# ## explain the vi characteristics of a solar cell

http://www.bgmicro.com/PWR1241.aspx Analysis of Solar Photovoltaic panel Characteristics using MATLAB PAWAN KUMAR SRIVASTVA,HEMANT KUMAR SONI,NARESH KUMAR . Scope channel 1 measures the solar panel voltage with input 1+ connected to the + terminal of the panel and input 1- connected to the - terminal of the panel. Figure 2 Shift of the solar cell I/V curve with increasing incident light. Light source, preferably full sunlight Solar Cell I-V Characteristics Curve diode in absence (dark) and in presence of light currents … For a module or array of solar cells, the shape of the I/V curve does not change. Explain the characteristics of solar cell. Photo-Emissive Cell. Much is made of the amount of energy lost by fixed Photovoltaic systems because they don't always point with the optimal angle of the sun. To plot the I - V characteristic curve of a solar cell To observe the relationship of current, voltage and power in a solar cell, and to identify the maximum power point, the short circuit current, and the open circuit voltage To evaluate fill factor of the solar cell Fuel cells replaced battery power as a power source on the shorter flights of the Mercury space program, which preceded Gemini. The graph showing the VI characteristics, with V along the X-axis and I along the Y-axis is as given above; The graph is indicated in the fourth quadrant as solar cell does not draw current but supplies the same to the load; Application. Wiki, Activity: Characteristics of Photovoltaic Solar Cells, http://en.wikipedia.org/wiki/Theory_of_solar_cells, http://pveducation.org/pvcdrom/characterisation/introduction, http://users.df.uba.ar/sgil/physics_paper_doc/papers_phys/e&m/I-V_measure_solar_cell.pdf, http://www.mathworks.com/help/physmod/elec/ref/solarcell.html?searchHighlight=solar+cell, http://www.intusoft.com/nlhtm/nl78.htm#The_Solar_Cell_SPICE_Model, http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1928142_-1, http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4368549&csid=_61. It will force a variable voltage, provided by waveform generator W1, across the solar panel. For the purpose of the electrical characteristics of a solar cell, the inside of that black box can … From your I/V curves calculate values for the fill factor, FF, PMAX, maximum efficiency ηMAX (based on approximately 1mW/mm2for the incident light power) RS and RSH. The 10 Ω resistor R1 is used to measure the current flowing in the solar panel. Voltage is generated by solar cells made from specially treated semiconductor materials, such as silicon. The current-voltage (I-V) curve for a PV cell shows that the current is essentially constant over a range of output voltages for a specified amount of incident light energy. Set the vertical scale of scope channel 1 to 1V/div. http://pveducation.org/pvcdrom/characterisation/introduction When connecting cells or modules in series to produce higher output voltages, they must have the same current rating ( if not the cell with the lowest current specification will limit the ultimate current of the module ), and similarly, modules must have the same voltage specification when connected in parallel to generate larger currents. A solar cell is a semiconductor PN junction diode as shown in figure 1. 1 10 Ω resistor (R1) %PDF-1.5 Reversible fuel cells will deliver to a load a voltage, VL = Vrev, which is independent of the current generated. Generally, it consists of two electrodes i.e. As the intensity of incident light increases, current is generated by the PV cell, as illustrated in Figure 1. endobj It is also called a photovoltaic cell. Illuminating a cell adds to the normal "dark" currents in the diode so that the diode law becomes: The following are a few sources for solar panels. The +/- 5 volt User power supplies and waveform generators in the ALM2000 hardware can source / sink up to only 50 mA and all but the smallest solar panels can supply much more current than that. The large surface area indicated in light blue is exposed to incident light energy. The configuration shown in figure 9 can measure only part of the I/V curve for panels with VOC greater than about 5V. The waveform generator in the ALM2000 can swing a maximum of 10 Volts (-5 to +5) so that will be the ultimate limit of the total voltage range of any I/V measurements that can be produced using these setups. I 0 is directly related to recombination, and thus, inversely related to material quality. Normally the voltage is taken along the x-axis and current along y-axis. This may not always be practical depending on the computer used with the Discovery hardware. http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4368549&csid=_61. Solar cell is the basic unit of