Automatic solar panel cleaning device with rotating brush

Abstract

Automatic solar panel cleaning device with rotating brush An automated system (1) for cleaning solar panels (2) comprises an upper frame body (3), lower frame body (4), conductive rails (5, 6), and a motorized cleaning head (7). The frame bodies include driving and driven wheels (31, 32, 41, 42) positioned at the upper and lower edges of a solar panel, enabling efficient horizontal locomotion across the panel surface. Dual conductive rails attach to the frame bodies and maintain an electrical potential difference to each other. The cleaning head electrically connects to these rails for power supply and features motorized wheels (71, 72) enabling vertical travel movement along the panel. Current flow reversal through the rails provides directional control of the cleaning head movement. The cleaning head incorporates a motorized rotating brush system mounted on an adaptive suspension mechanism that compensates for surface irregularities, maintaining consistent optimal contact pressure with the solar panel surface throughout the operation.

Description

[0001] Title: Automatic solar panel cleaning device with rotating brush

[0002] Technical field

[0003] The invention relates to the field of automatic cleaning devices. In particular, it concerns motorized devices for automatic cleaning of solar panels.

[0004] Abstract

[0005] A system for cleaning solar panels is disclosed, comprising an upper frame body a lower frame body, a first rail, a second rail and a cleaning head. The upper and lower frame bodies include driving and driven wheels that abut onto the upper and lower edges of a solar panel to facilitate locomotion against the horizontal direction. The first and second rails attach to the upper and lower frame bodies and have an electrical potential difference to each other. The cleaning head includes motorized wheels and means to electrically connect to the first and second rail to power said motorized wheels, enabling it to travel against the vertical direction. The current flow through the rails and cleaning head can be reversed to change the direction of travel of the cleaning head. The cleaning head also includes a motorized rotating brush on a suspension system that compensates for differences in the distance between the cleaning head and the solar panel’s top surface.

[0006] Background of the invention

[0007] The rapid advancement of solar energy technologies has significantly increased the reliance on photovoltaic (PV) systems for sustainable power generation. Solar panels are found on the ground or roofs in both commercial and residential settings and are typically installed in rows and at an inclination to maximize performance. However, the efficiency of solar panels can be substantially reduced due to the accumulation of dust, debris, and other contaminants that obstruct sunlight. Regular cleaning is essential to maintain optimal performance, however manual cleaning methods are labor-intensive and costly, can pose the risk of injury when working at heights and the efficacy can be inconsistent as it is dependent on the individual worker’s performance.

[0008] Most automated cleaning systems use a cleaning platform that moves along the panels, requiring costly infrastructure such as an external superstructure or rails for mounting and locomotingthe cleaning platform.

[0009] In addition, systems that require a constant supply of water or an electrical connection are difficult and time consumingto install since they require that electrical and plumbing connections are made.

[0010] The use of flexible hoses and electrical power cables also creates multiple technical challenges. There is a risk of entanglement with elements on the roof such as chimneys, antennas, the moving platform or the solar panels. There is also the risk of damage to the flexible hoses or electrical power cables as they bend and scrape on surfaces regularly, posing a leak or electrocution risk and requiring regular replacement.

[0011] Finally, solar panel cleaning systems using brushes suffer from inconsistent contact pressure and variable power consumption as the distance between the rotating brush and the solar panel’s surface varies due to brush wear and dynamic and stating loading on the solar panels and cleaning system causing deformations.

[0012] There is a need for a solar panel cleaning system which is largely autonomous, eliminating the need for a superstructure, water supply or electrical power cables. In addition, for cleaning systems utilizing brushes there is a need for maintaining consistent brush pressure on the solar panel’s surface.

