U.S. patent application number 14/975284 was filed with the patent office on 2016-04-14 for photovoltaic system with managed output.
The applicant listed for this patent is Matt Campbell, Robert Johnson, Adrianne Kimber, Carl J.S. Lenox. Invention is credited to Matt Campbell, Robert Johnson, Adrianne Kimber, Carl J.S. Lenox.
Application Number | 20160105027 14/975284 |
Document ID | / |
Family ID | 43854263 |
Filed Date | 2016-04-14 |
United States Patent
Application |
20160105027 |
Kind Code |
A1 |
Johnson; Robert ; et
al. |
April 14, 2016 |
PHOTOVOLTAIC SYSTEM WITH MANAGED OUTPUT
Abstract
Photovoltaic systems with managed output and methods for
managing variability of output from photovoltaic systems are
described. A system includes a photovoltaic module configured to
receive and convert solar energy to DC power. The system also
includes a sensor configured to detect a future change in solar
energy to be received by the photovoltaic module. The system
further includes a power conditioning unit coupled with the
photovoltaic module and the sensor.
Inventors: |
Johnson; Robert; (Richmond,
CA) ; Kimber; Adrianne; (Oakland, CA) ; Lenox;
Carl J.S.; (Oakland, CA) ; Campbell; Matt;
(Berkeley, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Johnson; Robert
Kimber; Adrianne
Lenox; Carl J.S.
Campbell; Matt |
Richmond
Oakland
Oakland
Berkeley |
CA
CA
CA
CA |
US
US
US
US |
|
|
Family ID: |
43854263 |
Appl. No.: |
14/975284 |
Filed: |
December 18, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12577613 |
Oct 12, 2009 |
9257847 |
|
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14975284 |
|
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Current U.S.
Class: |
307/24 ;
136/244 |
Current CPC
Class: |
H02J 3/381 20130101;
Y02E 10/56 20130101; H02S 50/00 20130101; H02S 40/34 20141201; H02J
3/383 20130101; H02J 2300/24 20200101 |
International
Class: |
H02J 3/38 20060101
H02J003/38; H02S 40/34 20060101 H02S040/34; H02S 50/00 20060101
H02S050/00 |
Claims
1. A photovoltaic system with managed output, the system
comprising: a photovoltaic module configured to receive solar
energy and convert the solar energy to DC power; a sensor
configured to detect a future change in solar energy to be received
by the photovoltaic module, the sensor comprising a pair of
modules, each module configured to detect an amount of solar energy
at a unique distance from the photovoltaic module; and a power
conditioning unit coupled with the photovoltaic module and the
sensor, wherein the power conditioning unit is configured to
condition the DC power from the photovoltaic module and to output
an amount of conditioned DC power based on the future change in
solar energy, and wherein the power conditioning unit controls the
output before and after the future change in solar energy occurs to
output the same amount of conditioned DC power before and after the
future change in solar energy occurs.
2. The photovoltaic system of claim 1, wherein the pair of modules
is configured to provide a delta in the amount of solar energy
detected by the pair of modules at the unique distances.
3. The photovoltaic system of claim 2, wherein the delta in the
amount of solar energy includes a difference in the amount of solar
energy detected at a first module subtracted from the amount of
solar energy detected at a second module.
4. The photovoltaic system of claim 3, wherein the delta in the
amount of solar energy detected by the pair of modules is
correlated with the unique distances from the photovoltaic
module.
5. The photovoltaic system of claim 4, wherein the amount of
conditioned DC power is a maximum amount of power the photovoltaic
module is expected to be capable of generating after the future
change in solar energy occurs, and wherein the amount of
conditioned DC power is less than an amount of power the
photovoltaic module is capable of generating before the future
change in solar energy occurs.
6. The photovoltaic system of claim 2, wherein the sensor further
comprises one or more additional modules, each additional module
positioned at a unique distance from the photovoltaic module.
