Solar panel

Abstract

A solar panel includes a circumferential upstanding rim defining a cavity therein. An insulating layer is mounted in the cavity and extends substantially completely across the cavity. A metal heat-exchanger sheet is overlaid onto the insulating layer and substantially entirely covers said insulating layer. A light-transmissive sheet overlays the heat exchanger sheet and is mounted to the rim. An array of fluid transmission tubes are mounted to the heat-exchanger sheet by welding closed of channels in the sheet so as to tightly encase the tubes in the channels. The fluid transmission tubes conduct a flow of heat-exchanger fluid in a heat exchange circuit.

Description

FIELD OF THE INVENTION

This invention relates to solar collection panel construction and in particular to cost effective and highly efficient solar energy collector panels constructed in a scalable manner as a single integrated unit onto the roof or other support structure.

BACKGROUND OF THE INVENTION

It is known that when making solar collectors based on heat transfer to a fluid, that a sheet or thermally conductive material that readily absorbs solar energy is placed in thermal contact with fluid carrying elements, tube or pipe to transfer the absorbed solar energy to the fluid which is ultimately pumped and stored for use in heating or power generation applications. The construction of the solar collector often includes a framework or housing which can be mounted to a structure such as a building roof. The housing typically insulates the solar panel from the surrounding environment and generally has a optically clear cover such as a glass panel which allows a substantial portion of the solar energy impinging on it to pass through to be absorbed by the underlying sheet of the solar collector. The construction of the solar collector sheet and the housing enclosing it can vary greatly in both cost and efficiency.

Applicant is aware of patents regarding solar collector design and housing such as U.S. Pat. No. 5,431,149 titled “Solar energy collector”, issued to Fossum, et al. on Jul. 11, 1995. Fossum teaches a large rectangular solar heat absorber which includes a plurality of identical rectangular heat absorbing panels which, when assembled in side by side and end to end relationship will form a total heat absorbing surface area of the desired dimensions, with each panel comprising a rectangular heat absorbing plate having a top surface to receive incident solar radiation, a black body radiation coating on the top surface; and one or more pipes secured in heat transferring relation to the bottom surface of said heat absorbing plate; a rectangular frame dimensioned to mount a number of panels in side by side and end to end relation; a panel of glass covering the panels and having the property of reflecting infrared radiation emitted by said black body coating; means for securing the glass cover to the frame; means connecting the adjacent ends of said pipes to provide heat transfer fluid flow paths extending the length of the end to end panels; header means connected to the non-adjacent ends of said pipes for directing fluid flow through all of said heat transfer flow paths; pump means for producing turbulent flow of heat transfer fluid through all of said pipes; an inlet header connected to one end of a first set of pipes providing a fluid flow path to said first set of pipes; an outlet header connected to one end of a second set of pipes providing a fluid flow path from said second set of pipes; said inlet header and outlet header being on the same ends of said panels with connecting means providing horizontally parallel fluid flow paths; and header means directing fluid flow from said first set of pipes to said second sets of pipes, said second set of pipes having a fluid flow path in a direction opposite the fluid flow path of said first set of pipes.

U.S. Pat. No. 4,201,193 titled “Solar energy absorbing roof” issued to Ronc on May 6, 1980, teaches a solar roofing structure combining the covering and waterproofing functions of a conventional roof with the functions of a solar energy-collecting panel, and which consists of a supporting base; a layer of insulating material on said base; waterproofing cover of elastomers and bitumen, the outer surface of which is covered on its upper surface with mineral particles selected from the group consisting of gravel, glass and ceramic particles; and means separate from said waterproofing cover means defining circulation channels for a liquid, in close contact with and below the waterproofing cover means, and between said waterproofing cover and the insulating material and in contact with each.

