U.S. patent application number 16/154617 was filed with the patent office on 2019-02-07 for systems, vehicles, and methods for maintaining rail-based arrays of photovoltaic modules.
The applicant listed for this patent is Alion Energy, Inc.. Invention is credited to Adam French, Kevin Hennessy.
Application Number | 20190044477 16/154617 |
Document ID | / |
Family ID | 52628888 |
Filed Date | 2019-02-07 |
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United States Patent
Application |
20190044477 |
Kind Code |
A1 |
French; Adam ; et
al. |
February 7, 2019 |
SYSTEMS, VEHICLES, AND METHODS FOR MAINTAINING RAIL-BASED ARRAYS OF
PHOTOVOLTAIC MODULES
Abstract
A system includes an elongated rail including support surfaces
and a mounting surface disposed between the support surfaces.
Photovoltaic modules can be coupled to the mounting surface and
raised relative to the support surfaces. A first maintenance
vehicle can include a cleaning head, actuator, motor, and support
legs. The support legs can suspend the cleaning head over the
photovoltaic modules and can be respectively movably coupled to the
support surfaces so as to laterally and sequentially move the
cleaning head parallel to the elongated rail and across each of the
photovoltaic modules responsive to actuation of the motor. At least
a portion of the cleaning head can be vertically movable between a
disengaged position spaced apart from the photovoltaic modules and
an engaged position in contact with at least one of the
photovoltaic modules responsive to actuation of the actuator.
Inventors: |
French; Adam; (San
Francisco, CA) ; Hennessy; Kevin; (Walnut Creek,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Alion Energy, Inc. |
Richmond |
CA |
US |
|
|
Family ID: |
52628888 |
Appl. No.: |
16/154617 |
Filed: |
October 8, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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14476458 |
Sep 3, 2014 |
10122319 |
|
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16154617 |
|
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61874290 |
Sep 5, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02S 40/10 20141201;
B08B 1/008 20130101; Y02E 10/40 20130101; B08B 1/04 20130101; A46B
13/02 20130101; F24S 40/20 20180501 |
International
Class: |
H02S 40/10 20060101
H02S040/10; A46B 13/02 20060101 A46B013/02; B08B 1/00 20060101
B08B001/00; B08B 1/04 20060101 B08B001/04; F24S 40/20 20060101
F24S040/20 |
Claims
1. A method for maintaining photovoltaic modules, the method
including: providing a first elongated rail including first and
second support surfaces and a first mounting surface disposed
between the first and second support surfaces, a first array of the
photovoltaic modules being coupled to the first mounting surface
and raised relative to the first and second support surfaces;
disposing a first maintenance vehicle on the first and second
support surfaces, the first maintenance vehicle including a first
cleaning head, a first actuator, a first motor, and first and
second support legs; suspending the first cleaning head over the
photovoltaic modules of the first array using the first and second
support legs, the first and second support legs being movably
coupled to the first and second support surfaces so as to laterally
and sequentially move the first cleaning head in a direction
parallel to the first elongated rail and across each of the
photovoltaic modules of the first array responsive to actuation of
the first motor; and moving at least a portion of the first
cleaning head between a disengaged position spaced apart from the
photovoltaic modules of the first array and a first engaged
position in contact with at least one of the photovoltaic modules
of the first array responsive to actuation of the first actuator,
the first and second support legs each including a joint, the first
actuator automatically increasing or decreasing an angle of the
joint such that a relative angle between the first maintenance
vehicle and each of the photovoltaic modules is adjusted according
to a tilt of that photovoltaic module.
2. The method of claim 1, the first cleaning head including a
second motor, the at least a portion of the first cleaning head
including a brush contacting at least one of the photovoltaic
modules of the first array when the first cleaning head is in the
first engaged position responsive to actuation of the first
actuator, the method further including rotating the brush along an
axis parallel to the photovoltaic modules of the first array
responsive to actuation of the second motor.
3. The method of claim 2, the first cleaning head further including
a wiper, the wiper contacting at least one photovoltaic module of
the first array when the at least a portion of the first cleaning
head is in the first engaged position, the method further including
at least partially wiping the at least one photovoltaic module of
the first array via the contact with the wiper.
4. The method of claim 1, wherein the first and second support legs
respectively are movably coupled to the first and second support
surfaces by first and second wheels that respectively contact and
rotate along the first and second support surfaces.
5. The method of claim 1, further including a second elongated rail
including third and fourth support surfaces and a second mounting
surface, a second array of the photovoltaic modules being coupled
to the second mounting surface and raised relative to the third and
fourth support surfaces.
6. The method of claim 1, wherein at least one of the first and
second support legs is adjustable so as to accommodate photovoltaic
modules at different angles than one another.
7. The method of claim 1, the first maintenance vehicle further
including a trimmer mechanism to remove vegetation.
8. A system for maintaining photovoltaic modules, the system
including: a first elongated rail including first and second
support surfaces and a first mounting surface disposed between the
first and second support surfaces, a first array of the
photovoltaic modules being coupled to the first mounting surface
and raised relative to the first and second support surfaces; and a
first maintenance vehicle disposed on the first and second support
surfaces, the first maintenance vehicle including a first cleaning
head, a first actuator, a first motor, and first and second support
legs, the first and second support legs suspending the first
cleaning head over the photovoltaic modules of the first array and
being movably coupled to the first and second support surfaces so
as to laterally and sequentially move the first cleaning head in a
direction parallel to the first elongated rail and across each of
the photovoltaic modules of the first array responsive to actuation
of the first motor, at least a portion of the first cleaning head
being movable between a disengaged position spaced apart from the
photovoltaic modules of the first array and a first engaged
position in contact with at least one of the photovoltaic modules
of the first array responsive to actuation of the first actuator,
the first and second support legs each including a joint, the first
actuator automatically increasing or decreasing an angle of the
joint such that a relative angle between the first maintenance
vehicle and each of the photovoltaic modules is adjusted according
to a tilt of that photovoltaic module.
9. The system of claim 8, the first cleaning head including a
second motor, the at least a portion of the first cleaning head
including a brush movable to contact at least one of the
photovoltaic modules of the first array in the first engaged
position responsive to actuation of the first actuator, the brush
further being rotatable along an axis parallel to the photovoltaic
modules of the first array responsive to actuation of the second
motor.
10. The system of claim 9, the first cleaning head further
including a wiper, the wiper being in contact with the at least one
photovoltaic module of the first array when the at least a portion
of the first cleaning head is in the first engaged position and
operable to at least partially wipe the at least one photovoltaic
module.
11. The system of claim 8, wherein the first and second support
legs respectively are movably coupled to the first and second
support surfaces by first and second wheels that respectively
contact and rotate along the first and second support surfaces.
12. The system of claim 8, further including a second elongated
rail including third and fourth support surfaces and a second
mounting surface, a second array of the photovoltaic modules being
coupled to the second mounting surface and raised relative to the
third and fourth support surfaces.
13. The system of claim 8, wherein at least one of the first and
second support legs is adjustable so as to accommodate photovoltaic
modules at different angles than one another.
14. The system of claim 8, the first maintenance vehicle further
including a trimmer mechanism to remove vegetation.
15. A system for maintaining photovoltaic modules, the system
including: a first elongated rail including first and second
support surfaces and a first mounting surface disposed between the
first and second support surfaces, a first array of the
photovoltaic modules being coupled to the first mounting surface;
and a first maintenance vehicle disposed on the first and second
support surfaces, the first maintenance vehicle including a first
cleaning head; at least a portion of the first cleaning head being
movable between a disengaged position spaced apart from the
photovoltaic modules of the first array and a first engaged
position in contact with at least one photovoltaic module of the
first array, the first cleaning head including: a brush; and a
wiper; the at least a portion of the first cleaning head including
the brush movable to contact the at least one photovoltaic modules
of the first array in the first engaged position, the wiper being
in contact with at least one photovoltaic module of the first array
when the at least a portion of the first cleaning head is in the
first engaged position and operable to at least partially wipe the
at least one photovoltaic module of the first array, and the at
least a portion of the first cleaning head further being movable to
a second engaged position in which the brush contacts at least one
photovoltaic module of the first array and the wiper does not
contact the first array.