7. The photovoltaic system of claim 2, further comprising: a
secondary sensor coupled with the sensor, the secondary sensor
selected from the group consisting of an anemometer, a wind vane, a
satellite data source, and a temperature sensor.
8. The photovoltaic system of claim 2, wherein the power condition
unit is configured to control an efficiency of the photovoltaic
module, wherein the power conditioning unit is an inverter
configured to invert the DC power from the photovoltaic module to
AC power, and wherein the inverter is configured to modify AC power
output from the inverter based on the future change in solar
energy.
9. A method for managing variability of output from a photovoltaic
system, the method comprising: detecting a future change in solar
energy to be received by a photovoltaic module, the detecting
performed by a sensor comprising a pair of modules, each module
configured to detect an amount of solar energy at a unique distance
from the photovoltaic module; conditioning DC power from the
photovoltaic module, wherein the DC power is converted from solar
energy; and outputting, from the photovoltaic system, an amount of
conditioned DC power based on the future change in solar energy,
wherein an output of the photovoltaic system is controlled before
and after the future change in solar energy occurs to output the
same amount of conditioned DC power before and after the future
change in solar energy occurs.
10. The method of claim 9, wherein the pair of modules is
configured to provide a delta in the amount of solar energy
detected by the pair of modules at the unique distances.
11. The method of claim 10 further comprising determining the delta
in the amount of solar energy, wherein the delta in the amount of
solar energy includes a difference in the amount of solar energy
detected at a first module subtracted from the amount of solar
energy detected at a second module.
12. The method of claim 11 further comprising correlating the delta
in the amount of solar energy detected by the pair of modules with
the unique distances from the photovoltaic module.
13. The method of claim 10, wherein the amount of conditioned DC
power is a maximum amount of power the photovoltaic module is
expected to be capable of generating after the future change in
solar energy occurs, and wherein the amount of conditioned DC power
is less than an amount of power the photovoltaic module is capable
of generating before the future change in solar energy occurs.
14. The method of claim 11, wherein the sensor further comprises
one or more additional modules, each additional module positioned
at a unique distance from the photovoltaic module.
15. A non-transitory machine-accessible storage medium having
instructions stored thereon which cause a data processing system to
perform a method for managing variability of output from a
photovoltaic system, the method comprising: detecting a future
change in solar energy to be received by a photovoltaic module, the
detecting performed by a sensor comprising a pair of modules, each
module configured to detect an amount of solar energy at a unique
distance from the photovoltaic module; conditioning DC power from
the photovoltaic module, wherein the DC power is converted from
solar energy; and outputting, from the photovoltaic system, an
amount of conditioned DC power based on the future change in solar
energy, wherein an output of the photovoltaic system is controlled
before and after the future change in solar energy occurs to output
the same amount of conditioned DC power before and after the future
change in solar energy occurs.
16. The non-transitory machine-accessible storage medium of claim
15, wherein the pair of modules is configured to provide a delta in
the amount of solar energy detected by the pair of modules at the
unique distances.
17. The non-transitory machine-accessible storage medium of claim
16, wherein the method further comprises determining the delta in
the amount of solar energy, wherein the delta in the amount of
solar energy includes a difference in the amount of solar energy
detected at a first module subtracted from the amount of solar
energy detected at a second module.
18. The non-transitory machine-accessible storage medium of claim
17, wherein the method further comprises correlating the delta in
the amount of solar energy detected by the pair of modules with the
unique distances from the photovoltaic module.
19. The non-transitory machine-accessible storage medium of claim
18, wherein the amount of conditioned DC power is a maximum amount
of power the photovoltaic module is expected to be capable of
generating after the future change in solar energy occurs, and
wherein the amount of conditioned DC power is less than an amount
of power the photovoltaic module is capable of generating before
the future change in solar energy occurs.
