Patent Application
20110099923
There is an ever-increasing focus on the discovery and utilization of alternative energy sources that do not consume natural resources and minimize the impact on the environment. Solar energy technology continues to advance, providing an increasingly efficient means for converting solar energy into electricity. However, a primary issue faced by the solar power industry is the cost of the equipment and the corresponding costs associated with installation of the solar equipment.
A conventional solar power system may include, at a minimum, a solar array attached to a pole or mast that is secured to a foundation. A tracking mechanism used to move the solar array and track the movement of the sun may provide the interface between the solar array and the mast. To secure the mast and corresponding solar array in place, the foundation is typically a concrete pier that is poured into a hole dug into the ground. The mast is then bolted to the foundation to secure the system in place. The electrical system is then connected from a local power source to the solar array, which includes separately grounding the electrical system to ground.
While functional, the conventional solar power system installation described above becomes cumbersome and expensive when applied to large numbers of arrays. The costs associated with the foundations, and specifically with the time required to install the foundations and attach the solar power systems to the foundations, often prohibit solar power from becoming a commercially viable option for many potential applications.
It is with respect to these considerations and others that the disclosure made herein is presented.
It should be appreciated that this Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to be used to limit the scope of the claimed subject matter.
Concepts and technologies described herein provide for a cost-effective method and system for installing a solar array. According to one aspect of the disclosure provided herein, a configuration of a helical anchor to be used for supporting a solar array is selected. The configuration may be selected according to soil conditions and other environmental factors associated with the installation location. The selected helical anchor is screwed into the ground to a depth that provides an underground portion that acts as a foundation, and an above-ground portion to which the solar array is to be attached. A solar tracking mechanism is attached to the solar array and to the top end of the helical anchor to connect the solar array to the helical anchor.
According to another aspect, a solar power system includes a solar array, a solar tracking mechanism, and a one-piece helical anchor. The solar tracking mechanism operates to reposition the solar array to track the movement of the sun. The helical anchor includes an above-ground portion that attaches to the solar tracking mechanism, and an underground portion that has at least one helical anchor blade to assist in screwing the anchor into the ground to provide a secure foundation for the solar array.
According to yet another aspect of the disclosure, a solar power system includes a solar array attached to a solar tracking mechanism. The solar tracking mechanism includes an azimuth drive that operates to rotate the solar array around an azimuth axis, and an elevation drive that operates to rotate the solar array around an elevation axis. The elevation drive is connected to a torque tube member attached to the solar array. The torque tube member is connected via a hinge pin to a stationary member that is attached to the azimuth drive. The torque tube member rotates around the hinge pin to raise and lower the solar array around the elevation axis. The solar tracking mechanism is further attached to an above-ground portion of a one-piece helical anchor. An underground portion of the anchor includes at least one helical anchor blade that assists in screwing the anchor into the ground to provide a secure foundation for the solar array. The helical anchor further acts as a ground rod connection that provides a direct electrical ground through the anchor directly to the surrounding earth.
The features, functions, and advantages that have been discussed can be achieved independently in various embodiments of the present disclosure or may be combined in yet other embodiments, further details of which can be seen with reference to the following description and drawings.
The following detailed description is directed to methods and systems for installing a solar power system for tracking the movement of the sun. As discussed above, traditional solutions for solar array installation are time consuming and expensive. Conventional installations include digging a hole in the ground for the concrete foundation. Doing so absorbs a significant number of man-hours, particularly if there are a large number of solar arrays being installed. After digging the holes, concrete must be mixed and poured into the holes, along with setting any rebar and pole-mounting bolts into the foundation. Again, this installation step takes a significant amount of time and expense associated with the costs of materials. The poles to which the solar arrays will be mounted are then bolted to the foundations prior to installing the solar arrays onto the poles. Bolting the poles to the foundations again requires a significant number of man-hours. The conventional installation materials and time required to set up a solar power system renders the alternative energy source cost prohibitive for many commercial applications.
