Patent Application
20130249293
This disclosure relates to photovoltaic solar panels, and, more specifically, to a solar panel having a functional back glass.
A conventional photovoltaic solar panel, whether having crystalline or thin film photovoltaic (PV) power generators, includes a PV power generating layer sandwiched between a transparent front substrate and a back substrate. Each of the substrates, commonly, is made of glass, and the terms “front glass” and “back glass” may be used to refer to these components. Ambient electromagnetic energy from, e.g., sunlight, is received at the PV power generating layer through the transparent front glass. A junction box is typically disposed on the back side of the back glass for interconnecting the solar panel to an adjacent solar panel and/or to a power bus. The back glass, which may be secured to the front glass with an epoxy, functions primarily as a mechanical component that, for example, prevents intrusion of moisture into the interior of the “sandwich”, provides mechanical rigidity of the assembled solar panel, and an attachment area for the junction box.
When integrated into an array, such solar panels are typically connected in a series string and deliver direct current (DC) output power thereto. The series string typically also includes, for example, a DC disconnect, an inverter for converting DC current to alternating current (AC), an AC disconnect, and a power meter. Such components are typically disposed externally to any individual solar panel. Alternatively, some such components may be disposed in the interior of a panel “sandwich” by displacing or covering part of the PV power generating layer.
As a result, undesirably, the above-described techniques entail a complex and expensive integration of components external to the solar panels, do not permit monitoring and control of an individual solar panel, and/or reduce the effective area of the PV power generating layer.
The systems, methods and devices of the disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein. One innovative aspect of the subject matter described in this disclosure can be implemented in a PV solar panel having a front glass, a back glass, and a PV power generating layer encapsulated between the front glass and the back glass. The PV power generating layer may include, for example, a planar array of crystalline solar cells, or a thin film PV layer. The PV power generating layer is configured to convert ambient electromagnetic energy, received through the front glass, to a direct current (DC) power output. The PV solar panel also includes at least one component, the at least one component including one or more of: a direct current to alternating current (DC-AC) inverter configured to convert the DC power output from the PV power generating layer to an AC power output, a battery, and an antenna. The at least one component is disposed behind the PV power generating layer.
In some implementations, the at least one component may be disposed on a surface of the back glass. The at least one component may be disposed on a front surface of the back glass, and encapsulated between the back glass and the PV power generating layer or may be disposed behind the back glass.
The DC-AC inverter may include a capacitor and an inductor; and one or both of the capacitor and the inductor are fabricated on the back glass. The back glass may be configured as a substrate for growing the capacitor and for deposition of the inductor. The DC-AC inverter may include a switching arrangement, a power transformer, a rectifier, a low pass filter and a resonator circuit.
In an implementation, the at least one component includes the battery, the battery being a thin form factor rechargeable battery having a thickness of less than approximately 10 millimeters.
In a further implementation, the at least one component includes the antenna and a radio frequency (RF) circuit, the antenna being a Zigbee or radio frequency identification (RFID) antenna.
The solar panel may include the DC-AC inverter, a logic control circuit, the antenna, and an RF circuit. Each of the DC-AC inverter, the logic control circuit, the battery, the antenna, and the RF circuit may be integrated as a module disposed behind the back glass. The solar panel may include one or more of: a sunlight photodetector, a temperature sensor, and wind velocity sensor. The antenna may be communicatively coupled to an array control center, and may transmit output data received from the logic control circuit or the at least one sensor to the array control center. The antenna may receive control signals from the array control center.
In some implementations a solar panel array includes a plurality of solar panels, connected in a string, each solar panel configured to produce an output power, and each solar panel including: a photovoltaic (PV) power generating layer encapsulated between the front glass and the back glass. Each solar panel includes a direct current to alternating current (DC-AC) inverter disposed behind a back surface of the PV generating layer; and the output power of each solar panel onto the string is only AC. The plurality of solar panels may be connected to the string in parallel. At least one solar panel may include an antenna that is communicatively coupled to an array control center. The at least one solar panel is configured to be monitored and controlled by the array control center, independent of any other solar panel in the solar panel array.
