Solar panel mounting system with aerodynamic ballast trays

Systems and methods for mounting one or more solar panels are disclosed. A tubular component can be provided. The tubular component can include a first curved portion configured to rise to a first height above and extending along a length of the tubular component. The first curved portion can have a predetermined diameter, a predetermined thickness, and a predetermined bend radius selected to support a first solar panel module attached by a first end at a first attachment point positioned at the first height. The first curved portion can include an elongated leg configured to support a deflector element projecting outwardly at a predetermined angle to the mounting surface. The tubular component also can include a distal end having a second curved portion configured to rise to a second height above and extending along the length of the tubular component. The distal end can have a second attachment point at the second height. The second attachment point can be separated from the first attachment point by a predetermined distance and can be configured to support a second end of a second solar panel module at a predetermined tilt.

BACKGROUND

Solar (photovoltaic) panels are often manufactured in the form of flat rigid structures. To facilitate the performance of the function of generating electricity, solar panels may be mounted in an area exposed to the sun or other source of light. Often, solar panels are mounted outdoors at an angle from the horizontal so that they will more directly face the sun during peak daylight hours as opposed to panels mounted flat on the ground. In some applications, a number of solar panels are mounted together in an array in order to combine the power generation capabilities of the individual panels. In many instances, mounting systems for solar panel arrays can retain the solar panels in place. This may be accomplished by attaching the solar panels to one another in a mounting system and/or by mounting the panels to the mounting system.

SUMMARY OF THE DISCLOSURE

Aspects and implementations of the present disclosure are directed to systems and methods for mounting solar panels. A solar panel mounting system can include a plurality of support members formed from tubular structural components. The tubular components may be provided as straight components and bent into desired shapes. The shapes of the tubular components may be designed to reduce material cost and complexity relative to other systems for mounting solar panels. For example, the simplified component structure and manufacturing processes can reduce cost while providing sufficient structural strength to support a plurality of solar panels, wind ballast trays, and ballast blocks.

One innovative aspect of the subject matter described in this disclosure can be implemented in a tubular component to support to support one or more solar panel modules above a mounting surface. The tubular component can include a first curved portion configured to rise to a first height above and extending along a length of the tubular component. The first curved portion can have a predetermined diameter, a predetermined thickness, and a predetermined bend radius selected to support a first solar panel module attached by a first end at a first attachment point positioned at the first height. The first curved portion can include an elongated leg configured to support a deflector element projecting outwardly at a predetermined angle to the mounting surface. The tubular component also can include a distal end having a second curved portion configured to rise to a second height above and extending along the length of the tubular component. The distal end can have a second attachment point at the second height. The second attachment point can be separated from the first attachment point by a predetermined distance and can be configured to support a second end of a second solar panel module at a predetermined tilt.

In some implementations, the tubular component can be formed from an electrically conductive material configured to provide an electrical path from the one or more solar panel modules to earth ground. In some implementations, the electrically conductive material can include aluminum or steel.

In some implementations, at least a portion of the tubular component can have a cross-sectional shape that is square, circular, or hexagonal. In some implementations, the predetermined bend radius can be in the range of 1.5 inches to 2.5 inches. In some implementations, the predetermined diameter can be in the range of 0.5 inches to 1.5 inches.

In some implementations, the predetermined thickness can be about 0.035 inches. In some implementations, the predetermined angle of the deflector element can be in the range of 40 degrees to 50 degrees. In some implementations, the tubular component also can include at least one mounting hole formed through the elongated leg, the mounting hole configured to receive a fastener for securing the deflector element to the elongated leg.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a deflector element for a solar panel module mounting system. The deflector element can include a tray, a first side wall coupled to a first edge of the tray and extending away from an upper surface of the tray, and a second side wall coupled to a second edge of the tray opposing the first edge of the tray. The second side wall can extend away from the upper surface of the tray, such that the tray, the first sidewall, and the second sidewall together define a channel for receiving a ballast weight. The first sidewall and the second sidewall can be arranged at angles of less than 90 degrees with the respect to the upper surface of the tray such that the first sidewall and the second sidewall exert a clamping force on the ballast weight when the ballast weight is positioned on the upper surface of the tray within the channel. The tray also can include a first security tab positioned at a first end of the tray and a second security tab positioned at a second end of the tray. The first security tab and the second security tab can be configured to be moved into positions protruding into the channel to prevent the ballast weight from sliding laterally within the channel.

