Automated system for cleaning solar panel

A system 100 for cleaning solar panels 304 arranged in a row includes a frame 102, rotating members 106 and a stationary brush 110. The frame 102 moves along the row of solar panels 304. The rotating members 106 interfaces with surface of the solar panel 304. An axis of rotation of the rotating members 106 is incident at an angle to the solar panels 304. The plurality of rotating members 106 are connected to the frame 102 to move with the frame 102 along the row of solar panels 304. The stationary brush 110 is engaged to the frame 102. The brush 110 interfaces with the surface of the solar panel 304 to unsettle foreign particles present on the surface of the solar panel 304, as the frame 102 traverses along the row of solar panels 304.

BACKGROUND

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to being prior an by inclusion in this section.

Field of the Invention

The subject matter in general relates to cleaning of solar panels. More particularly, but not exclusively, the subject matter relates to a robot for cleaning of the solar panels.

Discussion of the Related Field

The demand for energy is increasing day by day. It is challenging to meet the upcoming demand by relying on non-renewable energy sources as there is limited supply. To meet the existing demand, we need to concentrate on various other sources of energy like the renewable energy forms viz. solar, wind, hydropower and biomass, among others.

Solar energy is one form non-renewable energy source, which can be utilised to meet the upcoming demand. Solar energy can be converted to usable form like electricity using PV cells. These PV cells are stacked together to form a solar panel. These solar panels are installed in numbers to generate the required energy. Solar panels, as is well known, are installed mainly in open space. The solar panels are exposed to intense dust and other foreign particles, resulting in soiling, thereby reducing the efficiency of the solar panels. This creates a challenge of keeping the solar panel clean to achieve consistent output.

Several methods are adopted to clean the solar panels, some of which include manual cleaning. In manual cleaning, human labour cleans the solar panels using handheld cleaning articles, such as a mop. Apart from manual cleaning, machine assisted cleaning also exists. In such a technique, an individual cleans the solar panels using a machine, which the individual guides along the solar panels.

The above discussed techniques are generally acceptable when the quantity of panels to be cleaned is relatively less. However, to produce large quantum of energy output, solar panels are generally installed in masses spread across vast area. Cleaning such large deployment of solar panels employing the above discussed techniques is inefficient and impacts profitability of the installation. Maintenance cost increases as the number of workers required to clean the solar panels increase.

Additionally, in these techniques, water is primarily used to clean the solar panels, which results in consumption of another non-renewable source. Further, there would be a need of an additional setup for the storage of water and a pump setup to deliver water from the reservoir to the nozzle. This adds to the cost of the cleaning unit, as well as the maintenance cost.

There are some alternative solution wherein automated robots are used to clean the solar panels. These robots employ elongated rotating circular brushes, whose rotating axis is parallel to the surface of solar panels. The length of such brushes is fixed, thereby limiting the usage of such robots to a particular dimension of solar panels. A whole new setup would have to be manufactured to suit to each requirement. Also, some of the suspended dust tend to settle back on the panel as the rotation of the circular brush is also in the direction of movement of to the robot.

In view of the foregoing, there is a need for an alternative solution, which s simple, cost efficient, time efficient and eco-friendly.

SUMMARY

An embodiment provides a system for cleaning solar panels arranged in a row. The system comprises a frame configured to traverse along the row of solar panels. The frame comprises a plurality of rotating members interfacing with surface of the solar panel, wherein the axis of rotation of the rotating members is incident at an angle to a plane of the solar panels. The plurality of rotating members are connected to the frame to move with the frame along the row of solar panels. A stationary brush is engaged to the frame, wherein the brush interfaces with the surface of the solar panel to unsettle foreign particles present on the surface of the solar panel, as the frame traverses along the row of solar panels. The part of the frame to which the stationary brush is engaged to, defines a plurality of ports to suck air into the hollow frame and the portion of the frame opposite to the part of the frame to which the stationary brush is engaged to, accommodates a plurality of air blowers. The frame may allow passage of the air sucked by the plurality of ports to the plurality of air blowers. The system also comprises of pair of sensors, wherein at least one sensor is disposed on leading side of the frame and at least one sensor is disposed on the trailing end of the frame.

DETAILED DESCRIPTION

The following detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show illustrations in accordance with example embodiments. These example embodiments, which may be herein also referred to as “examples” are described in enough detail to enable those skilled in the art to practice the present subject matter. However, it may be apparent to one with ordinary skill in the art, that the present invention may be practised without these specific details. In other instances, well-known methods, procedures and components have not been described in detail so as not to unnecessarily obscure aspects of the embodiments. The embodiments can be combined, other embodiments can be utilized, or structural, logical, and design changes can be made without departing from the scope of the claims. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope is defined by the appended claims and their equivalents.

