The present invention is directed to apparatuses and methods to prevent power loss from cracked cells in solar panels.
The most common solar panel design utilizing a front glass coversheet and a polymer backsheet with copper interconnect wires between silicon cells is sensitive to the tensile stress related cracking of the cells when front side mechanical loads are applied to the panel through handling, snow load, or wind load. In spite of training, installation workers and Operations & Maintenance workers are also known to commonly walk on panels, and this pressure is also sufficient to crack cells. These cracks are often closed initially after formation with minimal power loss, but over time the cracks can open up such that metallization is discontinuous across the cracks, leading to higher than desired degradation rates and risks of hot spot heating. Several trends within the industry are helping to reduce the occurrence of such cracks, for example by using glass backsheets to place the cells in the neutral plane mechanically so that cells are not placed into tensile stress under load, or by using interconnect methods using electrically conductive adhesives to eliminate solder induced damage in the silicon, such as in shingled panels. Should cracks occur, the trend of using a higher number of interconnect wires on each cell reduces the potential power losses. Still other trends are adding to crack related risks such as reduced frame mass that allows module to bend more with applied loads, larger modules with center regions that are farther from the frame, thicker interconnect wires to carry the steadily increasing amounts of cell current which then cause more soldering induced microcracks in the silicon, and half-cut cells or even narrower shingled cells which have weak laser-cut edges from which cracks are more likely to propagate. In addition, a large installed base of panels exist which are more sensitive to cells cracking with only 2 or 3 busbars, and which already have a high density of cells cracks or which are sensitive to their formation in the future.
One feature seen in an increasing number of panels is an aluminum (Al) cross bar spanning the width on the rear side of panel and connected to the extruded Al frame on each side with screws. This stiffens the solar panel and effectively reduces the deflection (and thus tensile stress) vs load. Some of these panels even have a pad in the middle that lightly touches the backsheet or has a narrow air gap, and such a pad can further reduce panel deflection vs load. However, they have no effect on the panel other than when the front side pressure is being applied. In the inventors' experience, these lightweight, extruded Al bars have a limited effectiveness in reducing deflection vs load, and that the bars become permanently deformed at front side loads >3000 pascal (Pa)—well below the heavy snow load condition of 5400 Pa.
Panels in the field are most commonly attached with clamps or bolts to two metal rails that span the full width or length of the panel. Most commonly the rails extend across the short dimension of the panel (−1 meter wide) and intersect the long edges at the ⅕ and ⅘ points from one of the corners. A typical frame thickness is ˜35 millimeters (mm) with a lip or flange that touches the rails. Given a laminate thickness of ˜4.5 mm, this leaves a gap of over 30 mm between the backsheet and the rails. Some researchers have reported that at heavy snow load conditions, the modules can deflect this full gap distance and even touch the rails, but with such a high level of deflection, usually significant cell cracking will have occurred. On residential rooftops, panels may be fixed to point clamping elements rather than rails, leaving an even larger gap underneath the panel over which it can deform under front side loads.
Looking forward, the industry could benefit from more choices in improved panels designs and manufacturing methods where either the cells are less likely to crack in the first place, or if they do, the cracks are less likely to contribute to power loss. The industry could also benefit from methods to extend the lifetime of the already installed base of panels sensitive to crack related degradation.
The invention relates to apparatus and methods to mount solar panels in a way that the panels are supported from the rear side by spacer elements termed RailPads and RoofPads. These spacer elements press upon the rear side of the panel to displace regions of the panel away from the mounting structure. The support provided by the spacer elements reduces downward panel deflection from wind, snow, and other loads, thus minimizing tensile stress in the cells and thus minimizing solar cell crack formation and propagation. The upward bow in the panel places cells in a state of protective compressive stress. In a tensile stress state, there are forces being applied to the cells which are stretching them outward along the plane of the cells, as if there were a clamp along each edge of the cells pulling each edge away from the center. A small crack defect can be stretched apart so that it propagates into a long crack due to such forces. The opposite is true for cells in a state of compressive stress. Here there are forces being applied to the cells which are pushing inward along the plane of the cells, as if there were a clamp along each edge of the cells pushing inward toward the center. Any short crack defect will be pressed closed by such forces such that is less likely to propagate. Even when front side loads are applied to the solar panel, the loads may need to be very high for the stress levels to switch from compression to tension for many cells in the panel.