16. The system of claim 15, the first maintenance vehicle including
a first motor and first and second support legs, the first and
second support legs suspending the first cleaning head over the
photovoltaic modules of the first array and being movably coupled
to the first and second support surfaces so as to laterally and
sequentially move the first cleaning head in a direction parallel
to the first elongated rail and across each of the photovoltaic
modules of the first array responsive to actuation of the first
motor.
17. The system of claim 15, the first cleaning head further
comprising a fluid reservoir, the first cleaning head being
operable to dispense fluid from the fluid reservoir onto the at
least one photovoltaic module of the first array.
18. The system of claim 15, wherein the first and second support
legs respectively are movably coupled to the first and second
support surfaces by first and second wheels that respectively
contact and rotate along the first and second support surfaces.
19. The system of claim 15, further including a second elongated
rail including third and fourth support surfaces and a second
mounting surface, a second array of the photovoltaic modules being
coupled to the second mounting surface and raised relative to the
third and fourth support surfaces.
20. The system of claim 19, further including a row-to-row
mechanism configured to move the first maintenance vehicle from the
first elongated rail to the second elongated rail.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. patent application
Ser. No. 14/476,458, filed on Sep. 3, 2014 and entitled "Systems,
Vehicles, and Methods for Maintaining Rail-Based Arrays of
Photovoltaic Modules," which, in the turn, claims priority to U.S.
Provisional Patent Application No. 61/874,290, filed on Sep. 5,
2013 and entitled "Maintenance Vehicles for Photovoltaic Modules."
The entire contents of the priority applications are incorporated
by reference herein for all purposes.
BACKGROUND
[0002] The present invention is directed to photovoltaic modules
according to certain embodiments. More particularly, some
embodiments of the invention provide systems, vehicles, and methods
for maintaining rail-based arrays of photovoltaic modules. Merely
by way of example, embodiments of the invention have been applied
to cleaning rail-based arrays of photovoltaic modules. However, it
would be recognized that the invention has a much broader range of
applicability.
[0003] Photovoltaics convert sunlight into electricity, providing a
desirable source of clean energy. FIG. 1 is a simplified diagram of
a conventional photovoltaic array. The photovoltaic array 100
includes strings 1, 2, 3, 4, . . . n, where n is a positive integer
larger than or equal to 1. Each string includes photovoltaic (PV)
modules (e.g., solar panels) that are connected in series. The
photovoltaic array 100 is connected to a central inverter 110,
which provides an alternating current (AC) connection to a power
grid 120. FIG. 2 is a simplified diagram of a conventional
photovoltaic module. The photovoltaic (PV) module 210 includes a
junction box 220 on the backside of the PV module 210.
[0004] The installation of photovoltaic arrays often presents
logistical challenges. Not only does the site for the photovoltaic
array need to be properly prepared, but large quantities of
materials also need to be transported to and within the site. For
example, the site for the photovoltaic array may have existing
vegetation that would interfere with the installation and operation
of the photovoltaic array. This vegetation usually has to be
cleared. The site may also have uneven terrain that usually
requires extensive grading and earth moving. Once the site is
prepared, it is then often necessary to build an extensive
infrastructure on which the strings of PV modules 210 are to be
affixed. The PV modules 210 are then moved into position, affixed
to the structure, and interconnected so that power can be delivered
to the power grid 120. Each of these operations can be
time-consuming and expensive.
[0005] Once the photovoltaic array is in operation, additional
infrastructure often is used to support, maintain, evaluate, and
repair the array. In order to support the operation of the
photovoltaic array, equipment and materials routinely need to be
transported from one end of the array to another. For example, the
test equipment is transported to a PV module that is under
evaluation. In another example, the cleaning equipment is
transported to remove debris and dirt from the PV module. In yet
another example, an additional module is transported as replacement
for the defective module. Depending upon the terrain, soils, and
weather, simply getting equipment and materials from one end of the
array to another often poses significant challenges, especially if
the ground is muddy. As with the installation, these operational
needs can also be time-consuming and expensive.
[0006] Hence, it is highly desirable to improve techniques for
installation and operation of photovoltaic arrays.
SUMMARY OF INVENTION
[0007] The present invention is directed to photovoltaic modules
according to certain embodiments. More particularly, some
embodiments of the invention provide systems, vehicles, and methods
for maintaining rail-based arrays of photovoltaic modules. Merely
by way of example, embodiments of the invention have been applied
to cleaning rail-based arrays of photovoltaic modules. However, it
would be recognized that the invention has a much broader range of
applicability.
[0008] According one embodiment, a system for maintaining
photovoltaic modules is provided. The system can include a first
elongated rail including first and second support surfaces and a
first mounting surface disposed between the first and second
support surfaces, a first array of the photovoltaic modules being
coupled to the first mounting surface and raised relative to the
first and second support surfaces; and a first maintenance vehicle
disposed on the first and second support surfaces, the first
maintenance vehicle including a first cleaning head, a first
actuator, a first motor, and first and second support legs. The
first and second support legs can suspend the first cleaning head
over the photovoltaic modules of the first array and can be movably
coupled to the first and second support surfaces so as to laterally
and sequentially move the first cleaning head in a direction
parallel to the first elongated rail and across each of the
photovoltaic modules of the first array responsive to actuation of
the first motor. At least a portion of the first cleaning head can
be vertically movable between a disengaged position spaced apart
from the photovoltaic modules of the first array and a first
engaged position in contact with at least one of the photovoltaic
modules of the first array responsive to actuation of the first
actuator.
[0009] According to another embodiment, a method for maintaining
photovoltaic modules is provided. The method can include providing
a first elongated rail including first and second support surfaces
and a first mounting surface disposed between the first and second
support surfaces, a first array of the photovoltaic modules being
coupled to the first mounting surface and raised relative to the
first and second support surfaces; disposing a first maintenance
vehicle on the first and second support surfaces, the first
maintenance vehicle including a first cleaning head, a first
actuator, a first motor, and first and second support legs;
suspending the first cleaning head over the photovoltaic modules of
the first array using the first and second support legs, the first
and second support legs being movably coupled to the first and
second support surfaces so as to laterally and sequentially move
the first cleaning head in a direction parallel to the first
elongated rail and across each of the photovoltaic modules of the
first array responsive to actuation of the first motor; and
vertically moving at least a portion of the first cleaning head
between a disengaged position spaced apart from the photovoltaic
modules of the first array and a first engaged position in contact
with at least one of the photovoltaic modules of the first array
responsive to actuation of the first actuator.
[0010] Depending upon the embodiment, one or more benefits may be
achieved. These benefits and various additional objects, features,
and advantages of the present invention can be fully appreciated
with reference to the detailed description and accompanying
drawings that follow.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 is a simplified diagram of a conventional
photovoltaic array.
[0012] FIG. 2 is a simplified diagram of a conventional
photovoltaic module.
[0013] FIGS. 3A-3B are simplified diagrams showing perspective
views of a maintenance system and vehicle for maintaining at least
one rail based array of photovoltaic modules, according to certain
embodiments.
[0014] FIGS. 4A-4B are simplified diagrams showing perspective
views of a cleaning head and actuator in a first position,
according to certain embodiments.
[0015] FIG. 5A-5C are simplified diagrams showing perspective views
of a cleaning head and actuator in a second position, according to
certain embodiments.
[0016] FIG. 6A is a simplified diagram showing a perspective view
of an exemplary rail-to-rail mechanism for moving a maintenance
vehicle from a first rail based array of photovoltaic modules to a
second rail based array of photovoltaic modules, according to
certain embodiments.
