesthetic appearance. The reinforcing fibers 11 are commonly fiberglass and may be woven or non-woven. ~he reinforcing fibers provide the dimensional stability over a wide range of temperatures.
An example of such a membrane is that sold under the brand name Sucoflex (TM), available from PMS/Sucoflex of Torrance, California. Another example of a thermoplastic membrane is that sold under the brand name Rhenofol-C
available from Barra Corporation of America, West Caldwell, New Jersey.
An example o~ an elastomeric membrane in layer 10 is EDPM reinforced membrane sold under the name Hydroseal, available from American Hydrotech Inc. of Chicago, - .
, ' ' . ,' .
Illinois .
An example of a suitable modified bituminous material is the reinforced sheet, sold under the mark Tri-Ply-4 ~vailable from Tri-Ply Inc., of Madison He~ght~, Michigan 48071. For more examples see p~ge 19.
~ he selection of ro¢fing mater~ls for u~e ln a ~ven 6ituation i8 a complex subject ~ut is the ~;ame ~or the base layer 10 of the present invention ~s for roofing in general. A summary of the essential considerations and o the properties of thermoplastic, elastomeric and modified bituminous single-ply membranes is set forth in the paper by H. O. Laaly and o. Dutt entitled Single-Ply Roofing Membranes, Canadian Buildin~ Digest, CB~ 235 issued on February 1985, and a paper presented by H. ~. Laaly entitled "A Basis for Selecting Roo~ing Membranes", presented at the Second }nternational Symposium on Roofiny Technology, 1985, organized by NRCA, NBS, RILEM, ~ibrary of Congress catalog card 85-072090 ISBN 0-934-80900-3. The breadth of the possible selections of single-ply roofing membranes can be obtained from the Roofing Materials Guide, published semi-annually by National Roofing Contractors Association and the documents cited therein particularly:
~. ANSI/RMA IPR-3, 1985, 2. ASTM Standard for Vulcanized Rubber Sheets used in Single-Ply RooPing Membranes, and 3. ASTM D443~~85 Standard Specifications for Poly ~Vinyl Chloride~ Sheet Roofing. A large number of photovoltaic cell materials are available ~nd suitable for use in the present invention. These - include both those materials which are themselves flexible or, if rigid, can be subdivided and or~anized in a seqmented way so that they can be incorporated in a multi-layer construction of materials as disclosed herein which is, at least, sequentially ~lexible and, after manufacture~ can be bent between segm~nts ~o ~s to be rolled up for transport w~thout damage to the cell~
b Crystalline silicon solar cells ~ ~n example'of a suita,ble rigid material and will be disclosed in ,example I
herein. These cells are,typically q50 to 500 microns thick.
other suitable materials include amosphous siIicon or CulnSe2. The latter is 4 to 5 microns thick, it is fle~ible, and it can be electroplated on certain types of the materials disclosed. Additional materials include GaAs, CdTe and HgZnTe and the cascade constructions CdTe/CdS and CuInSe2/CdS. A d$sc~ssi~n of solar cell technology and these materials is given in the referenced arti~le by K. Zweibel in Chemical & Engineerinq News, July 7, 1986, pages 34-~8. In general, the selection of the above materials is made on the basis of cost and efficiency and ~t is not critical in the present invention which o~
the foregoing materials is incorporated subject to the constructional constraints for flexibility.
The cells are interconnected by conductors in a known' manner to produce suitable voltage and current. In the example shown, if of 4 rows, the conductors connect elements of each row in series, with the inner rows (22, ., shown) being connectQd to the outer rows by the ~us bars 24, 26 at one end, and with the other ends terminating in .
:
. - .
.. . :
36~B
parallel connection bus bars 28, 30 which serves to supply pl~s and minus polarities, as indicated.