20. The non-transitory machine-accessible storage medium of claim
16, wherein the sensor further comprises one or more additional
modules, each additional module positioned at a unique distance
from the photovoltaic module.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/577,613, filed on Oct. 12, 2009, the entire
contents of which are hereby incorporated by reference herein.
TECHNICAL FIELD
[0002] Embodiments of the present invention are in the field of
renewable energy and, in particular, photovoltaic systems with
managed output and methods for managing variability of output from
photovoltaic systems.
BACKGROUND
[0003] Common types of photovoltaic deployment include off-grid and
on-grid systems. Off-grid systems are typically small (e.g., 10s of
kilowatts at most) and tied closely to an energy storage system
such as a system of deep-cycle lead acid batteries or, in some
cases, to a fueled gen-set. In an off-grid configuration, the
energy stored in the battery acts as a buffer between energy
production and demand. As such, short-term variability in the solar
resource may not be an issue. On-grid systems, by contrast, may be
quite large, with systems up to the 100s of megawatts. To date,
sizing of on-grid systems may be such that existing methods of
handling load variability (e.g., by provision of ancillary services
from generators on the grid) have been sufficient to ensure
stability of the grid.
[0004] However, with advances in photovoltaic system technology,
ever larger systems are being proposed and actually installed for
use. Such larger systems may pose challenges for power management
in at least two end markets, e.g., in island- or micro-grid systems
or in very large photovoltaic plants integrated onto large grids.
In either case, there may be restrictions on the maximum allowable
ramp rates (both "up" and "down") that are permitted in order to
maintain grid stability. Typically, the proposed method of managing
variability of renewable resources is to add an energy storage
component. However, there may be a lack of reliable, commercially
proven, and cost effective storage unit compatible with a facility
scale at the 100s of kilowatts level or higher.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 illustrates a block diagram of a photovoltaic system
with managed output, in accordance with an embodiment of the
present invention.
[0006] FIG. 2 illustrates a Flowchart representing operations in a
method for managing variability of output from a photovoltaic
system, in accordance with an embodiment of the present
invention.
[0007] FIG. 3 illustrates a block diagram of an example of a
computer system configured for performing a method for managing
variability of output from a photovoltaic system, in accordance
with an embodiment of the present invention.
DETAILED DESCRIPTION
[0008] Photovoltaic systems with managed output and methods for
managing variability of output from photovoltaic systems are
described herein. In the following description, numerous specific
details are set forth, such as specific forms of power output, in
order to provide a thorough understanding of the present invention.
It will be apparent to one skilled in the art that embodiments of
the present invention may be practiced without these specific
details. In other instances, well-known data collection techniques,
such as insolation data collection, are not described in detail in
order to not unnecessarily obscure embodiments of the present
invention. Furthermore, it is to be understood that the various
embodiments shown in the Figures are illustrative representations
and are not necessarily drawn to scale.
[0009] Disclosed herein are photovoltaic systems with managed
output. In one embodiment, a system includes a photovoltaic module
configured to receive and convert solar energy to DC power. The
system also includes a sensor configured to detect a future change
in solar energy to be received by the photovoltaic module. The
sensor includes a portfolio of distributed photovoltaic systems or
a pair of modules, each module positioned at a unique distance from
the photovoltaic module. The system further includes a power
conditioning unit coupled with the photovoltaic module and the
sensor, the power conditioning unit configured to condition DC
power from the photovoltaic module and to modify power output from
the power conditioning unit based on the future change in solar
energy.
[0010] Also disclosed herein are methods for managing variability
of output from photovoltaic systems. In one embodiment, a method
includes detecting a future change in solar energy to be received
by a photovoltaic module. The detecting is performed by a sensor
including a portfolio of distributed photovoltaic systems or a pair
of modules, each module positioned at a unique distance from the
photovoltaic module. The method also includes outputting power,
from the photovoltaic system, based on the future change in solar
energy.
