Claims:WE CLAIM:

1. A solar Panel for real time monitoring of cell temperature in actual field conditions comprising solar cell string (3) interposed between two sheets (2, 4), which is covered by front glass panel (1) and module back sheet (6), wherein a passive RFID tag (5) is placed on one of the cells (3) for real time monitoring of cell temperature.

2. The solar Panel for real time monitoring of cell temperature in actual field conditions as claimed in the claim 1, wherein the cell string (3) includes Silicon (Si),Gallium Arsenide (GaAs), Cadmium Telluride (CdTe),Copper Indium Gallium Selenide (CIGS), brittle crystalline structures ( GaAs) or as flexible thin-film cells (Si, CdTe, CIGS).

3. The solar Panel for real time monitoring of cell temperature in actual field conditions as claimed in the claim 1 or 2, wherein the intermediate sheets (2,4) can be made of Ethylene-vinyl acetate (EVA) polymer, the module back sheet (6) can be made of Plastic or glass and front panel (1) can be made of glass.

4. The solar Panel for real time monitoring of cell temperature in actual field conditions as claimed in the claims 1-3, wherein the cells (3) are laminated in between EVA polymer sheets(2, 4) and the passive RFID tag (5) in the form of sheet, which is battery-free and maintenance-free is placed on one of the cells which can monitor the cell temperature in-situ for measuring the exact temperature.

5. The solar Panel for real time monitoring of cell temperature in actual field conditions as claimed in the claims 1-4, wherein said passive RFID sensor tag utilizing the RFMicron S3 chip can identify temperature of the cell, in which the tag can be affixed/embedded into most materials and has an average read range of 15-22 feet, in which the tag functions in a range between 40°C to +85°C.
, Description:SOLAR PANEL FOR REAL TIME MONITORING OF CELL TEMPERATURE IN ACTUAL FIELD CONDITIONS

FIELD OF THE INVENTION

[001] The present invention relates to Solar Panel with real time monitoring of cell temperature in actual field conditions.

[002] It is used to measure real time (in field) cell temperature of solar panel to analyse its performance i.e. effect of temperature on power generated.

BACKGROUND OF THE INVENTION

[003] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[004] Photovoltaic modules use light energy (photons) from the Sun to generate electricity through the photovoltaic effect. Most modules use wafer-based crystalline silicon cells or thin-film cells. The structural (load carrying) member of a module can be either the top layer or the back layer. Cells must be protected from mechanical damage and moisture. Most modules are rigid, but semi-flexible ones based on thin-film cells are also available. The cells are connected electrically in series, one to another to the desired voltage, and then in parallel to increase amperage. The wattage of the module is the mathematical product of the voltage and the amperage of the module. The manufacture specifications on solar panels are obtained under standard condition which is not the real operating condition the solar panels are exposed to on the installation site.
[005] Most solar modules are currently produced from crystalline silicon (c-Si) solar cells made of multicrystalline and monocrystalline silicon. In 2013, crystalline silicon accounted for more than 90 percent of worldwide PV production, while the rest of the overall market is made up of thin-film technologies using cadmium telluride, CIGS and amorphous silicon.

[006] There are many practical applications for the use of solar panels or photovoltaics. It can first be used in agriculture as a power source for irrigation. In health care solar panels can be used to refrigerate medical supplies. It can also be used for infrastructure. PV modules are used in photovoltaic systems and include a large variety of electric devices:
• Photovoltaic power stations
• Rooftop solar PV systems
• Standalone PV systems
• Solar hybrid power systems
• Concentrated photovoltaics
• Solar planes
• Solar-powered water purification
• Solar-pumped lasers
• Solar vehicles
• Solar panels on spacecrafts and space stations

[007] The temperature which a crystalline silicon solar cell experiences in field at a particular place and a particular time, affects the panel performance to a great extent. Higher the cell temperature, lower the voltage and hence efficiency. To know the actual cell temperature in real time is an essential requirement when analyzing the performance of an installed solar Photovoltaics (SPV) power plant or for designing a future SPV power plant. As on date the cell temperature can be measured using following methods:
1. Sticking a thermocouple at the back of the panel on the back sheet, which is usually tedlar or glass. These materials are bad conductors of heat hence real cell temperature cannot be observed accurately.