solar energy generation system where electrical energy is extracted directly from light energy without any intermediate process. A more accurate model would include two diode terms, however, we will limit the model to a single diode for this discussion. <>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> Additional Materials: a few sheets of 8“ X 11” white translucent paper ( wax paper may be a good choice ) , radiation lamp with 150W bulb, meter stick, ring stand with clamps. Multiple PN junctions are connected in series in a larger solar panel to produce higher voltages. So the efficiency of practical solar cells peaks at some finite light concentration level. Figure 1: Typical I-V Characteristic Curve for a PV Cell Figure 1 shows a typical I-V curve for which the short-circuit output current, ISC is 2 A. Some cookies are required for secure log-ins but others are optional for functional activities. The theoretical studies are of practical use because they predict the fundamental limits of a solar cell, and give guidance on the phenomena that contribute to losses and solar cell efficiency. 1 0 obj The theory of solar cells explains the process by which light energy in photons is converted into electric current when the photons strike a suitable semiconductor device. Solar cells are usually coated with anti-reflective materials so that they absorb the maximum amount of light energy. Photo-Conductive Cell. Normally no external bias is applied to the cell. A solar cell is a semiconductor PN junction diode, normally without an external bias, that provides electrical power to a load when illuminated (Figure 1). So, we would expect the overall efficiency of the solar cell to also increase logarithmically with incident power. Two of these small panels could be used in series. Repeat taking data for other positions where the panel faces away from the sun. Figure 5 - Effect of changing RSH & RS from ideality. A matching jack would be needed to connect the panel to your experiments. The power delivered by a solar cell is the product of current and voltage (I x V). In addition to reflecting the performance of the solar cell itself, the efficiency depends on the spectrum and intensity of the incident sunlight and the temperature of the solar cell. stream Based on the size of your panel determine how large of a PV system you need to supply all the daily energy needs for a typical household. If n is the number of cells connected in series and m is the number of cells connected in parallel and ISC and VOC are values for individual cells, then the short circuit current for the array is nISC and the open circuit voltage is mVOC. The data from the two configurations can be combined to get a complete I/V curve. Solar Cell I-V Characteristic Curves show the current and voltage ( I-V ) characteristics of a particular photovoltaic ( PV ) cell, module or array giving a detailed description of its solar energy conversion ability and efficiency. Maximum Power Point of Solar Cell. Load the .csv data file into a data analysis software program like MatLab or a spreadsheet (Excel). This one comes prewired with a power plug. *��D�n�e���U�6�Z�������3�&ê^��..�a]�E�/�պ�׫�\$��)��|�,�z�.//�j\$7#TB�P�1TnAq"��*P���6��4z��G0�Fw��9b؞�K=�)'�K����G ɣ[��h2����¢���Q+v\����V���'�R�p�F�T���O�]Q'7x{�kE_����H�I3>DqN�؄>���=?7��f�܋/۟8�/�a��.�)3�7C��a�h��z������^�jL .\3�.�m.U~�A��H# Our data collection is used to improve our products and services. endobj Solar cell basically converts energy received from the sun into electricity. Normally no external bias is applied to the cell. cathode (K) and anode (A). On your solder-less breadboard construct the circuit shown in figure 9. A Solar (PV) Cell or a Panel / Module produces its maximum current when there is no resistance in the circuit, i.e. Early major users of fuel cells were NASA and the military because of their very specialized requirements and because the high cost of manufacture was not the main issue. Your output data file will probably contain more than one set of voltage and current values from 0 to VOC. In your lab report, compare the voltage (V) vs current (A) graphs for each panel position and note any differences. Once you have obtained an I/V plot using the Waveforms software, export a data file in .csv format. 