[0017] FIG. 6B is a simplified diagram showing a perspective view
of another exemplary rail-to-rail mechanism for moving a
maintenance vehicle from a first rail based array of photovoltaic
modules to a second rail based array of photovoltaic modules,
according to certain embodiments.
[0018] FIG. 6C is a simplified diagram showing a perspective view
of yet another exemplary rail-to-rail mechanism for moving a
maintenance vehicle from a first rail based array of photovoltaic
modules to a second rail based array of photovoltaic modules,
according to certain embodiments.
[0019] FIG. 7 illustrates steps in an exemplary method for
maintaining at least one rail based array of photovoltaic modules,
according to certain embodiments.
DETAILED DESCRIPTION
[0020] The present invention is directed to photovoltaic modules
according to certain embodiments. More particularly, some
embodiments of the invention provide systems, vehicles, and methods
for maintaining rail-based arrays of photovoltaic modules. Merely
by way of example, embodiments of the invention have been applied
to cleaning rail-based arrays of photovoltaic modules. However, it
would be recognized that the invention has a much broader range of
applicability.
[0021] Illustratively, the rail-based arrays of photovoltaic
modules with which the present systems, vehicles, and methods can
be used can, in some embodiments, include an elongated rail
including first and second support surfaces and a first mounting
surface disposed between the first and second support surfaces. An
array of the photovoltaic modules can be coupled to the first
mounting surface and raised relative to the first and second
support surfaces. Optionally, a plurality of such rails can be
provided, and a corresponding array of photovoltaic modules can be
coupled to at least one mounting surface of each such rail. For
further details on exemplary rail-based arrays of photovoltaic
modules, see commonly assigned U.S. Patent Publication Nos.
2011/0284057 and 2013/0068275, the entire contents of both of which
are incorporated by reference herein.
[0022] Under one aspect of the present invention, a maintenance
vehicle can be configured to be disposed on the first and second
support surfaces of the elongated rail. The first maintenance
vehicle can include a cleaning head, an actuator, a motor, and
first and second support legs. In certain, non-limiting
embodiments, the maintenance vehicle can be configured so as
substantially to be supported only by the first and second support
surfaces, rather than being supported by the photovoltaic modules
themselves. As such, the maintenance vehicle can be moved along the
array so as to clean the photovoltaic modules of the array, without
imposing a significant load or torque on the photovoltaic modules
themselves other than that associated with cleaning the modules,
e.g., with a rotating brush that can be lowered into contact with
the modules.
[0023] FIGS. 3A-3B are simplified diagrams showing perspective
views of a maintenance system and vehicle for maintaining at least
one rail based array of photovoltaic modules, according to certain
embodiments. These diagrams are merely an example, which should not
unduly limit the scope of the claims. One of ordinary skill in the
art would recognize many variations, alternatives, and
modifications.
[0024] System 300 illustrated in FIGS. 3A-3B includes elongated
rail 310 and maintenance vehicle 320 for maintaining photovoltaic
modules 330, such as solar panels. Elongated rail 310 can include
one or more mounting surfaces, e.g., mounting surfaces 311 and 312,
that can serve as a mechanical substrate for mounting an array of
photovoltaic modules 330. For example, as can be seen in FIG. 3B,
photovoltaic module 330 can include one or more legs 331, 332 that
couple to the one or more mounting surfaces of elongated rail 310.
For example, photovoltaic module 330 can include at least one leg
that engages a first recess defined in elongated rail 310 that
defines a first mounting surface 311, and at least one leg that
engages a second recess defined in elongated rail 310 that defines
a second mounting surface 312. Optionally, the one or more legs are
coupled to the one or more mounting surfaces using adhesive.
Illustratively, the PV modules 330 can be or can include a
glass-to-glass module. Additionally, or alternatively, the one or
more mounting surfaces of elongated rail 310 or the legs 331, 332
of photovoltaic module 330, or both, can be configured such that
the photovoltaic module is disposed at a tilt angle. For example,
the tilt angle varies depending upon the geographic location (e.g.,
latitude or orientation) of the photovoltaic module 330 so as to
enhance the modules' energy capture from the light source (e.g.,
the sun).
[0025] Elongated rail 310 also can include one or more support
surfaces, e.g., support surfaces 313 and 314, that can serve as a
mechanical support for maintenance vehicle 320 such that the
maintenance vehicle can move along and in a direction parallel to
the elongated rail, e.g., while cleaning photovoltaic modules 330.
In the illustrated embodiment, the one or more mounting surfaces,
e.g., mounting surfaces 311 and 312, are disposed between the one
or more support surfaces, e.g., support surfaces 313 and 314.
Additionally, or alternatively, photovoltaic modules 330 are raised
relative to the one or more support surfaces, e.g., support
surfaces 313 and 314. In certain embodiments, first and second
vehicle support surfaces 313, 314 and the at least one mounting
surface, e.g., mounting surfaces 311, 312, are integrally formed
with one another of a common material shaped so as to define each
such surface. Additionally, or alternatively, the first and second
vehicle support surfaces and the at least one mounting surface can
be integrally formed of extruded concrete disposed on the ground.
In one example, elongated rail 310 is constructed from concrete, or
is constructed on site (e.g., being extruded in place using a
slip-form extrusion machine), or both.
[0026] Optionally, a plurality of elongated rails 310 optionally
can be provided, each including one or more mounting surfaces to
which photovoltaic modules 330 can be coupled, and one or more
support surfaces that can serve as a mechanical support for
maintenance vehicle 320. As described in greater detail below with
reference to FIGS. 6A-6C, the same maintenance vehicle 320 can be
used to maintain the photovoltaic modules 330 coupled to those
elongated rails 310; alternatively, a different maintenance vehicle
320 can be provided corresponding to each elongated rail so as
respectively to maintain the photovoltaic modules coupled to only
one of such rails. For example, in one embodiment, one vehicle is
used per row of solar panels. In yet another embodiment, one
maintenance vehicle is moved between rows by mechanism. In yet
another example, the maintenance vehicle uses one or more limit
switches to detect end-of-row.
[0027] As illustrated in FIGS. 3A-3B, maintenance vehicle 320 for
photovoltaic modules 330, such as solar panels, is disposed on and
movably coupled to the one or more support surfaces of elongated
rail 310, e.g., can be disposed on first support surface 313 and
second support surface 314. For example, the maintenance vehicle
rolls on an extruded concrete rail. Maintenance vehicle 320 can
include one or more support legs, e.g., first and second support
legs 321 and 322, and optionally can include three or more support
legs, e.g., first support leg 321, second support leg 322, third
support leg 323, and fourth support leg (not specifically
illustrated), as shown in the exemplary embodiment illustrated in
FIGS. 3A-3B. The one or more support legs respectively can be
coupled to one or more wheels, caterpillar treads, or the like
permitting locomotion of maintenance vehicle 320 along the one or
more support surfaces of elongated rail 310 in a direction parallel
to the elongated rail. For example, in the embodiment illustrated
in FIGS. 3A-3B, support leg 321 can be coupled to one or more
wheels 325 that are movably disposed on, e.g., can contact and move
along, first support surface 313, and support leg 322 can be
coupled to one or more wheels 326 that are movably disposed on,
e.g., can contact and move along, second support surface 314. In
one illustrative embodiment, maintenance vehicle 320 further can
include a third support leg, e.g., leg 323, that is movably coupled
to one of the first and second support surfaces 313, 314, e.g., by
a third wheel that is movably disposed on, e.g., can contact and
move along, that support surface.
[0028] In yet another example, the maintenance vehicle includes one
or more adjustable frames to accommodate one or more panel angles.
For example, in some embodiments, at least one of the support legs
is adjustable so as to accommodate photovoltaic modules at
different angles than one another. For example, in the embodiment
illustrated in FIGS. 3A-3B, support legs 321, 323 each include a
joint 329 the angle of which can be increased or decreased (e.g.,
automatically with an actuator, not illustrated or manually) so as
to modify the relative angle of one or more portions of maintenance
vehicle relative to photovoltaic modules 330.