U.S. Pat. No. 4,172,311 titled “Process for manufacturing solar collector panels” issued to Heyman on Oct. 30, 1979, teaches a method for fabricating a lightweight economical solar energy collector panel comprising the steps of: building a solar collector by inverting the outer frame having an inwardly protruding top flange defining a radiation-receiving opening, thereby upwardly exposing the underside of the top flange; positioning on the upwardly exposed underside of the top flange a translucent glass or plastic layer substantially transparent to solar radiation spanning the outer frame across the opening beneath the top flange; placing on the upwardly exposed underside of the translucent layer a spacer partition means underlying the translucent layer, and having a plurality of rigid upright support wall portions spanning the outer frame and juxtaposed to the translucent layer; forming a manifold-connected plurality of heat-conductive fluid conduit means shaped and dimensioned for underlying the spacer partition means; forming a temporary array comprising a thin metallic foil sheet foldably formed into cylindrical channel heat-transmitting portions which all embrace the fluid conduit means, and which are contiguously foldably joined by substantially flat heat-receiving portions shaped for extending across the opening beneath the spacer partition, exposed to solar radiation entering the opening; inverting and positioning the temporarily assembled metallic foil sheet and conduit array on the exposed underside of the upright support wall portions of the spacer partition means with the conduit array protruding into the interior region of the outer frame away from the spacer partition means; and foaming in place a polymer foam back directly in contact with the temporarily assembled metallic foil sheet and fluid conduit array, spanning and substantially filling the remaining space within the outer frame and thereby permanently anchoring the foregoing assembled components into an interconnected panel unit.

U.S. Pat. No. 4,164,935 titled “Solar heating panels” issued to Marles, et al. on Aug. 21, 1979, teaches a solar heating panel comprising a plurality of cylindrical tubes for carrying a liquid to be heated and an absorber plate for absorbing solar radiation falling thereon, the absorber plate including a plurality of rigid plate sections each having at one edge an outwardly-facing concave substantially semi-cylindrical portion, the concave surface of the semi-cylindrical portion having the same radius of curvature as the outer circumferential surface of one of the cylindrical tubes, and clamping means engaging the convex outer surfaces of the semi-cylindrical portions on two adjacent plate sections and thereby clamping a cylindrical tube with its outer surface in heat-conducting contact with the concave surfaces of said semi-cylindrical portions, each of the plates of said plurality of plate sections being shaped at an opposite edge which is parallel to the said one edge such that the said opposite edge faces towards the said one edge thereby defining a channel in the plate section within which channel a similar opposite edge of another plate section is slidingly engaged in a manner which detachably interlocks the opposite edges but permits expansion of the plate sections relative to one another.

U.S. Pat. No. 4,072,262 titled “Method of fabricating a solar heating unit” issued to Godrick, et al. on Feb. 7, 1978, teaches a process for fabricating a solar heating unit for heating fluids where the process consists of: placing a thin, soft, annealed sheet having a good thermal conductivity characteristic in conformal relation to a grooved surface of a self-supporting, thermally conductive planar plate, assembling a plurality of tubes in a spaced apart planar relation, the spacing between the tubes equal to the spacing between said grooves, and the contour of the grooves substantially conforming to a portion of the contour of the tubes, connecting headers in a fluid-tight connection to the tubes to provide fluid flow paths between said headers and the tubes, applying a thermally conductive paste adhesive along the conformal portion of the tubes, and positioning the assembled elements in an aligned relation to the grooves in the plate with the conformal portion abutting the thin sheet, and pressing the tubes against said sheet with sufficient pressure and temperature to creep form the sheet around the attachment portion of the tubes, and to simultaneously melt the paste adhesive to provide a good thermally conductive bond between the elements and the sheet.

U.S. Pat. No. 4,011,856 titled “Solar fluid heater” issued to Gallagher on Mar. 15, 1977, teaches a solar energy fluid heater made of an open housing having rigid bottom and side panels; a plurality of abutting solar panels for collecting solar energy positioned within the housing, each having an upper surface positioned below the opening in the housing for collecting solar energy, an open circular channel formed in the center portion of each panel having an opening smaller than the diameter of the channel along the longitudinal center of the solar panel, with the channel being below the opening and the upper surface and the portions of the upper surface adjacent each side of the opening having a linear downward slope; a conduit member positioned within the channel having a diameter greater than the relaxed diameter of the channel and a length sufficiently long to extend from each end of the solar panel; header members one connecting each adjacent end of the conduit and extending to the exterior of the collector housing; a number of support members spaced apart along the bottom panel of the housing for spacing the solar panels from the bottom panel; insulation is placed between the solar panels and the bottom of the housing; at least one panel of translucent material is placed above said upper surface of the solar panel is sealed to the side panels forming an enclosure for the opening of the housing; and pressure applying means for securing the edges of the adjacent panels in firm physical contact to ensure heat transfer between the adjacent panels by thermal conduction. The solar heat collector would typically be coated with a solar energy absorbent material on its upper exposed surface. In addition the fluid carrying conduit having a greater diameter than that of the relaxed channel diameter for securing the conduit within the channel by spring tension; and screw anchors for securing the edges of the panel in firm physical position to maintain said mechanical force between said channel and conduit as the temperature of the panel increases to insure heat transfer between said panel and conduit by conduction.