Utilizing the concepts and technologies described herein, a solar power system utilizes a helical anchor as the foundation, the mast to which a solar array is attached, and even the electrical ground for the solar power electrical system components. The helical anchor eliminates the need to dig a hole, pour a foundation, and attach a mast to the foundation. Instead, a single helical anchor is screwed into the ground to provide both a foundation and an above-ground mast to which the solar array is attached. The system and installation method described herein reduces the amount of materials needed to install solar power systems, and significantly reduces the number of man-hours required to install the solar power systems. The reduction in materials and installation time substantially decreases the costs associated with installing solar power systems, which in turn increases the commercial practicality of solar power generation systems.
In the following detailed description, references are made to the accompanying drawings that form a part hereof, and which are shown by way of illustration, specific embodiments, or examples. Referring now to the drawings, in which like numerals represent like elements through the several figures, a solar power system and corresponding installation according to the various embodiments will be described.
The solar array 106 is attached on the rear side to a torque tube 108. The torque tube 108 is used to structurally support the solar array 106, while providing an attachment location for a solar tracking mechanism 112. Conventionally, many solar power systems utilize solar tracking mechanisms to move the corresponding solar arrays in a manner that tracks the movement of the sun in order to increase the power production of the solar cells. Some solar power systems, such as the solar power system 100 shown in
In the embodiment shown in
The elevation drive 116 of the solar tracking mechanism 112 utilizes a piston 118 to rotate a torque tube member 122 with respect to a stationary member 120 in order to alter the elevation of the solar array 106. The piston 118 is connected to the torque tube member 122 and moves linearly within a cylinder 120, which is connected to a stationary member 124 of the solar tracking mechanism 112. It should be understood that the elevation drive, as well as the azimuth drive, may operate via pneumatic, electric, or hydraulic power, or may alternatively utilize any other type of mechanical, piezoelectric, or electro-mechanical actuator to rotate the torque tube member 122 in relation to the stationary member 124 without departing from the scope of this disclosure.
Conventional solar power systems often utilize some type of connecting structure that is attached to the solar array 106 and is then attached to a rotating element such as a hinge. The hinge is then connected to the mast and solar tracking mechanism. In contrast, according to various aspects of this disclosure, the torque tube 108 and corresponding torque tube member 122 becomes one half of the hinge. The torque tube member 122 that is welded, bolted, or otherwise attached to the torque tube 108 is connected to the stationary member 124 of the elevation drive 116 via a hinge pin 126. The hinge pin 126 contains two bearings that support the solar array rotation and associated loads. The stationary member 124 includes or is fixedly attached to a flat member that connects the elevation drive 116 to the azimuth drive 114. The interface between the solar tracking mechanism 112 and the helical anchor 110 will be discussed in detail below with respect to
Turning now to
As seen in
Being a one-piece apparatus, the helical anchor 110 is distinguished from any other type of anchoring system that utilizes an underground anchor and an above-ground structure that is then bolted to the underground anchor. By being manufactured from a single shaft that is screwed partially into the ground while presenting an above-ground mast, the helical anchor 110 offers the benefit of requiring fewer parts to manufacture, stock, maintain, and transport, as well as saving installation time since no above ground structure is bolted to the below ground anchor at ground level.
According to one implementation, the height 210 is approximately one half of the depth 212. More specifically, according to one implementation, the helical anchor 110 is approximately 15 feet in length with an above-ground height 210 of 5 feet and an underground depth 212 of 10 feet. According to this implementation, the helical anchor 110 may be manufactured from a steel pipe, be between 6-9 inches in diameter, and have a wall thickness of between 0.25-0.30 inches. This helical anchor 110 could adequately support a rectangular solar array as shown in
As can be seen in the enlarged view of the bottom end 206 of the helical anchor 110 shown in
As will be described in further detail below, the characteristics of the helical anchor blade 220 and corresponding helical anchor 110 may be dependent on the particular soil conditions of the installation site given the anticipated loads on the helical anchor 110 being installed. As can be seen in
One rotation of the helical anchor blade 220 is shown in
The precise pitch 224, outside diameter 228, number of turns of the helical anchor blade 220, and the depth 212 may depend on the particular soil characteristics of the installation location. For example, loosely packed soil may require a deeper installation, a decreased pitch 224, an increased number of turns of the helical anchor blade 220, one or more additional helical anchor blades 220A, and/or a wider outside diameter 228 than a helical anchor 110 used for compact soil installation. These helical anchor 110 characteristics would not only provide more helical anchor blade 220 surface area for providing a sound foundation for the solar power system 100, but when the helical anchor 110 is screwed into the ground using a hydraulic auger, for example, these helical anchor 110 characteristics operate to compact the soil to further strengthen the foundation of the solar power system 100.
