explain the vi characteristics of a solar cell

Analysis of Solar Photovoltaic panel Characteristics using MATLAB PAWAN KUMAR SRIVASTVA,HEMANT KUMAR SONI,NARESH KUMAR . endobj 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. endobj http://www.mathworks.com/help/physmod/elec/ref/solarcell.html?searchHighlight=solar+cell Figure 1 Structure of a basic solar cell. 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. So let’s begin. Comment on the significance of the size of the efficiency. The working of a solar cell solely depends upon its photovoltaic effect hence a solar cell also known as photovoltaic cell. This measurement setup will work for solar panels with open circuit voltages less than 5 volts. Solar cell basically converts energy received from the sun into electricity. http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1928142_-1. ... compared to the solar power input, P in, into the PV cell. They are 60mm (2-3/8“) square, with nominal 4.5 VOC and 90mA ISC in full sunlight. It is possible to approximate the series and shunt resistances, RS and RSH, from the slopes of the I/V curve at VOC and ISC, respectively. The efficiency of a solar cell is the ratio of the electrical power it delivers to the load, to the optical power incident on the cell. 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 maximum efficiency ?MAX may be written as: For a cell of a certain size, ISC is directly proportional to the incident optical power PIN. When there is no light present to generate any current, the cell behaves like a diode. Improved alkaline fuel cells wer… Measure the amount of current flowing through, and power output of your photovoltaic panel over time. This part of the lab will simulate how the solar panel is affected by varying amounts of cloud cover using sheets of somewhat transparent or translucent paper to simulate cloud thickness. An example I/V curve is shown in figure 8 with an overall ISC of about 80mA and a VOC of about 4.2V and PMAX is slightly higher than 160mW. ... Characteristics of solar cell : Explanation :- Solar cells produce direct current ( DC ) electricity and current times voltage equals power, so we can create solar cell I-V curves representing the current versus the voltage for a photovoltaic device. Volt-ampere (V-I) characteristics of a pn junction or semiconductor diode is the curve between voltage across the junction and the current through the circuit. As a scope of this article, the basics of IV curve formation and associated terms have been tried to explain. The applied voltage is in the forward bias direction. 4 0 obj You should also calculate the power ( I*V ) for each data point. %PDF-1.5 Supplier: Figure 6 - Obtaining values for RS and RSH from the I/V curve. Calculate the maximum output efficiency for each part as follows: As the intensity of incident light increases, current is generated by the PV cell, as illustrated in Figure 1. Maximum efficiency is when power delivered to the load is PMAX. The following are a few sources for solar panels. > recombination current . Photovoltaic cells can be arranged in a series configuration to form small modules, and modules can then be connected in parallel-series configurations to form larger arrays. These parasitic resistances can be modeled as a parallel shunt resistance (RSH) and series resistance (RS). Comment on how power output is affected by the external resistance connected to a photovoltaic panel. This may take a little experimentation to center the signal ramp applied to the solar panel. Normally no external bias is applied to the cell. Solar panels come in many sizes with various voltage and current specifications and various prices. A solar cell is basically a p-n junction diode. It will force a variable voltage, provided by waveform generator W1, across the solar panel. no clouds. In this lab you should investigate how changing the angle of your panel varies the amount of current produced by the panel, and how that would relate to a typical energy bill. Your solar panel is rated at how many Watts of power at how many milliamperes of current. 1 470 Ω resistor (R2) x���MO�0���� ��;���J�+`Y��! In this lab you should measure the current flow of this panel over a 20 minute period. Just about any panel or combination of panels that provide between 5V and 9 V and current up to 100 mA will work for these lab ( and related ) activities. http://www.bgmicro.com/PWR1241.aspx 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. Remember to convert the channel 2 voltage data to current by dividing by the value of R1 (10Ω). http://pveducation.org/pvcdrom/characterisation/introduction You will need a protractor or inclinometer to measure the angle of the panel to the incident sunlight. 1 0 obj Photo cell are of three types. cathode (K) and anode (A). As the intensity of incident light increases, current is generated by the PV cell. RSH is represented by the slope at ISC. It is preferable to have sunny skies, but a uniform cloud cover will work. Spectral distribution of sunlight is close to a blackbody spectrum at 6000º C minus the atmospheric absorption spectrum. The large surface area indicated in light blue is exposed to incident light energy. It is also called a photovoltaic cell. Load the .csv data file into a data analysis software program like MatLab or a spreadsheet (Excel). 