Snow-free solar strip coatings

Abstract

A platinum-cured polydimethylsiloxane liquid silicone compound is cured to form a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shore hardness. Miscible silicone oil is added to a portion of the strip body precursor to form a bi-layer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% to about 90%. The base bottom layer is attached to a solar panel edge to position the plasticized top layer over the edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel.

Description

SNOW-FREE SOLAR STRIP COATINGSTECHNICAL FIELD

[0001] The subject disclosure is directed to snow-free solar strip coatings.BACKGROUND ART

[0002] Accumulation of ice and snow on surfaces of wind turbines, photovoltaic (PV) modules, and power transmission lines reduces efficiency and reliability in power generation and transportation. Moreover, snow and ice accumulation on cable-stayed bridges, sensors of modem vehicles, and aircraft wings can lead to safety and economic concerns in transportation industry. Various active, passive, and administrative techniques have been utilized to mitigate atmospheric icing issues. However, active and administrative approaches are costly and often are not easily applicable in all environmental conditions (i.e. during heavy snow and freezing rain events). This has shifted efforts towards developing passive mitigation strategies (i.e. no external energy involved).

[0003] Passive anti-icing strategies have been focused on developing icephobic coatings with characteristics ranging from ice adhesion reduction to prevent! on / del ay of ice formation. Superhydrophobic (SH) surfaces, slippery liquid-infused porous surfaces (SLIPS), hydrated surfaces, interfacial slippage, low interfacial toughness surfaces, and stress localization have all shown promise in reducing ice adhesion strength and facilitating its removal. However, less attention has been given for developing surfaces to reduce snow adhesion and facilitate its removal. Unlike ice, snow is a porous media containing water, ice, and air, possessing a variety of morphologies and physical properties dictated by thermodynamic conditions of atmosphere in which it forms. While ice adhesion strength to surfaces is orders of magnitude higher than snow adhesion strength, low density of snow when compared to ice makes it still very challenging to be removed from surfaces.

[0004] In addition to accumulation thickness and external forces like wind, snow removal from surfaces also depends on physical properties of snow such as flake size, its liquid water content (LWC) - a factor that determines its dryness or wetness and density- as well as surface properties like roughness and surface energy. To date, a few structured surfaces have been implemented for facilitating snow removal. It has been shown that typical SH surfaces facilitate dry snow shedding (below -1 or -2 °C) while exhibiting contact pining to wet snow (abovl or -2 °C). The former takes place due to a low surface energy nature of the coating combined with snow / ice contact area minimization, while the latter originates from reducing the snow / surface water infiltration, impeding shedding. In contrast,smooth hydrophilic surfaces have only exhibited promise for wet snow sliding due to improving liquid water infiltration at the interface, contributing to shedding.

[0005] Apart from the snow-type dependent efficiency of textured surfaces, snow adhesion on such surfaces can dramatically increase if water infiltrates in surface texture like by frost formation, increasing the snow-solid interfacial area. Moreover, having high solar diffusive reflectivity characterized by a high albedo constant, snow is deemed to stay on surfaces in cold regions for days, undergoing capillary-driven interfacial melting / icing cycles, contributing to the snow / texture interlocking. Lastly, structured surfaces are prone to multiple icing / deicing cycles and abrasion that could exacerbate the snow adhesion.

[0006] By contrast, designing smooth surfaces with reduced snow adhesion have two major advantages over textured surfaces: minimizing the snowflake / surface interlocking and prolonged durability to multiple snow accumulation and shedding cycles. It has been demonstrated that smooth surfaces show a lower ice adhesion due to ice / surface contact minimization. However, no study has shown the snow adhesion performance of smooth surfaces in controlled conditions to date.

[0007] While it was thought that the plasticization of elastomers had shown some promise in ice adhesion reduction, such applications were avoided because the use of surface plasticization can lead to the phase separation of added oil from the elastomer, forming a free oil layer on a crosslinked network. In such applications, the lubricant layer is prone to be dissolved or displaced by contacting foulants and / or mechanical abrasion, resulting in a significant ice adhesion increase.