[0013] Summary of the invention

[0014] The solar panel cleaning system described in the present invention comprises of a frame that mounts directly onto a solar panel row and moves between panels. The frame comprises a top and bottom frame bodies that incorporate wheels allowing mounting onto the top and bottom edges of the solar panel row and a motor that rotates at least one of said wheels to move the frame along the width of the row of solar panels. The wheel dimensions and positioning are optimized to allow transversing the gaps between the solar panels. A battery and a small solar panel are attached onto the top frame to provide energy to the system without the need for an external power source. The frame also comprises two electrically conductive rails, attached between the top and bottom frames. A cleaning head with a rotating brush is mounted onto the rails and can move along the length of the solar panels. The rails conduct electricity to the cleaning head through the use of carbon brushes. As power transmission between the frame and the cleaning head utilizes elements of the frame, the need for exposed or moving wires is eliminated.

[0015] The cleaning head comprises a rotating brush mounted on a suspension system for consistent pressure on the solar panel and a wheel arrangement that allows to utilize the solar panel’s frame for locomotion without the need for additional rails or other superstructure.

[0016] This solution is distinguished by its autonomy, lowcost, lightweight construction and low maintenance to ensure uninterrupted and efficient solar energy production, offering an attractive return on investment (ROI) for solar power installations.

[0017] Brief description of figures

[0018] FIG. 1 : shows the solar panel cleaning system installed on a row of inclined solar panels.

[0019] FIG. 2: shows a trimetric view of the system with the solar panels omitted.

[0020] FIG. 3: shows a trimetric view of the frame, without the cleaning head.

[0021] FIG. 4: shows a trimetric view of the upper frame body from above.

[0022] FIG. 5: shows a trimetric view of the upper frame body from below.

[0023] FIG. 6: shows a side sectioned, orthographic view of the system on inclined solar panels.

[0024] FIG. 7: shows a magnified section of the upper frame body region encircled in FIG. 6.

[0025] FIG. 8: shows a side sectioned, orthographic view of the system on inclined solar panels.

[0026] FIG. 9: shows a magnified section of the lower frame body region encircled in FIG. 8.

[0027] FIG. 10: shows a trimetric view of the cleaning head.

[0028] FIG. 11 : shows a side sectioned, orthographic view of the system on inclined solar panels

[0029] FIG. 12: shows a magnified section of the cleaning head region encircled in FIG. 8.

[0030] Fig. 13: shows a front sectioned, orthographic view of the system on solar panels.

[0031] FIG. 14: shows a magnified section of the cleaning head region encircled in FIG. 13.

[0032] FIG. 15: shows the motorized brush suspension system.

[0033] Fig. 16: shows an orthographic plan view of the system installed on a row of solar panels.

[0034] FIG. 17: shows the circuit diagram of the system during the downward motion.

[0035] FIG. 18: shows the circuit diagram of the system during the upward motion.

[0036] FIG. 19: shows the path the cleaning head follows during a cleaning cycle.

[0037] FIG. 20: shows the system adapted for a solar panel installation with two rows.

[0038] FIG. 21 : shows the system adapted for solar panel rows with gaps.

[0039] Detailed description of the invention

[0040] The present invention concerns a solar panel cleaning system (1 ) suitable for solar panels (2) disposed in rows of any length, as illustrated in FIG. 1 . The system requires no permanent structures in place such as rails, mounts, water lines or electrical power lines.

[0041] Referringto FIG. 2 and FIG. 3, the solar panel cleaning system (1 ) is discussed in greater detail below. The solar panel cleaning system (1) comprises a frame (10) and a cleaning head assembly (7).

[0042] The frame as shown in FIG. 3 comprises an upper frame body (3), a lower frame body (4), a first rail (5) and a second rail (6).

[0043] The upper frame body (3) as illustrated in FIG. 4 includes at least one drive wheel (31) and at least one trailer wheel (32) that, as shown in FIG. 7, abut onto the upper side (22) of the upper lateral frame (21 ) of a solar panel (2) to facilitate locomotion against the horizontal direction (14). The upper frame body (3) also comprises at least one and preferably at least two roller wheels (33, 34, 35), illustrated in FIG. 5, that abut onto the lower side (23) of the upper lateral frame (21 ) of a solar panel (2).