[0011] A photovoltaic system with managed output may provide for
mitigation of an otherwise inherent variability of such a
photovoltaic system, particularly when integrated into an island-
or micro-grid. In accordance with an embodiment of the present
invention, a photovoltaic system with managed output controls solar
generation ramp rates and ensures stability of an electrical grid.
In an embodiment, a photovoltaic system with managed output is used
to mitigate variability for systems that reach a size or level of
penetration that impacts grid operations. A photovoltaic plant may
generate DC power which may be inverted to AC power for use on a
grid. In accordance with an embodiment of the present invention, an
inverter or power conditioning system provides the capability to
control the output of the photovoltaic plant, within the
constraints of the actual power being produced by the plant. That
is, the inverter or power conditioning system may be capable of
controlling the photovoltaic plant in a manner such that less
energy is exported to the grid than the plant is actually capable
of generating at a given time.
[0012] Ramp-up control may be readily achieved by a power
conditioning system. Accordingly, in an embodiment, situations
where photovoltaic energy production increases suddenly (e.g.,
partially cloudy conditions when the sun emerges from behind a
cloud) can be handled by a photovoltaic systems with managed
output. Management may be achieved by altering a Maximum Power
Point Tracking (MPPT) algorithm, which may generally be optimized
to maximize the energy harvest of the photovoltaic system. In an
embodiment, the MPPT algorithm is modified to produce less power
for appropriate periods of time. This approach may act to
temporarily lower the efficiency of the photovoltaic system modules
with fast and accurate control. In addition, in one embodiment,
photovoltaic system inverters are utilized to enhance grid
stability by providing or absorbing reactive power.
[0013] An approach to controlling photovoltaic system or plant
output include driving photovoltaic tracking systems such that the
tracking systems are not pointing at the sun, but this may be less
desirable from the standpoint of speed, accuracy, and level of
control. While potentially useful, such a method of control does
not directly address situations where the photovoltaic plant output
drops quickly (e.g., when the sun is occluded by rapidly moving
clouds). By contrast, in an embodiment, the need for energy storage
is reduced or eliminated by managing photovoltaic plant output. For
example, in accordance with an embodiment of the present invention,
prediction, on a minutes-ahead basis, of the extent and speed of
cloud cover is performed. In anticipation of a resulting change in
intensity of solar radiation, a photovoltaic plant output may be
reduced in a controlled fashion (e.g., respecting ramp rate limits)
to the level expected once the cloud cover is at its point of
maximum impact on photovoltaic plant production.
[0014] In an embodiment, methods for managing variability of output
from photovoltaic systems include using a power conditioning system
to skew the MPPT algorithm to lower the power output as a cloud
approaches and then, as the cloud passes overhead, to skew the MPPT
back towards the maximum power point in order to balance the
dropping insolation, effectively maintaining steady output at the
photovoltaic plant. Once insolation recovers, plant output may be
controlled as described above to ensure conformance to ramp rate
limits during ramp-up. The ability to control both power output
level and reactive power may significantly increase the value of a
photovoltaic system as a dispatchable resource. Such control may be
used not only to mitigate variability of the solar resource, but
also as a resource to help manage grid stability more generally,
e.g., in the event of conventional power plant shutdowns, line
faults, and other issues. In an embodiment, short-term forecasting
based on sensor networks or data from the photovoltaic plant itself
is used in conjunction with active inverter control to meet ramp
rate limitations without the need for energy storage. In an
embodiment, data from distributed systems is used to predict and
control the output of centralized systems or multiple systems
within high penetration control areas.
[0015] In an aspect of the present invention, photovoltaic systems
with managed output are described. FIG. 1 illustrates a block
diagram of a photovoltaic system with managed output, in accordance
with an embodiment of the present invention.
[0016] Referring to FIG. 1, a photovoltaic system 100 has managed
output. Photovoltaic system 100 includes a photovoltaic module 102
configured to receive and convert solar energy to DC power.