In some implementations, the ballast weight can include one or more concrete blocks. In some implementations, the tray also can include at least one threaded fastener configured to secure the deflector element to an adjacent deflector element. In some implementations, the tray also can include a plurality of slots along the length of the tray. The plurality of slots can be configured to be aligned with at least one mounting hole of a solar panel module support structure to which the deflector element is secured.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a system for mounting one or more solar panel modules above a supporting surface. The system can include at least one tubular component. The at least one tubular component can include a first curved portion configured to rise to a first height above and extending along a length of the tubular component. The first curved portion can have a predetermined diameter, a predetermined thickness, and a predetermined bend radius selected to support a first solar panel module attached by a first end at a first attachment point positioned at the first height. The first curved portion also can include an elongated leg configured to support a deflector element projecting outwardly at a predetermined angle to the mounting surface. The tubular component can include a distal end having a second curved portion configured to rise to a second height above and extending along the length of the tubular component and having a second attachment point at the second height. The second attachment point can be separated from the first attachment point by a predetermined distance and configured to support a second end of a second solar panel module at a predetermined tilt. The deflector element can include a tray, a first side wall coupled to a first edge of the tray and extending away from an upper surface of the tray, and a second side wall coupled to a second edge of the tray opposing the first edge of the tray. The second side wall can extend away from the upper surface of the tray, such that the tray, the first sidewall, and the second sidewall together define a channel for receiving a ballast weight. The first sidewall and the second sidewall can be arranged at angles of less than 90 degrees with the respect to the upper surface of the tray such that the first sidewall and the second sidewall exert a clamping force on the ballast weight when the ballast weight is positioned on the upper surface of the tray within the channel. The tray can include a first tab positioned at a first end of the tray and a second tab positioned at a second end of the tray. The first tab and the second tab can be configured to be moved into positions protruding into the channel to prevent the ballast weight from sliding laterally within the channel.

In some implementations, the system also can include a foot element positioned between a bottom surface of the at least one tubular component and the mounting surface to prevent damage to the mounting surface. In some implementations, the system can be configured to withstand winds of up to 150 miles per hour. In some implementations, the predetermined tilt of the second solar panel module can be opposed to the predetermined angle of the deflector element. In some implementations, the at least one tubular component can be formed from an electrically conductive material configured to provide an electrical path from the one or more solar panel modules to earth ground. In some implementations, the predetermined bend radius can be in the range of 1.5 inches to 2.5 inches. In some implementations, the predetermined angle of the deflector element can be in the range of 40 degrees to 50 degrees.

A system for mounting a solar panel above a supporting surface can include two rear support members in contact with the supporting surface. The system can include two front support members in contact with the mounting surface. The system can include a ballast tray extending between the two front support members and mounted on a front side of the front support members. The ballast tray can include a channel configured to support a ballast weight on an upper side of the ballast tray. Each of the rear support members and front support members can be formed from a tubular structure configured to bear the weight of a portion of the solar panel such that the solar panel is suspended above the supporting surface.

In some implementations, each of the tubular structures forming the front support member and the rear support members can have a thickness of about 0.035 inches. In some implementations, each of the tubular structures forming the front support member and the rear support members can have a diameter of about one inch. In some implementations, the tubular structures can be elongated members bent into a predefined shape so as to support the solar panel at a first predetermined angle and to support the ballast tray at a second predetermined angle.

These and other aspects and embodiments are discussed in detail below. The foregoing information and the following detailed description include illustrative examples of various aspects and embodiments, and provide an overview or framework for understanding the nature and character of the claimed aspects and embodiments. The drawings provide illustration and a further understanding of the various aspects and embodiments, and are incorporated in and constitute a part of this specification.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various concepts related to, and implementations of, solar panel mounting systems with aerodynamic ballast trays. The various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the described concepts are not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

FIGS. 1A-1Care various views of an array100of solar panels, according to an illustrative implementation. The array100is configured to be mounted on a substantially flat mounting surface, such as a roof. The array100includes four solar panels110a-110d(generally referred to as solar panels110). In various other implementations, the array100may include any number of solar panels110. The solar panels110are illustrated inFIG. 1as being mounted at an angle from the horizontal (i.e., an angle from the plane of the mounting surface), but in some embodiments, the solar panels110may be mounted at angles other than that illustrated inFIG. 1, or they may be mounted horizontally. The solar panels110may, in some implementations, be mounted at different angles throughout the array100and uniformly in others such as the one shown inFIG. 1. The array100also includes two ballast trays120aand120b(generally referred to as ballast trays120). These ballast trays120are located inFIG. 1facing what will be described herein as the front side of array100. What is described as the front side may correspond to a geographical North position of the array100. As shown here, the front side may be positioned approximately to the North so that the tilted faces of the solar panels110are directed generally toward the South, e.g., tilted to more squarely face the direction of the sun for an installation north of the equator.