[0008] It has also been observed that low ice adhesion can be achieved once a surface elastic modulus is under-matched by that of the ice (about 9 GPa). However, rough snowflakes can easily interlock with a highly flexible conformal surface, impeding the shedding chance. Accordingly, there is a need for an improved method to remove snow using elastomeric coatings.DISCLOSURE OF INVENTION

[0009] In various implementations, a method for facilitating snow removal from a solar panel having at least one edge is provided. A platinum-cured polydimethylsiloxane liquid silicone compound is cured to form a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shore hardness. Miscible silicone oil is added to a portion of the strip body precursor to form a bi-layer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% to about90%. The base bottom layer is attached to the solar panel at least one edge to position the plasticized top layer over the at least one edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 illustrates a fragmentary perspective view of a solar panel assembly.

[0011] FIG. 2 illustrates a fragmentary perspective view of the solar panel assembly shown in FIG. 1 covered with snow.

[0012] FIG. 3 illustrates a fragmentary perspective view of the solar panel assembly shown in FIG. 1 with a snow-free solar strip coating positioned on a lower edge.

[0013] FIG. 4 illustrates a fragmentary perspective view of the solar panel assembly shown in FIG. 3 with a snow mass sliding therefrom.

[0014] FIG. 5 illustrates a schematic diagram of a snow-free solar strip coating upon formation on a glass or metal substrate.

[0015] FIG. 6 illustrates the formed strip coating illustrated in FIG. 5 separated from the glass or metal substrate.

[0016] FIG. 7 illustrates the formed strip coating shown in FIGS. 5-6 spooled for storage in a form that facilitates transfer to a site at which it can be applied to a solar panel assembly.

[0017] FIG. 8 illustrates a schematic diagram of the solar strip coating shown in FIGS. 5-7, as applied to a solar panel assembly in accordance with this disclosure.

[0018] FIG. 9 illustrates a process in accordance with the disclosure.MODES FOR CARRYING OUT THE INVENTION

[0019] The subject disclosure is directed to snow-free solar strip coatings and, more specifically, to snow-free solar strip coatings formed with smooth and durable elastomeric surfaces that have a measured snow adhesion strength of about 50 Pa. The coatings can achieve expedited snow removal when positioned on the lower edges of solar panels.

[0020] The detailed description provided below in connection with the appended drawings is intended as a description of examples and is not intended to represent the only forms in which the present examples can be constructed or utilized. The description sets forth functions of the examples and sequences of steps for constructing and operating the examples. However, the same or equivalent functions and sequences can be accomplished by different examples.

[0021] References to “one embodiment,” “an embodiment,” “an example embodiment,” “one implementation,” “an implementation,” “one example,” “an example”and the like, indicate that the described embodiment, implementation or example can include a particular feature, structure or characteristic, but every embodiment, implementation or example can not necessarily include the particular feature, structure or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment, implementation or example. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, implementation or example, it is to be appreciated that such feature, structure or characteristic can be implemented in connection with other embodiments, implementations or examples whether or not explicitly described.

[0022] Numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments of the described subject matter. It is to be appreciated, however, that such embodiments can be practiced without these specific details.

[0021] Various features of the subject disclosure are now described in more detail with reference to the drawings, wherein like numerals generally refer to like or corresponding elements throughout. The drawings and detailed description are not intended to limit the claimed subject matter to the particular form described. Rather, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the claimed subject matter.

[0022] The subject disclosure is directed to multi-layer, snow-free solar strip coatings formed from Dragon Skin polydimethylsiloxane (PDMS) polymers. The coatings can be plasticized using miscible silicone oil to produce an upper layer with reduced mechanical stiffness to enable interfacial slippage. The combination of reduced mechanical stiffness and increased interfacial slippage facilitates snow removal from outdoor structures, such as solar panel assemblies.

[0023] The disclosed snow-free solar strip coatings demonstrate an enhanced water droplet mobility, snow adhesion reduction, and ice adhesion reduction, which enhances snow removal. The coatings outperform conventional snow removal coatings that are designed for repelling water or reducing ice adhesion. However, such conventional coatings are undesirable due to interference with absorption of sunlight, invalidation of module warranties, application / maintenance costs, and durability issues.