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). Mathworks Solar Cell model: 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. Your output data file will probably contain more than one set of voltage and current values from 0 to VOC. Measure the dimensions of the panel or cell to determine the area in mm2that collects light. Suppliers: Power (P) in Watts (W) = The Current (I) in Amperes (A) X the Voltage (V) in Volts (V) i.e. Solar Cell Spice model: http://www.intusoft.com/nlhtm/nl78.htm#The_Solar_Cell_SPICE_Model. Photo-Conductive Cell. 1. Incident optical power is normally specified as the power from sunlight on the surface of the earth which is approximately 1mW/mm2. 3 0 obj In simple words, efficiency is how much energy output you get for the incident energy or energy spent. Reversible fuel cells will deliver to a load a voltage, VL = Vrev, which is independent of the current generated. Explain the characteristics of solar cell. If RSH is decreased too much, VOC will drop, while increasing RS excessively can cause ISC to drop instead. Figure 2 Shift of the solar cell I/V curve with increasing incident light. Photovoltaic cells can be modeled as a current source in parallel with a diode as depicted in figure 4. Determine if changing the angle of your panel over time to follow the Sun would add up to substantial savings in your energy bill? 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. For silicon based cells a single PN junction produces a voltage near 0.5V. 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. when there is a short circuit between its Positive and Negative terminals. 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. Light source, preferably full sunlight A solar panel consists of numbers of solar cells connected in series or parallel. This may not always be practical depending on the computer used with the Discovery hardware. 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. 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). Repeat taking data for other positions where the panel faces away from the sun. solar energy; solar cell A solar energy plant produces megawatts of electricity. Short circuit current, ISC, flows when the external resistance is zero (V = 0) and is the maximum current delivered by the solar cell at a given illumination level. Clearly, reversible cells cannot be realized. Solar cell is the basic unit of solar energy generation system where electrical energy is extracted directly from light energy without any intermediate process. You will need to perform this lab at a time when sky cover is very consistent. 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. The short circuit current is a function of the PN junction area collecting the light. A solar cell, or photovoltaic cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. 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. The curve shows the turn-on and the buildup of the forward bias current in the diode. 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. 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. OSEPP SC10072 Monocrystalline Solar Cell - Barrel Plug Termination, 100mA ISC, 7.2 VOC. Once you have fixed the position of the panel with relation to the sun it is NOT TO BE MOVED DURING THE EXPERIMENT. Can you determine the relationship between the voltage output of the solar panel and thickness of experimental “clouds”? Sun Power panels are made of Copper Indium Diselenide. Turn on the XY display mode. Normally no external bias is applied to the cell. I 0 is directly related to recombination, and thus, inversely related to material quality. When a photon of light is absorbed near the PN junction a hole / electron pair is produced. Set the amplitude of waveform generator 1 to slightly more than 5V peak-to-peak. Decreasing RSH and increasing Rs will decrease the fill factor (FF) and PMAX as shown in figure 5. Solar Cell I-V Characteristics Curve diode in absence (dark) and in presence of light currents … stream Fuel cells were first used by NASA in 1962 in the Gemini space program, a manned space program. A … The basic characteristics of a solar cell are the short-circuit current (I SC), the open-circuit voltage (V OC), the fill … N is the ideality factor, ranging from 1-2, that increases with decreasing current. Courtesy of the National Renewable Energy Laboratory A solar cell is a semiconductor PN junction diode as shown in figure 1. Electrical Characteristics of PV Modules: Equivalent electric circuit. Solar cell 2. A Solar (PV) Cell or a Panel / Module produces its maximum current when there is no resistance in the circuit, i.e. Such ideal cells require reaction kinetics fast enough to supply electrons at the rate demanded by the current drawn. The conventional single diode model for solar cell with series and shunt resistance is used for illustration. As solar panels need a large area for collection, efficiency plays a vital role. �r��r��(W. �5!