In some embodiments, each row of solar panels110may have a corresponding ballast tray120, but in some embodiments, at least one of the rows of solar panels110in an array100may not have an accompanying ballast tray120. For example, in one embodiment, ballast trays are positioned only on solar panels110in the front-most row of the array100. In some embodiments, additional ballast trays may be mounted facing the lateral sides (e.g., the sides perpendicular to the front side) at the edges of the array, roughly perpendicular to the ballast trays120illustrated inFIG. 1. In another embodiment, ballast trays120are positioned only on the front and side edges of the array100. The ballast trays120are oriented at an angle opposed to the angle of the solar panels110. In some implementations, the ballast trays120are positioned so as to direct wind approaching the array100from the front side of the array100up and over the solar panels110. Wind that is permitted to pass underneath the solar panels110can create lift forces that tend to displace the array100from its position on the mounting surface. The ballast trays120can block at least a portion of such wind, thereby increasing the stability of the array100. In some implementations, wind impacting the ballast trays120from the front side of the array100can create downward forces on the array100. The downward forces created by the ballast trays120can further increase the stability with which the array100is mounted to the mounting surface.

The ballast trays120and solar panels110in this example are mounted on front support members130a-130d(generally referred to as front support members130). As discussed above, the front of the array100may, in some implementations, correspond to a geographical north position. Thus, the front support members130may also be referred to as north support members130. For simplicity, the these elements are primarily referred to as front support members130in throughout this disclosure. The front support members130are structural supports that may be used to support at least a portion of a solar panel110. In this implementation, the front support members130rest on the mounting surface. The solar panels110and ballast trays120are secured to the front support members130. The front support members130are described further below.

As shown inFIG. 1B, ballast trays120and solar panels110of the array100are also supported by middle support members160a-160d(generally referred to as middle support members160). The middle support members160are structural supports that may be used to support at least a portion of a solar panel110. In this implementation, the middle support members160rest on the mounting surface. The solar panels110and ballast trays120are secured to the middle support members160.

The ballast trays120each include a channel122aand122b, respectively (generally referred to as channels122). The channels122are configured to receive one or more ballast blocks such as the ballast blocks140a-140j(generally referred to as ballast blocks140). The ballast blocks140provide the support members130with additional mass that may assist in keeping the array100securely in place on the mounting surface. Ballast blocks140may in some implementations be made from a concrete mix. Ballast blocks140in some implementations may be made from any concrete mix that is intended to withstand the elements for an appropriate period of time, such as cement intended for outdoor applications and having an intended life span of greater than 30 years. Ballast blocks140may in some embodiments be made using a Portland Type III concrete with maximum water absorption of about 10%. This concrete is a high early strength, normal weight concrete with a fully cured strength of at least 2,500 psi, and is available from Precast Specialties Inc. of Abington, Mass. In some implementations, ballast blocks140may be formed from materials such as, for example, metal, natural or recycled rubber, or Quazite®, a polymer concrete available from Hubbell Lenoir City, Inc. of Lenoir City, Tenn., or other materials. An additional ballast tray150is placed beneath the solar panels110cand110d. The ballast tray150can be configured to receive one or more ballast blocks140to add additional weight to the array100.

Also shown inFIG. 1Bare rear support members180a-180d(generally referred to as rear support members180). As discussed above, the rear of the array100may, in some implementations, correspond to a geographical south position. Thus, the rear support members180may also be referred to as south support members180. For simplicity, the these elements are primarily referred to as rear support members180in throughout this disclosure. The rear support members180are structural supports that may be used to support at least a portion of a solar panel110. In this implementation, the rear support members1380rest on the mounting surface. The solar panels110are secured to the rear support members180. The rear support members180are described further below.

As shown inFIG. 1C, the channels122of the ballast trays120are configured to hold the ballast blocks140securely in place. For example, the side walls of the channels122are angled relative to the sides of the ballast blocks140. Therefore, the side walls of the channels122function as clamps that exert of a force on the ballast blocks140when the ballast blocks140are positioned within the channels122. This force helps to secure the ballast blocks140within the channels140, so that the ballast blocks140cannot easily fall out of or otherwise be removed from the channels122. Also shown inFIG. 1Care attachment mechanisms170aand170b(generally referred to as attachment mechanisms170). The attachment mechanisms170secure the solar panel110dto the middle support members160dand160c, respectively. A similar attachment mechanism is used to secure every other middle support member160, front support member130, and rear support member180to the respective solar panels110. In this implementation, each solar panel110is fastened to four of the various support members by four respective attachment mechanisms170.