[0044] The lower frame body (4) as illustrated in FIG. 9 includes at least one drive wheel (41 ) and at least one trailer wheel (42, not visible in the section view) that abuts onto the upper side (25) of the lower lateral frame (24) of a solar panel (2) to facilitate locomotion against the horizontal direction (14). The lower frame body (4) also comprises at least one and preferably at least two roller wheels (43, 44, 45) that abut or almost abut onto the lower side (26) of the lower lateral frame (24) of a solar panel (2).

[0045] As illustrated in shown in FIG. 5 and also in the schematics of FIG. 17 and FIG. 18, the first rail (5) and second rail (6) are attached to the upper frame body (3) and lower frame body (4) with electrically insulating material (51 , 61 ) in-between, and an electrical potential difference can be maintained between the first rail (5) and second rail (6).

[0046] The cleaning head assembly (7) includes at least one and preferably two motorized wheels (71 , 72) as shown in FIG. 12, and at least one pair of sliding electrical connectors (52, 62) that contact to the first rail (5) and second rail (6) respectively, conducting electrical power to the motorized wheels (71 , 72) to enable movement in the vertical direction (13). The sliding electrical conductors (52, 62), shown in FIG. 14, can comprise carbon brushes, copper brushes, collector shoes or other means familiar to a person having ordinary skill in the art.

[0047] FIG. 12 illustrates that the cleaning head assembly (7) further incorporates at least one and preferably at least two rollers (73, 74) biased by springs (75). Rollers (73, 74) are thus pressed against the lower side (53) of at least one and preferably both rails (5, 6) to enhance the traction on the motorized wheels (71 , 72).

[0048] The cleaning head assembly (7) features a motorized rotating brush (76) mounted on a suspension system designed to compensate for variations in the distance between the cleaning head assembly (7) and the top surface (20) of the solar panel (2), which may result from deflection of the rails (5, 6) or the solar panel (2) due to weight, wind load or other forces. As illustrated in FIG. 10 and FIG. 15, the suspension system comprises two brush mounts (77) onto which the motorized brush attaches. The brush mounts (77) can rotate within a limited range and independent to each other. Tension springs (78) attach to the mounts (77) to bias the motorized bush (76) towards the solar panel (2) to ensure consistent contact of the motorized brush (76) with the solar panel (6). The limited range of allowable rotation of the mounts (77) restricts the motorized brushes' (76) bristles from being overly compressed upon the solar panel (2), reducing the overall rotational resistance and thus the required torque and electrical power of the motorized brush (76).

[0049] During the upwards vertical movement of the cleaning head assembly (7) as indicated by arrow (13) of FIG. 2, current flows from the battery (37) to the first rail (5), then to the first sliding electrical connector (52), through the motorized wheels (71 , 72), then the second sliding electrical connector (62) and finally through the second rail (6) to return to the battery (37). The dashed arrow lines in FIG. 18 illustrate the current path. During this movement, the motorized brush (76) does not rotate. Since both the motorized wheels (71 , 72) and the motorized brush (76) are electrically parallelly connected to the rails (5, 6), this can be achieved by an electrical diode placed on the motorized brush circuit or other means familiar to a person having ordinary skill in the art.

[0050] At the upper end of its travel along the vertical direction (13), the upper frame body (3) contacts the cleaning head assembly (7), restrictingfurther movement. The restriction of movement in combination with the tractive force of motorized wheels (71 , 72) enhanced by the rollers (73, 74) results in a measurable spike in electrical current flow to the electrical motor of the motorized wheels (71 , 72). This spike in the electrical current is detected via an electronic circuit (38) which triggers an inversion of the electrical current along rails (5, 6) according to the programmed algorithm of the system, to initiate the downwards vertical movement of the cleaning head assembly (7).

