 So, far you have done the experiment of measuring the current voltage characteristic of a single module and you also done the experiment of measuring the current voltage characteristic of a series connected PV modules and series and parallel connected PV modules. Now, one important parameters when it comes to PV technology is the amount of energy that is generated. In theory the PV module will generate maximum energy when it is following the sun right which in that case the PV module is collecting all the radiation following on a PV module. But in practice we cannot always keep on focusing the PV module towards the sun and therefore, it is important to find out what will happen if PV module is fixed at a given location and what will happen if PV module is continuously following the sun. When PV module is continuously following the sun it is called the sun trekking. So, the in this experiment which is experiment number 3 the idea is to find out effect of sun trekking on energy generation from a PV module right. So, normally what happens PV modules are installed. So, if I have the north south normally my PV modules are installed like this. So, PV module should be south facing and the angle of the PV module should be equal to the latitude angle. So, this angle is equal to the phi which is the latitude angle of the location. So, if I am sitting in a Mumbai and I want to install PV module latitude angle of Mumbai is 19 degrees therefore, this PV module should be inclined 90 degree with respect to the horizontal surface and the face of the module should be in the south direction. So, this is the case of a PV module which is fixed at a given location and this is again optimized condition. So, this PV module will actually give higher electricity as compared to the PV module which is sitting flat on the ground. Now, we know that if PV module is continuously following the sun then the amount of energy generation will be higher. And for this reason that if PV module is like this and the sun radiation are coming like this then the interception area is equal to the surface area of the PV module. Now, instead of this if sun rays are coming like this then the effective area that is the effective area that is that a PV module is actually covering is less as compared to the area of the as compared to the area that it would have that it would have intercepted. And because of that when the plane of the PV module is not in the perpendicular of the solar radiation it is going to collect the lesser amount of radiation. And things are different in the early morning. So, in the early morning if your rays are coming like this and again in this case is rays are coming like this in this case the effective area that is intercepted by the module is less. Also in this case the there will be a reflection that will occur from the glass. And therefore, depending on the position of the sun if my sun is at this position I should keep my module like this if my sun is at this position I should keep my module like this or if my sun is in this position let us say evening position then I should keep my module like this. So, in all three cases the module is perpendicular to the sun. So, therefore, in this experiment what we need to find out is what will happen if you keep your module to a fixed angle like this or what will happen if you are actually changing your position of the module depending on the position of the sun. This kind of arrangement is called the sun tracking and therefore, idea is how much energy you will generate in this position if the module is fixed and how much energy you will generate in this position when your module is continuously following the sun. Obviously, in this case you expect that energy generation will be higher as compared to this case, but this requires extra arrangement because your module has to be changing position all the time. And therefore, extra arrangement is required in your laboratory kit that is provided to you the arrangement is made such that so that you can change the angle. So, you can change this angle and you can also change the orientation. So, arrangement is provided in your laboratory kit. So, that you can make the arrangement both in this east-west direction as well in the north-south direction. So, that you can actually make the make the arrangement in this particular condition. Now, the question is how to do the measurement of energy, right? First of all what we want to find out how much energy generation is occurring. Now, energy generation is basically power into time. Energy generation is nothing but a power into time. So, in your previous experiment what we have done is and what is this power? This is the peak power. This is the peak power or the maximum power of a module or a combination of a modules in a PVRA. So, what we need to do now is what we need to know? So, basically and this energy can then be given in terms of watt into hour. This will be the unit of energy. So, if we can measure the whatever generated in let us say some 3 hours time period in this arrangement and if we can find out whatever generated in this arrangement and we will know how much is the extra energy or whatever generated in this arrangement. How to do that? So, for this what we need to do is a quick experiment, quick measurement of quick measurement of P max is required in this arrangement and in the arrangement 2. So, in the arrangement 1, so I will call it. So, this is arrangement 1 and this is arrangement 2. So, now in this arrangement 1 which is the fixed module what we need to do is for example, we need to time, we need to find out the P m at that time and multiplication of P m and time will give me the energy generated in that time period. So, let us say I start my experiment at 2 o clock. So, at 2 o clock if I find the P m is let us say 10 watt, then I do the measurement again in this condition at say let us say 230, when I do the measurement again at 3 o clock, I do my measurement again at 330 and I do my measurement again at 4 o clock and I can continue doing this. So, let us say at 2 o clock my wattage is 10, at 230 my wattage was let us say 9 watt. So, between 2 to 230 in half an hour I assume that my wattage is constant. So, I multiply by, so when I multiply this power into 30 right. So, if I multiply 10 watt into 30 minute is 0.5 hour. So, 10 watt into 0.5 this is my energy. Now, this power is measured at 230 P m, I assume that next half an hour this remains constant. So, again my energy is 9 into 9 into 0.5. So, that is my energy generated. Again let us say I measure 9.5 watt in