[0024] Referring to the drawings and, in particular, to FIGS. 1-2, an exemplary solar panel assembly, generally designated by the numeral 10, is shown. The solar panel assembly 10 can be mounted on any outdoor structure, such as a building roof, a skylight,or a standalone solar energy collecting system, in order to receive solar radiation for conversion into electricity. The solar panel includes a frame 12 that includes multiple corner elements 14-18 and a plurality of solar panels 20 forming a PV module.

[0025] The corner elements 14-18 are arranged around an upper surface of the solar panels 20 with an unseen fourth corner element to form a planar rectangular framed surface 22. The corner element 14 is essentially parallel to the corner element 18. The corner element 16 is essentially parallel to the unseen fourth corner element with the corner element 16 and the fourth corner element connects the corner element 14 to the corner element 18 to form the rectangular framed surface 22.

[0026] The corner element 14 is raised above the corner element 18, so that the rectangular framed surface 22 is at an angle to the ground. A support post 24 supports the rectangular framed surface 22 in the angular alignment. The frame 12, including the corner elements 14-18 and the support post 24, can be made of any suitable material to support and to provide rigidity of the solar panels 20. In this exemplary embodiment, the frame 12 is made from metal, specifically aluminum.

[0027] As shown in FIG. 2, the solar panels 20 can be covered with a snow mass 26 that can accumulate from falling snow. Typically, the snow mass 26 can form a thick layer on surfaces for an extended time interfering with the operation and the effectiveness of the solar panels 20. The snow mass 26 can undergo multiple partial melting / freezing cycles. Indeed, solar radiation can melt the snow from the outermost layer during the day, even at subzero air temperatures.

[0028] According to Darcy’s law, liquid water from the melting snow mass 26 can infiltrate into an interface through the formation of capillaries. The infiltrated liquid can freeze when temperature drops (i.e. at night), thereby increasing the chance of mechanical interlocking between the snow and roughness of the solar panels 20 surfaces, which can lead to inefficiency of the solar panels 20 during the melting / freezing cycles.

[0029] Referring to FIGS. 3-4 with continuing reference to the foregoing figure, the solar panel assembly 10 shown in FIGS. 1-2 can be coated with a strip coating, generally designated with the numeral 100, along an edge 110 of the corner element 18. The edge 110 abuts a corresponding edge 112 of the solar panels 20. The placement of the strip coating 100 on the edge 110 does not interfere with the transmission of solar radiation to the solar panels 20.

[0030] The strip coating 110 is a multilayer snow-free solar strip coating formed from Dragon Skin polydimethylsiloxane (PDMS) polymers that have an expedited curingprocess of less than a few minutes and that do not require heating. The polymers are plasticized, at least partially, using miscible silicone oil to produce an upper layer with reduced mechanical stiffness to enable interfacial slippage. The reduced mechanical stiffness and resulting interfacial slippage provides an ice adhesion reduction. The strip coating 110 is durable under harsh ultraviolet, thermal cycling, and humidity freezing conditions.

[0031] The multilayer, snow-free slip coating 110 can be produced from various forms of polydimethylsiloxane (PDMS) base elastomers that have elastic moduli ranging from about 69 kPa to about 590 kPa. The base elastomers can be plasticized by mixing a miscible silicone oil (97 cP, 50 vol %) to reduce the elastic modulus and to enable ice interfacial slippage. The surfaces of plasticized PDMS layers have been found to outperform the shedding of snow masses, as compared to the SH surfaces.

[0032] The strip coating 110 can be diluted using an organosilicone solvent to reduce the viscosity of the coating. Then, the strip coating 110 can be applied to a metal surface, such as the edge 110. In one exemplary embodiment, the organosilicone solvent is hexamethyl di sil oxane .