In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one. In this document, the term “or” is used to refer to a nonexclusive “or,” such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated.

Referring to the figures, and more specifically toFIG.7an environment, such as a solar farm700in which systems100may be deployed for cleaning solar panels is illustrated. The solar farm700has solar panels304arranged in multiple rows702. In each of the rows702, may have multiple solar tables306. Each solar table306may have multiple solar panels304grouped together. There can be gap310between adjacent columns of solar panels304, and there can be gap704between adjacent solar tables306deployed in a row702. Each of the rows702may be provided with a system100to clean the solar panels304deployed in the respective row702. The system100traverses along the row702, while overcoming the gap310between adjacent columns of solar panels304and the gap704between adjacent solar tables306. The system100cleans the solar panels304as it traverses along the row702of solar panels304.

Referring toFIGS.1A-1B, the system100for cleaning the solar panels arranged in a row is discussed in greater detail. The system100includes a frame102, rotating members106, continuous tracks104aand104b, support wheels108a,108b,108c,108d, a stationary, brush110, sensors112a,112b,112c,112d, suction ports116, a filter unit (not shown in drawing), air blowers114and a motor (not shown in drawing).

The parts of the system100referred above are configured to co-operate with each other to facilitate cleaning of the solar planes along a row. Specifically, the frame102supports for the rest of the parts of the system100. The movement of the frame102along the row of solar panels is enabled by the continuous tracks104aand104b, which is driven by the motor. The support wheels108a,108b,108c,108don the other hand, provides stability as the system traverses along the row.

While, the continuous tracks104and the support wheels108enable traversing of the system100along the row of solar panels304, the cleaning of the solar panels304is enabled by the stationary brush110and the rotating members106. The stationary brush110provides the initial cleaning of the solar panel304by unsettling the foreign particles from the surface of the solar panels304. The suction ports116suck in the mixture of air and the foreign particles, which are unsettled by the stationary brush110. The filter unit filters the air with foreign particles therein. Dust free air is made available at the other end of the filter unit by isolating the foreign particles from the air. The filtered air is supplied to the air blowers114, which are positioned behind the rotating members106. The filtered air is blown through the air blowers114to blow away the foreign particles unsettled by the rotating members106. The air blown through the air blowers114may also blow away the foreign particles unsettled by stationary brush110, which may not have been sucked in by the suction ports116.

Movement of the System along a Row of Solar Tables

The configuration of the system100, which enables movement of the system100along the row of solar panels304is now discussed in greater detail. The movement of the system100is primarily enabled by the continuous tracks104. Each of the continuous tracks104may be disposed on either side of the frame102. In an embodiment, each continuous track104comprise of a plurality of wheels which drive a continuous band. Although in the figure, only two wheels are shown, there can be more than two wheels arranged adjacent each other by providing gaps therein to allow free rotation of the wheels, while ensuring that the continuous band is well supported underneath. The continuous band may be formed by thread or track plate. Alternatively, the band may be made of polymer-based material which allow the system100to grip on to the surface of the solar panel304eliminating the chances of sliding of the system100.

It may be noted that, as recited earlier, and illustrated inFIG.3andFIG.7, solar panels304are arranged in rows over a solar table306. Gap310and gap704may exist between adjacent solar panels304and solar tables306, respectively. Continuous tracks104enable the system100to traverse over the solar panel304and also the solar table306with ease, by navigating over the gaps310,704. Hence, the system100can be used in solar farms, which have a range of such gaps, without requiring customization to either the system100or the installations in the solar farm. Further, the continuous band allow the system100to stay intact on the surface of the solar panel304. Furthermore, the weight of the system100is relatively well distributed over the surface of the solar panel304, thereby eliminating point load which may cause stress on the solar panel304.

In an alternate embodiment, as illustrated inFIG.4, pair of wheels401are employed in lieu of the continuous tracks104.

While the continuous tracks104or the wheels401enable movement of the system100, it shall be noted that there is a need to keep the system100on its course. This is specifically required since the solar panels304are inclined and there are chances of the system100being dislodged from the intended course. Such a stability may be provided by support wheels108. A pair of support wheels108may be disposed on either side of the frame102. Support wheels108may be engaged to the frame102. The support wheels108rests on the edge308of the solar table306, as can be clearly viewed inFIG.3. The axis of rotation of the support wheels108is inclined at an angle to the solar table306. The employment of the support wheels108provide additional grip and support to the system100, by way of side support. The support wheels108glide along the edge308of the solar table306, as the system100traverses along the row of solar panels304.