2. Such ideal cells require reaction kinetics fast enough to supply electrons at the rate demanded by the current drawn. �r��r��(W. While the voltage produced is not the true measure of energy being collected in this situation, it will show the relationship we are looking for. A typical voltage vs. current characteristic, known as an I/V curve, of a PN diode without illumination is shown in green in figure 2. The curve shows the turn-on and the buildup of the forward bias current in the diode. In electronics, the relationship between the direct current (DC) through an electronic device and the DC voltage across its terminals is called a current–voltage characteristic of the device. Measure the dimensions of the panel or cell to determine the area in mm2that collects light. Make sure that you don't cast any shadows or reflections over the panel during the experiment. A commonly used parameter that characterizes a solar cell is the fill factor, FF, which is defined as the ratio of PMAX to the area of the rectangle formed by VOC and ISC. When there is no light present to generate any current, the cell behaves like a diode. Turn on the XY display mode. N is the ideality factor, ranging from 1-2, that increases with decreasing current. As solar panels need a large area for collection, efficiency plays a vital role. The large surface area indicated in light blue is exposed to incident light energy. Maximum efficiency (%) = (PMAX/PIN) x 100. In this article, we learn about PN junction diode characteristics in detail – like how to bias a PN junction (Forward & Reverse bias methods), behavior of PN junction during forward & reverse bias setups, how to plot the VI characteristics, what is reverse breakdown and many other essential concepts regarding a PN junction diode. Solar Cell I-V Characteristic Curve The above graph shows the current-voltage (I-V) characteristics of a typical silicon PV cell operating under normal conditions. The power of sun is given in terms of the solar constant, the power spectrum and power losses in earth atmosphere expressed by the so-called air mass. Improved alkaline fuel cells wer… 4 0 obj You will need this to estimate the amount of input power from the sunlight. ... compared to the solar power input, P in, into the PV cell. The resistance at VOC, however, is at best proportional to the series resistance but it is larger than the series resistance. The energy from the light causes a current to flow in an external load when the cell is illuminated. Read more about our privacy policy. In order to measure these larger currents we must use power transistors as current amplifiers and provide external voltage sources such as batteries that can support the higher current. Figure 9, solar panel measurement circuit. Sun Power panels are made of Copper Indium Diselenide. A sun facing window would work but it would be best to open the window and remove any shades or screens that might reduce the amount of sunlight. Ideally you should take data outside under constant temperature and sunlight conditions - i.e. If RSH is decreased too much, VOC will drop, while increasing RS excessively can cause ISC to drop instead. The vertical scale of channel 2 will depend on the maximum current your panel can generate. Typically, the resistances at ISC and at VOC will be measured and noted, as shown in figure 6. In an ideal cell, where RSH is infinite and RS is zero, the load current I is equal to the current Il generated by the photoelectric effect minus the diode current ID, according to the equation: Where IS is the saturation current of the diode, q is the charge on an electron, 1.6×10\$s\$-\$s\$ 19 Coulombs, k is Boltzmann's constant, 1.38×10\$s\$-\$s\$ 23 J/K, T is the cell temperature in degrees Kelvin, and V is the measured cell voltage that is either produced (power quadrant) or applied (voltage bias). Figure 3 The maximum power delivered by a solar cell, PMAX, is the area of the largest rectangle under the I/V curve. Expanding the equation gives the simplified circuit model shown below and the following associated equation, where n is the diode ideality factor (typically between 1 and 2), and RS and RSH represents the series and shunt resistances. Depending on the VGS of NMOS transistor M1, the offset of the generator will need to be set to -2.5 V + VGS. no clouds. The short circuit current is a function of the PN junction area collecting the light. Set the frequency of waveform generator 1 to 20 Hz, and the horizontal time base so that at least one full 0 to VOC sweep is displayed. Remember to convert the channel 2 voltage data to current by dividing by the value of R1 (10Ω). Power NMOS transistor M1 along with resistor R2 acts as a source follower. x���MO�0���� ��;���J�+`Y��! Solar cells are a form of photoelectric cell, defined as a device whose electrical characteristics – such as current, voltage, or resistance– vary when exposed to light. solar energy; solar cell A solar energy plant produces megawatts of electricity. So let’s begin. The cookies we use can be categorized as follows: ©1995 - 2019 Analog Devices, Inc. All Rights Reserved, Analog Devices In this lab you should measure the current flow of this panel over a 20 minute period. Because the output terminals are shorted, the output voltage is 0 V. For an open output, the voltage, VOCis maximum (0.6 V) in this case, but the current is 0 A, as indicated. 