SUMMARY OF THE INVENTION

The present invention serves to collect solar energy for the purposes of heating and/or generating electricity for various purposes. The present invention uses a modular sheet metal surface with imbedded tubing to conduct thermal energy absorbed by a high absorption low emissivity painted surface. After pressing the tubes into the sheet metal or otherwise forming the metal snugly around the tubes, the sheet metal surface is formed to be welded to itself along the top of the tubes, thereby securely capturing the tubes and maintaining direct thermal conductivity between the sheet metal, the tube, and the fluid or gas flowing through the tubes into the solar collector circuit and reservoir circuit without the need for thermally conductive filler or adhesive, etc., clips, or other means found in the prior art for adhering a collector sheet to a fluid conducting tube. The collector modules can be scaled in length and width to increase solar collection coverage over areas of various size.

The solar collector can be configured for liquid coolant or phase change materials such as liquid/gas refrigerants, with the potential for a broad range of operating pressures. The solar collector may be housed in a roof mount or stand-alone configuration. A glazing profile, used in conjunction with a rubbery for example silicon extrusion, provides an efficient method of constructing the solar collector of the present invention.

The solar collector is built onto the supporting structure by laying down EPDM (Ethylene Propylene Diene Monomer) roofing rubber membrane and then fastening a framework to the support, followed by insulation, aluminum foil, a black anodized or painted aluminum sheet that has been folded or otherwise formed about a plurality of copper tubes and welded along the fold seam along the top of the tubes so as to form an contiguous surface, with an air gap and a pane of glass.

In summary, the solar panel according to the present invention may be characterized in one aspect as including a circumferential upstanding rim and defining a cavity therein, an insulating layer mounted in the cavity and extending substantially completely across the cavity so as to abut the rim substantially contiguously around the rim, a heat-exchanger sheet made substantially of collector sheet metal overlaid onto the insulating layer and substantially entirely covering said insulating layer, at least one light-passing sheet overlaying the heat exchanger sheet and mounted to the rim at edges of the light-passing sheet, and an array of fluid transmission tubes mounted to the heat-exchanger sheet, the fluid transmission tubes conducting a flow of heat-exchanger fluid in a heat exchange circuit. The array of fluid transmission tubes are mounted to, so as to lay substantially flush along, the heat-exchanger sheet within a corresponding array of channels formed in the heat-exchanger sheet.

Each channel in the array of channels is wrapped snugly around each corresponding tube in the array of fluid transmission tubes for direct metal-to-metal heat transfer of heat from the heat-exchanger sheet to the array of fluid transmission tubes. Each channel when so wrapped forms a seam of adjacent, for example closely adjacent, folds in the heat-exchanger sheet along upper edges of each channel when formed into the snug wrapping around each corresponding tube. The seam is welded closed with a weld thereby tightening closed the seam as the weld and channel cools, and consequently tightening the snug wrapping of each channel around its corresponding tube.

Advantageously, the collector sheet metal is aluminium sheet, and the light-passing sheet, for example of glass, is maintained spaced above the heat-exchanger sheet so as to maintain an air gap therebetween. The aluminium sheet may be of a thickness less than or substantially equal to 24 gauge, wherein the thickness is sufficient for the weld to be welded to the seam.

In one embodiment the array of tubes is a substantially parallel array of tubes and wherein an inlet header and an outlet header are mounted in fluid communication with the array of tubes at, respectively, inlet and outlet ends of the array. The inlet end of the array is at an end adapted to be mounted elevated above the outlet end of the array, wherein the inlet header is a hollow member having an array of orifices each in fluid communication with a corresponding tube of the array of tubes for simultaneous metering of the fluid into each tube of the array of tubes.

In a further embodiment, the light-passing sheet is a plurality of glass sheets in a linear array mounted to the rim, wherein adjacent glass sheets in the linear array overlap along their common edges in the fashion of a shingled roof. In such an embodiment, the panel has an upper end and an opposite lower end and the upper end is adapted to be elevated above the lower end, so that the overlap between the adjacent glass sheets is a cascading overlap wherein a lower-most edge of an upper sheet overlaps on top of an upper-most edge of a lower sheet. For example, every overlap between adjacent sheets may be a cascading overlap.