In an implementation, a photovoltaic (PV) solar panel includes a front glass, a first back glass, a second back glass, and a PV power generating layer encapsulated between the front glass and the first back glass. The second back glass is disposed behind the first back glass and includes one or more of: a direct current to alternating current (DC-AC) inverter, a battery, and an antenna. The second back glass may be laminated to the back surface of the first back glass.
In another implementation an apparatus includes means for generating photovoltaic (PV) power, encapsulated between a front glass and a back glass of a PV solar panel, and having a back surface, the PV solar panel defining a planar area; means, disposed behind the back surface and proximate to the center of the planar area, for converting direct current (DC) power to alternating current (AC) power. The means for converting DC power to AC power may be disposed on a surface of the back glass. The means for converting DC power to AC power may include at least one capacitor and at least one inductor, and wherein one or more of the capacitor and the inductor are fabricated on the back glass.
In a further implementation, a method for fabricating a photovoltaic (PV) solar panel includes disposing, on a surface of a back glass of the PV solar panel, one or more of: a direct current to alternating current (DC-AC) inverter, a battery, and an antenna; and encapsulating a photovoltaic power generating layer between a front glass of the PV solar panel and the back glass. The at least one component is disposed behind the PV power generating layer. The at least one component may be disposed on a front surface of the back glass, and encapsulated between the back glass and the PV power generating layer. The DC-AC inverter may include at least one capacitor and at least one inductor, and one or more of the capacitor and the inductor may be fabricated on the back glass.
In another implementation, a method includes monitoring signals from at least one individual photovoltaic (PV) solar panel of a solar panel array, the signals being received from an antenna disposed on the individual PV solar panel; controlling one or both of the individual PV solar panel and the solar panel array, responsive to the received signals. The individual PV solar panel includes a front glass, a back glass, and a PV power generating layer encapsulated between the front glass and the back glass and the antenna is disposed behind the PV power generating layer.
The solar panel array may include a plurality of solar panels, and the output power output of each solar panel in the array may include only AC power. The controlling one or both of the individual PV solar panel and the solar panel array may be performed at an array control center remote from the solar panel array, independent of any other solar panel in the solar panel array.
Details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims. Note that the relative dimensions of the following figures may not be drawn to scale.
Like reference numbers and designations in the various drawings indicate like elements.
The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. Thus, the teachings are not intended to be limited to the implementations depicted solely in the Figures, but instead have wide applicability as will be readily apparent to one having ordinary skill in the art.
Described herein below are new techniques incorporating a photovoltaic (PV) solar panel having a front glass, a back glass, and a PV power generating layer encapsulated between the front glass and the back glass. One or more of a direct current to alternating current (DC-AC) inverter, a battery, and an antenna, is disposed behind the PV power generating layer. In some implementations, at least some components of the DC-AC inverter, the battery, and/or the antenna are disposed on a front surface of the back glass, encapsulated between the back glass and the PV power generator.
Particular implementations of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. By adding functionality to the back glass of a solar panel, in accordance with the present teachings, installation of an array of such solar panels is greatly simplified, while maintenance and other life cycle costs are significantly reduced. For example, when the DC-AC inverter, which may be configured as an integrated micro-inverter, is disposed in each solar panel behind the PV power generating layer, as described herein, each solar panel may deliver AC power, in parallel, to a string of solar panels or to an electrical grid. A need for external components such as an array inverter, and inverter disconnects, is thus avoided. Advantageously, because the DC-AC inverter is disposed behind the PV power generating layer, the entire planar area of the panel may be populated with PV power generating elements (e.g., solar cells, or an active PV thin film layer), without reserving part of the planar area for non-power generating components.
In addition, the present inventors have appreciated that an integrated solar panel, including a “functional back glass”, may enable simpler, less costly, system integration, while providing opportunities for more robust and granular array management and maintenance. As used herein, “functional back glass” broadly refers to a solar panel back glass that, in addition to the mechanical functionality of the prior art, includes, or has disposed thereon, one or more of a DC-AC inverter, a battery, and an antenna. In some implementations, the integrated solar panel of the presently disclosed techniques has substantially identical envelope dimensions, and mechanical interfaces as solar panels of the prior art. As noted above, the DC-AC inverter, the battery, the antenna, diagnostic and/or telecommunication components may be disposed in each solar panel, behind the PV power generating layer, thereby providing additional functionality without reducing the planar area available for the PV power generating layer. In some implementations, in-situ monitoring and diagnosis is facilitated by use of sensors and wireless communications components. In some implementations, the battery may be configured to locally store excess energy generated by the solar panel.