The solar cells 16 are laid ~t in a suitable pattern and are encapsulated in pottant 12 which provides p~rmanent fixation of cells in specific positi~n5, but 8110ws ~ome Alight ~isplacemen~ ~f e~ch ~ell ~hile prov~ng each ~ell with cushioned support. The pottant serves to encapsulate the cells and seal them from the effects of the elements, p~rticularly moisture and environmental pollutants. In general, the pottant should possess good structural properties at both high summer temperature extremes and cold winter temperature extremes to accommodate expansion and contraction of the cell and adjacent material in the composite roofing membrane without allowiny delamination of any of the layers. Thus~ it is desirable that the pottant match the thermal coefficient of expansion of the adjacent materials over a wide range. In addition, the pottant has to be transparent so that it doesn't absorb solar radiation in a significant amount. Examples of suitable pottants include EVA, and the elastomeric pottants EPDM and poly~rethane (clear cast, solvent dispersed).
Additional elastomeric pottants include ethylmethyl acry}ate and poly-n-butyl-acrylate.
of the above mentioned materials, EVA is most suitable, having a favorable melting/softening temperature of about 140C and is capable o~ encapsulating and bonding the solar cell layex into the structure without air bubbles to foxm a consolidated bubble-free structure.
The material of cover layer 14 is selected primarily to provide for durability upon exposure to the elementsO
lS
.
In general, the cover has to be flexi~le and transparent, being over 90~ transmissive to ~olar radiation and also does not absorb ~olar radiation. By durable is meant that it ic capable of resistiag the elements for 20 to 30 years.
~his ~mplies that ~t must ~e highly weatherp~o~f, ~olsture-proof, ~mpact resi tant, rea50nably thi~ ~Md u~able in the automated f~brication proced~res for ~s~embly of the combination roofing.
Examples of such mater~als include ~ealar, a PVF, which is very dirt resistant, has exrellent weather resistance properties and is impervious to mvisture.
Another ~aterial includes Kynar t a poly-vinylidene fl~oride havin/ low dirt affinity and also excell~ent ~eather resistance. These materials typically h~ve a melting point in excess of ~00C, and are s~rong eno~gh that they need not be made thick, but can ~e for~ed as ~n independent coating layer and placed ov~r the inte~mediate layer 12 of potting.
Additional ~aterials slaitable for the cover layer 14 incl~de the flexible plexiglasses DR-61K and V-811 from Rohn ~ Haas.
Example I
A base layer 10 was formed of flexible single-ply roofing membrane PVC sold under the trade designation Sucoflex by PMS/Sucoflex of Torrance, California. ~his ~embrane is a fused sandwich of carbon black filled PVC as a base layer with a grey PVC cover layer between which is disposed a non-woven fi~erglass reinforcing layer. The intermediate layer 12 is EVA: the cover layer 14 is PVF
r* T~ rk~ 16 ' '' ~ ', .' " ~ ' . ' ~, ~' '' . , .~
(Tedlar). Layers 10, 12, and 14 will be fused together to form a unitary mem~rane~ The solar cell construction is shown in particular in ~IGVRES 1 and 2 and consist of a plural i ty of crystalline E;ilicon cells which are arranged in ~n ordered array h~in~ rs~ws 22a, 22b, 22c, and columns 23a, 23b, 23c with spa~es 32~ 34 acros~ th~ width of the structure ~o tha~ it c~n ~e ~l~xed ~n the ~paces.
~dd~tionally, the Bpac~s ~se provided with a depression grooves 32a, 32b which further facilitates bending ~see FIGURES 2 and 3). For practical reasons the pottant layer can comprise two individual layers between which is laid the photovoltaic solar cell construction after which the cover layer is placed on tDp. The EVA plastic has a lower thermoplastic softening pDint than either the base layer or the cover layer so that it will soften/melt and adhere to these layers and form a l~mination with them with suitable processing. Typically processing incudes an autoclave heating of the assembled elements to a temperature above the softening point, i.e. slightly above 140C for EVA or a period of about 30 minutes so that full bonding and lamination between the layers can take place. The lamination can be vacuum deb~l~ed prior to autoclaving to assure the elimination of bubbles.
In one example of this construction, the thicknesses of the layers were as ~ollows: PVC base layer 10, 47 mil;
EVA layer 12, 10 mil ~ach; photovoltaic cell, 450 to 500 microns; and cover laye2 14~ 4 mils. A continuous run of roofing material of the type given in this example could be made to an arbitrary length in the ~ame manner as is done in the continuous web manufscture of nylon sheet.