FIGS. 2A-2Bare perspective views of a front support member230used in the array of solar panels shown inFIG. 1A, according to an illustrative implementation. The front support member230corresponds to the front support member130shown inFIGS. 1A-1C. The front support member230can be formed as a tubular component. In some implementations, the front support member230is formed from metal. For example, steel or aluminum may be used to form the front support member230. In other implementations, a metal alloy may be used. Metal may be a suitable material due to its ability to provide structural integrity to the frame. In addition, metal conducts electricity well, which can allow for an electrical path to earth ground through the front support member230. In other implementations, the front support member230can be formed from any material with sufficient structural rigidity to support the array of solar panels, regardless of electrical conductivity. For example, the structural supports may be formed from plastic or rubber.

In some implementations, the front support member230is hollow and has a square cross-sectional shape to increase structural efficiency. In other implementations, the front support member230may be solid or partially solid, and may have different cross sectional shapes. For example, the front support member230may have a circular, hexagonal, or I-beam cross sectional shape. As shown, the front support member230can be formed from a single tubular structure. This can promote ease of manufacturing and reduce the overall cost of the array of solar panels. For example, the front support member230can be formed into a straight tubular component and can then be bent into a predetermined or desired shape. In some implementations, the radius of curvature of the bent portions of the front support member230can be approximately two inches. In some other implementations, the front support member230may be formed from a plurality of structural members. For example, several structural members can be fused together in the shape of the front support member230.

The front support member230includes four mounting holes232a-232d(generally referred to as mounting holes230). Each of the mounting holes230is drilled through the entire front support member230. In some implementations, the mounting holes230can be used to fasten other components to the front support member230. For example, the mounting holes232aand232bcan be used to secure a ballast tray, such as the ballast tray120ashown inFIG. 1A, to the front support member230. Similarly, the mounting hole232ccan be used together with an attachment mechanism to fasten a solar panel such as the solar panels110shown inFIG. 1Ato the front support member230. In some implementations, one or more of the mounting holes232, such as the mounting hole232d, can be used for fasting a grounding device to the front support member230.

A portion of the front support member230extends substantially along the mounting surface for stability. In some implementations, the front support member230can include feet234aand234b(generally referred to as feet234) placed between the bottom of the front support member230and the mounting surface. In some implementations, a foot234may be made from any material that can be considered an “inert pad” by the roofing industry. In some implementations, feet234may be made from recycled, non-vulcanized crumb rubber, such as that available from Unity Creations Ltd. of Hicksville, N.Y. In other implementations feet234may be made from natural rubber, EPDM (Ethylene Propylene Diene Monomer—a rubber roofing material), or another roofing material that may protect the roof or other surface upon which array100may be mounted from damage by the material of front support member230. Feet234may be secured to the front support member230using a plastic fastener, such as a push-in, ribbed shank plastic rivet. In some implmenetations, an adhesive, such as, for example, epoxy (e.g., ChemRex 948) can be used.

FIGS. 3A-3Bare perspective views of a middle support member360used in the array of solar panels shown inFIG. 1A, according to an illustrative implementation. The middle support member360corresponds to the middle support member160shown inFIGS. 1A-1C. The middle support member360can be formed as a tubular component. In some implementations, the middle support member360is formed from metal. For example, steel or aluminum may be used to form the front support member230. In other implementations, a metal alloy may be used. Metal may be a suitable material due to its ability to provide structural integrity to the frame. In addition, metal conducts electricity well, which can allow for an electrical path to earth ground through the middle support member360. In other implementations, the middle support member360can be formed from any material with sufficient structural rigidity to support the array of solar panels, regardless of electrical conductivity. For example, the structural supports may be formed from plastic or rubber.

In some implementations, the middle support member360is hollow and has a square cross-sectional shape to increase structural efficiency. In other implementations, the middle support member360may be solid or partially solid, and may have different cross sectional shapes. For example, middle support member360may have a circular, hexagonal, or I-beam cross sectional shape. As shown, the middle support member360can be formed from a single tubular structure. This can promote ease of manufacturing and reduce the overall cost of the array of solar panels. For example, the middle support member360can be formed into a straight tubular component and can then be bent into its proper shape. In some implementations, the radius of curvature of the bent portions of the middle support member360can be approximately two inches. In some other implementations, the middle support member360may be formed from a plurality of structural members. For example, several structural members can be fused together in the shape of the middle support member360.

