Embodiments of the subject matter described herein relate generally to devices for cleaning parts of solar energy systems, such as solar energy receivers as well as reflective devices such as solar concentrators.
Photovoltaic (PV) cells, commonly known as solar cells, are well known devices for direct conversion of solar radiation into electrical energy. Generally, solar cells are fabricated on a semiconductor wafer or substrate using semiconductor processing techniques to form a p-n junction near a surface of the substrate. Solar radiation impinging on the surface of, and entering into, the substrate creates electron and hole pairs in the bulk of the substrate. The electron and hole pairs migrate to p-doped and n-doped regions in the substrate, thereby generating a voltage differential between the doped regions. The doped regions are connected to conductive regions on the solar cell to direct an electrical current from the cell to an external circuit. Solar cells can be coupled together electrically (e.g., in series) to form a solar, or PV, module.
In operation exposed to the ambient atmosphere, PV modules can collect dust, dirt, or other particulates, which can block some amount of solar radiation, which can ultimately reduce the amount of energy produced by the PV module.
At least one of the inventions disclosed herein includes the realization that despite the complex geometry, highly water efficient devices can be used for cleaning concentrated solar energy reflectors. Concentrated solar energy systems have a more complex geometry due to the incorporation of curved reflectors that are designed to concentrate sunlight onto a narrowly defined area, while tracking movement of the sun. Some of the known techniques for cleaning concentrating reflectors of solar energy systems rely on manually directing jets of water, for example, with pressure washers, and manually wiping down the mirrors. This approach leads to large amounts of water being used to clean concentrators.
An aspect of at least one of the inventions disclosed herein includes the realization that close fitting and finely aligned devices having mounted brushes, squeegees, and water sprayers can be used to clean concentrating solar reflectors with less water than current approaches.
Thus, in some embodiments, a solar device cleaning mechanism includes a plurality of debris removal surfaces arranged along a sunlight concentrating curvature geometry and at least one guide configured to follow a reference surface of the reflector so as to maintain alignment of the debris removal surfaces during a cleaning process.
Another aspect of at least one of the inventions disclosed herein includes the realization that a solar device cleaning mechanism can be configured to clean both a solar energy reflector and a solar energy receiver, simultaneously. As such, the cleaning device provides for an increase in cleaning efficiency by cleaning multiple distinct surfaces, simultaneously. One reason why such a device is practicable is that solar energy concentrators have a specific, finite geometry for capturing and reflecting sunlight onto a specified receiver. Thus, in a single solar system, many concentrators, having the same curvature and angular orientation are mounted with a specific orientation such that the aperture of the reflector is accurately aligned with the solar energy receiver so as to focus light into the desired shape and intensity onto the receiver, during the desired range of movement of sun tracking motion during use. As such, in a single solar system using such concentrating hardware, many or all of the concentrating reflectors are precisely or nearly the same size and mounted in the same or nearly the same orientation relative to receivers which are similarly the same size and mounted in the same orientation relative to the associated concentrator. The geometry is relatively complex because the curved concentrators and the receivers face each other in a non-perpendicular orientation.
Thus, in some embodiments, a solar system cleaning device includes two distinct sets of debris removal surfaces. A first set includes a plurality of debris removal surfaces extending along a solar energy concentrating curvature and a second set of debris removal surfaces extend in a roughly opposite direction aligned along a solar receiver surface.
In some embodiments, a concentrated solar energy collector cleaner can comprise a frame member and a first cleaning module supported by the frame member, the first cleaning module can include at least a first debris displacing member having a first cleaning surface extending along a curved shape. A first guide member can be configured to support the frame member during a cleaning movement of the cleaner with the first cleaning surface of the first debris displacing member in contact with a first curved reflective surface of a first solar concentrator.
In some embodiments, a concentrated solar energy collector cleaner can comprise a frame member extending along a longitudinal direction and a first cleaning module supported by the frame member, the first cleaning module can include at least a first debris displacing member having a first cleaning surface extending along a first curved shape. A second cleaning module can be supported by the frame member, the first cleaning module including at least a second debris displacing member having a second cleaning surface extending along a second curved shape. The first and second cleaning modules can be spaced from each other along the longitudinal direction.