[008] Using a non-contact infrared based temperature sensor. In this case also the radiations coming out from the Si surface have to pass through front glass which does not indicate the actual cell temperature. The inaccuracy may range from a few degrees to 20 degree C. These inaccuracies lead to wrong analysis.

Prior Art

[009] Some of the patents may be discussed herein below:
1. Patent number US20100236598A1 (Year of issue 2010) entitled “Embedded RFID solution for solar panels” deals with a method for producing a solar photovoltaic panel with an embedded RFID. This patent deals with process by which RFID is embedded. It is only used to store the information about the ratings and electrical properties of solar panel and does not deal with the information regarding actual cell temperature.

2. Patent number CN201725358U dated 07.07.2010 deals with an active RFID device which is powered by solar energy, It comprises a solar-cell panel which is connected with an energy converter. The energy converter is connected with an energy collecting controller which is connected with an energy temporary storage device which in turn is connected to a RFID control unit. The utility model utilizes a solar power supply and low power consumption to realize all functions of the traditional active RFID tag. This is again different from the present patent.

3. Patent number US8568026B2 (Year of issue 2011) discloses a temperature measurement system capable of operating in harsh environments including a temperature sensor having an antenna, diode, and dielectric layer disposed on any object, wherein the antenna includes a buried portion that extends through and is electrically coupled to the object. The antenna is configured to receive interrogating signals from a transmitter, and to transmit response signals corresponding to the resonant frequency of the temperature sensor and its harmonics which can detect the temperature of the object. This is different from present patent as it does not reveal anything regarding solar panels.

[0010] In view of the above, the present invention has been introduced which can obviate shortcomings of known arts and cater to the requirements, for which it is devised.

OBJECTS OF THE INVENTION:

[0011] An object of the invention is to provide Solar Panel for real time monitoring of cell temperature in actual field conditions.

[0012] Another object of the invention is to provide Solar Panel for real time monitoring of cell temperature in actual field conditions, which is simple in construction.

[0013] Still another object of the invention is to provide Solar Panel for real time monitoring of cell temperature in actual field conditions, which functions efficiently.

[0014] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION

[0015] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.

[0016] According to the invention, there is provided a solar Panel for real time monitoring of cell temperature in actual field conditions comprising solar cell string (3) interposed between two sheets (2,4), which is covered by front glass panel (1) and module back sheet (6), wherein a passive RFID tag (5) is placed on one of the cells (3) for real time monitoring of cell temperature.

[0017] The cell string (3) includes Silicon (Si),Gallium Arsenide (GaAs), Cadmium Telluride (CdTe),Copper Indium Gallium Selenide (CIGS), brittle crystalline structures ( GaAs) or as flexible thin-film cells (Si, CdTe, CIGS).

[0018] The intermediate sheets (2,4) can be made of Ethylene-vinyl acetate (EVA) polymer, the module back sheet (6) can be made of Plastic (PVF) or glass (for bi-facial modules) and front panel (1) can be made of glass.

[0019] The cells (3) are laminated in between EVA polymer sheets(2,4) and the passive RFID tag (5) in the form of very thin sheet, which is battery-free and maintenance-free is placed on one of the cells which can monitor the cell temperature in-situ for measuring the exact temperature.

[0020] The passive RFID sensor tag utilizing the RF Micron S3 chip can identify temperature of the cell, in which the tag can be affixed/embedded into most materials and has an average read range of 15-22 feet, in which the tag functions in a range between 40°C to +85 °C.
The present invention deals with embedding passive RFID temperature tag right on the cell during the solar panel fabrication on sample basis. This sample can be supplied with rest of the panels to evaluate the performance of the PV plant.

[0021] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0022] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0023] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING(S)

[0024] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-

[0025] Figure 1 shows: a solar Panel for real time monitoring of cell temperature in actual field conditions according to the present invention.