, : ; , .
Example II
., fhl'n ,~, 3his film photovoltaic c~lls are formed on a flexible ....
substrate, e.g. metal foil, and then laminated onto a flexible PVC base l~yer. The cells are ~elected from one of the materials a-Si, CdTe/CdS, and CuInSe2/CdS.
The following i~ an ~vailability table for exemplar roof~ng ~embr~ne~ of each class of ~ateria'ls suitable for use in the present invention.
Figure 4 fihows a current/voltage plot for a roofing constructed in accordance with the invention based on the following particulars:
Irradiation (insolation) lOQ milliwatt/cm2 - Temperature 20C
Voltage, at open circuit 11.47 volts Current, at short circuit ~98 amp -Voltage at max power 8.69 volts ~2~
EXAMPLES FOR SINGLE-PLY ROOFING MEMBRANES
:
A. MOD~FIED ~ITUMENOUS
_ 1) Barrett Company Product ~ame:
901 Washington St. RAM 20D0-Ca~iphalte Wilmington, DE 19801 2) Flex-Shield International Product æhme:
P.O. Box 1790 Flex 8hield Maxk 686 West Commerce ailbert, AZ 85284 3) Villas Roofing Systems Product Name:
Riverbridge Industrial Centra Villaplast Front and Lloyd Streets Villaflex Chester, PA 19013 _ _ B. THERMOPLASTIC
1) Duro-Last Roofing Product Name:
Duro-Last Copolymer 2) Alkor Company Prcduct Name:
1 Blue Hill Plaza Alkorplex PVC
Pearl River, NY 10965 3) Sarnafil, Inc. Product Name:
100 Dan Road Sarnafil PVC
Canton, MA 02021 C ELASTOMERIC (Rubber and Rubber-like) 1) Carlisle Syntec Systems Product Name:
P.O. Box 7000 Surseal MARS ~EPDM) Carlisle, PA 17013 - vulcanized 2) Diversitech General Product Name:
Building Systems Division Genseal P.o. Box 875 - vulcanized Toledo, OH 93696-0875 3) Goodyear Tire L Rubber Co. Product Name:
1144 East Market Street Versigard Akron, OH_ 99316 _ -_vuleanized D. NON-VULCANIZED ELASTOMERS
1) Dunlop Construction Product Name:
Toronto, Canada Dunseal (CSPE) - non-vulcanized 2) ~ond Cote System Product Name:
West Point, Georgia Bond Grey 35 (NBP) - non-vulcanized - acrylonitrite butadiene polymer 3) J. P. Stevens Product Name:
Easthampton, Massachusetts Hi-Tuff (CSPE) ~y
Claims (7)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A prefabricated multi-functional roofing system formed in elongated flexible sections of substantially uniform thickness constructed for being rolled up in lengths suitable for being transported to a building site for unrolling and for being affixed to a roof structure, comprising:
means forming an elongate section of flat, flexible single-ply roofing membrane adapted to extend over a said roof structure;
said roofing membrane having a top side for exposure to the elements and being heat reflective and a bottom side for being placed on a roof substrate of said roof structure to form a roof thereon, said membrane having a predetermined softening temperature, and further including a fibrous material for reinforcing said membrane over a wide range of temperatures;
means forming a plurality of photovoltaic cells distributed in a two dimensional flat array of rows and columns arranged continuously over said membrane;
electrical circuiting means for interconnecting said photovoltaic cells and for extracting electrical power therefrom, said circuiting means comprising a plurality of bus bars;
means forming a flat flexible thermoplastic pottant layer extending above and below said cells and over the area of said membrane to thereby mount, cover, and adhere said cells and circuiting means over the top side of the membrane in a predetermined pattern and to encapsulate the cells in a structure sufficiently flexible to be rolled up, said pottant layer having a second predetermined softening temperature and having a thermal coefficient of expansion compatible with said roofing system;
a flexible cover layer adhered on top of said roofing membrane, pottant layer, and photovoltaic cells, said cover layer being transparent, tough and weatherproof, and having a softening temperature higher than said pottant layer;
said membrane and said cover layer having predetermined first and second softening temperatures and said pottant layer having a third softening temperature lower than said first and second softening temperatures;
said membrane, pottant layer, and cover layer being assembled and joined into a composite structure by heating above the softening temperature of said pottant layer but below the softening temperature of said membrane and said cover layer to thereby fuse and adhere the layers together for forming said roofing system adapted to conform to said roof structure of any shape; and means for flexing associated with each of said layers for keeping said composite flexible enough to roll up, said flexing means including transversely extending space channels formed between adjacent columns of said array of photovoltaic cells and depression grooves formed within each of said space channels.