In some embodiments, a concentrated solar energy collector cleaner can comprise a frame member and means, supported by the frame member, for simultaneously cleaning a plurality of solar concentrating reflectors having parallel longitudinal axes, with a single movement of the frame member in a direction parallel to the longitudinal axes.
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 identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter of the application or uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
This specification includes references to “one embodiment” or “an embodiment.” The appearances of the phrases “in one embodiment” or “in an embodiment” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure.
Terminology. The following paragraphs provide definitions and/or context for terms found in this disclosure (including the appended claims):
“Comprising.” This term is open-ended. As used in the appended claims, this term does not foreclose additional structure or steps.
“Configured To.” Various units or components may be described or claimed as “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that the units/components include structure that performs those task or tasks during operation. As such, the unit/component can be said to be configured to perform the task even when the specified unit/component is not currently operational (e.g., is not on/active). Reciting that a unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. §112, sixth paragraph, for that unit/component.
“First,” “Second,” etc. As used herein, these terms are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, reference to a “first” drive module of a PV module cleaner does not necessarily imply that this cleaning module is the first cleaning module in a sequence; instead the term “first” is used to differentiate this cleaning module from another cleaning module (e.g., a “second” cleaning module).
“Based On.” As used herein, this term is used to describe one or more factors that affect a determination. This term does not foreclose additional factors that may affect a determination. That is, a determination may be solely based on those factors or based, at least in part, on those factors. Consider the phrase “determine A based on B.” While B may be a factor that affects the determination of A, such a phrase does not foreclose the determination of A from also being based on C. In other instances, A may be determined based solely on B.
“Coupled”—The following description refers to elements or nodes or features being “coupled” together. As used herein, unless expressly stated otherwise, “coupled” means that one element/node/feature is directly or indirectly joined to (or directly or indirectly communicates with) another element/node/feature, and not necessarily mechanically.
“Inhibit”—As used herein, inhibit is used to describe a reducing or minimizing effect. When a component or feature is described as inhibiting an action, motion, or condition it may completely prevent the result or outcome or future state completely. Additionally, “inhibit” can also refer to a reduction or lessening of the outcome, performance, and/or effect which might otherwise occur. Accordingly, when a component, element, or feature is referred to as inhibiting a result or state, it need not completely prevent or eliminate the result or state.
In addition, certain terminology may also be used in the following description for the purpose of reference only, and thus are not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “side”, “outboard”, and “inboard” describe the orientation and/or location of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import.
Embodiments of cleaning devices for solar energy collection systems and methods of use are described herein. In the following description, numerous specific details are set forth, such as specific structures and operations, in order to provide a thorough understanding of embodiments of the present disclosure. It is apparent to one skilled in the art that embodiments of the present disclosure can be practiced without these specific details. In other instances, well-known structures or techniques are not described in detail, for brevity. Moreover, some details of robotic cleaners are described in commonly owned U.S. application Ser. No 13/745,722, entitled “Mechanism for Cleaning Solar Collector Surfaces” by Grossman et al., filed on Jan. 18, 2013, and U.S. Provisional Patent Application No. 62/007,381, entitled “Solar Module Cleaner” by Grossman et al., filed on Jun. 3, 2014, both of which are attached as appendices and form part of the present disclosure. Furthermore, it is to be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale.
The present specification describes several types of known concentrated solar energy collection systems followed by descriptions of various embodiments of solar energy system cleaning devices as well as methods of using such cleaning devices. Various examples are provided throughout.
Turning now to the Figures,
The solar system 100 comprises a pier 110, a torque tube 120 supported by the pier 110, at least one cross beam 130 coupled to the torque tube 120. Several solar concentrators or reflector elements 140 are supported by a support structure 150 which couples to one or more of the cross beams 130. The support structure 150 couples one of the solar receivers 160 to one or more of the cross beams 130. In some embodiments, one or more of the solar receivers 160 can be coupled to the rear, non-reflective side of one or more solar concentrators 140. The torque tube 120 can rotate the assembled and positioned solar concentrators 140 and solar receivers 160 to track the sun during the day. By tracking the sun, the solar system 100 can receiver optimum irradiance during hours of sunlight.
The solar system 100 can adjust the position of the solar concentrators 140 to permit concentration of light from the sun 180 onto the solar receivers 160. The solar receivers 160 can be photovoltaic solar cells, or portions thereof, which convert the received sunlight into electrical current. Additional features can be incorporated into the solar system 100. For clarity and descriptive purposes, these are omitted.