Cleaning of Solar Panels

Configuration of the system100, which enables cleaning of the solar panels304, as the system100traverse along row of solar tables306is now discussed in greater detail.

Referring more particularly toFIGS.1A-4, the system100comprises rotating members106to achieve cleaning of the solar panels304for most part. The rotating members106may include strands, which may be of microfibre material. Using such soft material limits abrasion, thereby limiting the risk of harming the surface of solar panels304with scratches. As the system100traverse along the row of solar panel304the rotating members106rotate about its axis, thereby unsettling the foreign particles from the surface of the solar panel304.

The rotating members106may be detachably attached to the shaft202that runs along the length of the system100.

In an embodiment, axis of rotation of the rotating members106is inclined to the surface of the solar panels304. In other words, axis of rotation of the rotating members106is not parallel to the surface of the solar panels304.

In an embodiment, referring toFIG.6, the axis602of rotation of the rotating members106is oblique to the surface of the solar panel304. The oblique angle604provides better interface between the rotating members106and the surface of the solar panels304. The improved interface is in terms of the scooping effect that is generated as the rotating members106rotate. The foreign particles are scooped and momentarily suspended in the air, which is then blown away (discussed later), thereby increasing the efficiency of cleaning.

The oblique angle of incidence may be achieved by known methods. Such methods include employing a spring, wall-nut and gear arrangement. Employment of spring allow the rotating members106to be flexible when they interface with the surface of the solar panels304.

FIG.1A-4, illustrates a configuration in which the rotating members106are arranged in a single row. A gap is maintained between two rotating members106in a single row so that the strands of the rotating members106do not entangle. Such a configuration may result in relative inferior cleaning of the surface of the solar panels304that is aligned with the gap. An alternate configuration of the rotating members106is disclosed, in conjunction withFIG.5, to address the problem. In the embodiment ofFIG.5a plurality of rotating members106that may be detachably attached to shaft202are deployed in multiple rows502a,502b,502c. The rotating members106in a row502bare positioned between the rotating members106of the adjacent row502a,502c. This enables efficient cleaning, as the area of the solar panel304that is left out by the rotating members106in a row, is cleaned by rotating members106of the adjacent row, as the system100moves in the cleaning direction302.

In addition to the rotating members106enabling cleaning of the solar panels304, the cleaning effort is complemented by the stationary brush110, as recited earlier. The stationary brush110is engaged on the leading side120of the frame102. The stationary brush110comprises of fine bristles (e.g., made of polymer material), which interface with the surface of the solar panel304. A single stationary brush110or a plurality of brush110are disposed along the length of the system100. The initial unsettling of the foreign particles from the surface of the solar panels304is achieved by the stationary brush110.

A plurality of suction ports116are disposed along the length of the frame102on the leading side120of the frame102, behind the stationary brush110. Suction ports116are configured to suck in mixture of air and the foreign particles that are unsettled by the stationary brush110.

A filter unit (not shown in figure) is also configured with the frame102. The filter unit may be positioned between the plurality of the suction ports116and the plurality of the air blowers114within the frame102. Air sucked in from the suction ports116pass through the filter unit. The filter unit isolates the foreign particles from the air. Dust free air is made available at the other end of the filter unit. Filter unit can be replaced/cleaned over an interval of time as a part of maintenance.

A plurality of air blowers114are disposed along length of the frame102towards the trailing side130of the frame102behind the rotating members106. As system100traverses along the row of solar panels304, the stationary brush110and the rotating members106interface with the surface of the solar panels304unsettling the foreign particles. The air that is sucked in from the suction port116passes through the filter unit and blown through the air blowers114. The frame102is configured with the passage allowing the air to pass from the suction ports116to the air blowers114. Air blowers144are positioned behind the rotating members106to blow off the unsettled foreign particles that are suspending in air thereby resulting in effective cleaning of the solar panels304.

In an embodiment, the frame102may be hollow at least in part. The hollow portion of the frame102functions as a conduit for movement of air sucked in by the suction ports116to the air filter. Further, air exiting the air filter may be transferred to the air blowers114via another hollow portion of the frame102, which again functions as a conduit for movement of air from the air filter or air pump to the air blowers114.