[0051] During the downwards vertical movement of the cleaning head assembly (7) as indicated by arrow (12) of FIG. 2, the motorized brush (76) rotates in the direction indicated by arrow (19), which is opposite to the rotation of the motorized wheels (71 , 72), thus displacing any dust and debris from the solar panel’s top surface (20) towards the lower fame body (4). This simultaneous vertical movement of the cleaning head assembly (7) and rotation of the motorized brush (76) constitutes the cleaning action, which cleans a rectangular area (16) as long as the length of the solar panel (27) and as wide as the width (79) of the motorized brush (76). The dashed arrow lines in FIG. 17 illustrate the path electrical current takes during the downwards vertical movement.

[0052] At the lower end of its travel along the vertical direction (12), the lower frame body (4) contacts the cleaning head assembly (7), restrictingfurther movement. The restriction of movement in combination with the tractive force of motorized wheels (71 , 72) enhanced by the rollers (73, 74) results in a measurable spike in electrical current flow to the motorized wheels (71 , 72). This spike in the electrical current is detected via an electronic circuit (38) and triggers an interruption of the electrical current along rails (5, 6) according to the programmed algorithm of the system, to initiate the sideways step movement of the frame (10).

[0053] During the sideways step movement of the frame (10), a motor (36) rotates the at least one drive wheel (31 ) to move the frame by a preset distance (18) in the direction indicated by arrow (14) in FIG. 4 to position the frame (10) further along the panel’s row for the next cleaning action to occur. The preset distance (18) is defined to be smaller than the width (79) of the motorized brush (76), so that the area (16) of each cleaning action, illustrated by dashed line, partly overlaps with the area to be cleaned by the following cleaning action (17), illustrated by dotted line.

[0054] A first set of end stops (28) is installed at the outer corners of the row of solar panels. At the last sideways step movement of the frame (10), the end stops (28) contact the upper and lower frames (3, 4), restricting further movement. The restriction of movement in combination with the tractive force of drive wheels (31) results in a measurable spike in electrical current flow to the drive wheels motor (36). This spike in the electrical current is detected via an electronic circuit (38) and triggers the programmed parking action of the system.

[0055] During the parking action of the system, the cleaning head (7) performs one last cleaning action and then the current on the rails (5, 6) is interrupted. Then, the electrical current to the drive wheels motor (36) is reversed, so that the frame (10) moves sideways in the opposite direction (15) of the sideways step movements, until it reaches and contacts a second set of end stops (29) which restrict further movement. The restriction of movement in combination with the tractive force of drive wheels (31 ) results in a measurable spike in electrical current flow to the drive wheels motor (36). This spike in the electrical current is detected via an electronic circuit (38) and triggers the standby mode, where the device remains idle until the next cleaning cycle is initiated.

[0056] FIG. 19 illustrates the cleaning head (7) follows during a cleaning cycle. Arrows in continuous line (91) refer to a cleaning action, where the motorized brush (76) is in operation while the cleaning head (7) moves along the solar panel (2). Arrows in dashed line (92) illustrate the movements of the cleaning head (7) where the motorized brush (76) is not in operation. The long-dashed line (93) illustrates the path the cleaning head (7) takes duringthe parking action.

[0057] In one embodiment of the solar panel cleaning system (1 ), the rails (5,6) can be long enough to mount the frame (10) over two rows of solar panels (2), as illustrated in FIG. 20.

[0058] In another embodiment of the solar panel cleaning system (1 ), rails (1 ’) may substitute a missing solar panel to facilitate movement along an interrupted row of solar panels (2), as illustrated in FIG. 21 .

[0059] Other embodiments that utilize the principles as described in figures 1 to 21 are possible, and figures 1 to 21 should be viewed as examples of the principles embodied.