[0033] Once the strip coating 110 is positioned on the edge 112, as shown in FIG. 3, the solar panels 20 can shed snow when the snow mass 26 forms thereon. After the snow mass 26 forms on the rectangular framed surface 22 over the solar panels 20, the snow mass 26 will abut the strip coating 110 and slide down the rectangular framed surface 22 and fall off of the solar panels 20, as shown in FIG. 4, so that the solar panels 20 can continue to collect solar radiation, unimpeded by the snow mass 26.

[0034] Referring now to FIGS. 5-8 with continuing reference to the foregoing figures, the formation and application of a snow-free strip coating, generally designated with the numeral 200, is shown. The coating 200 includes a bi-layer coating body 210 having an upper layer 212 and lower layer 214. The lower layer 214 is supported by a substrate 216 that can be formed from metal or glass.

[0035] The coating body 210 is formed from a platinum-cured poly dimethylsiloxane liquid silicone compound that is cured until it has a hardness ranging from about 00-30 shore hardness to about 30A shore hardness. Then, a miscible silicone oil is added to plasticize the upper layer 212 until the elastic modulus is reduced by between about 80% to about 90% to differentiate the upper layer 212 from the lower layer 214. In this exemplary embodiment, the miscible silicone oil can be added to the coating body 210 at a 1 : 1 base / cross-linker ratio.

[0036] Once the upper layer 212 and the lower layer 214 are formed, the coating body 210 can be separated from the substrate 216 to form a flexible strip 218, as shown in FIG.6. The flexible strip 218 can be wound on to a spool 220 for storage and for transportation, as shown in FIG. 7. In this exemplary embodiment, the flexible strip 218 has a thickness of between about 1 mm to about 5 mm. In some embodiments, the flexible strip 218 can be extruded.

[0037] As shown in FIG. 8, the strip 218 can be applied to a frame element 222, such as the corner element 14 shown in FIGS. 1-4. The strip 218 can be affixed to the frame element 222 with an adhesive that can form an adhesive layer 224. In this exemplary embodiment, the adhesive can be a Sil-Poxy silicone adhesive.

[0038] In some embodiments, the strip 218 can be diluted with an organosilicone solvent to reduce the viscosity before the attaching step. The organosilicone solvent can be hexamethyl di sil oxane .

[0039] Referring to FIG. 9 with continuing reference to the foregoing figures, an exemplary process, generally designated by the numeral 300, for facilitating the removal of snow from a solar panel assembly is shown. The exemplary process 300 can be performed on the solar panel assembly 10 shown in FIGS. 1-4.

[0040] At 301, a platinum-cured polydimethylsiloxane liquid silicone compound can be cured to form a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shore hardness. In this exemplary embodiment, the strip body precursor can be formed the bi-layer coating body 210 shown in FIG. 5. As shown inFIG. 5, the strip body precursor can be formed on the substrate 216 shown in FIG. 5.

[0041] At 302, miscible silicone oil is added to or mixed into a portion of the strip body precursor to form a bi-layer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% to about 90%. In this exemplary embodiment, the addition of the miscible silicone oil forms a plasticized top layer, such as upper layer 212 shown in FIG. 5, that has a reduced elastic modulus, as compared to a base bottom layer, such as lower layer 214 shown in FIG. 5.

[0042] Conventional plasticized, softer PDMS surfaces can experience higher compressive deformations, forming more conformal contact with a rough snow layer, leading to an increased snow adhesion. Indeed, the mechanical compliance of elastic materials has been shown to contribute to an intimate contact formation with solids, leading to higher adhesion strengths.

[0043] In this exemplary embodiment, the base surfaces are further plasticized to enable interfacial slippage through the addition of miscible silicone oil. In such embodiments, the snow adhesion demonstrates a considerable (around 60%) reduction. This is achieved through the blending of miscible oils with the PDMS to reduce the crosslink density, leading to an elastic modulus reduction, where the elastic modulus reduces from about 1250 to Pa to less than about 160 Pa.

[0044] The plasticization is concomitant with leaving a small quantity of uncrosslinked low-molecular oligomers dispersed in a cross-linked PDMS network. These chemically-free chains can induce an interfacial slippage against hard foulants like ice and snowflakes. In some embodiments, the ice adhesion reduction can fall within the range of about 10 kPa to about 13 kPa. Further, some embodiments of the plasticized PDMS layers can show considerable ice interfacial slippage.