[0029] Maintenance vehicle 320 also can include first motor 327
configured to laterally and sequentially move the vehicle in a
direction parallel to elongated rail 310 and across each of the
photovoltaic modules 330 in the array responsive to actuation of
first motor 327. First motor 327 can be powered by any suitable
fuel source, e.g., can include a combustion motor, an electric
motor, or the like. In one example, the maintenance vehicle is
charged by one or more solar panels. For example, in the embodiment
illustrated in FIGS. 3A-3B, maintenance vehicle 320 further can
include a power source such as solar panel 328 or a battery (not
specifically illustrated) configured to provide power to first
motor 327, and optionally also to one or more other motors or
actuators of vehicle 320 such as those described elsewhere herein.
In one embodiment, solar panel 328 is operably coupled to a battery
so as to charge the battery and optionally also provide power to
maintenance vehicle 320 during daylight hours, and then battery can
continue to provide power to maintenance vehicle 320 at times when
solar panel 328 provides insufficient power, e.g., during nighttime
hours. Illustratively, maintenance vehicle 320 can include a
controller to which motor 327 can be coupled via a motor control
cable (controller and cable not shown in FIGS. 3A-3B). In one
embodiment, the maintenance vehicle is dispatched by wireless
control. For example, the wireless control is managed by web
interface. Illustratively, the controller of maintenance vehicle
320 can be in wired or wireless communication with a remote
computer via which a user can enter commands to maintenance vehicle
320, e.g., by a web interface. Such wireless communication with a
remote computer can utilize, for example, WiFi, WiMax, Bluetooth, a
cellular connection, or other suitable wireless connection. In one
illustrative embodiment, maintenance vehicle 320 includes antenna
399 such as illustrated in FIGS. 6A-6C.
[0030] Maintenance vehicle 320 also can include cleaning head 340
such as described in greater detail with reference to FIGS. 4A-5C.
In certain, non-limiting embodiments, the first and second support
legs can suspend the cleaning head over the photovoltaic modules of
the array. First and second support legs 321, 322 of maintenance
vehicle 320 can movably couple cleaning head 340 to the one or more
support surfaces of elongated rail 310 such that the cleaning head
can be laterally and sequentially moved in a direction parallel to
the elongated rail and across each of the photovoltaic modules 330
of the array responsive to actuation of motor 327. Additionally, as
described in greater detail with reference to FIGS. 4A-5C, at least
a portion of cleaning head 340 can be vertically movable between a
disengaged position spaced apart from photovoltaic modules 330 of
the array and one or more engaged positions in contact with at
least one of the photovoltaic modules of the array responsive to
actuation of an actuator. In one nonlimiting, illustrative
embodiment, at least a portion of cleaning head 340 has a
substantially fixed position relative to first and second support
legs 321, 322, and at least a portion of cleaning head 340 is
vertically movable relative to other portions of cleaning head 340
and relative to one or more photovoltaic modules 330. In other
embodiments, the entirety of cleaning head 340 is vertically
movable relative to first and second support surfaces 313, 314 and
relative to one or more photovoltaic modules 330.
[0031] As described in greater detail with reference to FIGS.
4A-5C, cleaning head 340 can include second motor 342, and the at
least a portion of cleaning head 340 can include a brush (not shown
in FIGS. 3A-3B) movable to contact at least one of the photovoltaic
modules 330 of the array in at least one engaged position
responsive to actuation of an actuator (not shown in FIGS. 3A-3B).
The brush can be rotatable along an axis parallel to the
photovoltaic modules 330 of the array responsive to actuation of
second motor 342. Additionally, or alternatively, and in certain
embodiments, such as illustrated in FIGS. 3A-3B, cleaning head 340
can include fluid reservoir 341 and a second actuator (not shown in
FIGS. 3A-3B). Cleaning head 340 can be operable to dispense fluid
from the fluid reservoir onto at least one of photovoltaic modules
330 of the array responsive to actuation of the second actuator. In
one example, the maintenance vehicle uses gravity fed water.
Optionally, as described with reference to FIGS. 4A-5C, cleaning
head 340 can include a wiper in contact with at least one
photovoltaic module 330 of the array when the at least a portion of
the first cleaning head is in an engaged position, and operable to
at least partially dry that photovoltaic module.
[0032] In yet another embodiment, the maintenance vehicle includes
one or more trimmer mechanisms to remove vegetation. Exemplary
trimmer mechanisms suitable for use in maintenance vehicle 320
include string trimmers, hedge trimmers, pole saws, tillers,
harrows, plows, and the like (not specifically illustrated in FIGS.
3A-3B), and can be powered by electricity or combustion, or by the
motion of maintenance vehicle 320.
[0033] As noted further above, at least a portion of cleaning head
340 can be vertically movable between a disengaged position spaced
apart from photovoltaic modules 330 of the array and one or more
engaged positions in contact with at least one of the photovoltaic
modules 330 responsive to actuation of an actuator. In one
illustrative embodiment, maintenance vehicle 320 includes a
three-position cleaning head and actuator. Additionally, in one
embodiment, the cleaning head can include a brush and a wiper or
squeegee. In one embodiment, the three-position cleaning head has
the following three positions:
[0034] Raised position: there is no contact with the panel;
[0035] Middle position: there is contact of the brush to the panel;
and
[0036] Lowered position: there is contact of brush and squeegee
with panel.
[0037] In another embodiment, the three-position cleaning head is
actuated by cable. For example, a cable is used to connect the
actuator to the cleaning head, allowing wheels to roll over the
surface of the panel and control height.
[0038] For example, FIGS. 4A-4B are simplified diagrams showing
perspective views of a cleaning head and actuator in a first
position, according to certain embodiments. These diagrams are
merely an example, which should not unduly limit the scope of the
claims. One of ordinary skill in the art would recognize many
variations, alternatives, and modifications. In one example, FIGS.
4A-4B illustrate a three-position cleaning head 340 in a raised
position. Cleaning head 340 includes fluid reservoir 341, motor
342, first actuator 343, brush 344, shield 345, motor control cable
346, wiper or squeegee 347, and actuator control cable 349. Fluid
reservoir 341 is configured so as to dispense fluid, such as water
or other cleaning liquid, onto photovoltaic module 330 or onto
brush 344 via a fluid tube, optionally responsive to actuation of a
second actuator (fluid tube and second actuator not shown in FIGS.
4A-4B). The fluid can be dispensed from fluid reservoir 341 under
the force of gravity, e.g., responsive to the second actuator
opening a valve permitting the fluid to drip onto brush 344 or
photovoltaic module 330 via the fluid tube. Alternatively, the
second actuator can pump the fluid from fluid reservoir 341 onto
brush 344 or photovoltaic module 330 via the fluid tube, e.g., can
spray or jet the fluid onto brush 344 or photovoltaic module
330.
[0039] Motor 342 is configured so as to rotate brush 344 along an
axis parallel to photovoltaic module 330. Motor 342 can include,
for example, an electric motor or a combustion motor. In one
illustrative embodiment, motor 342 shares a common power source
with motor 327 described above with reference to FIGS. 3A-3B, such
as solar panel 328 or a battery. Motor 342 can be connected to a
controller such as described elsewhere herein via motor control
cable 346.
[0040] First actuator 343 is configured so as to vertically move at
least a portion of cleaning head 340, e.g., at least brush 344 and
wiper or squeegee 347, between a raised or disengaged position such
as illustrated in FIGS. 4A-4B and one or more engaged positions
such as described further below with reference to FIGS. 5A-5C.
First actuator 343 can include, for example, a hydraulic actuator,
a pneumatic actuator, an electric actuator, or mechanical actuator.
In one illustrative embodiment, first actuator shares a common
power source with motor 327 described above with reference to FIGS.
3A-3B, such as solar panel 328 or a battery. First actuator 343 can
be connected to a controller such as described elsewhere herein via
actuator control cable 349.