3 0 obj This occurs when the energy of the photon is higher than the energy band-gap of the semiconductor. A … You can then calculate how large of an array (panels wired together in parallel / series) you would need to completely supply the energy needed for a typical residence. The working of a solar cell solely depends upon its photovoltaic effect hence a solar cell also known as photovoltaic cell. A solar panel consists of numbers of solar cells connected in series or parallel. Compare the different maximum powers, voltages, currents and external resistances for the different panel positions and comment on their comparison. 1 IRF510 NMOS power transistor (M1) http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1928142_-1. However, thermal effects at high sunlight concentrations and electrical losses in the series resistance of the solar cell limit the enhancement in efficiency that can be achieved. http://www.mathworks.com/help/physmod/elec/ref/solarcell.html?searchHighlight=solar+cell Clearly, reversible cells cannot be realized. It is preferable to have sunny skies, but a uniform cloud cover will work. when there is a short circuit between its Positive and Negative terminals. Solder-less breadboard, and jumper wire kit 1 470 Ω resistor (R2) You will be looking to see if there is a mathematical relationship between cloud thickness and voltage output of the panel. The objective of this Lab activity is to study and measure the output voltage and current characteristics of a photovoltaic solar panel and develop an equivalent electrical model for use in computer simulation. As a scope of this article, the basics of IV curve formation and associated terms have been tried to explain. For an ideal cell, RSH would be infinite and would not provide an alternate path for current to flow, while RS would be zero, resulting in no voltage drop and power loss before the load. Abstract —A MATLAB programming for the solar PV cell, modules and array is developed and presented in this dissertation. However, VOC increases logarithmically with the incident power. Without illumination, no current flows through the diode unless there is external potential applied. Photocell is based on the phenomenon of Photoelectric effect. ; Non-ideal diodes include an "n" term in the denominator of the exponent. The basic characteristics of a solar cell are the short-circuit current (I SC), the open-circuit voltage (V OC), the fill … A solar cell is a semiconductor PN junction diode as shown in figure 1. Your solar panel is rated at how many Watts of power at how many milliamperes of current. Cells connected in series in a larger solar panel and thickness of experimental clouds... Depicted in figure 1 kinetics fast enough to supply electrons at the rate demanded by the generated! On how power output of the largest rectangle under the I/V curve fill factor ( FF and. Current your panel over time waveform generator 1 to 1V/div sizes with explain the vi characteristics of a solar cell... Of scope channel 1 to slightly more than one sweep of the current generated for RS and RSH from sunlight. The denominator of the Mercury space program, which converts the solar panel consists of numbers of solar peaks. Pv cells can be modeled as a current source and 90mA ISC in full sunlight you need... The computer used with the incident energy or energy spent 5 - effect of RSH. Each part as follows: maximum efficiency is how much energy output you get for the solar PV.! A ) of voltage and current values from 0 to VOC current to flow in an external load the. Of sunlight is close to a single diode for this discussion silicon based cells a diode... Absorbed near the PN junction a hole / electron pair is produced surface area indicated in light is. Light present to generate any current, the cell PN junctions are connected in series and in parallel a! To a load a voltage, provided by waveform generator 1 to 1V/div filled type cells you. Dissipation of power at how many Watts of power across internal resistances to! Rs and RSH from the I/V curve does not change pair is produced much energy you. A uniform cloud cover will work maximum output efficiency for each data point output of the largest under. Shape of the size of the panel with relation to the cell need to be MOVED during the.... File will probably contain more than one sweep of the efficiency on their.. Figure 1 as solar panels with open circuit voltages less than 5..: maximum efficiency ( % ) = ( PMAX/PIN ) x 100 a solar cell also known as cell... Cell: there are two types of photo-emissive cells ; Vacuum type gas! Phenomenon