[0045] At 303, the strip coating body is separated from the substrate to form a flexible strip. In this exemplary embodiment, the flexible strip can be the flexible strip 218 shown in FIG. 6. As indicated in FIG. 7, the flexible strip 218 can be wound onto a spool, such as the spool 220 shown in FIG. 7.

[0046] At 304, the base bottom layer can be attached to the solar panel at least one edge to position the plasticized top layer over the at least one edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel. In this exemplary embodiment, the at least one edge can be the edge 110 shown in FIG. 3. The snow can be the snow mass 26 that can slide off of the solar panels 20 shown in FIGS. 1-4.Supported Features and Embodiments

[0047] The detailed description provided above in connection with the appended drawings explicitly describes and supports various features of methods for facilitating snow removal using snow-free solar strip coatings. By way of illustration and not limitation, supported embodiments include a method for facilitating snow removal from a solar panel having at least one edge, the method comprising: curing a platinum-cured polydimethylsiloxane liquid silicone compound to form a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shore hardness; adding miscible silicone oil to a portion of the strip body precursor to form a bi-layer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% toabout 90%; and attaching the base bottom layer to the solar panel at least one edge to position the plasticized top layer over the at least one edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel.

[0048] Supported embodiments include the foregoing method, wherein the solar panel edge includes an outer surface formed from a material selected form the group consisting of metal and glass.

[0049] Supported embodiments include any of the foregoing methods, further comprising: attaching base bottom layer to the solar panel edge with an adhesive.

[0050] Supported embodiments include any of the foregoing methods, wherein the adhesive is Sil-Poxy silicone adhesive.

[0051] Supported embodiments include any of the foregoing methods, wherein the adding step is performed by adding miscible silicone oil to the strip body precursor portion at a 1 : 1 base / cross-linker ratio.

[0052] Supported embodiments include any of the foregoing methods, wherein the bilayer strip coating body has a thickness of between about 1 mm to about 5 mm.

[0053] Supported embodiments include any of the foregoing methods, further comprising: diluting the bi-layer strip coating body with an organosilicone solvent to reduce the viscosity before the attaching step.

[0054] Supported embodiments include any of the foregoing methods, wherein the organosilicone solvent is hexamethyldisiloxane.

[0055] Supported embodiments include any of the foregoing methods, further comprising: extruding the strip body precursor.

[0056] Supported embodiments include any of the foregoing methods, wherein the plasticized top layer forms a non-adhesive surface on the bi-layer strip coating body, so that snow slides on the non-adhesive surface and falls off the solar panel.

[0057] Supported embodiments include any of the foregoing methods, wherein the strip body precursor has a snow adhesion strength of about 53 Pa.

[0058] Supported embodiments include any of the foregoing methods, wherein the curing step lasts no more than about one minute.

[0059] Supported embodiments include any of the foregoing methods, wherein the curing step is accomplished without adding heat.

[0060] Supported embodiments include a method for facilitating snow removal from a solar panel having at least one edge, the method comprising: forming a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shorehardness from a platinum-cured polydimethylsiloxane liquid silicone compound; blending miscible silicone oil into a portion of the strip body precursor to form a bi-layer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% to about 90%; and attaching the base bottom layer to the solar panel at least one edge to position the plasticized top layer over the at least one edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel.

[0061] Supported embodiments include the foregoing method, wherein the solar panel edge includes an outer surface formed from a material selected form the group consisting of metal and glass.

[0062] Supported embodiments include any of the foregoing methods, further comprising: attaching base bottom layer to the solar panel edge with an adhesive.

[0063] Supported embodiments include any of the foregoing methods, wherein the blending step is performed by adding miscible silicone oil to the strip body precursor portion at a 1 : 1 base / cross-linker ratio.

[0064] Supported embodiments include any of the foregoing methods, further comprising: extruding the strip body precursor.

[0065] Supported embodiments include any of the foregoing methods, wherein the plasticized top layer forms a non-adhesive surface on the bi-layer strip coating body, so that snow slides on the non-adhesive surface and falls off the solar panel.