this arrangement this can happen because there may because of the cloud it may be lower, but now it is higher. So, if I measure 9.5 watt and I assume that from 3 o clock till 330 my power remains constant. So, at 9.5 into 0.5 is my energy generated. So, at each point I need to find out the P max. Now, this is the fast you need to do work very fast right because within this you have to find out entire I V characteristic of a P V module and from P V entire I V characteristic of a P V module you need to find out V M. So, basically what does it mean? It means that at every half an hour you have to measure this graph every half an hour you measure this graph. So, basically at 2 P m you measure this at 230 P m you measure this again at 3 P m again you measure this every time you find P m P m P m use this P m value here the maximum power point and then multiply by the duration a gap after which you are measuring smaller the gap better it is, but the gap may be 15 minutes or 20 minutes or a half an hour. So, therefore in this case if you overall if you are doing 8 measurement you have to measure I V characteristic of your module 8 times, but hopefully by this experiment you will be very you will be expert in measuring the maximum power point of your module and therefore you will be able to find out the energy. What you need to do now? After 10 experiment you have to sum this. So, then you can say total energy generated during 3 hours duration of a module is this much. Now this module can be 1 module or combination of 2 modules 3 modules 4 modules whatever you want to have it can be this experiment can be done for a single module or a combination of module. So, in for arrangement 1 which is the fixed module you have made this table and for each P m I said I will let me repeat again for each P m you have to do the full I V care measurement basically the peak power you need to find out for each. So, you have to find out the peak power at 2 o clock you have to find out the peak power at 230 you have to find out the peak power or maximum power at 3 o clock 330 4 o clock 430. So, you will actually do some 6 to 8 measurement minimum 6 to 8 measurement multiply by the duration what is our assumption? Our assumption is that from 2 o clock till 230 the power remains same which is not the good assumption because we know that radiation intensity is changing, but we just want to find out what is the effect. Now same thing which you have done for same thing we have done for the assignment 1 you have to do the same thing for arrangement 2. Now both the experiment are kind of going parallel. So, therefore, if you have done this experiment at 2 o clock and if I want to make the same table again here suppose. So, I have to do the time here then I have to find out the P m I have to find out the energy. Suppose you have done that this experiment 2 o clock do your measurement and let us say do this experiment at 210 and do this experiment at 240 do this experiment at 310 and 340 same thing again at 210 at 210 you have to find out I m at 240 again you have to find out the whole I v character is 310 again you need to at 310 again you have to find out the whole I v characteristic at. So, for every time you need to find out the full I v character so that you can find out the maximum power point you can find out the maximum power point at 240 find out the maximum power point at 310 find out the maximum power point at 340 continue till at least 3 hours continue this duration for at least 3 hours now use those values here. So, what you will find out that this may have little higher value of power right because you are following the sun exactly you are following the sun exactly. So, you will have little higher value of powers it may be 9.5 it may be 10 it may be 8 you multiply how to get you multiply with the duration again you are assuming that from 210 to 240 your power generation remains same. So, you are multiplying by energy generated power is 10.5 is you multiply power generated and by the time duration which is half an hour. So, you will actually get 10.5 into 0.5 this your energy generated again 9.5 into 0.5 that is your energy generated again at the end do the same thing total energy generated in terms of watt hour. So, from this table you will have to measure the watt hour of this arrangement from this arrangement you will find the total watt hour generated and eventually the whole objective of this experiment is to compare how much extra energy you will generate in case of arrangement 2 right. This is very busy experiment because at every time you have to find out the I V characteristic for arrangement 1 and you have to find out the I V characteristic of arrangement 2. So, it is very busy experiment and a team of people can do this experiment very nicely. Again compare the energy generated from this and find out your conclusion about what is the advantage of sun trekking how much extra energy you can generate if you are following the sun in those 3 hours. Again there are several questions given at the end of your manual and you are requested to do this experiment measure do the measurement and try to answer the questions that are given at the end of the experiment. Thank you. In this experiment where we are trying to measure the impact of the sun trekking on the generation of energy as explained in the theory that trekking of the sun for the P V module results in a generation of excess energy or extra energy, but at the same time trekking also result in a manual adjustment or automatic adjustment of module according to the position of the sun. Normally P V modules are installed at an angle which is equal to the latitude angle. So, for example, in this case this is my on the right my is my west this is my east and this direction is basically a south direction. So, as you can see here the P V modules are now right now installed in the south direction which is not the optimum condition at the current condition and as you can see here that this is actually provided to find out whether the module are perpendicular to the sunlight or not. If you look at closely there is a shadow of the this pointer here and because which indicates that this modules are not in optimal condition. So, in many real life conditions the modules are installed fixed in the south direction. So, in this experiment we want to find out what energy can be generated, how much energy can be generated if modules are fixed, installed at the latitude angle in the south direction or if the modules are being tracked. In this particular situation as explained