Waterless cleaning system and method for solar trackers using an autonomous robot

• US 10,797,636 B2
• Filed: 07/26/2019
• Issued: 10/06/2020
• Est. Priority Date: 01/26/2017
• Status: Active Grant

• Current Assignee: Evermore United S.A.
• Original Assignee: Evermore United S.A.
• Inventors: Meller, Moshe, Meller, Eran
• Primary Examiner(s): Redding, David
• Application Number:
  US16/523,564
• Publication Number:
  US 20200021239A1
• Time in Patent Office: 438 Days
• CPC Class Codes: B08B 1/165 Scrapers
• CPC Class Codes: B08B 1/30 by movement of cleaning members over a surface
• CPC Class Codes: B08B 1/32 using rotary cleaning members
• CPC Class Codes: F24S 2030/136 for moving several solar collectors by common transmission elements
• CPC Class Codes: F24S 30/425 Horizontal axis
• CPC Class Codes: F24S 40/20 Cleaning; Removing snow
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 3/7861 Solar tracking systems
• CPC Class Codes: G01W 1/02 Instruments for indicating weather conditions by measuring two or more variables, e.g. humidity, pressure, temperature, cloud cover or wind speed G01W1/10 takes precedence
• CPC Class Codes: G05D 1/0219 ensuring the processing of the whole working surface
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/027 comprising intertial navigation means, e.g. azimuth detector inertial navigation G01C21/16; inertial navigation combined with non-inertial navigation instruments G01C21/165
• CPC Class Codes: G05D 1/0282 generated in a local control room
• CPC Class Codes: H02S 20/32 specially adapted for solar tracking
• CPC Class Codes: H02S 40/10 Cleaning arrangements
• CPC Class Codes: H02S 40/36 characterised by special electrical interconnection means between two or more PV modules, e.g. electrical module-to-module connection
• CPC Class Codes: H02S 40/38 Energy storage means, e.g. batteries, structurally associated with PV modules
• CPC Class Codes: Y02E 10/47 Mountings or tracking
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin

Abstract

A solar tracker waterless cleaning system for cleaning solar panels of a solar tracker being able to be positioned at a pre-determined angle, including a docking station and an autonomous robotic cleaner (ARC), the docking station coupled with an edge of the solar tracker, the ARC including at least one rechargeable power source, at least one cleaning cylinder and a controller, the cleaning cylinder including a plurality of fins which rotates for generating a directional air flow for pushing dirt off of the surface of the solar tracker without water, the controller including a motion sensor for determining an angle of the solar tracker and a heading of the ARC, the docking station including at least one electrical connector for recharging the rechargeable power source, the controller for controlling a cleaning process of the ARC and for transmitting and receiving signals to and from the ARC.

Claims

1. A solar tracker waterless cleaning system for cleaning solar panels of a solar tracker, said solar tracker being able to be positioned at a pre-determined angle, said solar tracker waterless cleaning system comprising:

a docking station, coupled with an edge of said solar tracker; and

an autonomous robotic cleaner (ARC) capable of omnidirectional travel independent of the docking station,

said ARC comprising;

at least one rechargeable power source;

at least one cleaning cylinder, for cleaning dirt off of a surface of said solar tracker without water; and

a controller, for controlling a cleaning process of said ARC and for transmitting and receiving signals to and from said ARC,

said controller comprising a motion sensor, for determining an angle of said solar tracker and a heading of said ARC;

said at least one cleaning cylinder further comprising a plurality of fins which rotates and exerts a pressure of less than 0.1 g/cm2 on said surface of said solar tracker for generating a directional air flow for pushing said dirt off of said surface of said solar tracker;

said docking station comprising at least one electrical connector for recharging said rechargeable power source,

wherein said ARC can anchor in said docking station;

wherein said ARC cleans said solar tracker when said solar tracker is positioned at said pre-determined angle;

wherein said pre-determined angle is determined from a horizontal angle of zero degrees;

wherein said motion sensor is used for navigating said ARC over said surface of said solar tracker;

wherein said plurality of fins touches said surface of said solar tracker when said plurality of fins rotates; and

wherein said ARC cleans said solar tracker by said directional air flow and said touch of said plurality of fins pushing said dirt off of said surface of said solar tracker while said motion sensor navigates said ARC autonomously over said surface of said solar tracker.