The invention relates to methods of making and installing spacer elements that limit the inward deflection of photovoltaic solar panels when front side mechanical loads are applied. By limiting bending of the panels, the silicon solar cells within the panels are prevented from seeing the high tensile stresses that accompany such bending, and thus they are less likely to form cracks that can degrade panel performance. Additionally, limiting the deflection can allow any cracks that are present in the solar cells to more likely remain in a tightly closed state that does not contribute to power loss. Additionally, by choosing spacer elements that force a small outward deflection of the panel surface, the cells can be kept in a protective state of compressive stress so that new cracks are even more unlikely to form, and if cracks are present, that they will be more likely to remain in a tightly closed state.
Various embodiments may provide a photovoltaic solar panel mounting system, comprising one or more spacer elements, wherein the one or more spacer elements are configured to be positioned between a rear side of a solar panel and one or more mounting rails supporting the solar panel such that, when the one or more spacer elements are so positioned, a face of the solar panel is deflected from a neutral position away from the one or more mounting rails after two or more clamps attach the solar panel to the one or more mounting rails.
Various embodiments may provide a rooftop photovoltaic solar panel mounting system, comprising one or more spacer elements, wherein the one or more spacer elements are configured to be positioned between a rear side of a solar panel and a rooftop surface such that a face of the solar panel is deflected from a neutral position away from the rooftop surface after two or more clamps attach the solar panel to one or more mounting elements fixed to the rooftop surface.
Various embodiments may provide a method for mounting a photovoltaic solar panel, the method comprising positioning one or more spacer elements between a rear side of a solar panel and a mounting surface such that a face of the solar panel is deflected from a neutral position in a direction outward from the mounting surface after attachment of the solar panel to the mounting surface.
The accompanying drawings, which are incorporated herein and constitute part of this specification, illustrate example aspects of the claims, and together with the general description given above and the detailed description given below, serve to explain the features of the claims.
The various aspects will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. References made to particular examples and implementations are for illustrative purposes, and are not intended to limit the scope of the claims.
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
References to “one embodiment” or “an embodiment” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics can be combined in any suitable manner consistent with this disclosure.
Terminology. The following paragraphs provide definitions and/or context for terms found in this disclosure (including the appended claims):
“About” or “approximately”. As used herein, the terms “about” or “approximately” in reference to a recited numeric value, including for example, whole numbers, fractions, and/or percentages, generally indicates that the recited numeric value encompasses a range of numerical values (e.g., +/−5% to 10% of the recited value) that one of ordinary skill in the art would consider equivalent to the recited value (e.g., performing substantially the same function, acting in substantially the same way, and/or having substantially the same result).
“Comprising” is an open-ended term that does not foreclose additional structure or steps.
“First,” “second,” etc. terms are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, reference to a “first” RailPad does not necessarily imply that this RailPad is the initial RailPad in a sequence; instead the term “first” may be used to differentiate this RailPad from another RailPad (e.g., a “second” RailPad).
The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise.
As used herein, the term “substantially” is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms “substantially,” “approximately,” and “about” can be substituted with “within [a percentage] of” what is specified, where the percentage includes 0.1, 1, 5, and 10 percent.
As used herein, “regions” can be used to describe discrete areas, volumes, divisions or locations of an object or material having definable characteristics but not always fixed boundaries.
In addition, certain terminology can also be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, and “side” describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology can include the words specifically mentioned above, derivatives thereof, and words of similar import.
The term “laminate” refers to all portions of the solar panel other that the perimeter frame portion.
The terms “solar panel” and “module” are synonymous.