Continuing the sample implementation discussed above with respect to the foot steel helical anchor 110 supporting the 8 foot by 18 foot solar array 106, the helical anchor 110 may include a helical anchor blade 220 having a single turn as shown in
Turning now to
Known soil analysis techniques may be used to determine the characteristics of the soil at the installation location. Based on this analysis, any number of helical anchor features discussed above may be selected and utilized to predict the load bearing capacity of the selected helical anchor. This predicted load-bearing capacity may be compared with the predicted loads to be experienced by the helical anchor 110 at that location to determine if the selected anchor configuration is acceptable. If not, further engineering analysis may be performed utilizing various anchor characteristics until a configuration of the helical anchor 110 that meets all predicted load-bearing requirements has been selected.
The helical anchor 110 configuration may also include material considerations. For example, depending on the environmental conditions to which the solar power system 100 will be exposed, the type of material used to manufacture the helical anchor 110 and corresponding helical anchor blade 220, the outside diameter of the helical anchor 110 and inside diameter 226 of the helical anchor blade 220, the thickness of the material, and the total length of the helical anchor 110 may change. To decrease the material and installation costs, the least robust helical anchor 110 configuration may be selected that will sustain safe operations of the solar power system 100 according to the environmental conditions at the specific installation location.
Returning to
From operation 504, the routine 500 continues to operation 506, where the selected helical anchor 110 is screwed into the ground 208 at the installation location to the proper installation depth 212. The solar tracking mechanism 112 is bolted or otherwise attached to the solar array 106 at operation 508. The routine 500 continues from operation 508 to operation 510, where the solar tracking mechanism 112, with the attached solar array 106, is attached to the helical anchor 110. As described above with respect to
At operation 512, the power and communication wires are connected between the control box 128 and the external supply box 202, and to the applicable components of the solar power system 100. This operation may include the connection of any applicable air or hydraulic lines if utilized by the solar tracking mechanism 112 as described above. This operation may also include connecting the solar tracking mechanism 112 to a controller that provides the appropriate control signal input to the solar tracking mechanism in order to accurately track the movement of the sun. The controller may be within the control box 128, the external supply box 202, or may be a part of the solar tracking mechanism 112. The ground wires are connected to the grounding connection 218 of the helical anchor 110 to ground the electrical components of the solar power system at operation 514, and the routine 500 ends.
From the description provided herein, it should be clear that the helical anchor 110 and corresponding method of installation provides a significant reduction in the amount of time and money required to install solar power systems. Rather than utilizing concrete foundations and bolts to secure a mast to the foundation, the helical anchor 110 described herein allows for a simplified installation that includes merely screwing the appropriate anchor in the ground. Not only does this process save installation time, but the reduction in the required materials also saves money in manufacturing, storing, maintaining, and transporting those materials to the installation sites. Reducing the time and costs associated with solar power systems and corresponding installations of these systems will advance the use of solar power as an alternative energy source as these systems become commercially viable for a larger number of energy applications.
The subject matter described above is provided by way of illustration only and should not be construed as limiting. Various modifications and changes may be made to the subject matter described herein without following the example embodiments and applications illustrated and described, and without departing from the true spirit and scope of the present disclosure, which is set forth in the following claims.
This invention was made with Government support under contract number DE-FC36-07GO17052 awarded by the Department of Energy. The government has certain rights in this invention.