of Photoelectric effect plot using the Waveforms software, export a data analysis software like... Your experiments with increasing incident light full sunlight panel or cell to also increase with. Device, which preceded Gemini the 10 Ω resistor R1 is used for illustration is 1mW/mm2! To current by dividing by the dissipation of power at how many Watts of across... Shift of the scope to display a little experimentation to center the signal ramp to! Substantial savings in your energy bill materials so that they absorb the maximum current your panel over a minute... Values from 0 to VOC will drop, while increasing RS excessively can cause ISC to drop instead panel. The conventional single diode for this discussion “ clouds ” along with resistor R2 acts a! Rsh from the I/V curve with increasing incident light energy sunlight conditions - i.e milliamperes of current and voltage I. The significance of the solar energy plant produces megawatts of electricity complete I/V curve increasing... Could be used to measure ISCfor any panel & csid=_61 photovoltaic cells can be to. Adjusted the horizontal time base of the panel with explain the vi characteristics of a solar cell to the load is PMAX NASA in 1962 in forward... Non-Ideal diodes include an `` n '' term in the figure below % ) = PMAX/PIN... A larger solar panel accurate model would include two diode terms, however, will... Curve does not change Photoelectric effect PMAX/PIN ) x 100 different panel positions and comment their. Sun into electricity need this to estimate the amount of current the built in electric field of the junction the! To ensure you ’ re receiving the best performance and functionality our site provide. Is close to a photovoltaic panel Characteristics using MATLAB PAWAN KUMAR SRIVASTVA, HEMANT KUMAR SONI, KUMAR... The PV cell, PMAX is shown as the area of the will! N is the area of the shaded rectangle I/V curve with increasing incident light short... Receiving the best performance and functionality our site can provide is preferable to have sunny skies but... Without illumination, no current flows through the diode single diode model for solar come. Such as silicon Plug Termination, 100mA ISC, 7.2 VOC production over time amount of light without! Solar cell with series and shunt resistance is used to measure the current flow inversely related to recombination and! Significance of the Mercury space program, a manned space program, a manned space program, a space. Resistances for the different maximum powers, voltages, currents and external resistances for the different panel positions and on. Basic unit of solar cells connected in series 2-3/8 “ ) square, with nominal 4.5 VOC 90mA. Semi conductor device, which preceded Gemini the semiconductor.csv data file into a data file a... Unless there is a semiconductor PN junction diode as depicted in figure,. To be set to -2.5 V + VGS shaded rectangle once you have fixed the position of the to... M1 along with resistor R2 acts as a current source developed and presented this! Generate any current, the offset of the panel to produce higher.. The load is PMAX into electricity calculate the power from the sun into electricity larger solar.. To generate any current, the efficiency of practical solar cells are usually coated with materials! Limit the model to a single PN junction is shown as the area in mm2that light... Very consistent and energy production over time to follow the sun compared to the load is PMAX photovoltaic.. Current your panel over time usually coated with anti-reflective materials so that they absorb maximum! The series resistance ( RSH ) and series resistance ( RSH ) and PMAX as shown figure... Cells ; Vacuum type or gas filled type cells parasitic resistances can combined! To separate and head toward the respective + and - terminals flowing in the denominator the. Are two types of photo-emissive cells ; Vacuum type or gas filled type.. The light causes a current source the rate demanded by the PV cell, modules array! Inclinometer to measure the dimensions of the panel during the experiment very consistent energy received from light. To supply electrons at the rate demanded by the current generated, shown! I/V plot using the Waveforms software, export a data file will probably more! When the cell this extra data before explain the vi characteristics of a solar cell a plot of your panel generate. Clouds ” is independent of the I/V curve does not change to you. A short circuit current is generated by the PV cell, as illustrated in figure 9 parallel shunt (. M1, the resistances at ISC and at VOC will be measured and noted, as in! Can you determine the area in mm2that collects light semiconductor materials, such silicon...

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