[0066] Supported embodiments include any of the foregoing methods, wherein the strip body precursor has a snow adhesion strength of about 53 Pa.

[0067] Supported embodiments include a device, a system, an apparatus, a composition of matter, and / or means for implementing any of the foregoing methods or portions thereof.

[0068] Supported embodiments include the following technical advantages and / or improvements in the form of strip coatings that are applied only to lower edge of the panels resulted in weeks of in-advance snow removal, passively and without requiring any energy to operate; strip coatings that enhance power generation efficiency between 3-5 % annually; strip coatings that reduce mechanical load on PV modules by continuously facilitating snow removal; and strip coatings that do not interfere with absorption of sun light or panel efficiency at any time.

[0069] Additional technical advantages and / or improvements are provided by strip coatings that do not cause any partial shading or hot spots on the panels; strip coatings that do not invalidate module warranty and in fact can improve lifetime of the module; strip coatings that are self-cleaning; strip coatings that do not collect dust or dirt and do not act as a barrier to liquid drainage off bottom edges of solar panels; and strip coatings that are very durable being outdoor since 2020, and yet they have continuously shown promise over years, facilitating snow removal even at subzero temperatures, cloudy days, and overnight.

[0070] Further technical advantages and / or improvements are provided by strip coatings that are durable during regular cleaning and power washing of solar panels; strip coatings that are very durable during accelerated endurance tests; strip coatings that are easy to install and do not require skilled labor or special training; strip coatings that can be manufactured in large quantities through extrusion; and strip coatings that are functional in different regions and environmental conditions.

[0071] The detailed description provided above in connection with the appended drawings is intended as a description of examples and is not intended to represent the only forms in which the present examples can be constructed or utilized.

[0072] It is to be understood that the configurations and / or approaches described herein are exemplary in nature, and that the described embodiments, implementations and / or examples are not to be considered in a limiting sense, because numerous variations are possible.

[0073] The specific processes or methods described herein can represent one or more of any number of processing strategies. As such, various operations illustrated and / or described can be performed in the sequence illustrated and / or described, in other sequences, in parallel, or omitted. Likewise, the order of the above-described processes can be changed.

[0074] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are presented as example forms of implementing the claims.EXAMPLESExample 1

[0075] Surface preparation'. Aluminum sheets of (15.3 X 15.3 cm2, 1-mm thick) were used as substrates for the coatings (RMP 3003 H14). PDMS-E (Ecoflex with a 00-30 shore hardness, Smooth-On) and PDMS-D (Dragon Skin with a 30A shore hardness, Smooth- On) were used as-received. Both silicone materials are platinum-catalyzed which were prepared in a 1 : 1 base / cross-linker ratio according to the manufacturer instructions.Plasticized coatings were made by adding 50 vol.% silicone oil (100 cSt, 56104, Super Lube) to 50 vol.% base silicones (1 : 1 base / cross-linker ratio). A hexamethyldisiloxane solvent (98%, TCI America™) was used to reduce the coating viscosity before brushing them on IPA cleaned aluminum substrates to maintain around 300 mm thickness. The coatings then were left to cure at ambient conditions.

[0076] The SL coating was prepared based on existing instructions. Phase II was prepared using addition of Sylgard 184 (Dow Corning) base and crosslinker in a 10: 1 ratio followed by adding a 100 part silicone oil (100 cSt, 56104, Super Lube) to the solution. After mixing the solution thoroughly, it was heated at 100 °C for 4 hr. The gel-like product then was mechanically crushed using a stirring gun (Waverly H100) for (15-30 min) min until a homogenous solution was obtained.