means forming an elongate section of flat, flexible single-ply roofing membrane adapted to extend over a said roof structure;
said roofing membrane having a top side for exposure to the elements and being heat reflective and a bottom side for being placed on a roof substrate of said roof structure to form a roof thereon, said membrane having a predetermined softening temperature, and further including a fibrous material for reinforcing said membrane over a wide range of temperatures;
means forming a plurality of photovoltaic cells distributed in a two dimensional flat array of rows and columns arranged continuously over said membrane;
electrical circuiting means for interconnecting said photovoltaic cells and for extracting electrical power therefrom, said circuiting means comprising a plurality of bus bars;
means forming a flat flexible thermoplastic pottant layer extending above and below said cells and over the area of said membrane to thereby mount, cover, and adhere said cells and circuiting means over the top side of the membrane in a predetermined pattern and to encapsulate the cells in a structure sufficiently flexible to be rolled up, said pottant layer having a second predetermined softening temperature and having a thermal coefficient of expansion compatible with said roofing system;
a flexible cover layer adhered on top of said roofing membrane, pottant layer, and photovoltaic cells, said cover layer being transparent, tough and weatherproof, and having a softening temperature higher than said pottant layer;
said membrane and said cover layer having predetermined first and second softening temperatures and said pottant layer having a third softening temperature lower than said first and second softening temperatures;
said membrane, pottant layer, and cover layer being assembled and joined into a composite structure by heating above the softening temperature of said pottant layer but below the softening temperature of said membrane and said cover layer to thereby fuse and adhere the layers together for forming said roofing system adapted to conform to said roof structure of any shape; and means for flexing associated with each of said layers for keeping said composite flexible enough to roll up, said flexing means including transversely extending space channels formed between adjacent columns of said array of photovoltaic cells and depression grooves formed within each of said space channels.
2. The roofing system as in claim 1 wherein said photovoltaic cells are formed of rigid photovoltaic material of relatively small dimensions and interconnected by a plurality of wires.
3. The roofing system as in claim 1 wherein said single ply roofing membrane is a flexible waterproof base membrane, and a top side layer is constructed especially to withstand exposure to the elements and damage from sunlight.
4. The roofing system as in claim 3 wherein said photovoltaic cells are formed of rigid photovoltaic material of relatively small dimensions and interconnected by a plurality of wires.
5. A prefabricated multi-functional roofing system formed in sections having uniform thickness and extending over a substantial area and formed to be flexible so as to be rolled up in lengths suitable for being transported to a building site for unrolling and bonding together in side by side relation to complete a roof structure, comprising:
means forming a flexible single-ply roofing membrane layer adapted to extend over said area;
means forming a plurality of solar cells distributed in a two dimensional array continuously over said area, said array having a plurality of transversely extending space channels between adjacent groups of solar cells and including depression grooves formed therein for permitting rolling up and unrolling of said array;
means interconnecting said cells to enable generation of a predetermined voltage and current therefrom;
means forming a pottant layer extending above and below said cells and throughout said area to thereby encapsulate the cells into a structure sufficiently flexible to be rolled up, said pottant layer having a thermal coefficient of expansion compatible with said roofing system; and means forming a transparent protective layer extending throughout said area on top of said pottant layer, said pottant layer integrating the layers into a unitary assembly by fusing them together into a flexible system under heat, said roofing system adapted to conform to said roof structure of any shape.