The middle support member360may include six mounting holes362a-362f(generally referred to as mounting holes362). Each of the mounting holes360is drilled through the entire middle support member360. In some implementations, the mounting holes360can be used to fasten other components to the middle support member360. For example, the mounting holes362aand362bcan be used to secure a ballast tray, such as the ballast tray120bshown inFIG. 1A, to the middle support member360. Similarly, the mounting hole362ccan be used together with an attachment mechanism to fasten a solar panel such as the solar panels110shown in FIG.1A to the front support member230. The portion of the support member360that includes the mounting hole362crises to a first height selected to support a front portion of a solar panel. The mounting hole362ealso can be used together with an attachment mechanism to fasten another solar panel such as the solar panels110shown inFIG. 1Ato the middle support member360. The mounting hole362eis positioned on a distal end of the support member360which includes a curved portion rising to a second height. Thus, the middle support member360can support two separate solar panels; one fastened to via the mounting hole362cand one fastened via the mounting hole362e.

A portion of the middle support member360extends substantially along the mounting surface for stability. In some implementations, the middle support member360can include feet364aand364b(generally referred to as feet364) placed between the bottom of the front support member360and the mounting surface. In some implementations, the feet364may be made from any material that can be considered an “inert pad” by the roofing industry, including any of the materials identified above in connection with the feet234shown inFIGS. 2A-2B.

FIGS. 4A-4Dare perspective views of a rear support member used in the array of solar panels shown inFIG. 1B, according to an illustrative implementation. The rear support member460corresponds to the rear support member180shown inFIGS. 1B and 1D. The rear support member460can be formed as a tubular component. In some implementations, the front support member460is formed from metal. For example, steel or aluminum may be used to form the rear support member460. In other implementations, a metal alloy may be used. Metal may be a suitable material due to its ability to provide structural integrity to the frame. In addition, metal conducts electricity well, which can allow for an electrical path to earth ground through the rear support member460. In other implementations, the rear support member460can be formed from any material with sufficient structural rigidity to support the array of solar panels, regardless of electrical conductivity. For example, the rear support member460may be formed from plastic or rubber.

In some implementations, the rear support member460is hollow and has a square cross-sectional shape to increase structural efficiency. In other implementations, the rear support member460may be solid or partially solid, and may have different cross sectional shapes. For example, the rear support member460may have a circular, hexagonal, or I-beam cross sectional shape. As shown, the rear support member460can be formed from a single tubular structure. This can promote ease of manufacturing and reduce the overall cost of the array of solar panels. For example, the rear support member460can be formed into a straight tubular component and can then be bent into a predetermined or desired shape. In some implementations, the radius of curvature of the bent portions of the rear support member460can be approximately two inches. In some other implementations, the rear support member460may be formed from a plurality of structural members. For example, several structural members can be fused together in the shape of the rear support member460.

The rear support member460includes four mounting holes462a-462d(generally referred to as mounting holes462.) Each of the mounting holes460is drilled through the entire rear support member460. In some implementations, the mounting holes460can be used to fasten other components to the front support member230. For example, the mounting holes462cand462dcan be used to secure a ballast tray, such as the ballast tray150shown inFIG. 1B, to the rear support member460. Similarly, the mounting holes462aand462bcan be used together with an attachment mechanism to fasten a solar panel such as the solar panels110shown inFIG. 1Ato the rear support member460. In some implementations, one or more of the mounting holes464can be used for fasting a grounding device to the rear support member460.

A portion of the rear support member460extends substantially along the mounting surface for stability. In some implementations, the rear support member460can include a foot464placed between the bottom of the rear support member460and the mounting surface. In some implementations, the foot464may be made from any material that can be considered an “inert pad” by the roofing industry. In some implementations, the foot464may be made from recycled, non-vulcanized crumb rubber, such as that available from Unity Creations Ltd. of Hicksville, N.Y. In other implementations the foot464may be made from natural rubber, EPDM (Ethylene Propylene Diene Monomer—a rubber roofing material), or another roofing material that may protect the roof or other surface upon which array100may be mounted from damage by the material of rear support member460. The foot464may be secured to the rear support member460using a plastic fastener, such as a push-in, ribbed shank plastic rivet. In some implementations, an adhesive, such as, for example, epoxy (e.g., as ChemRex 948) can be used.

