 Now, let us start the actual process of learning this course, which is titled as Solar Fertile Types, Fundamentals, Technologies and Applications. Over a period of time that is next 10 days, you will you will learn about the fundamentals which means, Semiconductor, Material for Solar Cell Application, what are the semiconductor you are using, what are the basic properties of semiconductor, what is p-n junction, how p-n junction is utilized as a solar cell, what are the parameters of solar cell, what are the technologies for solar cell and what are the other balance of systems. So, for example, what is the power electronic side of it, how much is the solar radiation that you get, how you design a solar PV system based on availability of solar radiation and so on. There are wide range of topics that are covered in this in this workshop and I am sure by the end of it, if you go through it successfully, you will learn lot from it. So, the first lecture is about solar PV for our energy needs. So, can we use solar photovoltaic technology to fulfill our energy needs and in the first lecture, I will give a brief overview of the energy scenario of the country and of the world and then we will see how this energy required for our country can be obtained using solar photovoltaic technologies. All these slides are on the Moodle. So, you may not write each and everything this that is on the slide. So, as I said there will be lectures, the labs and tutorials, there is a quiz, multiple choice questions, there is a quiz, multiple choice question and the question and the session. So, these are the contents of this lectures. I am also giving some references on the photovoltaics that you can use. The reference one for example, is a very nice book on solid state electronic devices by Banjish treatment, it is very nice book and easily available in Indian market. The second book which many of you have already received the book which I have authored called solar photovoltaics fundamentals technologies and applications. This is published by Tinti Sol of India in 2009 and what you have received is the second edition of this book. So, you can refer to this book also for lot of materials that will be discussed in this course. There is a very good book on physics of semiconductor devices by SMZ and some other references that if you have access you can go through. So, there are lot of material available and you can go through this material. The references that I am citing here is mainly on the solar photovoltaic cells, technologies, fabrications, physics, etcetera. The other instructor of this course Professor Fernandez will actually give you what are the books that you can use for the power electronic side of it, the electronic side of this. Now, this is the planning of the lectures that I will be giving solar photovoltaic for our energy needs the sun and earth. So, basically talking about solar radiation, solar energy collection and how the collectors are solar PV modules to be oriented so that you can get the maximum radiation. Then we will go on to the introduction of solar semiconductor for solar cells the charge carrier transport which is very important how the electrons move in a semiconductor, how the electrons and holes are generated. So, we talk about the carrier generation and recombination, the reverse process of generation then actually make a come to the p-n junction device and how this p-n junction device acts as a solar cell. So, p-n junction as a solar cell and then we actually come to the application side. So, what are the main parameters of solar cell and how this parameters are or optimize how we quantify this parameters based on this parameter how we design a solar cell. So, that your efficiency is maximum so that the current and voltage that you get from your solar cell is maximum. Then we will move on to the technology side that is a fabrication how a solar cell is fabricated, how a thin film technology is different from the crystalline silicon wafer based technologies. So, you might have heard of this term already a thin film solar cell and crystalline silicon solar cell. So, that will see the difference between these two technologies and then the solar PV modules. So, how a individual solar cell is utilized to make a solar PV modules how the cells are connected and how do you design a module so that you can get a given amount of current and voltage and power out of it. Then performance of PV modules in the field when actually the modules are installed in the field the performance is different than the performance in the laboratory for example and how does the change in the temperature affects the performance of the module, how does the change in the radiation affects the performance of the module. Then finally, we use this module to design a PV system and the job of a PV system is to fulfill our energy requirement, it may be a household requirement, it may be a industry electricity requirement, it may be a institutes electricity requirement or it may be a big power plant of the megawatt level size. So, this is kind of outline of the lectures which I am going to give, but as I told a professor Fernandez who will actually talk about the other side of it the balance subsystem the power electronics will actually give the details of his lectures. As per the plan today there are two lectures this lecture and the next one the next lecture is supposed to be given by