The support structure 150 can refer to one or more components coupling the solar concentrators 140 to the cross beam 130, the solar receivers 160 to the cross beam 130, the solar receivers 160 to the solar concentrators 140, or a combination thereof. For example, the support structure 150 can refer to all components coupling the pier 110 to the solar receiver 160, including the torque tube 120, the cross beam 130, and, in some embodiments, the solar concentrators 140. The support structure 150 can refer to components which couple a solar receiver 160 to a solar concentrator 140, such as when a solar receiver 160 is mounted on the rear, non-reflective side of a solar concentrator 140. In still other embodiments, the support structure 150 can refer to components, members, or elements which couple a solar concentrator 140 to the cross beam 130. In still other embodiments, the support structure 150 can refer to components which couple a solar concentrator 140 to the torque tube 120 and can include one or several cross beams 130.
The solar concentrator 140 directs the concentrated sunlight 184 to a predetermined location on the solar receiver 160. The solar receiver 160 includes a photovoltaic solar cell or a photovoltaic solar cell unit. The concentrated sunlight 184 preferably impinges on the solar cell 162 to enable electrical energy generation. The solar receiver 160 can include several components interoperating to produce electrical energy, such as interconnects connecting two or more photovoltaic solar cell units, an encapsulate, a carrier, a heat sink, and so on.
One face of the solar receiver 160 can be positioned to face toward the solar concentrator 140, thereby receiving the concentrated sunlight 184. This face preferably includes the photovoltaic solar cell 162 and can also include a protective layer over the photovoltaic solar cell 162. During use, the solar system 100 is positioned, for example, with a sun-tracking drive system (not shown) such that the concentrated sunlight 184 reflected by the solar concentrator 140 impinges on the photovoltaic solar cell 162, and not other portions of the solar receiver 160, thereby increasing the electrical output of the solar cell 162 and, consequently, overall system efficiency.
Two or more adjacent sets of solar concentrators 140 with their corresponding solar receivers 160 can be present, increased to any desired number. For purposes of descriptive clarity, six sets of such concentrators 140 and solar receivers 160 are shown in
As described herein, the light receiving surfaces of solar collection receivers 160, as well as the concentrators 140 can accumulate dirt, dust, or other particulates (e.g., airborne particulates) that can block light that would otherwise be incident on the collector surface. Such accumulation can reduce the potential power output of the solar collector(s).
The frame 202 can be in any configuration, with sufficient stiffness and strength for supporting the desired components, which can include any combination of the devices 204, 206, 208, 210, 212, noted above, or other devices. In the illustrated embodiment, the frame 202 includes a body portion 220, a first cleaning module support portion 222, which in the illustrated embodiment, includes an upper support 224 and a lower support 226. Additionally, the frame 202 can include a second cleaning module support portion 230 configured for supporting the second cleaning module 206. The frame 202 also includes a guide support portion 236 which includes, in the illustrated embodiment, a roller support 238 and a cross member 240, described in greater detail below. As shown in
In the illustrated embodiment, the body 220 of the frame 202 is made from a plate member, with a plurality of weight relieving holes. However, the frame 202 and a body 220 can be made in any configuration desired.
The cleaning device 200 can include one or more cleaning modules 204, 206 for cleaning portions of a solar energy system. As used herein, the term “cleaning module” is used interchangeably with the term “cleaning head.” The cleaning modules 204, 206 can include one or more components for removing accumulated particulate from surfaces of a solar energy system. For example, the cleaning modules 204, 206 can include rotating or fixed brushes, and/or one or more squeegees, and/or any other type of debris removal devices, which can be considered debris displacement devices or members, or any combination of the above.
The illustrated embodiments of the cleaning device 200 includes a “dual-squeegee” configuration described in more detail below. However, other squeegee arrangements can also be used, for example, single squeegee arrangements, or arrangements with no squeegees. One or more of the squeegees can function as a fluid removal element, for example, by removing fluids, such as cleaning liquids or other fluids, which may have debris suspended therein.
Additionally, the illustrated embodiment of the cleaning device 200 includes additional, optional, upstream brushes, which can be in the form of fixed single blade brushes, double brush assemblies, rotating brushes, or other types of brushes. One of more of the brushes can be configured to impart mechanical energy so as to loosen debris and suspend such debris in a clearing fluid, such as water or other cleaning liquids or fluids applied to the surfaces to be cleaned.