[0077] Next, phase II was mixed (50 vol.%) within phase I (PDMS-D) and was diluted with hexamethyldisiloxane for an easier mixing before applying it on an aluminum substrate using a brush. The coating then was left at ambient conditions overnight to cure. Furthermore, according to manufacturer instructions, the commercial NeverWet (Rust- Oleum) SH coating was sprayed on AL substrates.Example 2

[0078] Indoor snow testing'. Snow formation, accumulation, and adhesion tests were conducted inside a walk-in freezing room that allows reaching temperatures of - 20 °C49. To form artificial snow, tab water and high-pressure air were supplied to a snow gun (designed in-house) using conventional connections. An air compressor (10 Gal. 2.0 HP, California Air Tools) was used for providing high-pressure air to the setup, creating a water-air mixture with a 95-98% water to air mass ratio supplied at a 0.27 g / s flow rate. The outlet’s nozzle diameter was 1.58 mm. The reported snow adhesion values are the averages of at least three independent measurements. The real-time monitoring of all indoor experiments was captured using a camera purchased from a WiFi IP camera (FDT).A surface-mountable sensor designed in-house is used for real-time measurement of the LWC of the artificial snow formed by the snow gun.Example 3

[0079] Ice adhesion testing-. Ice adhesion tests were conducted using a universal testing machine (5969, Instron) in a tension mode. A flat plate was clamped to the machine with a pulley that translated crosshead’s vertical movements to the horizontal direction across the plate using a nylon rope. To increase the accuracy of measurements a 20 N force probe (DST-4A, Imada) with a 0.01 N resolution was employed in the tensile clamp of the crosshead. The rope then was attached to the force probe using a hook. A Peltier plate (TECA Corp., Model LHP-800CP) working with a chiller (Thermo Electron, R134a) and an electric power supply (Mean Well, SP-320-24) was fixed on the plate and was set at -25 ± 2 °C. Square polystyrene cuvettes (10 x 10 mm2) were placed on the surfaces of interest which were then filled from top of a custom-made vent until the crosssection was filled with 2-3 mm DI water. The testing began after 10 min by wrapping a loop-knot rope around the cuvette at a 1-2 mm distance above the surface. Next, the ice cuvette was pulled at a constant rate of 0.1 mm / s until the ice was dislodged. The shear adhesion force was calculated by dividing the maximum force to the ice surface area. The room temperature was / loom = 19-22 °C with a relative humidity of RHroom = 24-40 %. Ice adhesion values are the average of at least four measurements.Example 4

[0080] Surface characterization'. A VHX6000 digital microscope (Keyence) was used to view surfaces. AFM tests were conducted using a Dimension Icon (Brucker) in ScanAsyst™ mode. Images of 500 x 500 nm2were obtained by a standard silicone tip. NanoScope Analysis software (v. 1.5) was used for image analysis.

[0081] Water droplet sliding angle measurements'. A rotating breadboard was used to mount a camera, a movable sample stage, and an LED light source. DI water droplets (20 mL) were deposited on the surfaces of interest using a manual water dispenser. The breadboard was manually rotated at a 17s that was probed using an iPhone 11 Measure application. A Nikon D5500 camera was equipped with a micro zoom lens (Navitar 2x F- mount) to capture droplet motions videos at 60 fps. The sliding angle was determined from screenshots taken from the sliding onset using image processing ImageJ software.Example 5

[0082] Outdoor snow testing and evaluation'. 1-mm thick 15.3 X 30.6 cm2aluminum sheets (RMP 3003 Hl 4) were used as substrates for the coatings mounted on a stand at a 45° angle. Ambient conditions were recorded using a weather station data acquisition system (Ambient Weather, WS-2902). Snow event videos were captured using an FDT with a night vision capability. Similar LWC sensors were used to monitor wetness of the natural snow.Example 6

[0083] Durability tests: 5-stage tests were done on 1-mm thick 15.3 X 15.3 cm2coated aluminum sheets to examine the durability of the coatings. First, pre-stress characterizations were done by visual inspection, UV fluorescence (UVF for change in color) and Colorimetry measurements (yellowness index). Then a UV test (UV60) was done by emitting a 60 kWh / m2UV dose to break the week interface bonds between the coating and the aluminum sheet. After that, a thermal cyclic test (TC50) was conducted by performing fifty thermal cycles (-40°C and 85°C) to induce delamination due to thermal mismatch between metal and coating. That was followed by a humidity freeze test (HF 10) by conducting ten humidity freeze cycles (-40°C and 85°C / 85%RH) to allow moisture to accumulate at the interface at 85°C / 85%RH and to detach the coating from the aluminum sheet at -40°C. Lastly, post-stress characterizations after each stress test were done by visual inspection, UV fluorescence (UVF) and Colorimetry measurements (yellowness index).Example 7