Photovoltaic system 100 also includes a sensor 104 configured to
detect a future change in solar energy to be received by
photovoltaic module 102. Photovoltaic system 100 further includes a
power conditioning unit 108 coupled with photovoltaic module 102
and sensor 104.
[0017] In accordance with an embodiment of the present invention,
sensor 104 includes a portfolio of distributed photovoltaic systems
110 or a pair of modules 112, each module positioned at a unique
distance (L and L') from photovoltaic module 102, or both. In one
embodiment, sensor 104 is the portfolio of distributed photovoltaic
systems 110. In a specific embodiment, the portfolio of distributed
photovoltaic systems 110 includes nearby residential or commercial,
or both, photovoltaic systems from a predetermined geographic area.
In one embodiment, sensor 104 is the pair of modules 112. In a
specific embodiment, the pair of modules 112 is configured to
provide a delta in energy detected by the pair of modules 112. For
example, the difference in detected solar radiation at one module
is subtracted from the solar radiation detected at the second
module and correlated with distance and bearing (e.g. L vs. L'). In
a particular embodiment, sensor 104 further includes one or more
additional modules 113, each module positioned at a unique distance
from photovoltaic module 100.
[0018] Sensor 104 may further include or be associated with
additional sensing systems to better target real time changes in
energy input to photovoltaic module 102. For example, in an
embodiment, sensor 104 further includes a network of insolation
sensor modules 114 arranged around the perimeter of, or
interspersed with, photovoltaic system 100. In another embodiment,
sensor 104 further includes a network of still cameras or a
combination of still and video cameras 116. In an embodiment,
photovoltaic system 100 further includes a secondary sensor 118
coupled with sensor 104, secondary sensor 118 composed of a sensor
such as, but not limited to, an anemometer, a wind vane, a
satellite data source, or a temperature sensor. In another
embodiment, photovoltaic system 100 further includes a
neural-network 120 configured to compute a value for the future
change in solar energy detected by sensor 104.
[0019] In accordance with an embodiment of the present invention,
power conditioning unit 108 is configured to condition DC power
from photovoltaic module 102 and to modify power output from the
power conditioning unit based on the future change in solar energy.
For example, in one embodiment, power conditioning unit 108 is an
inverter, the inverter configured to invert, to AC power, DC power
from photovoltaic module 102. In that embodiment, the inverter is
also configured to modify AC power output from the inverter based
on the future change in solar energy. In an alternative embodiment,
power conditioning unit 108 conditions DC power from photovoltaic
module 102 and then outputs the conditioned DC power based on the
future change in solar energy.
[0020] In another aspect of the present invention, methods are
provided for managing variability of output from photovoltaic
systems. FIG. 2 illustrates a Flowchart 200 representing operations
in a method for managing variability of output from a photovoltaic
system, in accordance with an embodiment of the present
invention.
[0021] Referring to operation 202 of Flowchart 200, a method for
managing variability of output from a photovoltaic system includes
detecting a future change in solar energy to be received by a
photovoltaic module. In accordance with an embodiment of the
present invention, the detecting is performed by a sensor including
a portfolio of distributed photovoltaic systems or a pair of
modules, each module positioned at a unique distance from the
photovoltaic module, or both.
[0022] In one embodiment, detecting the future change in solar
energy to be received by the photovoltaic module includes detecting
by the portfolio of distributed photovoltaic systems. In a specific
embodiment, the portfolio of distributed photovoltaic systems
includes nearby residential or commercial, or both, photovoltaic
systems from a predetermined geographic area. In one embodiment,
detecting the future change in solar energy to be received by the
photovoltaic module includes detecting by the pair of modules. In a
specific embodiment, the pair of modules is configured to provide a
delta in energy detected by the pair of modules. For example, the
difference in detected solar radiation at one module is subtracted
from the solar radiation detected at the second module and
correlated with distance and bearing. In a particular embodiment,
the sensor further includes one or more additional modules, each
module positioned at a unique distance from the photovoltaic
module.