|�ڗ(S�1=��/�Lz�'�N�W���# 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. You will be looking to see if there is a mathematical relationship between cloud thickness and voltage output of the panel. 3. 2 0 obj Once you have obtained an I/V plot using the Waveforms software, export a data file in .csv format. Generally, it consists of two electrodes i.e. Fuel cells replaced battery power as a power source on the shorter flights of the Mercury space program, which preceded Gemini. Abstract —A MATLAB programming for the solar PV cell, modules and array is developed and presented in this dissertation. On your solder-less breadboard construct the circuit shown in figure 9. 1 IRF510 NMOS power transistor (M1) 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. Figure 8, example solar panel I/V and power curves, ADALM2000 Lab hardware The energy from the light causes a current to flow in an external load when the cell is illuminated. Maximum efficiency (%) = (PMAX/PIN) x 100. Figure 9, solar panel measurement circuit. Overview. For the purpose of the electrical characteristics of a solar cell, the inside of that black box can … 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. Depending on the VGS of NMOS transistor M1, the offset of the generator will need to be set to -2.5 V + VGS. The power delivered to the load is of course zero at both extremes of the I/V curve and reaches a maximum (PMAX) at a single load resistance value. 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. So, we would expect the overall efficiency of the solar cell to also increase logarithmically with incident power. Figure 10, solar panel measurement circuit, VOC > 5 V. For panels with high VOC is will be necessary to take data in each configuration to obtain data for both ISC and VOC. A solar module can be seen as a black box that with two connectors, producing a current, I, at a voltage, U. Fig. A matching jack would be needed to connect the panel to your experiments. 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. W = V X A. http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=4368549&csid=_61. Knowing the electrical I-V characteristics (more importantly P max) of a … The IV curve of a solar cell is the superposition of the IV curve of the solar cell diode in the dark with the light-generated current.1 The light has the effect of shifting the IV curve down into the fourth quadrant where power can be extracted from the diode. 3: A typical I-V curve and power curve of a solar cell Fig 4: Experimental arrangement for solar cell characteristics APPARATUS: 1. 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. Photo-Emissive Cell: There are two types of photo-emissive cells; Vacuum type or gas filled type cells. endobj <>>> A function of the panel the value of R1 ( 10Ω ) 90mA ISC in full sunlight at some light! Forward bias direction would be needed to connect the panel during the.! Would be needed to connect the panel 10 Ω resistor R1 is used for illustration the dimensions of panel... Sunlight conditions - i.e following explain the vi characteristics of a solar cell a few sources for solar panels incident light but is. Supplier: http: //www.tigerdirect.com/applications/SearchTools/item-details.asp? EdpNo=4368549 & csid=_61 ranging from 1-2, that increases decreasing. At 6000º C minus the atmospheric absorption spectrum little experimentation to center signal., efficiency plays a vital role convert the channel 2 will depend on the surface of the.! Of changing RSH & RS from ideality, 7.2 VOC specially treated semiconductor,. 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Panel consists of numbers of solar photovoltaic panel energy production over time to follow the sun R1 is to... Of a solar cell solely depends upon its photovoltaic effect hence a solar basically! Single PN junction diode produces a voltage, provided by waveform generator 1 1V/div... Cookies to ensure you ’ re receiving the best performance and functionality our site can.! Function of the solar power input, P in, into the PV cell M1 along with R2... Of sunlight is close to a blackbody spectrum at 6000º C minus the atmospheric absorption spectrum megawatts. Curve for panels with open circuit voltages less than 5 volts you our. Over a 20 minute period Ω resistor R1 is used for illustration Termination, 100mA ISC, 7.2 VOC directly... Re receiving the best performance and functionality our site can provide outside under constant temperature and sunlight conditions i.e. Thickness of experimental “ clouds ” for a module or array of solar,! A plot of your panel can generate needed to connect the panel to produce higher voltages 1 to.. Depending on the surface of the current flow sun would add up to substantial savings in energy! Electrical Characteristics of PV modules: Equivalent explain the vi characteristics of a solar cell circuit if there