[0026] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO PREFERRED EMBODIMENT(S) OF THE INVENTION

[0027] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0028] The present invention relates to an invention pertinent to a technology regarding a solar Panel for real time monitoring of cell temperature in actual field conditions.
[0029] The standard test conditions (STC) widely used in industry for testing of photovoltaic solar panel specifies the cell temperature of 25°C and an irradiance of 1000 W/m2 with an air mass 1.5 (AM1.5). However in India, Africa and several other countries where along with a lot of sunlight there is a lot of heat as well, the cell temperature in the field conditions at such places reaches much higher than 25°C leading to a reduction in the output power of PV modules. Therefore, the amount of power generated is far less than the rated peak power of a solar PV plant for hot climates. This happens because the crystalline silicon solar cell has a negative power coefficient with the temperature.

[0030] For example at present the existing Al-BSF crystalline silicon technology offers a negative power coefficient of ~0.40% /degrees Celsius. This means if the cell temperature increases by 50 degrees Celsius then there is power loss of 20%.

[0031] This solar panel of the invention is provided with an in built RFID temperature sensor which can monitor the temperature of solar cell in the field. The standard moduling is carried out by employing back sheet and front glass. The cells are laminated in between EVA polymer sheet. A passive RFID tag which is battery-free and maintenance-free is placed on one of the cells which can monitor the cell temperature in-situ for measuring the exact temperature to which the solar cell heats up in the field conditions when put to practical use. It can be retrieved by any RFID reader available in the market and performance of solar panel can be analysed accurately.

[0032] Thus in the present invention, a Passive temperature sensor is embedded in the panel during its fabrication. A passive RFID sensor tag utilizing the RFMicron S3 chip can identify temperature of the cell very accurately as it is very close to the silicon surface. These tags can be affixed or embedded into most materials and have an average read range of 15-22 feet. The tags function in a range between 40°C to +85 °C covering operating conditions for most equipment and environments. Said solar panel with an in built RFID temperature sensor can monitor the temperature of solar cell in field. This temperature detection helps to analyse the performance of solar panel in actual field conditions.

[0033] Here in this particular embodiment of the invention as illustrated in Fig. 1, Si cells have been adopted. However, the cell includes Gallium Arsenide (GaAs), Cadmium Telluride (CdTe),Copper Indium Gallium Selenide (CIGS), brittle crystalline structures ( GaAs) or as flexible thin-film cells (Si, CdTe, CIGS).

Fabrication methodology:

[0034] In the PV moduling process, different layers are placed as shown in Fig 1. During layup, the front glass (1) is placed first and then an Ethylene-vinyl acetate (EVA) sheet (2) is placed on the glass (1). The Si solar cell string (3) is placed next. Before placing the second EVA sheet (4), an RFID tag (5) is placed on one of the cells and then second EVA sheet(4) is placed followed by the module back sheet (6). Eventually,the module is laminated using a standard laminator. The passive RFID tag which is battery-free and maintenance-free senses the temperature and the signal can be monitored in-situ by using any RFID reader and thereafter performance of solar panel can be analysed wirelessly.

[0035] The intermediate sheets (2, 4) can be made of EVA polymer, the module back sheet (6) can be made of Plastic (PVF) or glass as per the application of module and front panel (1) can be made of glass . However, it is given as example. Other materials readily apparent to a person skilled in the art are also within ambit of the invention.

Advantageous Features of The Invention
- The quality and accuracy of data generated by these tags are impressive.
- These data can give feedback on the field performance of different solar panels
- The data can help in identifying which panel is suitable for which geographical location so as to maximize the power conversion efficiency.
- Measurement of the actual cell temperature of a solar panel in the actual field conditions.
- Analyses the power loss by a PV power plant in field conditions when integrated with IV characteristics.
- Very easy to read the temperature and no adverse effect on solar panel performance.
- Simple and cost effective battery free RFID in the form of thin sheets placed on the cell itself giving very accurate value of the temperature of the cell.

[0036] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0037] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0038] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0039] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0040] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0041] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0042] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.