An array of solar panels configured along the lines of the present teachings provides a number of advantages with respect to the known art, particularly where a large array of solar panels is contemplated. For example, each solar panel may be configured to automatically monitor, and transmit, to an array control center, its PV energy conversion status, and/or automatically warn of a need for preventative maintenance when it senses potentially hazardous environmental conditions, such as extreme temperature or wind speed.
According to one innovative aspect of the subject matter described in this disclosure, a PV solar panel includes a front glass, a back glass, and a PV power generating layer encapsulated between the front glass and the back glass. The PV solar panel also includes one or more of the following components, disposed behind the PV power generating layer: a DC-AC inverter, a battery, and an antenna.
In some implementations, back glass 130 may include an access hole (“opening”) 131 through which electrical wiring from, for example, PV power generating layer 120 may be passed. Opening 131 may be located, as illustrated, proximate to a substantially central portion of a planar area defined by the perimeter of back glass 130. Enclosure 140 may be disposed proximate to opening 131, on the back side of back glass 130. Enclosure 140 may have similar functionality and external dimensions as the aforementioned conventional junction box. In addition, enclosure 140 may house one or more additional electrical components or elements. For example, one or more of a DC-AC inverter configured to convert the DC power output from the PV power generating layer 120 to an AC power output, a battery, and an antenna, may be disposed within enclosure 140.
Back glass 130, advantageously, may be provided with one or more regions 132 within which electrical elements may be disposed and/or fabricated as described herein below. Each region 132 may be proximate to the front side or the back side of back glass 130. Region 132 may, as illustrated, be proximate to opening 131.
Advantageously, in some implementations at least parts of the DC-AC inverter, the battery, and the antenna may be fabricated on, or disposed proximate to, an inner surface of the back glass. In some implementations, by selecting appropriate thin form components, the thickness of the panel “sandwich” for such implementations may be negligibly larger, or substantially the same as, the prior art. In some implementations the aforementioned components may be encapsulated together “inside the sandwich,” with the result that excellent environmental tolerance and longer system lifetime may be provided.
DC-AC inverter 251 may be configured to convert power output from the PV power generator to an AC power output as described in more detail herein below. Battery 253 may be configured to locally store excess energy, generated by solar panel 100. Antenna 255 may include, for example, a Zigbee antenna or a radio frequency identification (RFID) antenna, accompanied by appropriate radio frequency (RF) circuits. As described in more detail herein below, antenna 255 may be communicatively coupled to an array control center (not shown).
Advantageously, thin form factor electronic components 377 may be disposed on or proximate to front surface 133 of back glass 130, and be encapsulated together with PV power generating layer 120. In some implementations, thin form factor electronic components 377 may be disposed in regions 132 proximate to opening 131, as illustrated in
Enclosure 140, as illustrated, may be disposed behind back glass 130, proximate to opening 131. Enclosure 140 may include components of DC-AC inverter 251, battery 253 and/or antenna 255 other than thin form factor components 377. The components of DC-AC inverter 251, battery 253 and/or antenna 255 within enclosure 140 may be electrically coupled to thin form factor components 377 by way of electrically conductive paths 378. Components included in enclosure 140 may advantageously include, for example, bulk form components or high heat dissipating components. The bulk form components may include those components having a thickness greater than a gap distance between front glass 110 and back glass 130 or that have lateral dimensions incompatible with the PV solar panel. The heat dissipating components may include metallic components like aluminum radiators and heat sinks.
Electrically conductive paths 378 are illustrated, for clarity, as transiting through back glass 130, but this is not necessarily so. Conductive paths 378 may include, for example, metallic traces disposed on front surface 133 of back glass 130, back surface 134 of back glass 130 and/or circumferential surface 135 of opening 131.