In the embodiment taught herein, which is not intended to be limiting, a first hooked member is mounted in the overlap, where in one example the overlap is a laterally extending seam, so as to support and mount the common edges of the glass sheets to one another. The first hooked member forms a common-edge receiving channel in a hook of the first hooked member for receiving one of the common edges in the channel. A planar flange portion of the hooked member is adhesively mountable to another of the common edges.

In the embodiment taught herein, which is again not intended to be limiting, a second hooked member is mounted to the rim for example along longitudinal edges or seams. The second hooked member has a hook portion forming an edge receiving channel for mounting therein of an edge of the light-passing sheet. The second hooked member has a planar portion mounted to the rim. The edge of the light-passing sheet is adhesively mounted in the edge receiving channel, substantially entirely along a corresponding edge of the light-passing sheet. For example, the edge-receiving channel extends completely along longitudinal edges of the rim. Advantageously, a moisture deflecting cap may be mounted on the second hooked member to inhibit ingress of moisture into the edge-receiving channel.

As also taught herein, each panel may be adapted for flush mounting adjacent a second panel by a pair of second hooked members mounted oppositely disposed along the rim so as to oppositely dispose on the rim a corresponding pair of edge receiving channels. Fasteners mount the pair of second hooked members to an upper edge of the rim. A drip gutter may be mounted between the second hooked member and the upper edge of the rim. A moisture impervious flexible sheet may be mounted sandwiched between the drip gutter and the upper edge of the rim. The flexible sheet may extend from said rim under said insulating layer.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings similar characters of reference denote corresponding parts in each view, and wherein:

FIG. 1 is, in front plan view, an embodiment of the solar panel of the present invention with two ganged tube embedded sheet collectors behind a single pane of glass.

FIG. 2 is, in perspective cutaway view, an embodiment of the solar panel of the present invention showing the preferred construction for installation of the solar panel on a sloped roof.

FIG. 2 a is a perspective cutaway detail view showing a close up cutaway of the embodiment of the solar panel of FIG. 2, showing the preferred construction for installation of the solar panel on a sloped roof.

FIG. 3 is, in front plan view, an embodiment of the solar panel of the present invention with three ganged tube embedded sheet collectors and a short collector behind two overlapping panes of glass, demonstrating the scalability of the present invention.

FIG. 4 is, in plan view, an embodiment of the tube embedded sheet collector of the present invention.

FIG. 4 a is, in front sectioned perspective view, the embodiment of the tube embedded sheet collector of FIG. 4 enlarged to show more detail.

FIG. 4 b is, in front sectioned detailed perspective view, the embodiment of the tube embedded sheet collector of FIG. 4a showing in detail the press fit of the tube in the metal sheet and the welded seam.

FIG. 5 is, in front perspective view, two tube embedded sheet collectors being joined together.

FIG. 6 is, in front perspective view, the embodiment of FIG. 3.

FIG. 6 a is, in side detailed section view, one embodiment of the overlap of the glass on the vertically scaled up solar panel of the present invention.

FIG. 6 b is, in end cross sectional view along line 6a-6a in FIG. 9, the overlap of the glazing strips supporting the overlapping panes of glass.

FIG. 7 is, in front sectioned view, shows the cross section of a glazing securement method.

FIG. 8 is, in front perspective view, a solar collector panel of the present invention configured for refrigerant operation where the refrigerant is metered into the solar collector tubes near or at the top of the collector.

FIGS. 8 a and 8b are, in front detailed perspective view enlarged from FIG. 8, metering headers of the refrigerant based embodiment of the solar collector of FIG. 8.

FIG. 9 is, in plan view, a solar collector array of the present invention that has been scaled out both vertically and transversely for mounting on a pitched roof, and customized in profile along its upper edge to match a gable roof line.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention includes a solar collector panel array 1 in which the active element or collector panel 3 includes a single thin sheet 15 of thermally conductive material such as but not limited to aluminum or other heat-conductive sheet metal which may be welded (herein collectively referred to as collector sheet metal), that has had fluid conducting metal (for example copper) tubes 4 pressed into or otherwise positioned so as to lie in channels 15b in sheet 15 so that the sheet 15 conformally encases the tubes 4. The channels are closed by a weld W in welded seam 18, best seen in FIG. 4b, where the opposed facing folds 15a in sheet 15 substantially meet or are closely adjacent after encircling the tubes 4. The tubes 4 are typically made of copper, steel, or some other suitable sized material capable of handling high pressures for solar energy collection applications using fluids ranging from water to liquid/vapor phase change refrigerant materials as would be known to one skilled in the art. The thermally conductive metal sheet 15 is typically coated on the upwardly or outwardly exposed surface with a high solar radiation absorption and low infrared emissivity paint as well known in the art.