In the following description, numerous specific details are set forth, such as specific operations, in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to one skilled in the art that embodiments of the present disclosure can be practiced without these specific details. In other instances, well-known techniques are not described in detail in order to not unnecessarily obscure embodiments of the present disclosure
In this work, we detail the design and implementation of spacer elements located behind a solar panel to limit panel deflection from front side loads and to place cells in a protective compressive stress state, and thereby reduce panel degradation from cracked solar cells. Two general embodiments are detailed, one where the RailPad spacer elements are support by the mounting rail(s) to which the solar panel is attached, and other where a flat surface such as a rooftop provides this support to the RoofPad spacer element(s). In a tensile stress state, there are forces being applied to the solar cells which are stretching them outward along the plane of the solar cells, as if there were a clamp along each edge of the solar cells pulling each edge away from the center. The opposite is true for solar cells in a state of compressive stress. In solar cells in a state of compressive stress there are forces being applied to the solar cells which are pushing inward along the plane of the solar cells, as if there were a clamp along each edge of the solar cells pushing inward toward the center. Even when front side loads are applied to the solar panel, the loads may need to be very high for the stress levels to switch from compression to tension for many solar cells in the panel.
In one embodiment of the present invention, a spacer element, termed by the inventors as a “RailPad,” is placed on the middle of each rail to eliminate the space between the backsheet of the solar panel and the rail such that when front side loads are applied, the average deflection of the panel is far lower than would be the case without the RailPad. With lower deflection levels, cell cracking will be greatly reduced, and/or mass can be removed from elsewhere in the panel to reduce costs and open up new markets for lighter weight panels. The RailPads could be attached to the rails either in the factory, in the field prior to installation, or added as a retrofit to pre-existing systems. The RailPads may be attached to the rails by press fitting, sliding into grooves, screwing or bolting down, welding, or by adhesive bonding. The RailPads could also be an inherent part of the rail, for example by sheet metal bending or deformation. In order to maximize the benefit, the RailPad thickness is chosen such that the RailPads press on the backsheet to deflect the face of the solar panel upward and place the cells under protective compressive stress. An additional benefit of pressing upward on the face of the solar panel relates to wind bursts that have the potential to rapidly bang the panel against the RailPads, potentially causing damage over time. If for example an air gap were to be left between the RailPad and the rear side of the solar panel, front side wind bursts could bang the rear side of the solar panel against the RailPads. In the case of mounting the rear side of the solar panel flush against the top surface of the RailPads, then rapidly changing rear side wind bursts could lift the panel outward and away from the RailPad surface, followed by a release of wind load or a reversal of wind load which then bangs the rear side of the solar panel against the RailPads. By preloading the rear side of the solar panel with the pressure from the RailPads, then some range of rear side wind bursts will be unable to lift the module away from the RailPad surface, thus eliminating completely some banging events. For stronger wind bursts that do manage to lift the module away from the RailPads, any subsequent banging will be lower in severity.
In order to prevent damage occurring in the interface region between the RailPads and the panel, the RailPads may have soft elastomeric top layer. A preferred embodiment of such an elastomer is silicone rubber which has excellent weathering properties. Other possible elastomers include, but are not limited to, ethylene propylene diene monomer (EPDM) rubber, butyl rubber, neoprene, and urethane. The majority of the thickness of the RailPads should be stiff to resist deflection, low-cost, and durable under decades of outdoor exposure such as extruded Al, steel, and hard plastics. In some embodiments, RailPads may be formed from a non-metal material, such as plastic. RailPads formed from non-metal materials may be advantageous in that the non-metal RailPads may not require grounding. In some embodiments, RailPads may be grounded to the rails to prevent the RailPads from being energized. The grounding of the RailPads may be achieved in any manner, such as by bonding washers, WEEB (Washer, Electrical Equipment Bonding) mounts, star washers, and/or flange nuts.
In another embodiment, the RailPad spacing element is attached to the backsheet of the solar panel in the locations directly opposite where the rails will be in order to accomplish the same goals as above. Again, as in the above embodiment, the RailPads could be attached to the panels either in the factory, in the field prior to installation, or added as a retrofit to pre-existing systems. Again, as in the above embodiment, the RailPad thickness is chosen such that under no front-side load, the RailPads press on the rail to deflect the glass and place the cells under protective compressive stress.
In some embodiments, the long axis of the RailPads are approximately colinear with the long axis of the rails onto which they are placed. In other embodiments, the long axis of the RailPads may be approximately perpendicular the long axis of the rails.