professor Fernandez, but today I am taking both the lectures the lecture one that is a PV as energy source and some part of the solar radiation talking about sun and earth moment I will take this two lectures today. So, let us start everybody is with me so far all the remote centers are with me now let us start. So, look at the energy scenario and the process what is happening world energy scenario Indian energy scenario and the most important question is can a solar PV supply all over energy needs that is the most important question that you want to learn. Just to begin with I thought I will just kind of revise the units of energy, energy is the capacity of body to perform work everybody have studied that it is a driving force for the change or it is the potential difference which can drive the current in electrical circuits. So, the many ways the many forms of energy the nuclear energy there is electrical energy there is a chemical energy there is a light energy there is a potential energy and so on. So, energy has a many form which can actually be used to perform a given task. Similar to the many units smaller and big units for the distance for example, we have units of nanometer, micrometer, centimeter, kilometer and so on. Similar to that energy also can be measured in the many units some units are very small some units are very large for example, calorie is 1 unit of energy joule is another unit of energy electron volt is another unit of energy. The relationship are given here so 1 calorie is about 4.184 joule 1 electron volt which is the smallest unit of energy is 1.6 times transfer minus 19 joules ok. So, very very small amount of energy then people also use some people also use what is called British thermal unit and it is 1.05 kilo joules all the energy I have given in terms of the kilo joule. So, there is also unit of arg transfer 7 arg is 1 joule. So, if you put them in order in terms of the size of the unit British thermal unit is larger than the calorie, calorie is larger than the joule, joule is larger than the arg and arg is larger than the electron volt. In this particular course we are talking or going to talk about 1 unit which is the electron volt. So, when we talk about the semiconductors when you talk about the electrons when you talk about the photon they carry very small amount of energy and therefore, we use electron volt as our unit of energy ok. Other unit is joule which is commonly used, but let me ask you question what is the energy unit for your electricity bill right when you pay electricity bill we pay in number of unit ok. So, somebody might be paying a bill for 30 units somebody paying for 100 units 150 units. So, what is that 1 unit of electricity? That is 1 unit of electricity that we pay bill for ok. So, 1 unit of electricity is actually 1 kilowatt hour ok. 1 kilowatt hour basically means that 1 kilowatt of load when it turns for 1 hour it consumes 1 kilowatt of a watt hour of energy ok. One simple thing that you know, but I just want to repeat that energy is actually power to the time that so, if the load for example, if you have a bulb of 100 watt if your bulb of 100 watt and it is running for 10 hours the bulb of 100 watt is running for 10 hours. So, what you have is 1000 watt hour that is your energy consumed by the bulb of 100 watt for 10 hours ok now 1000 is 1 kilo. So, we can also write it 1 kilowatt hour this is how we write in short. So, 1 kilowatt hour is actually 1 unit of electricity ok. So, this is the most commonly used unit in our daily life. So, 1 kilowatt hour is 1 electricity unit fine. So, let us come back to this 1 kilowatt hour is 1 unit of electricity and how much is this in terms of the joule ok it is again very simple watt is joule per second and you multiply by hour 1 hour is 3600 second. So, you will find that 1 kilowatt hour is 3600 kilo joules of energy. So, we should know this conversion because we very often we will see the energy units either in joules or in kilowatt hour kilowatt hour is a very large unit joule is a smaller unit and electron volt is very small unit. There is even bigger unit of energy that people use which is called as TOE that is tons of oil equivalent TOE is tons of oil equivalent. It is the energy released from burning of 1 ton of oil of a given calorific value and it typically amounts for about 42 giga joule of energy 42 into 10 is for 9 joule of energy that is 1 ton of oil equivalent. You can also using the relationship between kilowatt hour in joule using the relationship between TOE and joule you can also convert into ton of oil equivalent is actually 11634 kilowatt hour. So, now putting all the energy units together we have very small unit which is electron volt and we have very large unit which is tons of oil equivalent. And what unit that normally we use in our daily life is basically electricity unit is kilowatt hour. So, just keep this in mind and this was just to revise basic energy units. Moving on to the next how much energy is required how much energy is required in the world. So, when I pause for a second or 10 second or 20 second basically I am pausing so that you can think about the answer or you can make a guess of answer do not tell anybody just for yourself and then we can come back to that. So, how much energy is required in the world and what is the world energy scenario. So, for example, this graph gives you energy consumed this is the total energy