[0041] Brush 344 can include a plurality of bristles that extend
substantially radially from a central rod coupled to motor 342 (rod
not shown in FIGS. 4A-4B). The plurality of bristles can include a
material of sufficient strength and stiffness such that rotation of
the bristles against photovoltaic module 330, optionally in the
presence of fluid disposed from fluid reservoir 341, can remove
debris, dust, or dirt from photovoltaic module 330, with sufficient
softness and flexibility as to do so substantially without damaging
the photovoltaic module. Exemplary materials that can be suitable
for use in the bristles of brush 344 include nylon and
polypropylene. Shield 345 can include a flat or shaped metal or
plastic sheet that partially surrounds brush 344 so as to inhibit
the rotation of brush 344 from flicking debris, dust, or dirt onto
a different portion of photovoltaic module 330 or an adjacent
photovoltaic module when brush 344 is rotating and in contact with
photovoltaic module 330, e.g., as described in greater detail below
with reference to FIGS. 5A-5C.
[0042] Wiper or squeegee 347 can include a flexible hydrophilic
material, such as natural rubber, silicone rubber, or other polymer
such as ethylene propylene diene monomer (EPDM). Wiper or squeegee
347 can be configured so as to be oriented substantially parallel
to and out of contact with photovoltaic module 330 in the raised
position such as illustrated in FIGS. 4A-4B. For example, wiper or
squeegee 347 can include pivot stop/panel rotation stop 348. FIGS.
4A-4B illustrate an exemplary position that includes, e.g.,
cleaning head in raised position, where neither brush not squeegee
contacts glass surface of solar panel. For example, the squeegee
position is aligned to brush head by one or more pivot stop, such
as one or more panel rotation stops.
[0043] FIG. 5A-5C are simplified diagrams showing perspective views
of a cleaning head and actuator in a second position, according to
certain embodiments. These diagrams are merely an example, which
should not unduly limit the scope of the claims. One of ordinary
skill in the art would recognize many variations, alternatives, and
modifications. FIGS. 5A-5C illustrate, e.g., cleaning head in
lowered position and actuator, e.g., cleaning head in lowered
position where brush and squeegee both contact glass surface of
solar panel. For example, responsive to actuation of actuator 343
via actuation control cable 349, either brush 344 or both brush 344
and wiper or squeegee 347 can be lowered into contact with
photovoltaic module 330. For example, at least a portion of
cleaning head 320 (e.g., brush 344 and wiper or squeegee 347) can
be vertically movable, responsive to actuation of actuator 343, to
a first engaged position (e.g., lowered position) in which both the
brush and the wiper or squeegee contact photovoltaic module 330 of
the array. Additionally, or alternatively, at least a portion of
cleaning head 320 (e.g., brush 344 and wiper or squeegee 347) can
be vertically movable, responsive to actuation of actuator 343, to
a second engaged position (e.g., middle position) in which the
brush contacts photovoltaic module 330 of the array and the wiper
does not contact the array. The first and second engaged positions
can be discrete positions. Depending on which portion(s) of
cleaning head 320 are moved so as to contact photovoltaic module
330, e.g., either brush 344 or both brush 344 and wiper or squeegee
347, such portion(s) can be moved laterally and sequentially in a
direction parallel to elongated rail 310 and across each of the
photovoltaic modules 330 of the array responsive to actuation of
motor 327 such as discussed above with reference to FIGS.
3A-3B.
[0044] Additionally, responsive to actuation of motor 342 via motor
control cable 346, brush 344 can be rotated so as to clean the
surface of photovoltaic module 330. For example, the bristles of
brush 344 can sweep debris, dirt, or dust off of the surface of
photovoltaic module 330. Additionally, fluid from fluid reservoir
341 can be dispensed onto brush 344 or onto photovoltaic module
330, which can facilitate cleaning photovoltaic module 330. For
example, as illustrated in FIGS. 3A-3B, photovoltaic module 330 can
be disposed at a panel angle. Fluid dispensed from fluid reservoir
341 can collect the debris, dirt, or dust swept off of the surface
of photovoltaic module 330, and the fluid then can flow to the
bottom of module 330 under the force of gravity due to the panel
angle of module 330. Additionally, or alternatively, in embodiments
in which both brush 344 and wiper or squeegee 347 are in a position
in which they are brought into contact with a photovoltaic module
330 and then moved laterally and sequentially in a direction
parallel to elongated rail 310 and across photovoltaic modules 330
of the array, wiper or squeegee 347 can at least partially dry
those modules. Additionally, or alternatively, in the lowered
position, the one or more panel rotation stops are free of the
squeegee, allowing the squeegee to follow glass surface of the
solar panel. For example, as shown in FIG. 3C, panel rotation stop
348 can allow wiper or squeegee 347 to obtain one or more angles so
as to follow a corresponding angled surface of photovoltaic module
330. According to certain embodiments, in the raised position and
the middle position, the one or more panel rotation stops are
engaged when the squeegee is lifted, aligning the squeegee to be
parallel with surface of the panel.
[0045] Note that each of the various actuators and motors that can
be included in maintenance vehicle 320 optionally can be powered by
a common power source as one another, e.g., each can be powered by
a common solar panel 328 or a common battery of vehicle 320.
Alternatively, some of the actuators and motors can share a first
common power source with one another, and others of the actuators
and motors can share a second common power source with one another.
Alternatively, each actuator and each motor can include its own
power source.
[0046] Additionally, note that each of the various actuators and
motors that can be included in maintenance vehicle 320 optionally
can be controlled by a common controller as one another, e.g., each
can be suitably connected to (such as by respective cabling) and
controlled by a common controller of vehicle 320 that can be in
wired or wireless communication with a remote computer that
includes an interface by which a user may enter instructions, e.g.,
a web interface, that can be transmitted via an appropriate signal
to the controller for implementation. The controller can include a
memory and a processor coupled to the memory. The memory can store
instructions for causing the processor to receive the instructions
from the remote computer and then suitably to implement the
instructions.
[0047] Illustratively, such instructions can include a speed of
motor 327, which can control the rate at which cleaning head 340
passes over the photovoltaic modules 330 of the array and the start
and stop times of motor 327 or rules defining when motor 327 should
automatically start and stop; a speed of motor 342, which can
control the rate at which brush 344 rotates and the start and stop
times of motor 342 or rules defining when motor 342 should
automatically start and stop; a speed of actuator 343, which can
control the rate at which brush 344 and wiper or squeegee 347 can
be moved vertically relative to the photovoltaic modules 330 and
the start and stop times of actuator 343 or rules defining when
actuator 343 should automatically start and stop; or a speed of the
second actuator that controls dispensing of fluid from the fluid
reservoir onto brush 344 or at least one of photovoltaic modules
330 of the array and the start and stop times of the second
actuator or rules defining when the second actuator should
automatically start and stop. Additionally, or alternatively,
maintenance vehicle 320 can include a limit switch configured to
detect one or both ends of elongated rail 310. The limit switch can
be in operable communication with the controller.
[0048] In one illustrative, nonlimiting example, the controller
suitably is programmed (e.g., remotely, such as by web interface)
so as to detect a first end of elongated rail 310 based on a signal
from a limit switch, and responsive to such detection, to actuate
actuator 343 so as to lower brush 344 and optionally also wiper or
squeegee 347 from a disengaged position into an engaged position.
The controller also can be programmed so as to detect that actuator
343 properly positioned brush 344 and optionally also wiper or
squeegee 347, and responsive to such detection, to actuate motor
342 so as to rotate brush 344 and to actuate the second actuator
(not illustrated) so as to dispense fluid from fluid reservoir 341
onto brush 344 or photovoltaic module 330. The controller also can
be programmed so as to detect that brush 344 properly is rotating
and that fluid properly is being or has been dispensed, and
responsive to such detection, to actuate motor 327 so as to
laterally move maintenance vehicle 320, and thus to move brush 344
and optionally also wiper or squeegee 347, across the photovoltaic
modules 330 of the array. The controller also can be programmed so
as to detect a second end of elongated rail 310 based on a signal
from the limit switch, and responsive to such detection, to actuate
actuator 343 so as to raise brush 344 and optionally also wiper or
squeegee 347 from the engaged position into a disengaged position,
to terminate actuation of motor 342 so as to stop rotation of brush
344, and to terminate actuation of motor 327 so as to stop lateral
movement of vehicle 320.