In some embodiments, the top surface of the RailPad is flat. In other embodiments the top surface is curved which may result in more uniform force applied to the rear side of the laminate or in a force profile that best protects the solar cells. In other embodiments even though the top surface of the RailPad is flat prior to installation, the RailPad may bend in a way such that it is curved after installation, for example if the long axis of the RailPad is oriented perpendicular to the supporting rail such that the rail supports the RailPad only near the center of the RailPad.
In some embodiments, the solar panels are implemented within a single-axis tracker installation where each solar panel is clamped to a single rail which rotates over the course of each day to keep the front face of the solar panels oriented toward the sun. This single rail, sometime termed a “tube” is often clamped to the frame of the solar panels near the middle of the long edge of the frames. By introducing a RailPad between this tracker rail tube and the rear side of a solar panel, as the tracker rail tube rotates, the relative positions of the solar panel rear surface, the RailPad, and the tracker rail tube remain constant and no stress is placed on the system. Some solar panels have features such as junction boxes, cables, and crossbars on the rear side in the middle region which might interfere with the placement of some RailPad embodiments. Alternative embodiments may be necessary in such cases to avoid this interference. For example, to avoid junction boxes and cables, a shorter single RailPad, multiple shorter RailPads, or RailPads with depressions or cutout regions could be implemented.
In some embodiments where no rails are used in mounting the panels to roofing structures, but rather the panels are attached to point clamping elements, a differently designed spacer element which the inventers term a “RoofPad” can be used to limit the panel deflection under front side loads. The RoofPads could be likewise be attached to the roof or to the panel during initial installation or added as a retrofit to pre-existing systems. The RoofPads may be attached to the roof by a variety of methods, including but not limited to screwing down, bolting down, or by bonding with adhesive. The RoofPad thickness is chosen such that under no front-side load, the RailPads press on the backsheet to deflect the glass and place the cells under protective compressive stress. As explained about for RailPads, there may be an undesireable range of gaps or deflection amounts where banging from wind could occur.
In some embodiments, the RailPad may be installed prior to installation of the solar panel. In such embodiments, the action of clamping the frame of the solar panel to the supporting structure will cause the deflection of the laminate to occur. In other embodiments, the RailPad may be installed after installation of the solar panels. In such embodiments, the deflection of the laminate may be enacted by pressing by hand or with a tool to make room for insertion of the RailPad, and upon release of this pressure, the laminate rests on the RailPad top surface. Alternatively, the deflection of the laminate may occur as a result of the RailPad insertion process, for example by pressing two parts together or by rotating a cam feature.
In a preferred embodiment for mounting a solar panel on flat surfaces, RoofPad spacer elements 113 have an optional top cushioning layer 114. The frame 101 of the solar panel is secured by corner clamps 111 to corner support structures 110 that are attached to the roof 112 or another flat surface. One or more RoofPad spacer elements 113 are secured to the roof 112 in order to limit deflection from front side loads. As with the RailPads, the thickness of the RoofPad spacer elements 113 can be chosen to provide outward deflection (i.e., away from (e.g., in the about normal direction out from) the rooftop 112 and/or away from (e.g., in the about normal direction out from) the rail 110) of the laminate 102 to employ the protection of compressive stress on the solar cells.
In one preferred embodiment the standard solar panel consists of an extruded aluminum frame 101 that surrounds a laminate 102 that consists of glass, encapsulant, interconnected solar cells, and polymer backsheet. The solar panel is secured by metal clamps 104 to metal rails 103 that extend below the panel across either the width or length of the panel. To the rails 103 or to the back of the laminate 102 are attached RailPad spacer elements 106 that have an optional top cushioning layer 105. The total thickness of the RailPad spacer element 106 and cushioning layer 105 is chosen so that after clamping, the laminate 102 is bowed outward away from the rails 103 (i.e., away from the rooftop and/or away from the rails 103). Such outward deflection places the solar cells in a protective state of compressive stress. In one preferred variation, rather than a single long spacing element, multiple shorter RailPads 109 and surface cushioning layers 108 are used.