Claims

CLAIMS1 . An automatic cleaning system (1 ) for cleaning a row of photovoltaic panels (2), said automatic cleaning system comprising:• a frame (10) that mounts directly onto a row of solar panels (2) and moves between panels along said row of solar panels in the horizontal direction, said frame comprises a top frame (3) and bottom frame (4) bodies that each of which comprise wheels (31 ,32, 41 ,42) for enabling mounting onto the top and the bottom edges of the solar panel row and allowing movement, and a motor that rotates at least one of said wheels to move the frame (10) along the width of the row of solar panels (2), said frame further comprises a first rail (5) and a second rail (6), said first and second rails connect said top frame body (3) and said bottom frame body (4), to form a rectangular structure;• a cleaning head (7) assembly, said cleaning head assembly (7) is mounted onto the rails (5,6) and moves along the length of the solar panels, and wherein said cleaning head (7) comprises a rotating brush (76), and a wheel arrangement (71 ,72) that enables movement of said cleaning head along said frame, in the vertical direction, said automatic cleaning system characterised in that said first and second rails (5,6) are electrically conductive rails, attached between the top and bottom frames, wherein said rails conduct electricity to the cleaning head to provide power for the operation of the cleaning head (7).

2. An automatic cleaning system according to claim 1 , further comprising an energy supply system, said energy supply system comprising a battery and a small solar panel, wherein said energy supply system is attached onto the top frame to provide energy to the system without the need for an external power source.

3. An automatic cleaning system according to claim 1 , wherein said frame (10) mounts directly onto a solar panel row and moves between photovoltaic panels and wherein said frame (10) comprises a first rail (5) and a second rail (6), an upper frame body (3), and a lower frame body (4), and wherein said upper frame body (3) comprises at least one drive wheel (31 ) and wherein said at least one driver wheel (31 ) abut onto the upper side (22) of the upper lateral frame (21 ) of a solar panel (2) to facilitate locomotion against the horizontal direction (14), and wherein the lower frame body (4) comprises at least one drive wheel (41 ) that abuts onto the upper side (25) of the lower lateral frame (24) of a solar panel (2) to facilitate locomotion against the horizontal direction (14), and wherein at least one and preferably at least two roller wheels (43, 44, 45) abut or almost abut onto the lower side (26) of the lower lateral frame (24) of a solar panel (2).

4. An automatic cleaning system according to claim 1 , wherein said the first rail (5) and second rail (6) are attached to the upper frame body (3) and lower frame body (4) with electrically insulating material (51 , 61) in-between, and an electrical potential difference can be maintained between the first rail (5) and second rail (6).

5. An automatic cleaning system according to claim 4, wherein at least one pair of sliding electrical connectors (52, 62) contact the first rail (5) and second rail (6) respectively, conducting electrical power to the cleaning head assembly.

6. An automatic cleaning system according to claim 5, wherein said sliding electrical conductors (52, 62) comprise carbon brushes, copper brushes, collector shoes or other means familiarto a person having ordinary skill in the art.

6. An automatic cleaning system accordingto claim 1 , wherein said cleaning head assembly (7) further comprises at least one and preferably at least two rollers (73, 74) biased by springs (75), wherein said rollers (73, 74) are pressed against the lower side (53) of at least one and preferably both rails (5, 6) to enhance the traction on the motorized wheels (71 , 72).

7. An automatic cleaning system accordingto claim 1 or claim 6, wherein said cleaning head assembly (7) comprises a motorized rotating brush (76) mounted on a suspension system, said suspension system compensates for variations in the distance between the cleaning head assembly (7) and the top surface (20) of the solar panel (2), which may result from deflection of the rails (5, 6) or the solar panel (2) due to weight, wind load or other forces.

8. An automatic cleaning system according to claim 7, wherein said suspension system comprises two brush mounts (77) onto which the motorized brush attaches and wherein said brush mounts (77) rotate independent to each other, and wherein tension springs (78) attach to said mounts (77) to bias the motorized bush (76) towards the solar panel (2) and ensure consistent contact of the motorized brush (76) with the solar panel (2).