[0049] Additionally, as noted further above with reference to FIGS.
3A-3B, system 300 can include a plurality of elongated rails 310,
each of which can include one or more support surfaces and one or
more mounting surfaces to which a respective array of photovoltaic
modules 330 can be coupled. For example, a first elongated rail can
include first and second support surfaces and a first mounting
surface to which is coupled a first array of photovoltaic modules
that are raised relative to the first and second support surfaces,
and a second elongated rail can include third and fourth support
surfaces and a second mounting surface to which is coupled a second
array of photovoltaic modules that are raised relative to the third
and fourth support surfaces. Different maintenance vehicles can be
provided and used so as to maintain the first and second arrays of
photovoltaic modules. For example, a first maintenance vehicle such
as described above with reference to FIGS. 3A-5C can be disposed on
the first and second support surfaces of the first elongated rail
so as to maintain the first array of photovoltaic modules, and a
second maintenance vehicle also such as described above with
reference to FIGS. 3A-5C can be disposed on the third and fourth
support surfaces of the second elongated rail so as to maintain the
second array of photovoltaic modules.
[0050] Alternatively, one maintenance vehicle can be moved between
rows by mechanism. For example, the system can include a row-to-row
mechanism configured to move a maintenance vehicle from the first
elongated rail to the second elongated rail. Illustratively, such a
row-to-row mechanism can include at least one track that couples
the first support surface of the first elongated rail to one of the
third and fourth support surfaces of the second elongated rail, and
that couples the second support surface of the first elongated rail
to the other of the third and fourth support surfaces of the second
elongated rail. In one embodiment, the row-to-row mechanism moves
one maintenance vehicle to service two or more rows of solar
panels. For example, the row-to-row mechanism is actuated by the
maintenance vehicle. In another example, the row-to-row mechanism
is actuated by a dedicated drive located on the ground with an
independent power supply. In another embodiment, one or more solar
panels are used to charge the row-to-row mechanism. In yet another
embodiment, the row-to-row mechanism is dispatched based on
presence of one or more maintenance vehicles. In yet another
embodiment, the row-to-row mechanism is dispatched based on
centralized wireless control.
[0051] In one illustrative, nonlimiting example, FIG. 6A is a
simplified diagram showing a perspective view of an exemplary
rail-to-rail mechanism for moving a maintenance vehicle from a
first rail based array of photovoltaic modules to a second rail
based array of photovoltaic modules, according to certain
embodiments, e.g., row-to-row mechanism for moving the maintenance
vehicle from one row to the next row of solar panels. This diagram
is merely an example, which should not unduly limit the scope of
the claims. One of ordinary skill in the art would recognize many
variations, alternatives, and modifications. Rail-to-rail mechanism
600 illustrated in FIG. 6A includes first track 601, second track
602, and optional platform 605. Upon reaching the end of first
elongated rail 310 including first support surface 313 and second
support surface 314 to which maintenance vehicle 320 is movably
coupled, the maintenance vehicle can move off of the end of first
elongated rail 310 and either directly onto first and second tracks
601, 602 or onto optional platform 605 that can be supported by
first and second tracks 601, 602. Maintenance vehicle 320 can
travel along first and second tracks 601, 602, or can be moved by
optional platform 605 along first and second tracks 601, 602,
towards and into alignment with the end of second elongated rail
310' including third support surface 313' and fourth support
surface 314'. Maintenance vehicle 320 can travel off of first and
second tracks 601, 602 or off of optional platform 605 onto the
third support surface 313' and fourth support surface 314' of
second elongated rail 310' so as to maintain photovoltaic modules
330 of second elongated rail 310'. In the embodiment illustrated in
FIG. 6A, first track 601 can be considered to couple first support
surface 313 to third support surface 313', and second track 602 can
be considered to couple second support surface 314 to fourth
support surface 314'. Other configurations are possible.
[0052] For example, FIG. 6B is a simplified diagram showing a
perspective view of another exemplary rail-to-rail mechanism for
moving a maintenance vehicle from a first rail based array of
photovoltaic modules to a second rail based array of photovoltaic
modules, according to certain embodiments, e.g., a row-to-row track
for moving the maintenance vehicle from one row to the next row of
solar panels. This diagram is merely an example, which should not
unduly limit the scope of the claims. One of ordinary skill in the
art would recognize many variations, alternatives, and
modifications. For example, the row-to-row track allows connection
between two rows to maintain correct south-facing orientation.
Rail-to-rail mechanism 600' illustrated in FIG. 6B includes first
track 601', second track 602', and optional platform 605'. Upon
reaching the end of first elongated rail 310 including first
support surface 313 and second support surface 314 to which
maintenance vehicle 320 is movably coupled, the maintenance vehicle
can move off of the end of first elongated rail 310 and either
directly onto first and second tracks 601', 602' or onto optional
platform 605' that can be supported by first and second tracks
601', 602'. Maintenance vehicle 320 can travel along first and
second tracks 601', 602', or can be moved by optional platform 605'
along first and second tracks 601', 602', towards and into
alignment with the end of second elongated rail 310' including
third support surface 313' and fourth support surface 314'.
Maintenance vehicle 320 can travel off of first and second tracks
601', 602' or off of optional platform 605' onto the third support
surface 313' and fourth support surface 314' of second elongated
rail 310' so as to maintain photovoltaic modules 330 of second
elongated rail 310'. In the embodiment illustrated in FIG. 6B,
first track 601' can be considered to couple first support surface
313 to fourth support surface 314', and second track 602' can be
considered to couple second support surface 314 to third support
surface 313'. Other configurations are possible.
[0053] For example, FIG. 6C is a simplified diagram showing a
perspective view of yet another exemplary rail-to-rail mechanism
for moving a maintenance vehicle from a first rail based array of
photovoltaic modules to a second rail based array of photovoltaic
modules, according to certain embodiments, e.g., row-to-row track
for moving the maintenance vehicle from on row to the next row of
solar panels. This diagram is merely an example, which should not
unduly limit the scope of the claims. One of ordinary skill in the
art would recognize many variations, alternatives, and
modifications. Rail-to-rail mechanism 600'' illustrated in FIG. 6C
includes first track 601'', second track 602'', third track 603'',
fourth track 604'', and optional platform (not specifically
illustrated). Upon reaching the end of first elongated rail 310
including first support surface 313 and second support surface 314
to which maintenance vehicle 320 is movably coupled, the
maintenance vehicle can move off of the end of first elongated rail
310 and either directly onto first and second tracks 601'', 602''
or onto the optional platform that can be supported by first and
second tracks 601'', 602''. Maintenance vehicle 320 can travel
along first and second tracks 601'', 602'', or can be moved by the
optional platform along first and second tracks 601'', 602''
towards an intermediate position at which maintenance vehicle 320
then can travel along third and fourth tracks 603'', 604'' or can
be moved by the optional platform along third and fourth tracks
603'', 604'' towards and into alignment with the end of second
elongated rail 310' including third support surface 313' and fourth
support surface 314'. Maintenance vehicle 320 can travel off of
third and fourth tracks 603'', 604'' or off of the optional
platform onto the third support surface 313' and fourth support
surface 314' of second elongated rail 310' so as to maintain
photovoltaic modules 330 of second elongated rail 310'. In the
embodiment illustrated in FIG. 6C, first and second tracks 601'',
602'' can be considered to couple first support surface 313 to
third support surface 313', and third and fourth tracks 603'',
604'' can be considered to couple second support surface 314 to
fourth support surface 314'. Other configurations are possible.