In a preferred embodiment for mounting a solar panel on a single axis tracker rail tube 120, a RailPad spacer element 115 with an optional cushioning layer 105 has a U-bolt tube clamp element 116 placed into a hole in the spacer element 115. The clamp element 116 is rotated into an upright position to allow it to be inserted between the module laminate 102 and the tracker tube 120. By then rotating the clamp element 90 degrees, a cam 119 is engaged to press against the tracker tube 120 and displace the spacer element 115 away from the tracker tube 120, thereby deflecting the laminate 102 outward (i.e., away from the rooftop) and placing the cells in compressive stress. To secure the clamp element in place, a keeper plate 117 is added to the two ends of the clamp element 116 extending out beyond the tracker tube 120, and the plate 117 is secured in place by adding nuts 118 to the threaded ends of the clamp element 116. The design allows mounting of this RailPad assembly either before or after the clamping of the solar panel to the tracker rail tube 120.
In another preferred embodiment for mounting a solar panel on a single axis tracker rail tube 120, a RailPad spacer bottom element 121 is placed on the tracker rail tube 120 such that fixing regions 122 stamped and deformed out of the side planes of the spacer element 121 press strongly against the sides of the tracker rail tube 120 to keep the bottom spacer element 121 fixed in place. The bottom spacer element 121 height is such that it can fit in the gap between the laminate 102 and the tracker rail tube 120. A RailPad spacer top element 123 with an optional cushioning layer 105 is then slid from the side onto the spacer bottom element 121. The spacer top element 123 is the lifted away from the spacer bottom 121 to deflect the laminate 102 upward, and the spacer top element is fixed in place by inserted pins or bolts 124 into holes within the spacer elements 121 and 123.
In another preferred embodiment for mounting a solar panel on rails 125, a RailPad spacer bottom element 126 with an optional cushioning layer is placed on a rail underneath an existing solar panel or underneath where a solar panel will later be placed. The bottom spacer element 126 height is such that it can fit in the gap between a laminate and the rail 125, and it has side elements to keep it from falling off the rail 125. A RailPad spacer top element 127 is then slid from the side onto the spacer bottom element 126 which causes the top element 127 to rise away from the rail 125 and deflect the laminate away from the rail 125. The top element 127 engages the bottom element 126, and has a feature to lock with the rail 125 when it is in place. Holes 128 in the elements allow the elements to be wired to the rail to prevent movement or to be joined together with the insertion of a pin or bolt 129. In some configurations, two rails 125 are used for each solar panel. The RailPad elements 126, 127 may be made from metal extrusion or stamped metal.
In another preferred embodiment for mounting a solar panel on rails, a RailPad 129 may be made out of a single piece of sheet metal, bent in such fashion that no extra elements are needed to install it. The RailPad 129 in this embodiment has sheet metal ratchet elements 130 that engage with the bent triangular elements 131, with the sheet metal being doubled for strength in certain regions, and an optional cushioning layer 105 on top. The rachet elements 130 may be all punched inwards so that the height may be adjustable in the field, or only select ones may be punched inward so that only a fixed height is achieved
In another preferred embodiment for mounting a solar panel on a single axis tracker rail tube 120, a RailPad spacer bottom element 134 is placed on the tracker rail tube 120 such that fixing regions 122 stamped and deformed out of the side planes of the spacer element 134 press strongly against the sides of the tracker rail tube 120 to keep the bottom spacer element 134 fixed in place. The bottom spacer element 134 height is such that it can fit in the gap between the laminate 102 and the tracker rail tube 120. A RailPad spacer top element 135 with an optional cushioning layer is then slid from the side onto the spacer bottom element 134. A cam 136 is then placed between the top element 135 and the bottom element 134 and rotated with a tool 137 to lift the laminate 102 upward. After fixing the spacer elements 134, 135 in place with a bolt or pin through holes 128, the cam 136 and tool 137 can be removed.
The integration of the spacer element (e.g., RailPad 302, 402) as part of the mounting rail (e.g., 300, 400) may negate a need for a separate step of inserting a spacer element between the panel and the rail after mounting the solar panel and/or a step of attaching the spacer element to the rail (e.g., step 1502) as the mounting rail (e.g., 300, 400) itself already includes the RailPad (e.g., RailPad 302, 402) as an integral portion of the mounting rail (e.g., 300, 400).