[0023] The sensor may further include or be associated with
additional sensing systems to better target real time changes in
energy input to the photovoltaic module. For example, in an
embodiment, the sensor further includes a network of insolation
sensor modules arranged around the perimeter of, or interspersed
with, the photovoltaic system. In another embodiment, the sensor
further includes a network of still cameras or a combination of
still and video cameras. In an embodiment, detecting the future
change in solar energy to be received by the photovoltaic module
further includes detecting by a secondary sensor coupled with the
sensor. The secondary sensor is composed of a sensor such as, but
not limited to an anemometer, a wind vane, a satellite data source,
or a temperature sensor. In another embodiment, detecting the
future change in solar energy to be received by the photovoltaic
module further includes computing, by a neural-network, a value for
the future change in solar energy.
[0024] Referring to operation 204 of Flowchart 200, the method for
managing variability of output from a photovoltaic system further
includes outputting power, from the photovoltaic system, based on
the future change in solar energy. In accordance with an embodiment
of the present invention, the power conditioning unit is configured
to condition DC power from the photovoltaic module and to modify
power output from the power conditioning unit based on the future
change in solar energy. For example, in one embodiment, the power
conditioning unit is an inverter, the inverter configured to
invert, to AC power, DC power from the photovoltaic module. In that
embodiment, the inverter is also configured to modify AC power
output from the inverter based on the future change in solar
energy. In an alternative embodiment, the power conditioning unit
conditions DC power from the photovoltaic module and the outputs
the conditioned DC power based on the future change in solar
energy.
[0025] In an embodiment, the present invention is provided as a
computer program product, or software product, that includes a
machine-readable medium having stored thereon instructions, which
is used to program a computer system (or other electronic devices)
to perform a process or method according to embodiments of the
present invention. A machine-readable medium may include any
mechanism for storing or transmitting information in a form
readable by a machine (e.g., a computer). For example, in an
embodiment, a machine-readable (e.g., computer-readable) medium
includes a machine (e.g., a computer) readable storage medium
(e.g., read only memory ("ROM"), random access memory ("RAM"),
magnetic disk storage media or optical storage media, flash memory
devices, etc.).
[0026] FIG. 3 illustrates a diagrammatic representation of a
machine in the form of a computer system 300 within which a set of
instructions, for causing the machine to perform any one or more of
the methodologies discussed herein, is executed. For example, in
accordance with an embodiment of the present invention, FIG. 3
illustrates a block diagram of an example of a computer system
configured for performing a method for managing variability of
output from a photovoltaic system. In alternative embodiments, the
machine is connected (e.g., networked) to other machines in a Local
Area Network (LAN), an intranet, an extranet, or the Internet. In
an embodiment, the machine operates in the capacity of a server or
a client machine in a client-server network environment, or as a
peer machine in a peer-to-peer (or distributed) network
environment. In an embodiment, the machine is a personal computer
(PC), a tablet PC, a set-top box (STB), a Personal Digital
Assistant (PDA), a cellular telephone, a web appliance, a server, a
network router, switch or bridge, or any machine capable of
executing a set of instructions (sequential or otherwise) that
specify actions to be taken by that machine. Further, while only a
single machine is illustrated, the term "machine" shall also be
taken to include any collection of machines (e.g., computers or
processors) that individually or jointly execute a set (or multiple
sets) of instructions to perform any one or more of the
methodologies discussed herein.
[0027] The example of a computer system 300 includes a processor
302, a main memory 304 (e.g., read-only memory (ROM), flash memory,
dynamic random access memory (DRAM) such as synchronous DRAM
(SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 306 (e.g.,
flash memory, static random access memory (SRAM), etc.), and a
secondary memory 318 (e.g., a data storage device), which
communicate with each other via a bus 330.