In some implementations, thin form factor electronic components 477a and thin form factor electronic components 477b may be disposed in regions 132 proximate to opening 131, as illustrated in
Enclosure 140, as illustrated, may be disposed behind back glass 130, proximate to opening 131. Enclosure 140 may include components of DC-AC inverter 251, battery 253 and/or antenna 255 other than thin form factor components 477a and 477b. The components of DC-AC inverter 251, battery 253 and/or antenna 255 within enclosure 140 may be electrically connected to thin form factor components 477a and to thin form factor components 477b by, respectively, electrically conductive paths 378 or conductors 379.
In the illustrated implementation, thin form factor electronic components 477a are disposed external to the space enclosed by enclosure 140, and may be electrically coupled to components of DC-AC inverter 251, battery 253 and/or antenna 255 disposed therein by way of electrically conductive paths 378. Electrically conductive paths 378 are illustrated, for clarity, as transiting through back glass 130, but this is not necessarily so. Electrically conductive paths 378 may include, for example, metallic traces disposed on back surface 134 of back glass 130.
In the illustrated implementation, thin form factor electronic components 477b are, advantageously, disposed internal to the space enclosed by enclosure 140, and may be electrically coupled to components of DC-AC inverter 251, battery 253 and/or antenna 255 disposed therein by way of conductors 379.
In the illustrated implementation, thin form factor electronic components 477a and 477b are disposed on or proximate to back surface 534 of second back glass 130. Thin form factor components 477a and 477b may include, for example, capacitors, inductors, antenna or battery components, as described in more detail herein below.
Enclosure 140, as illustrated, may be disposed behind second back glass 537, proximate to opening 131. Enclosure 140 may include components of DC-AC inverter 251, battery 253 and/or antenna 255 other than thin form factor components 477a and 477b. Components of DC-AC inverter 251, battery 253 and/or antenna 255 may be electrically connected to thin form factor components 477a and to thin form factor components 477b by, respectively, electrically conductive paths 378 or conductors 379.
In the illustrated implementation, thin form factor electronic components 477a are disposed external to the space enclosed by enclosure 140, and may be electrically coupled to components of DC-AC inverter 251, battery 253 and/or antenna 255 disposed therein by way of electrically conductive paths 378. Electrically conductive paths 378 are illustrated, for clarity, as transiting through second back glass 537, but this is not necessarily so. Electrically conductive paths 378 may include, for example, metallic traces disposed on back surface 534 of second back glass 537.
In the illustrated implementation, thin form factor electronic components 477b are disposed internal to the space enclosed by enclosure 140, and may be electrically coupled to components of DC-AC inverter 251, battery 253 and/or antenna 255 disposed therein by way of conductors 379.
Second back glass 537 may be secured to first back glass 536 by, for example, an epoxy or other adhesive. In an implementation, first back glass 536 is a back glass of a conventional solar panel. A benefit of such an implementation is that an existing, conventional solar panel may be readily upgraded or retrofitted.
It will be understood that the arrangements described hereinabove represent example implementations, and that numerous variations thereof are within the contemplation of the present inventors. For example, referring still to
As indicated above, the present inventors have appreciated that DC-AC inverter 251 may include at least some thin form factor electronic components 377 which may advantageously be disposed proximate to a surface of, for example, back glass 130. The thin form factor electronic components 377 may include passive devices configured in a thin, planar form factor so as to have an inconsequential impact on an effective thickness of back glass 130.
In some implementations, moreover, back glass 130 is configured as a substrate upon which thin form factor electronic components 377 may be integrated. For example, back glass 130 may be used as a substrate for a growing large-area dielectric capacitor, and may conveniently permit deposition of thin form factor inductors as described in more detail herein below. Advantageously, at least some thin form factor electronic components 377 may be configured as microelectromechanical systems (MEMS) devices that include structures having sizes ranging from about one micron to hundreds of microns.