Also shown inFIGS. 4A-4Dis a swaged section465of the rear support member460. The swaged section can be formed to have a smaller cross-sectional shape than the other sections of the rear support member460as well as the front support member230shown inFIGS. 2A and 2Band the middle support member360shown inFIGS. 3A and 3B. In some implementations, the swaged section465of the rear support member460can be configured to be inserted into a portion of the middle support member360. Such an arrangement is shown, for example, inFIG. 1D, in which the rear support member180D is inserted into the middle support member160d. Thus, the swaged section465of the rear support member460can “telescope” within a section of the middle support member to change the overall length of the support frame.

FIGS. 5A-5Bare various views of an attachment mechanism570used in the array of solar panels shown inFIG. 1C, according to an illustrative implementation. The attachment mechanism570corresponds to the attachment mechanism170shown inFIG. 1A. The attachment mechanism570can be used to mount a solar panel to a front support member, such as the front support member230shown inFIGS. 2A-2B, a middle support member, such as the middle support member360shown inFIGS. 3A-3B, or a rear support member, such as the rear support member460shown inFIGS. 4A-4D. The attachment mechanism570includes a flat upper portion571coupled to a flange572. Mounting holes573aand573b(generally referred to as mounting holes573) are positioned along the sides of the attachment mechanism and arranged in a coaxial fashion with respect to one another. The attachment mechanism570also includes a bolt574and a nut575.

The function of the attachment mechanism570is most readily understood with reference toFIG. 1C, which shows the attachment mechanism170asecuring solar panel110dto middle support member160d. Referring now toFIGS. 1C and 5A-5B, the attachment mechanism570can be fastened to a middle support member160by aligning the mounting holes573of the attachment mechanism570with mounting holes on the middle support member160. A mechanical fastener, such as a bolt, nail, screw, or metal rivet can then be placed through the mounting holes to secure the attachment mechanism570to the middle support member160. Next, an edge of the solar panel110can be placed in contact with the flat upper portion571of the attachment mechanism570. The solar panel110can be positioned such that a mounting hole in the edge of the solar panel is aligned with the bolt574. As shown inFIG. 5A, the bolt574fits through a slot in the attachment mechanism570. In some implementations, the slot may be about 0.75 inches in length. The slot can allow the bolt574to be joined to a variety of solar panel modules which may have mounting holes positioned at slightly different locations. The bolt574can then be placed through the mounting hole in the solar panel110and can be secured with the nut575. When secured in this fashion, the flange572also comes into contact with the solar panel110to provide additional support and to ensure that the attachment mechanism570remains securely aligned with the solar panel110. The serrated portion of the bolt574also can break an annodization layer included in a solar panel module or in the solar panel module frame, thereby forming a conductive path to facilitate grounding. In some implementations, the flange572can also facilitate calculation of the power density of the solar panel array100. For example, power density can be a function of solar panel width. Because the flange572contacts the solar panels100at their front and rear edges, the width of each solar panel is substantially equal to the distance separating the flanges572of attachment mechanisms570in adjacent rows of the array100. Knowledge of this separation distance therefore provides knowledge of the width of each solar panel110. As a result, the power density of the entire array can be calculated with relative ease.

In some implementations, the solar panels110may have mounting holes drilled in pre-selected locations along the edges of the solar panels110. A technician can select an appropriate mounting hole for use with the attachment mechanism570at the installation site. In other implementations, the mounting hole may be formed through the edge of the solar panel at the installation site, as part of the installation process. It should be understood that the attachment mechanism570can also be used in a similar manner to attach a solar panel110to another point on a middle support member160(e.g., using the mounting hole362eshown inFIGS. 3A-3B) or on a front support member230(e.g., using the mounting hole232cshown inFIGS. 2B-2C).

FIGS. 6A-6Bare perspective views of a ballast tray620used in the array of solar panels shown inFIG. 1A, according to an illustrative implementation. The ballast tray620corresponds to the ballast trays120shown inFIG. 1A. The ballast tray620includes a channel650and two security tabs622aand622b(generally referred to as security tabs622). The ballast tray620also includes slots such as the slot624along its length. In some implementations, the ballast tray620may also include one or more threaded fasteners690.