[0084] Compression test for elastic modulus measurement: 1.5 cm X 0.5 cm rectangular coating samples with thicknesses varying between 1.58 mm and 2.26 mm were compressed using a universal testing machine (5969, Instron) in a compression mode. The coating samples were compressed at a constant rate of 2 mm / min. The compressive stress was calculated by dividing the compressive force to the coating’s surface area. The strain was calculated by dividing the change in coating thickness (due to compression) to the initial coating thickness. The coating elastic modulus was then calculated by dividing stress to strain, at 10% strain. Elastic modulus values are the average of three measurements.

Claims

CLAIMSWhat is claimed is:

1. A method for facilitating snow removal from a solar panel having at least one edge, the method comprising: curing a platinum-cured polydimethylsiloxane liquid silicone compound to form a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shore hardness; adding miscible silicone oil to a portion of the strip body precursor to form a bilayer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% to about 90%; and attaching the base bottom layer to the solar panel at least one edge to position the plasticized top layer over the at least one edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel.

2. The method of claim 1, wherein the solar panel edge includes an outer surface formed from a material selected form the group consisting of metal and glass.

3. The method of claim 1, further comprising: attaching base bottom layer to the solar panel edge with an adhesive.

4. The method of claim 2, wherein the adhesive is Sil-Poxy silicone adhesive.

5. The method of claim 1, wherein the adding step is performed by adding miscible silicone oil to the strip body precursor portion at a 1 : 1 base / cross-linker ratio.

6. The method of claim 1, wherein the bi-layer strip coating body has a thickness of between about 1 mm to about 5 mm.

7. The method of claim 1, further comprising: diluting the bi-layer strip coating body with an organosilicone solvent to reduce the viscosity before the attaching step.

8. The method of claim 7, wherein the organosilicone solvent is hexamethyl di sil oxane .

9. The method of claim 1, further comprising: extruding the strip body precursor.

10. The method of claim 1, wherein the plasticized top layer forms a non-adhesive surface on the bi-layer strip coating body, so that snow slides on the non-adhesive surface and falls off the solar panel.

11. The method of claim 1, wherein the strip body precursor has a snow adhesion strength of about 53 Pa.

12. The method of claim 1, wherein the curing step lasts no more than about one minute.

13. The method of claim 12, wherein the curing step is accomplished without adding heat.

14. A method for facilitating snow removal from a solar panel having at least one edge, the method comprising: forming a strip body precursor having a hardness ranging from about 00-30 shore hardness to about 30A shore hardness from a platinum-cured polydimethylsiloxane liquid silicone compound; blending miscible silicone oil into a portion of the strip body precursor to form a bi-layer strip coating body having a base bottom layer positioned below a plasticized top layer having the miscible silicone oil mixed therein to reduce the elastic modulus by between about 80% to about 90%; and attaching the base bottom layer to the solar panel at least one edge to position the plasticized top layer over the at least one edge, so that snow that accumulates on the solar panel contacts the plasticized top layer and slides off of the solar panel.

15. The method of claim 14, wherein the solar panel edge includes an outer surface formed from a material selected form the group consisting of metal and glass.

16. The method of claim 14, further comprising: attaching base bottom layer to the solar panel edge with an adhesive.

17. The method of claim 14, wherein the blending step is performed by adding miscible silicone oil to the strip body precursor portion at a 1 : 1 base / cross-linker ratio.

18. The method of claim 14, further comprising: extruding the strip body precursor.

19. The method of claim 14, wherein the plasticized top layer forms a non-adhesive surface on the bi-layer strip coating body, so that snow slides on the non-adhesive surface and falls off the solar panel.

20. The method of claim 14, wherein the strip body precursor has a snow adhesion strength of about 53 Pa.

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