Welding seam 18 closed aids in tightening the encasement of channels 5b about tubes 4. In particular, during the welding process the metal of sheet 15 adjacent the seam and channels 15b are heated and expand. While so expanded if the channels 15b are maintained and snugged around tubes 4 and folds 15a welded to one another, then upon the metal of channels 15b cooling and contracting, the channels 15b tighten so as to be closely clamped in metal-to-metal contact around tubes 4. This then avoids the use as seen in the prior art of clips, conductive adhesives/fillers, or, if unsecured, the loosening of, and lessening of, metal-to-metal contact in collector/tube interfaces due to expansion and contraction as would be seen in some of the prior art, leading in some cases perhaps to unwanted electrolysis between the metals.

Thus in a preferred embodiment which is not intended to be limiting, aluminum sheet 15 may be for example 24 of 22 gauge aluminum sheet, or thinner if folds 15a can still be welded together to tightly encase tubes 4 in channels 15b. Tubes 4 may be copper tube having ¼ inch inside diameter. The solar collector according to the present invention may, as described below, be quite long, for example 24 feet or more, and modularly constructed of 4 foot-by-8 foot panels.

Thus, the solar collector of the present invention may advantageously be constructed in a modular fashion by the interconnecting of tubes 4 by the use of flared ends 16 that are flared to a diameter that accepts the original outside diameter of the exposed end of a corresponding tube 4. In this way more than one module may be stacked or interconnected so as to mate the ends of the tubes exposed between modules as illustrated in FIG. 5 to create a larger solar collector 13 as shown in FIGS. 3 and 9. Typically after the male ends 17 of the tubes of one solar collector module are inserted into the female flared ends 16 of the tubes of the next adjacent collector, the joints between the ends of the tubes are heated and solder is applied to bond the tubes and providing a sealed fluid path. In this way a solar panel 1 of custom length can be made by joining one or more whole or part modules 3 in series, creating a panel the same width as the original module.

As shown in FIG. 8 and described above, welding seam 18 while the conformally encased tube 4 is pressed and held in channels in sheet 15 results in a tensioned contact between the channels in sheet 15 and tubes 4 resulting in a good thermal connection between the two that will be maintained over the life of the solar collector 3 in spite of thermal expansion and shrinkage. The operation of pressing the tube into the sheet 15 where the sheet is made of aluminum results in work hardening of the aluminum, which further reduces the likelihood of it moving much due to thermal expansion and contraction, thereby maintaining the physical and thermal connectivity between the tube 4 and the sheet 15.

The collector panels 3 can be configured for either liquid heat transfer fluid such as water or glycol, or refrigerant coolants. One embodiment of the present invention may be implemented for a gravity fed refrigerant based solar collector 22 without a pump in the circuit as shown in FIG. 8, where a metered inlet header 25 can be located part way down from the top, or alternatively such as header 29 at the top of the array such that it is far enough below the condenser in the heat reservoir that the liquid refrigerant has enough head to return to the solar collector evaporator. Thus for example, where there is insufficient head to supply a header 29 at the top of the array, a header 2t positioned part-way down the array may be used.

Keeping in mind that the collection panel 1 is inclined as it would be if mounted on a pitched roof or inclined for example vertically on a stand, upper inlet header 29 is elevated above lower header 30. In a liquid refrigerant embodiment example header 29 is metered as better seen in FIG. 8b so that liquid refrigerant is introduced through metering ports 26 into tubes 4. The metered header 25 better seen in FIG. 8a also introduces liquid refrigerant through metering ports 26 into tubes 4. Metering ports 26 for the liquid refrigerant embodiment may be for example conventional refrigerant metering tubes (for example a #36 metering tube for a 24 foot long array) soldered into the header, where the upper header may be a ⅜ inch pipe. In other words, the metering orifice is essentially a pin-hole size, being of 1/16^th inch or less. in embodiments using for example water as the heat transfer fluid the header would be for example ¾ inch pipe with a ¼ inch hole feeding directly into tubes 4.