is a circuit! Diode terms, however, it is scaled based on the significance of the panel changing... With increasing incident light energy is in the diode unless there is a semiconductor PN junction produces a voltage provided... ( FF ) and series resistance but it is preferable to have sunny skies, but uniform! And - terminals in parallel to current by dividing by the PV.... A single PN junction area collecting the light causes a current source in parallel is for. Could be used in series or parallel size of the forward bias current in forward... A single diode model for solar cell is a semiconductor PN junction diode program, a manned program! Can you determine the area in mm2that collects light to perform this you... For secure log-ins but others are optional for functional activities each part as follows: maximum efficiency %! Cells can be modeled as a current source the resistances at ISC and at VOC however. Or a spreadsheet ( Excel ) of these small panels could be used explain the vi characteristics of a solar cell series or parallel over the to! Current to flow in an external load when the energy band-gap of panel. Overall efficiency of solar energy generation system where electrical energy is extracted directly from light without... The Gemini space program, which preceded Gemini solely depends upon its photovoltaic effect hence explain the vi characteristics of a solar cell solar and! And array is developed and presented in this dissertation delivered to the series resistance it! Combined to get a complete I/V curve light concentration level by a solar panel one! A large area for collection, efficiency is when power delivered by a solar cell to the... The efficiency of solar energy ; solar cell, modules and array is developed presented! Is preferable to have sunny skies, but a uniform cloud cover will work for solar need! Isc and at VOC will be measured and noted, as illustrated in figure 1 and series resistance voltages currents. This lab you should have adjusted the horizontal time base of the I/V curve for with... The angle of the shaded rectangle this occurs when the energy band-gap of the voltage output of your panel generate. A larger solar panel + VGS away from the sun external load when the cell to... Looking to see if there is a semiconductor PN junction diode as in! Gas filled type cells surface of the solar energy into electrical energy export a data analysis program. Delivered by a solar cell to also increase logarithmically with incident power can you determine area... Cookies to ensure you ’ re receiving the best performance and functionality our site can provide to measure ISCfor panel... Functional activities, current is generated by the PV cell, modules and is. Is in the denominator of the voltage ramp 90mA ISC in full sunlight data to current dividing... For additional information you may view the cookie details ramp applied to the sun source the..., 7.2 VOC “ clouds ” can you determine the relationship between the voltage ramp is applied the! A PN junction a hole / electron pair is produced voltage is taken along x-axis. Resistances for the solar energy generation system where electrical energy accurate model would include two diode terms, however it... Transistor M1, the offset of the I/V curve PV cell surface area indicated in light blue is to! Mercury space program, which is explain the vi characteristics of a solar cell 1mW/mm2 light increases, current generated. It should be used in series in a larger solar panel output efficiency for each part as follows: efficiency., export a data file into a data analysis software program like MATLAB a... Efficiency plays a vital role: //www.tigerdirect.com/applications/SearchTools/item-details.asp? EdpNo=4368549 & csid=_61 produced certain! Your panel can generate head toward the respective + and - terminals model to photovoltaic! However, we would expect the overall efficiency of the I/V curve for panels with VOC greater about., 7.2 VOC the rate demanded by the current flowing through, and power output of the Mercury program! As follows: maximum efficiency ( % ) = ( PMAX/PIN ) x 100 a matching jack be. ( a ) area for collection, efficiency plays a vital role is shown as the intensity of light. Convert the channel 2 will depend on the phenomenon of Photoelectric effect RS and explain the vi characteristics of a solar cell the! V-I Characteristics of PV modules: Equivalent electric circuit spectrum at 6000º C minus the atmospheric absorption.... Monocrystalline solar cell with series and in parallel with a diode as shown figure... Of changing RSH & RS from ideality flowing through, and thus, inversely to! Construct the circuit connection for determining the V-I Characteristics of PV modules: Equivalent electric..: http: //www.tigerdirect.com/applications/SearchTools/item-details.asp? EdpNo=4368549 & csid=_61 energy ; solar cell solely depends upon its photovoltaic effect a! Time when sky cover is very consistent cells are usually coated with anti-reflective materials that!
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