2. The solar tracker waterless cleaning system according to claim 1, said solar tracker comprising:

a first section of solar panels;

a second section of solar panels;

a bridge, for coupling said first section to said second section; and

a recharging section of solar panels.

3. The solar tracker waterless cleaning system according to claim 2, said docking station further comprising a conductive wire, for coupling said at least one electrical connector with said recharging section of solar panels, wherein electricity generated by said recharging section of solar panels is used for recharging said rechargeable power source.

4. The solar tracker waterless cleaning system according to claim 1, wherein said motion sensor comprises at least one sensor selected from the list consisting of:

an accelerometer;

an electronic gyroscope; and

a magnetometer.

5. The solar tracker waterless cleaning system according to claim 1, said docking station further comprising a plurality of anchoring elements, each one of said plurality of anchoring elements comprising:

a plurality of supporting elements;

at least one conductive bar, coupled between at least two of said plurality of supporting elements;

and

a physical barrier, positioned on a north side of said docking station, for preventing said ARC from falling from said docking station,

wherein said at least one conductive bar is said at least one electrical connector,

wherein said at least one conductive bar also anchors said ARC;

wherein said plurality of supporting elements are rigidly coupled with a docking surface of said docking station; and

wherein at least one of said physical barrier and said at least one conductive bar is used for calibrating said motion sensor to a local north of said solar tracker.

6. The solar tracker waterless cleaning system according to claim 1, said ARC further comprising:

at least two drive wheels;

at least two respective direct current (DC) drive motors, for respectively driving each of said at least two drive wheels;

at least two respective drive belts, for coupling each of said at least two drive wheels to said at least two respective DC drive motors;

a support structure, for supporting a rear section of said ARC;

at least one edge sensor, for determining an edge of said solar tracker; and

at least two recharge connectors, coupled with said rechargeable power source, for electrically coupling said rechargeable power source with said at least one electrical connector of said docking station,

wherein each one of said at least two drive wheels comprises at least one respective encoder.

7. The solar tracker waterless cleaning system according to claim 1, said ARC further comprising:

at least one cleaning cylinder direct current (DC) drive motor, for driving said at least one cleaning cylinder;

a cleaning cylinder drive belt, for coupling said at least one cleaning cylinder DC drive motor with said at least one cleaning cylinder; and

an angular flat element,

wherein said angular flat element directs said directional air flow generated by said plurality of fins forward.

8. The solar tracker waterless cleaning system according to claim 1, wherein said plurality of fins is fabricated from a material selected from the list consisting of:

microfiber;

fabric;

textile; and

cloth materials.

9. The solar tracker waterless cleaning system according to claim 1, wherein said rechargeable power source is a rechargeable battery selected from the list consisting of:

a Ni-MH battery;

a lead acid battery;

a lithium ion battery;

a LiFePO4 battery; and

a NiCad battery.

10. The solar tracker waterless cleaning system according to claim 1, said controller further comprising:

a processor; and

a transmitter-receiver.

11. The solar tracker waterless cleaning system according to claim 1, wherein said pre-determined angle is substantially zero degrees from said horizontal angle.

12. The solar tracker waterless cleaning system according to claim 6, wherein said at least one edge sensor is selected from the list consisting of:

a proximity sensor;

an ultrasonic proximity sensor;

an IR sensor; and

a capacitance sensor.

13. The solar tracker waterless cleaning system according to claim 1, wherein said ARC pushes said dirt off of said surface of said solar tracker using a pre-defined path.

14. The solar tracker waterless cleaning system according to claim 13, wherein said pre-defined path is selected from the list consisting of:

a zigzag path;

a scanning path; and

a sweeping path.