means forming a flexible single-ply roofing membrane layer adapted to extend over said area;
means forming a plurality of solar cells distributed in a two dimensional array continuously over said area, said array having a plurality of transversely extending space channels between adjacent groups of solar cells and including depression grooves formed therein for permitting rolling up and unrolling of said array;
means interconnecting said cells to enable generation of a predetermined voltage and current therefrom;
means forming a pottant layer extending above and below said cells and throughout said area to thereby encapsulate the cells into a structure sufficiently flexible to be rolled up, said pottant layer having a thermal coefficient of expansion compatible with said roofing system; and means forming a transparent protective layer extending throughout said area on top of said pottant layer, said pottant layer integrating the layers into a unitary assembly by fusing them together into a flexible system under heat, said roofing system adapted to conform to said roof structure of any shape.
6. A prefabricated multi-functional roofing system formed in sections having uniform thickness over a substantial planar area and formed in flexible sections constructed for being rolled up in lengths suitable for being transported to a building site for unrolling and bonding together in side by side relation to complete a roof structure, comprising:
means forming a section of flat, flexible single-ply roofing membrane adapted to extend over said area;
means forming a plurality of photovoltaic cells distributed in a two dimensional flat array continuously over said area, said array having a plurality of transversely extending space channels between adjacent groups of photovoltaic cells for permitting rolling up and unrolling of said array, said space channels further comprising depression grooves formed therein;
wiring means interconnecting said cells for enabling generation of a predetermined voltage and current therefrom;
means forming a flat pottant layer extending above and below said cells and over the area of said section for encapsulating the cells into a structure sufficiently flexible to be rolled up, said pottant layer having a thermal coefficient of expansion compatible with said roofing system; and means for forming a flat transparent protective cover layer extending throughout said area on top of said pottant layer, said roofing system being integrated into a unitary assembly by heating the several layers to cause the pottant layer to fuse the single-ply roofing membrane, said plurality of photovoltaic cells, said wiring means, and said cover layer together into a flexible section of said roofing system adapted to conform to said roof structure of any shape.
means forming a section of flat, flexible single-ply roofing membrane adapted to extend over said area;
means forming a plurality of photovoltaic cells distributed in a two dimensional flat array continuously over said area, said array having a plurality of transversely extending space channels between adjacent groups of photovoltaic cells for permitting rolling up and unrolling of said array, said space channels further comprising depression grooves formed therein;
wiring means interconnecting said cells for enabling generation of a predetermined voltage and current therefrom;
means forming a flat pottant layer extending above and below said cells and over the area of said section for encapsulating the cells into a structure sufficiently flexible to be rolled up, said pottant layer having a thermal coefficient of expansion compatible with said roofing system; and means for forming a flat transparent protective cover layer extending throughout said area on top of said pottant layer, said roofing system being integrated into a unitary assembly by heating the several layers to cause the pottant layer to fuse the single-ply roofing membrane, said plurality of photovoltaic cells, said wiring means, and said cover layer together into a flexible section of said roofing system adapted to conform to said roof structure of any shape.
7. A prefabricated multi-functional roofing system formed in elongated flexible sections of substantially uniform thickness constructed for being rolled up in lengths suitable for being transported to a building site for unrolling and for being affixed to a roof structure, comprising:
a roof substrate formed within said roof structure;
means for forming an elongate section of flat, flexible single-ply roofing membrane extending over said roof substrate;
said roofing membrane having a top side for exposure to the elements and being heat reflective and a bottom side for being placed on said roof substrate to form a roof thereon, said membrane having a predetermined softening temperature, and further including a fibrous material for reinforcing said membrane over a wide range of temperature;
means for forming a plurality of photovoltaic cells distributed in a two dimensional flat array continuously over said membrane, said array having a plurality of transversely extending space channels between adjacent groups of said photovoltaic cells for permitting rolling up and unrolling of said array, each of said space channels including a depression groove formed therein;
electrical circuiting means for interconnecting said photovoltaic cells and for extracting electrical power therefrom, said circuiting means comprising a plurality of bus bars;
means forming a flat flexible thermoplastic pottant layer extending above and below said cells and over the area of said membrane to thereby mount, cover, and adhere said cells and circuiting means over the top side of the membrane in a predetermined pattern and to encapsulate the cells in a structure sufficiently flexible to be rolled up, said pottant layer having a second predetermined softening temperature and having a thermal coefficient of expansion compatible with said roofing system;
a flexible cover layer adhered on top of said roofing membrane, pottant layer, and photovoltaic cells, said cover layer being transparent, tough and weatherproof, and having a softening temperature higher than said pottant layer;
said membrane and said cover layer having predetermined first and second softening temperatures and said pottant layer having a third softening temperature lower than said first and second softening temperatures; and said membrane, pottant layer, and cover layer being assembled and joined into a composite structure by heating above the softening temperature of said pottant layer but below the softening temperature of said membrane and said cover layer to thereby fuse and adhere the layers together for forming said roofing system adapted to conform to said roof structure of any shape.