With continued reference to
The first cleaning module 204 is configured to remove debris from and thus clean a concentrating reflector, such as the reflectors 140 illustrated in
Similarly, the first and second squeegees 252, 254, of the first cleaning module 204 can be mounted to the frame 202 so as to follow the contour of a surface to be cleaned, and in the present embodiment, the curvature of concentrators 140. Like the brush member 250, the squeegee members 252, 254 function more desirably when compressed from the relaxed state. With some squeegee designs, the squeegee members 252, 254 can be mounted to the frame 202 so as to be compressed by approximately one-eighth of an inch during use. Thus, the squeegee members 252, 254 can be mounted such that when they are compressed by approximately one-eighth of an inch, they follow the contour of the concentrators 140. This functionality is schematically illustrated in
As shown in
With reference to
Although, as noted above, any type of brush or squeegee members can be used for the device 200, some brush members 250, 251 and squeegee members 252, 254 can require approximately 15 newtons per linear foot to be compressed by the magnitudes noted above, one-quarter of an inch for the brush members 250, 251 and one-eighth of an inch for the squeegee members 252, 254. Thus, in some embodiments, the total weight of the cleaning device 200 is adjusted to provide enough force to provide compression of all the brush members and squeegee members included in all of the included cleaning modules, for example, first and second cleaning modules 204, 206. Wheels 270 can be mounted at a spacing 266 to limit the compression of the brushes 250, 251 and squeegees 252 and 254 during use.
With continued reference to
As noted above with reference to
In the illustrated embodiment, the rollers 270 are positioned to roll directly on the surface of the concentrators 140. However, in other embodiments, the rollers 270 can be arranged to roll along the top edge of a concentrator 140, described in greater details below with reference to the embodiment of
With continued reference to
With reference to
The second cleaning module 206 can include the same or similar arrangement of brushes 250, 251 and/or squeegees 252, 254. Additionally, the second cleaning module 206 can be guided in the proper or desired direction of movement with one or more wheels and/or rollers, 270.
Optionally, the guide mechanism 208 can include additional guides 271 mounted to the cross member 240. The additional rollers 271 can be configured to ride along the top edge of receivers 160, for providing additional support and alignment of the cleaning device 200 during use.
As noted above, the second cleaning module 206 can be configured to clean the surface of the receivers 160 simultaneously as the first cleaning module 204 is cleaning the surfaces of the concentrators 140. Thus, the second cleaning module 206 can be configured with the same alignment and compression characteristics as those described above with regard to the first cleaning module 204 and with reference to
With continued reference to
With reference to
Positioned as such, as shown in
With reference to
As explained above with reference to
With reference to
Further, with reference to
In such a configuration, the total weight of the cleaning device 300, under the force of gravity, can generate significant loads onto receivers 160. Thus, in the illustrated embodiment, the rollers 370 are only provided on the rightmost (as viewed in
With reference to 14, during use, the cleaning device 300 can be pushed in the direction of arrow 396, with the use of the handle 390. Additionally, although not shown, liquid delivery device hoses can be connected to the various included sprayer heads described above with reference to the cleaning device 200 for delivering liquid during cleaning Additionally, a supply of cleaning liquid can be attached to such liquid delivery devices for delivering liquid during use. For example, a truck including a cleaning fluid reservoir and one or more pumps can be driven alongside of the solar energy device during cleaning.
Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even where only a single embodiment is described with respect to a particular feature. Examples of features provided in the disclosure are intended to be illustrative rather than restrictive unless stated otherwise. The above description is intended to cover such alternatives, modifications, and equivalents as would be apparent to a person skilled in the art having the benefit of this disclosure.
The scope of the present disclosure includes any feature or combination of features disclosed herein (either explicitly or implicitly), or any generalization thereof, whether or not it mitigates any or all of the problems addressed herein. Accordingly, new claims may be formulated during prosecution of this application (or an application claiming priority thereto) to any such combination of features.
This application claims the benefit of U.S. Provisional Application No. 62/095,561 filed Dec. 22, 2014, entitled “Solar Module Cleaner” by Jeanty et al., the entire contents of which are hereby incorporated by reference.
Number | Date | Country | |
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62095561 | Dec 2014 | US |