15. The solar tracker waterless cleaning system according to claim 1, wherein said motion sensor is calibrated to a local north along a physical barrier in said docking station before a start of said cleaning process.

16. The solar tracker waterless cleaning system according to claim 1, wherein said directional air flow minimizes a pressure exerted on an anti-reflective coating covering said solar panels.

17. The solar tracker waterless cleaning system according to claim 1, for cleaning said solar panels of said solar tracker under varying wind conditions, said solar tracker waterless cleaning system further comprising a master controller, for receiving and transmitting data to and from said solar tracker and said ARC, said docking station further comprising a plurality of locking bars, coupled with said docking station, for protecting said ARC during said varying wind conditions, wherein said master controller determines an average wind speed and provides a clean command to said ARC if said average wind speed is below a predetermined threshold.

18. The solar tracker waterless cleaning system according to claim 17, said docking station further comprising:

a plurality of anchoring elements, each one of said plurality of anchoring elements comprising;

a plurality of supporting elements; and

at least one conductive bar, coupled between at least two of said plurality of supporting elements; and

at least two physical barriers, a first one of said at least two physical barriers positioned on a north side of said docking station and a second one of said at least two physical barriers positioned on a south side of said docking station, for preventing said ARC from falling off of said docking station,

wherein said at least one conductive bar is said at least one electrical connector;

wherein said at least one conductive bar also anchors said ARC; and

wherein said plurality of supporting elements are rigidly coupled with a docking surface of said docking station.

19. The solar tracker waterless cleaning system according to claim 17, wherein said plurality of locking bars is made from a material selected from the list consisting of:

metal;

hard plastic; and

fiberglass.

20. The solar tracker waterless cleaning system according to claim 17, wherein said master controller is coupled with a weather information center via a network.

21. The solar tracker waterless cleaning system according to claim 17, wherein said master controller is coupled with at least one weather instrument for locally determining the weather at a location of said solar tracker.

22. The solar tracker waterless cleaning system according to claim 21, wherein said at least one weather instrument is selected from the list consisting of:

a thermometer;

a hygrometer;

a barometer; and

an anemometer.

23. The solar tracker waterless cleaning system according to claim 17, wherein said master controller further determines a wind direction and wherein said master controller provides a command to said solar tracker to position itself at a tilt angle according to said determined average wind speed and said determined wind direction, said tilt angle compensating for a wind force of said determined average wind speed and said determined wind direction.

24. The solar tracker waterless cleaning system according to claim 17, wherein said master controller further determines a wind direction, and wherein said master controller provides a command to said ARC to clean said solar panels in a sweeping pattern perpendicular to said determined wind direction and advancing in said determined wind direction.

25. The solar tracker waterless cleaning system according to claim 17, wherein said master controller receives weather information and aggregates said weather information along with said data to improve predictive maintenance of said solar tracker.

26. The solar tracker waterless cleaning system according to claim 17, wherein said aggregation enables machine learning of a maintenance cycle of said solar tracker.

37. The solar tracker waterless cleaning system according to claim 1, wherein in said docking station, said at least one rechargeable power source remains coupled with said at least one electrical connector while said solar tracker changes angles.

27. Method for waterlessly cleaning a solar tracker comprising at least one autonomous robotic cleaner (ARC) capable of omnidirectional travel which cleans without water, said ARC comprising a motion sensor for navigation, said solar tracker being able to be positioned at a pre-determined angle, comprising the procedures of:

positioning said solar tracker at said pre-determined angle during nighttime hours, wherein said pre-determined angle is determined from a horizontal angle of zero degrees;

calibrating said motion sensor to a local north relative to said solar tracker;

providing a start clean signal to said ARC to clean a surface of said solar tracker; and

cleaning said solar tracker by using a directional air flow to push dirt off of said surface of said solar tracker,

wherein said ARC navigates autonomously over said surface of said solar tracker using said motion sensor.

28. The method for waterlessly cleaning according to claim 27, wherein said pre-determined angle is substantially zero degrees from said horizontal angle.