Although the primary motivation for the invention as described above relates to a reduction in silicon solar cell crack related degradation, the benefits of the invention extend to other degradation modes of silicon solar cell based solar panels and to solar panels based on other technologies, such as thin films of CIGS (Copper Indium Gallium Selenide), CdTe (Cadmium Telluride), CdSeTe (Cadmium Selenium Telluride), and perovskites. For example, introducing compressive stress and limiting tensile stress may be beneficial for interconnect wire fatigue problems, conductive adhesive contact resistivity problems, thin film adhesion problems, encapsulant and backsheet delamination problems, glass cracking problems, and edge seal integrity problems.
Various embodiments may include a photovoltaic solar panel mounting system, comprising one or more spacer elements, wherein the one or more spacer elements are configured to be positioned between a rear side of a solar panel and one or more mounting rails supporting the solar panel such that, when the one or more spacer elements are so positioned, a face of the solar panel is deflected from a neutral position away from the one or more mounting rails after two or more clamps attach the solar panel to the one or more mounting rails. In some embodiments, the one or more spacer elements may be configured to be fixed to the one or more mounting rails. In some embodiments, the one or more spacer elements may be configured to be fixed to the rear side of solar panel. In some embodiments, a distance the face of the solar panel is deflected from a neutral position may be from 0.1 to 4 centimeters (cm). In some embodiments, a distance the face of the solar panel is deflected from a neutral position may be from 0.4 to 2.5 cm. In some embodiments, the system may further comprise the one or more mounting rails, the two or more clamps, and the solar panel, wherein the solar panel has a short axis and a long axis. In some embodiments, the one or more mounting rails may be configured to run parallel to the short axis of the solar panel after the two or more clamps attach the solar panel to the one or more mounting rails. In some embodiments, the one or more mounting rails may be configured to run parallel to the long axis of the solar panel after the two or more clamps attach the solar panel to the one or more mounting rails. In some embodiments, the one or more mounting rails may be a single rail configured to operate as center tube in a tracking photovoltaic system. In some embodiments, the system may further comprise the one or more mounting rails, the two or more clamps, and the solar panel, wherein the solar panel has an axis across which the one or more mounting rails are configured to span when the one or more spacer elements are positioned between the rear side of the solar panel and the one or more mounting rails supporting the solar panel, and wherein the one or more spacer elements are configured such that a sum of lengths of the one or more spacer elements on each of the one or more mounting rails have a value between 1% and 99.9% of a length of the axis of the solar panel when the one or more spacer elements are positioned between the rear side of the solar panel and the one or more mounting rails supporting the solar panel. In some embodiments, the system may further comprise the one or more mounting rails, the two or more clamps, and the solar panel wherein the solar panel has an axis across which the one or more mounting rails are configured to span when the one or more spacer elements are positioned between the rear side of the solar panel and the one or more mounting rails supporting the solar panel, and wherein the one or more spacer elements are configured such that a sum of lengths of the one or more spacer elements on each of the one or more mounting rails have a value between 4% and 90% of a length of the axis of the solar panel when the one or more spacer elements are positioned between the rear side of the solar panel and the one or more mounting rails supporting the solar panel. In some embodiments, the one or more spacer elements are comprised of one or more of a metal, a plastic, an elastomer, a wood, a ceramic, a composite. In some embodiments, the system may further comprise a layer of elastomer material affixed to a side of each of the one or more spacer elements such that the layer of elastomer is configured to contact the rear side of the solar panel when the one or more spacer elements are positioned between the rear side of the solar panel and the one or more mounting rails supporting the solar panel. In some embodiments, the one or more spacer elements may be configured to be kept in place through pressure applied when the one or more spacer elements are positioned between the rear side of the solar panel and the one or more mounting rails supporting the solar panel without being rigidly affixed to the rear side of the solar panel or the one or more mounting rails. In some embodiments, the one or more spacer elements are an integral part of the one or more mounting rails. In some embodiments, the surface may be a rooftop surface.