A comparatively larger sized system100may be required to clean the surface of the solar panel304when the size of the solar panel304is large. Manufacturing and transportation of gigantic system may pose significant challenges.FIG.8illustrates an alternate embodiment of a system100, depicting a modular configuration. The modular configuration comprises of a plurality of frames. The frames may be engaged together using a plurality of brackets802. The brackets802and the frame may have a plurality of holes therein, configured to engage the frames through any of the disposed holes, enabling the system100to be configured according to the size of the solar panel. The system100comprises of a plurality of motors804, each of which drive the rotating members106and the continuous tracks104or wheels401individually. The modular configuration of the system100enables easy transportation and maintenance of the system100in modules, also easing the assembly and disassembly of the system100.

Power Transmission

In an embodiment, a single motor may be configured to drive the rotating members106and the continuous tracks104or wheels401. The motor may be engaged to the frame102. The motor150is connected to the battery unit138. Referring specifically toFIG.2, schematic of power transfer arrangement is discussed. Rotation of motor shaft is transferred to the rotating members106and the continuous tracks104or wheels401using an arrangement of shafts202and gear arrangement (204and206). The gear arrangement204,206may be bevel gear arrangement. Alternatively, worm gear arrangement may be used, or a combination may be used. The motor may solitarily drive all the rotating members106and the continuous tracks104. Since all the members are connected to the same motor using gear mechanism (204and206) the speed of all the members are interdependent on the speed of the motor. The speed would remain proportional throughout the system100. The frame102may encompass the shafts202, which run along the length of the frame102. The rotating members106are attached to the shaft202by gear arrangement206. The shaft202is also connected to the continuous tracks104by means of other gear arrangement204. Alternatively, multiple motors may be used.

In an alternate embodiment as illustrated inFIG.8, all the rotating members106and the continuous tracks104or wheels401may be individually driven by separate motors804. The motors804may be powered by a battery138engaged on one side of the frame. Connection from the battery138to the motors804may be done externally.

Automation

It may be noted that, as recited earlier, the system100is engaged in cleaning the row of solar panels304. The extent of cleaning may be measured to keep track of the efficiency of system in cleaning the solar panels304. Furthermore, multiple systems100may be deployed over multiple rows702of solar table306in the solar farm700. The systems100deployed may be operated centrally from a control room. The systems100may be programmed to work at a specific interval of time. In an embodiment, the system100may additionally programmed to meet a pre-set benchmark of cleanliness, such that the system100continues to perform its operation until the benchmark is met.

In an embodiment, sensors112may be employed to determine the performance and efficiency of the system100. Sensors112may be disposed on opposite sides of the frame102, wherein at least one sensor112is positioned towards the leading side120of the frame102and the other sensor112is positioned towards a trailing side130of the frame102. The optical sensor112detects the amount of light reflecting off the surface of the solar panels304, thereby calculating the extent of soiling. The sensors112positioned towards the leading side120of the frame102detect the amount of light reflection from the surface of the solar panel304, which is used to determine the extent of foreign particles settled on the surface of the solar panels304. Likewise, the data from the sensors112positioned towards the trailing side130of the frame102is used to determine the extent of de-soiling of the solar panels304. The system100by itself, a controlling system by itself, or a human operator by way of input, may decide to continue traverse movement of the system100till the difference is within an acceptable value.

In an embodiment, instead of deploying sensors to determine the difference in values from them, one of more sensors112may be deployed, and the value(s) obtained from them may be compared against a benchmark. The system100by itself, a controlling system by itself, or a human operator by way of input, may decide to continue traverse movement of the system100till the benchmark is met. This embodiment reduces the number of sensors112used, thereby being more cost efficient. In an embodiment, based on quantum of soiling, the speed of the rotating members106is varied to perform cleaning.

In an embodiment, a control panel132is provided, which may include LED indicators134and start/stop switch136. The LED indicators134may indicate the battery level and the status of the system100. The start/stop switch may be is used to control the system100.

The processes described above is described as a sequence of steps. This was done solely for the sake of illustration. Accordingly, it is contemplated that some steps may be added, some steps may be omitted, the order of the steps may be re-arranged, or some steps may be performed simultaneously.

Although embodiments have been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader spirit and scope of the system and method described herein. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense.

Many alterations and modifications of the present invention will no doubt become apparent to a person of ordinary skill in the art after having read the foregoing description. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. It is to be understood that the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the personally preferred embodiments of this invention.