[0028] Processor 302 represents one or more general-purpose
processing devices such as a microprocessor, central processing
unit, or the like. More particularly, in an embodiment, the
processor 302 is a complex instruction set computing (CISC)
microprocessor, reduced instruction set computing (RISC)
microprocessor, very long instruction word (VLIW) microprocessor,
processor implementing other instruction sets, or processors
implementing a combination of instruction sets. In one embodiment,
processor 302 is one or more special-purpose processing devices
such as an application specific integrated circuit (ASIC), a field
programmable gate array (FPGA), a digital signal processor (DSP),
network processor, or the like. Processor 302 executes the
processing logic 326 for performing the operations discussed
herein.
[0029] In an embodiment, the computer system 300 further includes a
network interface device 308. In one embodiment, the computer
system 300 also includes a video display unit 310 (e.g., a liquid
crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric
input device 312 (e.g., a keyboard), a cursor control device 314
(e.g., a mouse), and a signal generation device 316 (e.g., a
speaker).
[0030] In an embodiment, the secondary memory 318 includes a
machine-accessible storage medium (or more specifically a
computer-readable storage medium) 331 on which is stored one or
more sets of instructions (e.g., software 322) embodying any one or
more of the methodologies or functions described herein, such as a
method for associating a load demand with a variable power
generation. In an embodiment, the software 322 resides, completely
or at least partially, within the main memory 304 or within the
processor 302 during execution thereof by the computer system 300,
the main memory 304 and the processor 302 also constituting
machine-readable storage media. In one embodiment, the software 322
is further transmitted or received over a network 320 via the
network interface device 308.
[0031] While the machine-accessible storage medium 331 is shown in
an embodiment to be a single medium, the term "machine-readable
storage medium" should be taken to include a single medium or
multiple media (e.g., a centralized or distributed database, or
associated caches and servers) that store the one or more sets of
instructions. The term "machine-readable storage medium" shall also
be taken to include any medium that is capable of storing or
encoding a set of instructions for execution by the machine and
that cause the machine to perform any one or more of the
methodologies of embodiments of the present invention. The term
"machine-readable storage medium" shall accordingly be taken to
include, but not be limited to, solid-state memories, and optical
and magnetic media.
[0032] It is to be understood that embodiments of the present
invention may be relevant where the size of a photovoltaic system
is such that it has a material impact on the operation or
maintenance of a utility power system. In one embodiment, the
material impact occurs at a level where the peak power of the
photovoltaic system is significant relative to the peak capacity of
the portion of the grid the system that it is tied into. In a
specific embodiment, the level is approximately above 10% of a
feeder, a substation, or a regulation service capacity. However,
other embodiments are not limited to such levels.
[0033] It is also to be understood that for sensor modules, each
module and each sensor of each "sensor module" may tied to separate
power conditioning systems, or each sensor module pair may be tied
to a power conditioning system separate from other sensor module
pairs.
[0034] Thus, photovoltaic systems with managed output and methods
for managing variability of output from photovoltaic systems have
been disclosed. In accordance with an embodiment of the present
invention, a system includes a photovoltaic module configured to
receive and convert solar energy to DC power. The system also
includes a sensor configured to detect a future change in solar
energy to be received by the photovoltaic module. The sensor
includes a portfolio of distributed photovoltaic systems or a pair
of modules, each module positioned at a unique distance from the
photovoltaic module. The system further includes a power
conditioning unit coupled with the photovoltaic module and the
sensor, the power conditioning unit configured to condition DC
power from the photovoltaic module and to modify power output from
the power conditioning unit based on the future change in solar
energy. In one embodiment, the sensor is the portfolio of
distributed photovoltaic systems, the portfolio of distributed
photovoltaic systems comprising nearby residential or commercial,
or both, photovoltaic systems from a predetermined geographic area.
In another embodiment, the sensor is the pair of modules, the pair
of modules configured to provide a delta in energy detected by the
pair of modules.
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