[0054] Note that in embodiments in which the row-to-row mechanism
includes a platform coupled to the at least one track and
configured to carry the maintenance vehicle from the first
elongated rail 310 to the second elongated rail 310', e.g.,
platform 605 coupled to tracks 601 and 602, or platform 605'
coupled to tracks 601' and 602', or platform coupled to tracks
601'', 602'', 603'', and 604'', the row-to-row mechanism optionally
can include a power source and a motor coupled to the platform and
configured to move the platform based on power from the power
source. Exemplary power sources include DC electrical power such as
from a photovoltaic module or solar panel, or batter, and AC
electrical power, such as from an electrical grid.
[0055] FIG. 7 illustrates steps in an exemplary method for
maintaining at least one rail based array of photovoltaic modules,
according to certain embodiments. This diagram is merely an
example, which should not unduly limit the scope of the claims. One
of ordinary skill in the art would recognize many variations,
alternatives, and modifications. Method 700 illustrated in FIG. 7
includes providing an elongated rail including first and second
support surfaces and a mounting surface disposed between the first
and second support surfaces, an array of photovoltaic modules being
coupled to the mounting surface and raised relative to the first
and second support surfaces (701). In one illustrative, nonlimiting
example, elongated rail 310 described above with reference to FIGS.
3A-3B can be provided including first and second support surfaces
313, 314 and first and second mounting surfaces 311, 312 disposed
therebetween. A plurality of photovoltaic modules 330 can be
coupled to first and second mounting surfaces, e.g., via legs 331,
332, that can raise photovoltaic modules 330 above first and second
support surfaces 313, 314.
[0056] Referring again to FIG. 7, method 700 further can include
disposing a maintenance vehicle on the first and second support
surfaces, the maintenance vehicle including a cleaning head,
actuator, motor, and first and second support legs (702). In one
illustrative, nonlimiting example, maintenance vehicle 320
described above with reference to FIGS. 3A-5C can be disposed on
first and second support surfaces 313, 314 of elongated rail 310,
e.g., via wheels or caterpillar treads coupled to first and second
support legs 322, 323, and any other (optional) legs that vehicle
320 can include. In this example, maintenance vehicle 320 also
includes cleaning head 340 including actuator 343 and motor
327.
[0057] As illustrated in FIG. 7, method 700 also can include
suspending the cleaning head over the photovoltaic modules of the
array using the first and second support legs, the first and second
support legs being movably coupled to the first and second support
surfaces so as to laterally and sequentially move the cleaning head
in a direction parallel to the elongated rail and across each
photovoltaic module of the array responsive to actuation of the
motor (703). In one illustrative, nonlimiting example, maintenance
vehicle 320 illustrated in FIGS. 3A-3B can suspend cleaning head
340 over photovoltaic modules 330 of the array using first and
second support legs 321, 322 and any other (optional) legs that
vehicle 320 can include. The first and second support legs 321, 322
can be movably coupled, e.g., via wheels or caterpillar treads, to
first and second support surfaces 313, 314. Actuation of motor 327
can cause maintenance vehicle 320 to laterally move along elongated
rail 310 in a direction parallel to elongated rail 310, so as to
laterally and sequentially move cleaning head 340 in a direction
parallel to elongated rail 310 and across photovoltaic modules 330
of the array.
[0058] Referring again to FIG. 7, method 700 also can include
vertically moving at least a portion of the cleaning head between a
disengaged position spaced apart from the photovoltaic module of
the array and an engaged position in contact with at least one
photovoltaic module of the array responsive to actuation of the
actuator (704). In one nonlimiting, illustrative example, as
discussed above with reference to FIGS. 4A-5C, actuator 343 can
cause brush 344 and wiper or squeegee 347 to be raised or lowered
relative to photovoltaic module 330, e.g., such that brush 344 or
both brush 344 and wiper or squeegee 347 can contact photovoltaic
module 330. In an alternative embodiment, an actuator can cause
additional portions, or even the entirety, of cleaning head 340 to
be raised or lowered so as to contact photovoltaic module 330. As
discussed with reference to FIGS. 4A-5C, additional motors or
actuators can cause additional actions that can facilitate cleaning
photovoltaic module 330. For example, actuation of a second motor
342 can cause rotation of brush 344 about an axis parallel to
photovoltaic module 330, or actuation of a second actuator (not
illustrated) can cause fluid to be dispensed from fluid reservoir
341 onto brush 344 or onto photovoltaic module 330.
[0059] Note that the steps of method 700 can be performed in any
suitable order. For example, disposing the maintenance vehicle on
the first and second support surfaces (702) can occur concurrently
with suspending the cleaning head over the photovoltaic modules of
the array using the first and second support legs (703). That is,
performing the disposing also may perform the suspending.
Additionally, laterally and sequentially moving the cleaning head
in a direction parallel to the elongated rail (703) can be
performed before, during, or after vertically moving at least a
portion of the cleaning head between the disengaged and engaged
positions (704). In one illustrative, nonlimiting example, as
mentioned above with reference to FIGS. 4A-5C, a controller of
maintenance vehicle 320 suitably can be programmed to actuate
actuator 343 so as to lower at least a portion of cleaning head 340
into contact with photovoltaic module before actuating motor 327 so
as to cause lateral movement of cleaning head 340.
[0060] According to yet another embodiment, a system for
maintaining photovoltaic modules is provided. The system can
include a first elongated rail including first and second support
surfaces and a first mounting surface disposed between the first
and second support surfaces, a first array of the photovoltaic
modules being coupled to the first mounting surface and raised
relative to the first and second support surfaces; and a first
maintenance vehicle disposed on the first and second support
surfaces, the first maintenance vehicle including a first cleaning
head, a first actuator, a first motor, and first and second support
legs. The first and second support legs can suspend the first
cleaning head over the photovoltaic modules of the first array and
can be movably coupled to the first and second support surfaces so
as to laterally and sequentially move the first cleaning head in a
direction parallel to the first elongated rail and across each of
the photovoltaic modules of the first array responsive to actuation
of the first motor. At least a portion of the first cleaning head
can be vertically movable between a disengaged position spaced
apart from the photovoltaic modules of the first array and a first
engaged position in contact with at least one of the photovoltaic
modules of the first array responsive to actuation of the first
actuator. For example, the system is implemented according to at
least FIGS. 3A-3B, 4A-4B, 5A-5C, and 6A-6C.
[0061] In another example, the first cleaning head includes a
second motor, the at least a portion of the first cleaning head
including a brush movable to contact at least one of the
photovoltaic modules of the first array in the first engaged
position responsive to actuation of the first actuator, the brush
further being rotatable along an axis parallel to the photovoltaic
modules of the first array responsive to actuation of the second
motor. In another example, the first cleaning head further includes
a fluid reservoir; and a second actuator, the first cleaning head
being operable to dispense fluid from the fluid reservoir onto at
least one of the photovoltaic modules of the first array responsive
to actuation of the second actuator. In another example, the first
cleaning head further includes a wiper, the wiper being in contact
with at least one photovoltaic module of the first array when the
at least a portion of the first cleaning head is in the first
engaged position and operable to at least partially dry the at
least one photovoltaic module of the first array. In another
example, the at least a portion of the first cleaning head further
is vertically movable, responsive to actuation of the first
actuator, to a second engaged position in which the brush contacts
at least one photovoltaic module of the array and the wiper does
not contact the array.
[0062] In another example, the first and second support legs
respectively are movably coupled to the first and second support
surfaces by first and second wheels that respectively contact and
rotate along the first and second support surfaces. In another
example, the first maintenance vehicle further includes a third
support leg movably coupled to one of the first and second support
surfaces by a third wheel that respectively contacts and rotates
along the one of the first and second support surfaces. In another
example, the first maintenance vehicle further includes a limit
switch configured to detect an end of the first elongated rail.