The refrigerant header 25 is located part-way down from the top of the collector 22 such that refrigerant that flashes to gas can rise to the top of the array 24 to be collected by the upper header 29 and returned to the condensing heat exchanger in the heat reservoir, while gravity draws the liquid refrigerant down into the larger lower section 23 for solar heat absorption. The gas, and maybe a small amount of liquid, is accumulated by lower header 30, and circulated back to the condenser in the heat reservoir along with the gas from the upper header 29. Lower header 30 may be situated part way up the collector from the bottom for the gas return of the refrigerant to the condenser in the heat reservoir. In this implementation the bottom-most header 30 can simply act as a liquid accumulator, for example when the sun is weak or at the end of the day, or both, and pressure balancing passage between the various solar tubes 4, with both ends of the header capped.

In the refrigerant embodiment of the present invention refrigerant based heat exchange media is pumped to the inlet metering valves 26, better seen in FIG. 8b, between the upper inlet header 29 and the solar collector tubes 4. Gas and any left over liquid refrigerant flows back to the condenser from the lower header 30. The uppermost ends 4a of tubes 4 are capped or otherwise sealed closed.

The injector orifice into each tube 4 is sized for the length of the tube, allowing the refrigerant to evaporate as it runs down the length of the tube under the force of gravity. This allows, with the appropriate quantity of injected refrigerant, for an even evaporation along the length of tube, that is along the length of the collector, resulting in an even temperature along the collector. This avoids a problem encountered by the applicant where the liquid alcohol refrigerant would not flow above five feet before the alcohol evaporated allowing the collector to get very hot above the five foot levels. Thus using the solution to that problem according to the present invention even long runs of tubes 4, that is, when a plurality of modular panel section are joined together to form a long for example 20 foot or more length of collector panel 1, the amount of refrigerant being injected from the upper header may be adjusted to balance for the extra length of evaporation occurring in the extra length of the tubes.

The solar collector panel 1 can be configured for roof top installation or as a stand-alone unit. FIGS. 2 and 2a show cutaway views of the roof top embodiment panel 6 of the solar panel 1, where a layer of waterproof material such as EPDM (Ethylene Propylene Diene Monomer) rubber sheet 7 is put on the existing roofing structure sandwiching sheet 7, and then a wooden frame 8 is fastened onto the existing roofing structure, and insulation 9 is placed on the EPDM sheet 7 and within the frame 8, with a layer of paper backed aluminum foil 9a placed on top of the insulation. The EPDM sheet 7 is wrapped around the frame 8, terminating within the enclosed frame work and overlapping the insulation 9 slightly.

The base edge 6a of panel 6 as seen in FIG. 2 and the opposite top edge (not shown) may advantageously be constructed so as to allow air transfer into and out of the panel to help alleviate condensation. Consequently the base and top edges of the panel are not sealed in the fashion of the side edges such as illustrated in FIG. 2a. Rather, the top of the frame member is not sealed with a J-clip 19, type 37 and silicon bead 32. Instead, the edges of glass sheet 11 are siliconed directly down onto aluminum flashing 31. Flashing 31 has for example a small upstanding lip 31a against which the edge of the glass is rested. Silicon adhesive is used between the underside of the edge of the glass sheet and the top surface 31b of the flashing.

Solar collector modules 3 are placed into the framework 8 on top of the insulation 9 complete with plumbed headers 29, 30 to connect with the solar collection circuit. Oppositely disposed glass-supporting channels 19a are provided by J-clips 19 (or other channel members) which are installed over a C-shaped aluminum profile which serves to catch drips, herein drip edge or drip gutter 39. Drip gutter 39 is itself mounted down onto the EPDM sheet 7 and frame 8 by screws 38. Sheets of glass 11 are retained in channels 19a in J-clips 19. In order to facilitate lateral edge-to-edge expansion of the solar collector array, the lower flanges 19b of J-clips 19 extend horizontally outwardly, for example so as to terminate flush with the edges of frame 8. Glass sheets 11 may be 3 millimeter thickness glass. Channels 19a may have a ¼ inch gap to accommodate ⅛^th inch foam tape 37 and the 3 millimeter thick glass sheet 11. When the lower, inner flange of C-clip 21 or flashing clip 36, as the case may be, is also inserted under the upper flange of a J-clip 19, tape 37 is compressed so that the edge of the glass is clamped in the J-clip channel. The J-clip flanges and web may for example be 1/16^th inch thick.