In some implementations, the ballast tray620is formed from metal. For example, steel or aluminum may be used to form the ballast tray620. In other implementations, a metal alloy may be used. Metal may be a suitable material due to its ability to provide structural integrity to the frame. Metal also can provide for an electrical path to earth ground through the ballast tray620. Furthermore, due to its low cost and malleability, forming the ballast tray620from a metal can reduce the overall production cost and complexity of the ballast tray620. For example, the ballast tray620can be formed from a flat sheet of metal. The sheet can be cut to the correct dimensions and can then be bent into the proper shape. Therefore, in some implementations, the ballast tray620can be formed from a single piece of material.

The ballast tray620can be mounted to structural members such as the front support members230shown inFIGS. 2A-2Bor the middle support members360shown inFIGS. 3A-3B. For example, the ballast tray620can be positioned such that the slots624are aligned with mounting holes on the desired support structure. Bolts or other mechanical fasteners can be place through the slots624and mounting holes to secure the ballast tray620to the support structure. Because there are many slots624along the length of the ballast tray620, particular knowledge of the position of the mounting holes on the support structures is not required at the time of manufacturing. Rather, it can be assumed that the large number of slots624will provide adequate ability to reposition the ballast tray620such that it can be fastened to the desired support structures at the installation site. Thus, the slots624simplify the manufacturing and installation process for the ballast tray620.

The security tabs622help to ensure that the ballast blocks will not easily slide out or be removed from the ballast tray ballast tray620when the ballast tray620is in use. For example, as shown inFIG. 6B, the security tab622acan be bent at an angle of approximately 90 degrees so that it protrudes in the channel650. The security tab622bcan also be bent into a similar position, however it is shown in its original position inFIG. 6Bfor illustrative purposes. In some implementations, after the ballast blocks have been installed in the channel650at the installation site, a technician can pull the security tabs622downward. The protruding security tabs622can then prevent the ballast blocks from sliding along the length of the channel650and falling out the sides of the ballast tray620. As discussed above, the sidewalls of the channel650can also serve as clamps to put pressure on the ballast blocks, thereby securing them in place within the channel650.

The threaded fasteners690may be included on the ballast tray620to facilitate connecting adjacent ballast trays to one another for added structural integrity. In some implementations, the threaded fastener690may be a Rivnut manufactured by Cardinal Components, Inc., or a PEM fastener manufactured by Penn Engineering and Manufacturing Corp. As shown inFIG. 1A, each row of the array may include several ballast trays joined together. In some implementations, some of the ballast trays may include threaded fasteners690so that adjacent ballast trays may be connected. In some implementations, longer ballast trays620do not include threaded fasteners690, while shorter ballast trays620do include threaded fasteners690. In some implementations, the threaded fasteners690may be preinstalled before the ballast trays620are delivered to the installation site. Therefore, technicians can work more quickly to install the ballast trays620in the array100at the installation site, as the threaded fasteners can be preinstalled.

FIGS. 7A-7Bare side views of an array100of solar panels110, according to an illustrative implementation. The array100is similar to the array100shown inFIGS. 1A-1C. For example, the array100includes a plurality of solar panels110, two of which (e.g., solar panels110aand110b) are shown inFIG. 7A. Middle support members such as the middle support member160support the solar panels100above a supporting surface. A ballast tray120rests on the middle support member160and supports a ballast block140. An alternative support member190is also shown overlaid on the middle support member160. The alternative support member190is shown only for comparison and illustrative purposes and is not part of the system or required to support the solar panels110, the ballast tray120, and the ballast block140. The system including the middle support member160can be used to realize several advantages relative to systems that include support members similar to the alternative support members190. Several of these advantages are addressed below.

The cross-sectional views ofFIGS. 7A and 7Bshow that the alternative support member190is a solid piece of material from the level of the supporting surface to the upper edge of the alternative support member190. The alternative support member190therefore in some implementations requires a significant amount of material to manufacture, which can result in increased cost as well as increased weight. In some implementations, the alternative support member190is formed from metal and can weigh in the range of about 15 pounds to about 25 pounds. In contrast, the middle support member160can be formed from a tubular metal structure which requires significantly less material to manufacture. In some implementations, the middle support member160can be formed from a steel tube having a thickness of about 0.035 inches. The tube may have a diameter in the range of about 0.5 inches to about 1.5 inches and may have a square cross-sectional shape. In some implementations, the tube may have a diameter of about 1 inch. Other cross-sectional shapes may also be used for the tubular structure used to form the middle support member160.

For ease of manufacturing, the middle support member160may be formed from a straight tubular structure that is bent into a predetermined shape or profile, such as a profile providing, establishing or maintaining a predetermined set of one or more characteristics, such as the tilt angle of the solar panels110, the horizontal and vertical distances between the solar panels110and the ballast trays120, the tilt angle of the ballast trays120, the bend radius of middle supports160, and the strength of the overall array100. These predetermined characteristics are described further below.

