Solar module cleaner

Abstract

A photovoltaic (PV) module cleaning system can include a robotic cleaning device and a support system. The support system can be configured to provide a metered fill to the robotic cleaning device. In some embodiments, the robotic cleaning device and include a curved cleaning head. Various techniques for deploying a robotic cleaning device on PV modules include out-and-back, leapfrog, among others.

1 . A photovoltaic (PV) module cleaning system, comprising:
 a robotic cleaning device configured to clean a plurality of PV modules; and   a support system configured to provide a first metered fill amount of liquid to a reservoir onboard the robotic cleaning device,   wherein the first metered fill amount is based on a soiling level of the plurality of PV modules.   
     
     
         2 . The PV module cleaning system of  claim 1 , wherein the support system is further configured to:
 receive an indication of an amount of liquid remaining in the onboard reservoir, wherein the indication is indicative of the soiling level; and   based on the indication, determine the first metered fill amount of liquid to provide to the onboard reservoir.   
     
     
         3 . The PV module cleaning system of  claim 1 , wherein the support system is further configured to:
 provide a second metered fill amount of liquid to the onboard reservoir, wherein the first fill amount of liquid is different than the second fill amount of liquid.   
     
     
         4 . The PV module cleaning system of  claim 1 , wherein the first metered fill amount of liquid is less than a capacity of the onboard reservoir. 
     
     
         5 . The PV module cleaning system of  claim 1 , wherein the robotic cleaning device is further configured to apply a substantially constant amount of liquid per unit area to the plurality of PV modules. 
     
     
         6 . The PV module cleaning system of  claim 5 , wherein to apply the substantially constant amount of liquid per unit area, the robotic cleaning device is configured to adjust a speed of travel along the plurality of PV modules. 
     
     
         7 . The PV module cleaning system of  claim 1 , wherein the robotic cleaning device is further configured to provide an indication of which modules of the plurality of PV modules have been cleaned. 
     
     
         8 . The PV module cleaning system of  claim 1 , wherein the robotic cleaning device is further configured to:
 travel in a first direction along a first row of the plurality of PV modules until reaching an end of the first row;   apply a cleaning head of the robotic cleaning device to modules of the first row while traveling in a second direction opposite the first direction; and   receive the first metered fill amount of liquid from the support system.   
     
     
         9 . The PV module cleaning system of  claim 8 , further comprising another robotic cleaning device, wherein the other robotic cleaning is configured to:
 travel in the first direction along a second row of the plurality of PV modules, wherein the second row is adjacent to the first row; and   apply a cleaning head of the other robotic cleaning device to modules of the second row while traveling in the second direction.   
     
     
         10 . A method for cleaning photovoltaic (PV) modules, the method comprising:
 a first robotic cleaning device traveling in a first direction along a first row of PV modules;   the first robotic cleaning device changing direction to travel in a second direction opposite the first direction; and   the first robotic cleaning device applying a first cleaning head to modules of the first row of PV modules while traveling in the second direction.   
     
     
         11 . The method of  claim 10 , further comprising:
 a second robotic cleaning device traveling in the second direction along a first row of adjacent PV modules;   the second robotic cleaning device changing directions to travel in the first direction; and   the second robotic cleaning device applying a second cleaning head to modules of the first row of adjacent PV modules while traveling in the first direction.   
     
     
         12 . The method of  claim 10 , further comprising:
 a second robotic cleaning device traveling in the first direction along a second row of PV modules, wherein the second row is adjacent to the first row;   the second robotic cleaning device traveling in the second direction along the second row;   the second robotic cleaning device applying a second cleaning head to modules of the second row; and   the first robotic cleaning device cleaning a third row of PV modules that is adjacent to the second row.   
     
     
         13 . The method of  claim 10 , further comprising:
 after cleaning the first row of PV modules, the first robotic cleaning device receiving liquid from a support system; and   the first robotic cleaning device cleaning a second row of PV modules.   
     
     
         14 . The method of  claim 10 , further comprising:
 the first robotic cleaning device providing an indication to the support system of a remaining amount of liquid in a reservoir onboard the first robotic cleaning device; and   the first robotic cleaning device receiving a fill amount of liquid from the support system, wherein the fill amount is based on the remaining amount.   
     
     
         15 . The method of  claim 10 , wherein changing direction is based on a sensor of the first robotic cleaning device sensing an end of the first row of PV modules. 
     
     
         16 . A robotic cleaning device, comprising:
 a curved cleaning head having a middle portion curved toward a front side of the robotic cleaning device relative to edge portions of the curved cleaning head; and   an actuator configured to apply the curved cleaning head to a photovoltaic (PV) module with substantially uniform pressure across a length of the curved cleaning head.   
     
     
         17 . The PV module cleaning apparatus of  claim 16 , further comprising at least one squeegee disposed in a rear portion of the curved cleaning head. 
     
     
         18 . The PV module cleaning apparatus of  claim 17 , further comprising a brush disposed in a front portion of the curved cleaning head wherein the actuator is configured to apply the brush and the at least one squeegee with substantially uniform pressure. 
     
     
         19 . The PV module cleaning apparatus of  claim 16 , wherein the actuator is configured to apply the curved cleaning head at edges of the cleaning head. 
     
     
         20 . The PV module cleaning apparatus of  claim 16 , wherein the actuator is a parallel-linkage mechanism.