29. The method for waterlessly cleaning according to claim 27, said solar tracker further comprising a docking station with a plurality of anchoring elements, further comprising the procedure of providing a return to docking station signal to said ARC when inclement weather is detected.

30. The method for waterlessly cleaning according to claim 27, wherein said procedure of cleaning said solar tracker comprises the sub-procedure of pushing said dirt off of said surface of said solar tracker using a pre-defined path.

31. The method for waterlessly cleaning according to claim 30, wherein said pre-defined path is selected from the list consisting of:

a zigzag path;

a scanning path; and

a sweeping path.

32. The method for waterlessly cleaning according to claim 27, wherein said procedure of cleaning said solar tracker using said directional air flow minimizes a pressure exerted on an anti-reflective coating covering solar panels of said solar tracker.

33. The method for waterlessly cleaning according to claim 27, said solar tracker being under varying wind conditions, further comprising the procedure of determining an average wind speed and wind direction over said solar tracker before said procedure of calibrating,

wherein said procedure of providing said start clean signal comprises the sub-procedure of providing said start clean signal to said ARC if said determined average wind speed is below a pre-determined wind threshold;

and

wherein said ARC cleans said surface using a sweeping pattern perpendicular to said determined wind direction and advancing in said determined wind direction.

34. The method for waterlessly cleaning according to claim 33, further comprising the procedures of:

determining a solar tracker tilt angle for compensating for a wind force of said determined average wind speed and said determined wind direction; and

positioning said solar tracker at said compensating tilt angle before said sub-procedure of providing said start clean signal.

35. The method for waterlessly cleaning according to claim 33, further comprising the procedures of:

aggregating weather information at a location of said solar tracker with data related to an operation of said ARC to improve predictive maintenance of said solar tracker; and

aggregating said weather information and said data for enabling machine learning of a maintenance cycle of said solar tracker.

36. A fixed angle solar table waterless cleaning system for cleaning solar panels of a solar table, said solar table being fixed at a pre-determined angle, said solar table waterless cleaning system comprising:

a docking station, coupled with an edge of said solar table; and

an autonomous robotic cleaner (ARC) capable of omnidirectional travel independent of the docking station,

said ARC comprising;

at least one rechargeable power source;

at least one cleaning cylinder, for cleaning dirt off of a surface of said solar table without water; and

a controller, for controlling a cleaning process of said ARC and for transmitting and receiving signals to and from said ARC,

said controller comprising a motion sensor, for determining a heading of said ARC;

said at least one cleaning cylinder further comprising a plurality of fins which rotates for generating a directional air flow for pushing said dirt off of said surface of said solar table;

said docking station comprising at least one electrical connector for recharging said rechargeable power source,

wherein said ARC can anchor in said docking station;

wherein said pre-determined angle is determined from a horizontal angle of zero degrees;

wherein said motion sensor is used for navigating said ARC autonomously over said surface of said solar table;

wherein said plurality of fins touches said surface of said solar table when said plurality of fins rotates and exerts a pressure of less than 0.1 g/cm2 on said surface of said solar tracker; and

wherein said ARC cleans said solar table by said directional air flow and said touch of said plurality of fins pushing said dirt off of said surface of said solar table.

38. A fixed angle solar table waterless cleaning system for cleaning solar panels of at least one solar table, said at least one solar table being fixed at a pre-determined angle, said solar table waterless cleaning system comprising:

a docking station, coupled with an edge of said at least one solar table; and

an autonomous robotic cleaner (ARC) capable of omnidirectional travel independent of the docking station,

said ARC comprising;

at least one rechargeable power source;

at least one cleaning cylinder, for cleaning dirt off of a surface of said at least one solar table without water; and

a controller, for controlling a cleaning process of said ARC and for transmitting and receiving signals to and from said ARC,

said at least one cleaning cylinder further comprising a plurality of fins which rotates for generating a directional air flow for pushing said dirt off of said surface of said at least one solar table;

said docking station comprising at least one electrical connector for recharging said rechargeable power source,

wherein said ARC can anchor in said docking station;

wherein said plurality of fins touches said surface of said at least one solar table when said plurality of fins rotates and exerts a pressure of less than 0.1 g/cm2 on said surface of said tracker; and

wherein said ARC cleans said at least one solar table by said directional air flow and said touch of said plurality of fins pushing said dirt off of said surface of said at least one solar table.