In some implementations, the middle support160can be bent into a predetermined shape selected to support the solar panels110at a predetermined angle. For example, the angle at which the solar panels110are supported may be selected to substantially face the sun during daylight hours. In implementations in which the array100is mounted on a roof or other horizontal surface, a relatively small tilt angle may be desired to ensure that the solar panels110are oriented towards the sun in order to capture a large amount of solar energy. For example, the middle support160may be configured to maintain a tilt angle of 5 degrees or 10 degrees for the solar panels110. In some implementations, the orientation of the array100may also be adjusted to further cause the surfaces of the solar panels110to face the sun. For example, for installations in the northern hemisphere, the middle supports160may be configured to support the solar panels at a predetermined angle towards the south.

In some implementations, the middle support members160can be bent into a predetermined shape selected to maintain predetermined vertical and horizontal distances between the solar panels110and the ballast trays120. For example, the vertical distance between the upper edge of a ballast tray120and the upper edge of a solar panel110can serve as a ventilation gap. In some implementations, this predetermined vertical distance between the upper edge of each ballast tray120and the upper edge of each solar panel110can be in the range of about 2 inches to about 5 inches. The predetermined horizontal distance between the lower edge of the solar panels110and the lower edge of the ballast trays120can provide space for a technician to access the components of the array100during installation or repair operations. To allow a technician to walk safely between the rows of solar panels110in the array100, the middle support structure160may be bent into a desired shape selected to provide adequate walking space between the rows of solar panels110in the array100. For example, in some implementations, the middle support structure160may be bent into a shape such that the ballast trays120are positioned away from the solar panels110by a distance of about 6 inches or more.

In some implementations, the middle support member160can be bent into a predetermined profile selected to support the ballast trays120at a predetermined angle. The angle at which the ballast trays are supported can impact the aerodynamics of the array100as well the walk space between the ballast trays and the solar panels. In some implementations, the middle support members160may be formed into a shape selected to support the ballast trays at an angle in the range of about 40 degrees to about 50 degrees, which can provide sufficient walk distance between the ballast trays and the lower edge of the solar panels while also providing adequate wind deflection capability. In some other implementations, the middle support members160may be configured to support the ballast trays120at other suitable angles.

In some implementations, the middle support structure160may be formed into a profile by bending the tubular structure forming the middle support structure160at a predetermined bend radius. The bend radius may be selected for structural strength as well as ease of manufacturing. For example, in some implementations, bending the middle support member160at a radius of curvature of in the range of about 1.5 inches to about 2.5 inches can result in sufficient structural strength to support the solar panels110, ballast trays120, and ballast blocks140. In some implementations, the bend radius can be about 2 inches. In some implementations, the middle support members may also be configured to support a predetermined load weight, which may come from the weight of the solar panels110and ballast trays120populated with up to five ballast blocks as well as other forces resulting from environmental conditions in the area where the array100is installed. For example, in some implementations, the middle support member160may be configured to support about 60 pounds per square inch of snow. In some other implementations, the middle support member160may be configured to support about 90 pounds per square inch of snow. The middle support member160also can be configured to withstand winds up to about 150 miles per hour.

The middle support member160can maintain a predetermined profile substantially the same as the profile of the alternative support member190. However, the middle support member160can be formed from significantly less material than the alternative support member190. For example, the middle support member160is formed with structural material mainly positioned at the perimeter of the profile of the middle support member160, where the other components of the array100connect to the middle support member160. Because the interior region of the profile shape of the middle support member160are not used to connect other components of the array100, it is unnecessary to have structural material in the interior region. In contrast, the alternative support member190is formed from structural material defining the profile and filling the interior region as well. Therefore, the alternative support member190requires significantly more material to define the same profile as the middle support member160. Thus, in some implementations, the middle support member160can be formed using about one third of the structural material needed to form the alternative support member190. However, because the middle support member160can be formed from a hollow tubular structure having high structural strength, the strength of the middle support member160can provide as much structural support as the alternative support member190. Furthermore, using a tubular structure to form the middle support member160facilitates ease of manufacturing. For example, the tubular structure is an inexpensive component that is commercially available, and it can simply be bent into a predetermined shape to form the middle support member160. No additional tools or manufacturing equipment are necessary, which further reduces the cost of the middle support structure160relative to the alternative support structure190.