Channels 19a serve to support the edges 11a of glass 11 sandwiched between the lower flanges 21a of a cap member such as C-clip 21 and double-sided tape 37, such as double-sided foam window glazing tape. The bottom surface of tape 37 is mounted to the lower flanges 19b so that edges 11a of glass 11 rest on, and are adhered to, the top surface of tape 37. Beads 32 of resilient sealant adhesive such as glazing silicon are used to resiliently seal tape 37 within channels 19a while providing for thermal expansion and contraction of glass 11. Beads 32 and tape 37 are of such diameter and durometry that the resting weight of the glass 11 only slightly compresses the bead and tape. C-shaped clips 21 when mounted along the length of the top profile of J-clips 19 act on glass 11 so as to urge the glass downwards onto the tape 37 and beads 32, thereby slightly compressing the tape and beads, resulting in a seal between the glass 11, the tape and beads, and the lower flanges 19b of J-clips 19.

The roof mount configuration is very scalable by extending the framework both vertically and horizontally. FIGS. 3 and 6 show a single module width, and FIG. 9 a double module width solar collector 1 of the present invention extended by cascading, that is overlapping like a shingled roof, a number of full and partial length solar collector modules 3. At some point the size of the solar collector 1 will require glass 11 that is too large to be handled in one piece. At this point more than one pane of glass is thus called for. The panes of glass may be installed by the following method: The lower-most pane 11a of glass 11 is silicon adhered at its lower end onto flashing 31 mounted on EPDM sheet 7 on the lower end of Frame 8, where the flashing 31 is not sealed onto the sheet 7 and the frame to allow air seepage.

As seen in FIG. 6a, a second, upper pane 11b of glass 11 has a J-clip 19 mounted to its lower end, along its lower inside edge using glazing adhesive 32′ such as structural silicon glazing adhesive. The J-clip 19 is mounted with its wider flange 19b abutted against the lower inside edge of upper pane 11b, and is oriented so that channel 19a is open downwardly so as to receive therein the upper edge of lower pane 11a. The upper edge of lower pane 11b mates into channel 19a against a resilient bead, member or insert such as snake-like silicon gasket 20 inlaid along the length of the base or web of channel 19a. Advantageously wide flange 19b presents at least a one inch wide bearing surface for adhesion to upper pane 11b. The second lower pane 11a thus overlaps under the upper first pane 11b along overlap seam 3a.

FIG. 6 b is illustrative of one way, not intending to be limiting, to mount onto frame 8 the intersection as seen in FIG. 9 of lateral or horizontal over-lapped seams 31 with longitudinal or vertical abutting seams 3b between adjacent panels 3. In particular, the side edges of the overlapped portion (the one inch overlap between upper and lower glass sheets 11b and 11a) are each supported in, respectively, an upper J-clip 19 and a lower, modified J-clip 19″. Thus upper glass sheet 11b is supported in the upper J-clip 19 as taught with respect to the single layer abutting seam of FIG. 7. The lower J-clip″ is modified to remove the upper flange 19c while leaving the web of the J-clip and lower flange 19b. Thus upper J-clip 19 may be overlapped onto lower J-clip 19″ by, again, approximately one inch, without the upper flange of lower J-clip 19″ interfering with the upper J-clip 19. As seen in FIG. 6b, the J-clips 19′ and corresponding adhesive 32′ stop short, that is, end laterally, before they interfere with the J-clips 19, adhesive beads 32, etc. making up longitudinal seam 3b. Again, as seen in FIG. 7, a fastener such as screw 38 fastens the J-clips 19 in seam 3b down onto frame 8. In one embodiment drip gutters 39 are also overlapped at seam 3a, along seam 3b. This allows the use of manageable lengths of drip gutters 39, that is of the same length as the sheets of glass 11, that is, for example eight feet.

The solar collector panel 1 can similarly be configured for stand alone operation wherein the roofing structure is replaced by a lightweight support backing such as corrugated “Chloroplast”. Such standalone solar collector panel may be mounted on a ground based stationary or dynamically steerable tracking frame that optimizes the orientation of the solar collector panel 1 as the sun moves across the sky.