in the laboratory you need to find out the energy generated in let us say 3 hour duration of the time period. In order to find out the energy generation you need to have the power at that particular time and the time duration. So, for example, what we are doing is for we will measure the I V condition characteristic of a module again you can take one single module, two module, three module or four module in various combinations. So, even if you want to find out the energy generation from one single module you can do that or you want to find out the energy generation from two single module you can do that. So, you need to find out the energy in this particular case an energy when you are tracking the sun and I will show you how you can track the sun. So, in this case if you find out the power peak power which you can do by current and voltage measurement and multiply by the duration of time and you need to take the same reading of the peak power in this position for every 20 minutes or every 30 minutes. So, within the period of 3 hours you will have roughly about 6 to 8 readings. So, when you multiply the peak power 6 to 8 reading means you are finding 6 to 8 times the I V characteristic you are finding 6 to 8 times the peak power you are multiplying the time. So, this is one position in which you will make the 6 to 8 readings in which the modules are facing due south. Now, the second position again which is the position corresponding the sun tracking you need to make the similar number of measurement and see how much energy is generated. So, you need to find and the main difference that comes from this condition when the modules are not optimally focusing the sun and when modules are optimally focusing the sun is the current. So, in this case I have connected one single module in the short circuit condition and you can see here the short circuit current right now you can see here the short circuit current right now is 0.11 ampere. Now, this is not the optimal condition. So, when we do the sun tracking what we want is the sunlight is always perpendicular to the module and that perpendicular to the module can be obtained if the shadow of this nail does not fall anywhere else. So, now I will show you how to make arrangement your setup is with the arrangement in which you can change you can change this angle up and down and you can also change the you can also change here. So, you can also change the direction here. So, now if I make this arrangement such that the shadow of this nail should not fall. So, still there is a shadow I will keep changing the position of the module will keep changing the position of the module. Now, the shadow is decreasing shadow is decreasing if I increase angle further. So, now you are almost in a situation when there is no shadow following right. So, this shadow of this nail is not following anywhere else and therefore, which means that modules are now in a perpendicular to the sunlight. Let us look at the difference what it will make in the current. So, let us look at the difference what it will make to the current. So, look at here earlier case same time same condition the module was producing about 0.11 ampere, but now the module is producing 0.29 ampere current right. So, now if you do the power measurement in this condition your peak power condition peak power will be higher than the case when your modules are facing the south direction. And therefore, if you are in a situation when your your modules are always facing the sun which means the sun rays are perpendicular to the module then you are producing more power. And if you consider this power integrated over a period of time in this experiment we are doing this measurement for 3 hours. So, basically you can find out that energy generated when you are following the sun is higher than the energy generated when your module are facing the view south direction. So, again you have to do the measurement in this position when there is no sun there is no shadow of this nail here again you have to do the 6 to 8 measurement. So, you make this measurement bring the down your module back to the south position take the measurement bring down your module in this position of no shadow take the measurement and you keep doing this measurement 6 to 8 times in each position. In each position what measurement you are doing basically you are doing the complete IV measurement and basically you are trying to find out the peak power of your module in that particular situation. And when you multiply peak power by the duration or the gap in which no measurement is done that is your energy produced in that particular time period you sum up the energy in both the cases and you compare how much energy is produced in this particular case when the modules are perpendicular to the sunlight and the case when your modules are fixed at an angle which is equal to the latitude angle and facing the south. So, this of course this is the manual tracking and you are moving your module in such a way that your panel is always perpendicular to sunlight, but in real time you can do the manual tracking also you can do the automatic tracking. So, there are automatic trackings are available which you can which can focus the module always toward the sun. So, the objective of this experiment is to show you the difference in the amount of energy that can be generated from the same module if module are fixed south facing or if the module are always taking the sun. Hopefully you will do this measurement. So, you are going to do this kind of measurement you will measure the time you will measure the voltage you will measure the current, but most importantly you will find out the peak power. Now, for each time you need to find out what is the maximum power if you want to find out the maximum power you have to find out the I V characteristic of that particular time and you multiply by the time during which you have the measurement for which you are calculate considering this power and therefore, you can find out the energy required. So, this is well explained in the theory part of this experiment. So, if you do this measurement in both the position 6 to 8 times during the 3 hours duration you will find out how much energy is generated when you are tracking the sun and how much energy is generated when the modules are facing the south direction and the comparison of that will give you clear advantage of the sun tracking as compared to the fixed arrangement of the modules. Again I hope you will learn lot from doing this experiment I wish you all the best. Thank you.