9. An automatic cleaning system according to claim 8, wherein said brush mounts (77) rotate within a limited range, said limited range of motion restricts the motorized brushes' (76) bristles from being overly compressed upon the solar panel (2) and reduces the overall rotational resistance and thus the required torque and electrical power of the motorized brush (76).

10. An automatic cleaning system accordingto claim 5, wherein during the upwards vertical movement of the cleaning head assembly (7), current flows from the battery (37) to the first rail (5), then to the first sliding electrical connector (52), through the motorized wheels (71 , 72), then the second sliding electrical connector (62) and finallythrough the second rail (6) to return to the battery (37) and wherein during this movement, the motorized brush (76) does not rotate.

11. An automatic cleaning system according to claim 10, wherein current flow is controlled by an electrical diode placed on the motorized brush circuit, enabled by the electrical structure wherein both the motorized wheels (71 , 72) and the motorized brush (76) are electrically para llelly connected to the rails (5, 6).

12. An automatic cleaning system according to any of the preceding claims, wherein as the cleaning head assembly (7) travels along the frame, at the upper end of the cleaning head assembly (7) travel along the vertical direction (13), the upper frame body (3) contacts the cleaning head assembly (7), restricting further movement and wherein the restriction of movement in combination with the tractive force of motorized wheels (71 , 72) enhanced by the rollers (73, 74) results in a measurable spike in electrical current flowto the electrical motor of the motorized wheels (71 , 72) and wherein said spike in the electrical current is detected via an electronic circuit (38) which triggers an inversion of the electrical current along rails (5, 6) according to a programmed algorithm of the system, to stop and then reverse wheel movement to initiate the downwards vertical movement of the cleaning head assembly (7).

13. An automatic cleaning system according to any of the preceding claims, wherein as the cleaning head assembly (7) travels along the frame the motorized brush (76) rotates in the direction opposite to the rotation of the motorized wheels (71 , 72), thus displacing any dust and debris from the solar panel’s top surface (20) towards the lower fame body (4) and wherein the simultaneous vertical movement of the cleaning head assembly (7) and rotation of the motorized brush (76) constitutes the cleaning action, which cleans a rectangular area (16) as long as the length of the solar panel (27) and as wide as the width (79) of the motorized brush (76).

14. An automatic cleaning system according to any of the preceding claims, wherein during the sideways step movement of the frame (10), a motor (36) rotates the at least one drive wheel (31 ) to move the frame by a preset distance (18) to position the frame (10) further along the panel’s row for the next cleaning action to occur and wherein said preset distance (18) is defined to be smaller than the width (79) of the motorized brush (76), so that the area (16) of each cleaning action, partly overlaps with the area to be cleaned by the following cleaning action (17).

15. An automatic cleaning system according to any of the preceding claims, wherein a first set of end stops (28) is installed at the outer corners of the row of solar panels and wherein at the last sideways step movement of the frame (10), the end stops (28) contact the upper and lower frames (3, 4), restricting further movement, said restriction of movement in combination with the tractive force of drive wheels (31 ) results in a measurable spike in electrical current flow to the drive wheels motor (36), wherein thisspike in the electrical current is detected via an electronic circuit (38) to trigger a programmed parking action of the system.

16. An automatic cleaning system according to claim 16, wherein during said parking action of the system, comprises a sequence wherein,• the cleaning head (7) performs one last cleaning action and then the current on the rails (5, 6) is interrupted• the electrical current to the drive wheels motor (36) is reversed• the frame (10) moves sideways in the opposite direction (15) of the sideways step movements, until it reaches and contacts a second set of end stops (29) which restrict further movement• the restriction of movement in combination with the tractive force of drive wheels (31) results in a measurable spike in electrical current flow to the drive wheels motor (36)• the spike in the electrical current is detected via an electronic circuit (38) and triggers the standby mode wherein the device remains idle until the next cleaning cycle is initiated.

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