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In block 812, a dielectric material 714 such as alumina may be deposited about a surface of the stacked layered structure 750, resulting in stacked layered structure 751 as shown in
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Although the foregoing description relates to fabrication of capacitors and inductors as MEMS devices on back glass 130, in some implementations, other components may be integrated onto a surface of back glass 130. For example, a thin form factor rechargeable battery, such as a Li-ion battery may be contemplated. In some implementations, such a battery may have a thickness of less than one millimeter. The battery may be configured to locally store excess energy generated by the solar panel 100. In addition, solar panel 100 may include performance meters and environmental sensors, components, at least, of which may be integrated onto a surface of, for example, back glass 130. For example, solar panel 100 may include output current and voltage sensors, a sunlight photodetector, a temperature sensor, a battery state of charge detector, and/or a MEMS-based wind velocity sensor, such as an ultrasonic or piezoelectric air flow sensor.
In some implementations, one or more antennas may be provided, including, for example, a Zigbee antenna or an RFID antenna, accompanied by appropriate RF circuits, components, at least of which may be integrated onto a surface of, for example, back glass 130. The antennas may be communicatively coupled to an array control center, for example.
In some implementations, a logic control circuit may be configured to provide for panel identification, in-situ monitoring, and diagnosis. In some implementations, a wireless transceiver may be provided that automatically sends an error signal to the array control center 1410 in the event of an anomaly. In response to a command from the array control center 1410, or, in some implementations, autonomously, the panel current output may be cut off in the event of an anomaly. Responsive to the received signals, array control center 1410 may send commands to individual solar panels 100 to, e.g., cut off panel output current in the event of a malfunction. Thus, an individual solar panel 100 may be configured to be monitored and controlled by array control center 1410, independent of any other solar panel in the solar panel array.
At block 1520, the PV power generating layer may be encapsulated between a front glass of the PV solar panel and the back glass, at least one of the DC-AC inverter, the battery, and the antenna being disposed behind the PV power generating layer. Details of some implementations of the PV solar panel have been described above.
At block 1620 the individual PV solar panel and/or the solar panel array may be controlled, responsive to the received signals. For example, the solar panel current output may be cut off in the event of an anomaly. Advantageously, this may be accomplished from a remote array control center. In an implementation, the control center is configured to monitor and control at least some individual PV solar panels in the solar panel array, independent of any other solar panel in the solar panel array.
The various illustrative logics, logical blocks, modules, circuits and algorithm steps described in connection with the implementations disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. The interchangeability of hardware and software has been described generally, in terms of functionality, and illustrated in the various illustrative components, blocks, modules, circuits and steps described above. Whether such functionality is implemented in hardware or software depends upon the particular application and design constraints imposed on the overall system.
The hardware and data processing apparatus used to implement the various illustrative logics, logical blocks, modules and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, controller, microcontroller, or state machine. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some implementations, particular steps and methods may be performed by circuitry that is specific to a given function.
In one or more aspects, the functions described may be implemented in hardware, digital electronic circuitry, computer software, firmware, including the structures disclosed in this specification and their structural equivalents thereof, or in any combination thereof. Implementations of the subject matter described in this specification also can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions, encoded on a computer storage media for execution by, or to control the operation of, data processing apparatus.
If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. The steps of a method or algorithm disclosed herein may be implemented in a processor-executable software module which may reside on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that can be enabled to transfer a computer program from one place to another. A storage media may be any available media that may be accessed by a computer. By way of example, and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that may be used to store desired program code in the form of instructions or data structures and that may be accessed by a computer. Also, any connection can be properly termed a computer-readable medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above also may be included within the scope of computer-readable media. Additionally, the operations of a method or algorithm may reside as one or any combination or set of codes and instructions on a machine readable medium and computer-readable medium, which may be incorporated into a computer program product.
Various modifications to the implementations described in this disclosure may be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the claims are not intended to be limited to the implementations shown herein, but are to be accorded the widest scope consistent with this disclosure, the principles and the novel features disclosed herein. The word “exemplary” is used exclusively herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other possibilities or implementations.
Certain features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.
Similarly, while operations are depicted in the drawings in a particular order, a person having ordinary skill in the art will readily recognize that such operations need not be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Further, the drawings may schematically depict one more example processes in the form of a flow diagram. However, other operations that are not depicted can be incorporated in the example processes that are schematically illustrated. For example, one or more additional operations can be performed before, after, simultaneously, or between any of the illustrated operations. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the implementations described above should not be understood as requiring such separation in all implementations, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.