Various embodiments may include a rooftop photovoltaic solar panel mounting system, comprising one or more spacer elements, wherein the one or more spacer elements are configured to be positioned between a rear side of a solar panel and a rooftop surface such that a face of the solar panel is deflected from a neutral position away from the rooftop surface after two or more clamps attach the solar panel to one or more mounting elements fixed to the rooftop surface. In some embodiments, the one or more spacer elements may be configured to be fixed to the rooftop surface. In some embodiments, the one or more the spacer elements may be configured to be fixed to the rear side of the solar panel. In some embodiments, a distance the face of the solar panel may be deflected from a neutral position may be from 0.1 to 4 cm. In some embodiments, a distance the face of the solar panel may be deflected from a neutral position may be from 0.4 to 2.5 cm. In some embodiments, the one or more spacer elements are comprised of one or more of a metal, a plastic, an elastomer, a wood, a ceramic, a composite. In some embodiments, the system may further comprise a layer of elastomer material affixed to a side of each of the one or more spacer elements such that the layer of elastomer is configured to contact the rear side of the solar panel when the one or more spacer elements are positioned between the rear side of the solar panel and the rooftop surface. In some embodiments, the one or more spacer elements may be configured to be kept in place through pressure applied when the one or more spacer elements are positioned between the rear side of the solar panel and the rooftop surface without being rigidly affixed to the rear side of the solar panel or the rooftop surface. In some embodiments, the system may further comprise the solar panel, wherein the one or more spacer elements are configured such that a sum of areas of surfaces of the one or more spacer elements contacting the rear side of the solar panel when the one or more spacer elements are positioned between the rear side of the solar panel and the rooftop surface has a value between 2% and 90% of an area of the solar panel. In some embodiments, the system may further comprise the solar panel, wherein the one or more spacer elements are configured such that a sum of areas of surfaces of the one or more spacer elements contacting the rear side of the solar panel when the one or more spacer elements are positioned between the rear side of the solar panel and the rooftop surface has a value between 5% and 50% of an area of the solar panel.
Various embodiments may include a method for mounting a photovoltaic solar panel, the method comprising positioning one or more spacer elements between a rear side of a solar panel and a mounting surface such that a face of the solar panel is deflected from a neutral position in a direction outward from the mounting surface after attachment of the solar panel to the mounting surface. In some embodiments, the mounting surface comprises one or more rails. In some embodiments, the mounting surface comprises a rooftop. In some embodiments, the method may further include attaching the solar panel to the mounting surface after the positioning of the one or more spacer elements between the rear side of the solar panel and the mounting surface. In some embodiments, the method may further include attaching the solar panel to the mounting surface before the positioning of the one or more spacer elements between the rear side of the solar panel and the mounting surface. In some embodiments, the positioning the one or more spacer elements between the mounting surface and the rear side of the solar panel causes the face of the solar panel to be deflected outward. In some embodiments, the method may further include applying pressure to the rear side of the solar panel prior to positioning the one or more spacer elements between the rear side of the solar panel and the mounting surface, and releasing the pressure to the rear side of the solar panel after positioning the one or more spacer elements between the rear side of the solar panel and the mounting surface thereby causing the rear side of the solar panel to contact the one or more spacer elements.
Various aspects illustrated and described are provided merely as examples to illustrate various features of the claims. However, features shown and described with respect to any given aspect are not necessarily limited to the associated aspect and may be used or combined with other aspects that are shown and described. Further, the claims are not intended to be limited by any one example aspect.
The foregoing method descriptions and the process flow diagrams are provided merely as illustrative examples and are not intended to require or imply that the steps of the various aspects must be performed in the order presented. As will be appreciated by one of skill in the art the order of steps in the foregoing aspects may be performed in any order. Words such as “thereafter,” “then,” “next,” etc. are not intended to limit the order of the steps; these words are simply used to guide the reader through the description of the methods. Further, any reference to claim elements in the singular, for example, using the articles “a,” “an” or “the” is not to be construed as limiting the element to the singular.
The preceding description of the disclosed aspects is provided to enable any person skilled in the art to make or use the claims. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects without departing from the scope of the claims. Thus, the claims are not intended to be limited to the aspects described herein but are to be accorded the widest scope consistent with the following claims and the principles and novel features disclosed herein.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 62/798,521 entitled “Method to strengthen mounted solar panels” filed Jan. 30, 2019, the entire contents of which are incorporated herein by reference.
Number | Date | Country | |
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62798521 | Jan 2019 | US |