[0063] In another example, the system further includes a second
elongated rail including third and fourth support surfaces and a
second mounting surface, a second array of the photovoltaic modules
being coupled to the second mounting surface and raised relative to
the third and fourth support surfaces. In another example, the
system further includes a second maintenance vehicle disposed on
the third and fourth support surfaces, the second maintenance
vehicle including a second cleaning head, a second actuator, a
second motor, and third and fourth support legs, the third and
fourth support legs suspending the second cleaning head over the
photovoltaic modules of the second array and being movably coupled
to the third and fourth support surfaces so as to laterally and
sequentially move the second cleaning head in a direction parallel
to the second elongated rail and across each of the photovoltaic
modules of the second array responsive to actuation of the second
motor, at least a portion of the second cleaning head being
vertically movable between a disengaged position spaced apart from
the photovoltaic modules of the second array and a second engaged
position in contact with at least one of the photovoltaic modules
of the second array responsive to actuation of the second
actuator.
[0064] In another example, the system further includes a row-to-row
mechanism configured to move the first maintenance vehicle from the
first elongated rail to the second elongated rail. In another
example, the row-to-row mechanism includes at least one track, the
at least one track coupling the first support surface to one of the
third and fourth support surfaces and coupling the second support
surface to the other of the third and fourth support surfaces. In
another example, the at least one track includes a first track
coupling the first support surface to the third support surface,
and a second track coupling the second support surface to the
fourth support surface. In another example, the at least one track
includes first and second tracks coupling the first support surface
to the third support surface, and third and fourth tracks coupling
the second support surface to the fourth support surface. In
another example, the row-to-row mechanism further includes a
platform coupled to the at least one track and configured to carry
the first maintenance vehicle from the first elongated rail to the
second elongated rail. In another example, the row-to-row mechanism
includes a power source and a motor coupled to the platform and
configured to move the platform based on power from the power
source.
[0065] In another example, at least one of the first and second
support legs is adjustable so as to accommodate photovoltaic
modules at different angles than one another. In another example,
the first maintenance vehicle further includes a solar panel
configured to provide power for actuating the first actuator and
the first motor. In another example, the first maintenance vehicle
further includes a trimmer mechanism to remove vegetation. In
another example, the first maintenance vehicle is wirelessly
controllable. In another example, the wireless control is
manageable via a web interface. In another example, the first and
second vehicle support surfaces and the at least one mounting
surface are integrally formed with one another. In another example,
the first and second vehicle support surfaces and the at least one
mounting surface are integrally formed of extruded concrete
disposed on the ground.
[0066] According to another embodiment, a method for maintaining
photovoltaic modules is provided. The method can include providing
a first elongated rail including first and second support surfaces
and a first mounting surface disposed between the first and second
support surfaces, a first array of the photovoltaic modules being
coupled to the first mounting surface and raised relative to the
first and second support surfaces; disposing a first maintenance
vehicle on the first and second support surfaces, the first
maintenance vehicle including a first cleaning head, a first
actuator, a first motor, and first and second support legs;
suspending the first cleaning head over the photovoltaic modules of
the first array using the first and second support legs, the first
and second support legs being movably coupled to the first and
second support surfaces so as to laterally and sequentially move
the first cleaning head in a direction parallel to the first
elongated rail and across each of the photovoltaic modules of the
first array responsive to actuation of the first motor; and
vertically moving at least a portion of the first cleaning head
between a disengaged position spaced apart from the photovoltaic
modules of the first array and a first engaged position in contact
with at least one of the photovoltaic modules of the first array
responsive to actuation of the first actuator. For example, the
method is implemented at least according to FIG. 7.
[0067] In another example, the first cleaning head includes a
second motor, the at least a portion of the first cleaning head
including a brush contacting at least one of the photovoltaic
modules of the first array when the first cleaning head is in the
first engaged position responsive to actuation of the first
actuator, the method further including rotating the brush along an
axis parallel to the photovoltaic modules of the first array
responsive to actuation of the second motor. In another example,
the first cleaning head further includes a fluid reservoir and a
second actuator, the method further including dispensing fluid from
the fluid reservoir onto at least one of the photovoltaic modules
of the first array responsive to actuation of the second actuator.
In another example, the first cleaning head further includes a
wiper, the wiper contacting at least one photovoltaic module of the
first array when the at least a portion of the first cleaning head
is in the first engaged position, the method further including at
least partially dry the at least one photovoltaic module of the
first array via the contact with the wiper. In another example, the
method includes vertically moving the at least a portion of the
first cleaning head, responsive to actuation of the first actuator,
to a second engaged position in which the brush contacts at least
one photovoltaic module of the array and the wiper does not contact
the array.
[0068] In another example, the first and second support legs
respectively are movably coupled to the first and second support
surfaces by first and second wheels that respectively contact and
rotate along the first and second support surfaces. In another
example, the first maintenance vehicle further includes a third
support leg movably coupled to one of the first and second support
surfaces by a third wheel that respectively contacts and rotates
along the one of the first and second support surfaces. In another
example, the first maintenance vehicle further detects an end of
the first elongated rail using a limit switch.
[0069] In another example, the method further includes providing a
second elongated rail including third and fourth support surfaces
and a second mounting surface, a second array of the photovoltaic
modules being coupled to the second mounting surface and raised
relative to the third and fourth support surfaces. In another
example, the method further includes disposing a second maintenance
vehicle on the third and fourth support surfaces, the second
maintenance vehicle including a second cleaning head, a second
actuator, a second motor, and third and fourth support legs;
suspending the second cleaning head over the photovoltaic modules
of the second array using the third and fourth support legs, the
third and fourth support legs being movably coupled to the third
and fourth support surfaces so as to laterally and sequentially
move the second cleaning head in a direction parallel to the second
elongated rail and across each of the photovoltaic modules of the
second array responsive to actuation of the second motor; and
vertically moving at least a portion of the second cleaning head
between a disengaged position spaced apart from the photovoltaic
modules of the second array and a second engaged position in
contact with at least one of the photovoltaic modules of the second
array responsive to actuation of the second actuator.
[0070] In another example, the method further includes moving the
first maintenance vehicle from the first elongated rail to the
second elongated rail using a row-to-row mechanism. In another
example, the row-to-row mechanism includes at least one track, the
at least one track coupling the first support surface to one of the
third and fourth support surfaces and coupling the second support
surface to the other of the third and fourth support surfaces. In
another example, the at least one track includes a first track
coupling the first support surface to the third support surface,
and a second track coupling the second support surface to the
fourth support surface. In another example, the at least one track
includes first and second tracks coupling the first support surface
to the third support surface, and third and fourth tracks coupling
the second support surface to the fourth support surface. In
another example, the row-to-row mechanism further includes a
platform coupled to the at least one track, the method further
including carrying the first maintenance vehicle from the first
elongated rail to the second elongated rail using the platform. In
another example, the row-to-row mechanism includes a power source
and a motor coupled to the platform and moving the platform based
on power from the power source.
[0071] In another example, the method further includes adjusting at
least one of the first and second support legs so as to accommodate
photovoltaic modules at different angles than one another. In
another example, the first maintenance vehicle further includes a
solar panel providing power for actuating the first actuator and
the first motor. In another example, the first maintenance vehicle
further includes a trimmer mechanism, the method further including
removing the vegetation with the trimmer. In another example, the
method further includes wirelessly controlling the first
maintenance vehicle. In another example, the wireless control is
via a web interface. In another example, the method includes
forming the first and second vehicle support surfaces and the at
least one mounting surface integrally with one another. In another
example, integrally forming the first and second vehicle support
surfaces and the at least one mounting surface includes extruding
concrete onto the ground.
[0072] Although specific embodiments of the present invention have
been described, it will be understood by those of skill in the art
that there are other embodiments that are equivalent to the
described embodiments. For example, various embodiments and/or
examples of the present invention can be combined. Accordingly, it
is to be understood that the invention is not to be limited by the
specific illustrated embodiments, but only by the scope of the
appended claims.
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