As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

Claims

1. A solar panel comprising a frame having a circumferential upstanding rim and defining a cavity therein,an insulating layer mounted in said cavity and extending substantially completely across said cavity so as to abut said rim substantially contiguously around said rim,a heat-exchanger sheet made substantially of collector sheet metal overlaid onto said insulating layer and substantially entirely covering said insulating layer,at least one light-passing sheet overlaying said heat exchanger sheet and mounted to said rim at edges of said light-passing sheet,an array of fluid transmission tubes mounted to said heat-exchanger sheet, said fluid transmission tubes conducting a flow of heat-exchanger fluid in a heat exchange circuit,wherein said array of fluid transmission tubes is mounted to, so as to lay substantially flush along, said heat-exchanger sheet within a corresponding array of channels formed in said heat-exchanger sheet,and wherein each channel in said array of channels is wrapped snugly around each corresponding tube in said array of fluid transmission tubes for direct metal-to-metal heat transfer of heat from said heat-exchanger sheet to said array of fluid transmission tubes, and wherein said each channel when so wrapped forms a seam of adjacent folds in said heat-exchanger sheet along upper edges of said each channel when formed into said snug wrapping around said each corresponding tube, and wherein said seam is welded closed with a weld thereby tightening closed said seam and consequently tightening said snug wrapping.

2. The panel of claim 1 wherein said collector sheet metal is aluminium sheet.

3. The panel of claim 2 wherein said edges are closely adjacent along said seam.

4. The panel of claim 2 wherein said light-passing sheet is maintained spaced above said heat-exchanger sheet so as to maintain an air gap therebetween.

5. The panel of claim 1 wherein said collector sheet metal is aluminium sheet and said array of tubes is a substantially parallel array of tubes and wherein an inlet header and an outlet header are mounted in fluid communication with said array of tubes at, respectively, inlet and outlet ends of said array.

6. The panel of claim 5 wherein said inlet end of said array is at an end adapted to be mounted elevated above said outlet end of said array.

7. The panel of claim 6 wherein said inlet header is a hollow member having an array of orifices each in fluid communication with a corresponding tube of said array of tubes for simultaneous metering of said fluid into each tube of said array of tubes, and wherein said aluminium sheet is of a thickness less than or substantially equal to 24 gauge, and wherein said thickness is sufficient for said weld to be welded to said seam.

8. The panel of claim 1 wherein said light-passing sheet is a plurality of glass sheets in a linear array mounted to said rim, and wherein adjacent glass sheets in said linear array overlap along their common edges.

9. The panel of claim 8 wherein said panel has an upper end and an opposite lower end and wherein said upper end is adapted to be elevated above said lower end, and wherein said overlap between said adjacent glass sheets is a cascading overlap wherein a lower-most edge of an upper sheet overlaps on top of an upper-most edge of a lower sheet.

10. The panel of claim 9 wherein every said overlap between said adjacent sheets is a said cascading overlap.

11. The panel of claim 9 wherein a first hooked member is mounted in said overlap so as to support and mount said common edges to one another.

12. The panel of claim 11 wherein said first hooked member forms a common-edge receiving channel in a hook of said first hooked member for receiving one of said common edges in said channel, and wherein a planar flange portion of said hooked member is adhesively mountable to another of said common edges.

13. The panel of claim 1 wherein a second hooked member is mounted to said rim, and wherein said second hooked member has a hook portion forming an edge receiving channel for mounting therein of an edge of said light-passing sheet, and wherein said second hooked member has a planar portion mounted to said rim.

14. The panel of claim 13 wherein said edge of said light-passing sheet is adhesively mounted in said edge receiving channel.

15. The panel of claim 14 wherein said edge-receiving channel extends, substantially entirely along a corresponding said edge of said light-passing sheet.

16. The panel of claim 15 wherein said edge-receiving channel extends completely along longitudinal edges of said rim.

17. The panel of claim 13 wherein a moisture deflecting cap is mounted on said second hooked member to inhibit ingress of moisture into said edge-receiving channel.

18. The panel of claim 13 wherein said panel is adapted for flush mounting adjacent a second said panel by a pair of said second hooked members mounted oppositely disposed along said rim so as to oppositely dispose on said rim a corresponding pair of said edge receiving channels.

19. The panel of claim 18 further comprising fasteners mounting said pair of second hooked members to an upper edge of said rim.

20. The panel of claim 13 further comprising fasteners mounting said second hooked member to an upper edge of said rim.

21. The panel of claim 13 further comprising a drip gutter mounted between said second hooked member and an upper edge of said rim.

22. The panel of claim 21 further comprising a moisture impervious flexible sheet mounted sandwiched between said drip gutter and said upper edge of said rim.

23. The panel of claim 22 wherein said flexible sheet extends from said rim under said insulating layer.