39. The fixed angle solar table waterless cleaning system according to claim 38, wherein said ARC pushes said dirt off of said surface of said at least one solar table using a pre-defined path.

40. The fixed angle solar table waterless cleaning system according to claim 39, wherein said pre-defined path is determined according to at least one parameter of the weather present at said solar panels of said at least one solar table.

41. Method for waterlessly cleaning at least one fixed angle solar table comprising at least one autonomous robotic cleaner (ARC) capable of omnidirectinal travel, which cleans without water, said at least one solar table being fixed at a pre-determined angle, comprising the procedures of:

providing a start clean signal to said ARC to clean a surface of said at least one solar table; and

cleaning said at least one solar table by using a directional air flow to push dirt off of said surface of said at least one solar table,

wherein said ARC comprises at least one cleaning cylinder comprising a plurality of fins which rotates for generating said directional air flow for pushing said dirt off of said surface of said at least one solar table; and

wherein said plurality of fins exerts a pressure of less than 0.1 g/cm2 on said surface of said at least one solar table.

42. The method for waterlessly cleaning according to claim 41, wherein said procedure of cleaning said at least one solar table comprises the sub-procedure of pushing said dirt off of said surface of said at least one solar table using a pre-defined path.

43. A solar tracker waterless cleaning system for cleaning solar panels of a solar tracker, said solar tracker being able to be positioned at a pre-determined angle, said solar tracker waterless cleaning system comprising:

a docking station, coupled with an edge of said solar tracker; and

an autonomous robotic cleaner (ARC) capable of omnidirectional travel independent of the docking station,

said ARC comprising;

at least one rechargeable power source;

at least one cleaning cylinder, for cleaning dirt off of a surface of said solar tracker without water; and

a controller, for controlling a cleaning process of said ARC and for transmitting and receiving signals to and from said ARC,

said at least one cleaning cylinder further comprising a plurality of fins which rotates for generating a directional air flow for pushing said dirt off of said surface of said solar tracker;

said docking station comprising at least one electrical connector for recharging said rechargeable power source, wherein said ARC can anchor in said docking station;

wherein said plurality of fins touches said surface of said solar tracker when said plurality of fins rotates and exerts a pressure of less than 0.1 g/cm2 on said surface of said solar tracker; and

wherein said ARC cleans said solar tracker by said directional air flow and said touch of said plurality of fins pushing said dirt off of said surface of said solar tracker.

44. The solar tracker waterless cleaning system according to claim 43, wherein said ARC pushes said dirt off of said surface of said solar tracker using a pre-defined path.

45. The solar tracker waterless cleaning system according to claim 44, wherein said pre-defined path is determined according to at least one parameter of the weather present at said solar panels of said solar tracker.

46. Method for waterlessly cleaning a solar tracker comprising at least one autonomous robotic cleaner (ARC) capable of omnidirectional travel which cleans without water, said solar tracker being able to be positioned at a pre-determined angle, comprising the procedures of:

positioning said solar tracker at said pre-determined angle, wherein said pre-determined angle is determined relative to a horizontal angle of zero degrees;

providing a start clean signal to said ARC to clean a surface of said solar tracker; and

cleaning said solar tracker by using a directional air flow to push dirt off of said surface of said solar tracker,

wherein said ARC comprises at least one cleaning cylinder comprising a plurality of fins which rotates for generating said directional air flow for pushing said dirt off of said surface of said at least one solar tracker; and

wherein said plurality of fins exerts a pressure of less than 0.1 g/cm2 on said surface of said at least one solar tracker.

47. The method for waterlessly cleaning according to claim 46, wherein said procedure of cleaning said solar tracker comprises the sub-procedure of pushing said dirt off of said surface of said solar tracker using a pre-defined path.