3053b/3 25
a roof substrate formed within said roof structure;
means for forming an elongate section of flat, flexible single-ply roofing membrane extending over said roof substrate;
said roofing membrane having a top side for exposure to the elements and being heat reflective and a bottom side for being placed on said roof substrate to form a roof thereon, said membrane having a predetermined softening temperature, and further including a fibrous material for reinforcing said membrane over a wide range of temperature;
means for forming a plurality of photovoltaic cells distributed in a two dimensional flat array continuously over said membrane, said array having a plurality of transversely extending space channels between adjacent groups of said photovoltaic cells for permitting rolling up and unrolling of said array, each of said space channels including a depression groove formed therein;
electrical circuiting means for interconnecting said photovoltaic cells and for extracting electrical power therefrom, said circuiting means comprising a plurality of bus bars;
means forming a flat flexible thermoplastic pottant layer extending above and below said cells and over the area of said membrane to thereby mount, cover, and adhere said cells and circuiting means over the top side of the membrane in a predetermined pattern and to encapsulate the cells in a structure sufficiently flexible to be rolled up, said pottant layer having a second predetermined softening temperature and having a thermal coefficient of expansion compatible with said roofing system;
a flexible cover layer adhered on top of said roofing membrane, pottant layer, and photovoltaic cells, said cover layer being transparent, tough and weatherproof, and having a softening temperature higher than said pottant layer;
said membrane and said cover layer having predetermined first and second softening temperatures and said pottant layer having a third softening temperature lower than said first and second softening temperatures; and said membrane, pottant layer, and cover layer being assembled and joined into a composite structure by heating above the softening temperature of said pottant layer but below the softening temperature of said membrane and said cover layer to thereby fuse and adhere the layers together for forming said roofing system adapted to conform to said roof structure of any shape.
3053b/3 25
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000583543A CA1289618C (en) | 1988-11-18 | 1988-11-18 | Photovoltaic solar cells in combination with single-ply roofing membranes |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000583543A CA1289618C (en) | 1988-11-18 | 1988-11-18 | Photovoltaic solar cells in combination with single-ply roofing membranes |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1289618C true CA1289618C (en) | 1991-09-24 |
Family
ID=4139129
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000583543A Expired - Lifetime CA1289618C (en) | 1988-11-18 | 1988-11-18 | Photovoltaic solar cells in combination with single-ply roofing membranes |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1289618C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2133927A1 (en) * | 2008-06-13 | 2009-12-16 | S.A. Imperbel N.V. | Method for manufacturing a bituminous membrane |
| CN118694292A (en) * | 2024-08-22 | 2024-09-24 | 西安多点科技发展有限公司 | Photovoltaic module frame and photovoltaic module |
-
1988
- 1988-11-18 CA CA000583543A patent/CA1289618C/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2133927A1 (en) * | 2008-06-13 | 2009-12-16 | S.A. Imperbel N.V. | Method for manufacturing a bituminous membrane |
| CN118694292A (en) * | 2024-08-22 | 2024-09-24 | 西安多点科技发展有限公司 | Photovoltaic module frame and photovoltaic module |
| CN118694292B (en) * | 2024-08-22 | 2024-10-29 | 西安多点科技发展有限公司 | Photovoltaic module frame and photovoltaic module |
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