consumed by the way the energy total energy includes electricity it includes energy in the transport it includes energy in the cooking biomass everything and it is given in terms of exa-joule and one exa-joule is tens for 18 joule one exa-joule is tens for 18 joule and this is given with respect to time. So, you can see that in about 1980s the energy worldwide energy consumption was about 300 exa-joules which is now increasing very regularly and in 2005 the energy consumed by the world was about 488 exa-joules 488 times tens for 18 joules huge amount of energy. So, you can convert this exa-joule into the water also here it is given tera-water 1 tera is tens for 12. So, the actually the energy consumed in terms of tera-water is 138000 tera-watt hours it is equivalent to the power plant of 15.7 tera-watt if the 15.7 tera-watt and tera is tens for 12. So, if a power plant of 15.7 tera-watt and note this number runs throughout the day throughout the year then you will actually generate this amount of energy. So, basically what you need in the world is a power plant of a 15.7 tera-watt which is working all the time and if that power plant is working all the time it will generate enough energy which is consumed by the world all over the world as of now. So, eventually want to compare this number 15.7 0.7 tera-watt and how much is the solar radiation that is coming towards and how that number is compared. So, that is why just keep note of this number and we know that energy requirement is growing all the time and this graph is very clear that energy requirement is growing all the time and it is growing because of the two factor very strong factor the population is growing and the you might have be aware of the recent news that you know our world population has crossed now 7 billion people that is one factor that is causing the increase. The second is the gross domestic product or the GDP is also increasing and increase GDP requires increase amount of energy consumption. Therefore, there are many developing countries or underdeveloped countries which needs to develop and therefore, the GDP will increase their GDP will increase and the energy requirement will increase. So, therefore, in order to keep a pace with the population growth and GDP grows we definitely have to produce more and more energy in the coming years. So, from where this energy will come that is the question from where this energy will come and this is just another slide to show you that how closely the GDP growth is linked with the energy growth. Here the numbers are given in terms of tons of oil equivalent tons of oil equivalent TOE metric tons of oil equivalent and here the GDP in billion dollars and you can see that it is very closely related how the GDP growth is resulting in the energy consumption growth. So, which is very simple and easy to understand this is a very interesting graph that suggests that the human development index. Now, the human development index is an index which accounts for the quality of life of the people which account for the literacy rate which accounts for the income which accounts for the health. So, human development index 1 is absolutely idle living conditions human development index is 0 or is a very pathetic condition. So, now I can see that and this human development index is plotted as a function of annual per capita electricity consumption. So, the electricity as our unit that you know now kilo watt hour varies from 2000, 6000, 8, 10,000 and 16,000. You can see that as the electricity consumption increase how the human development index increase the important part is in this part when the curve is very steep. So, for a small increase in the electricity consumption there is a large increase in the human development index. India is somewhere here about 0.5 human development index just about that and if I and I right now our per capita per year energy consumption is about 600 units or 600 kilo watt hour per capita per year. If you go from 600 to just 2000 in our standard of living can increase significantly which means our income will increase our health condition will increase our literacy will increase. So, the development human development is also related with electric with energy consumption and that makes all the way more important that we you produce more energy and solar photolytics can be one way of doing that. What are the various renewable energy sources? You know it well, fossil energy, so coming from coal, oil, gas, renewable energy, coming from wind, solar, radiation, biomass, nuclear energy, coming from the nuclear fuels, gravitational energy that is because of the interaction between the sun and earth, gravitational forces and geothermal energy. These are the various ways resources that can be used to supply our energy demand. Right now all over the world the dominant supply of our energy requirement is coming from the fossil energy which you know that it causes pollution, there is a environmental damage there is increase in CO2 I will show you some of the slides for that. Renewable energy especially the solar is a tremendous potential I mean to show you the slides on that can be very useful, but there are other sources that can also be used. So, let us look at what is our primary fossil fuel based energy and how it can fulfill the requirement. So, as I said the world as a whole primarily using the fossil fuel based energy these are the data from 2002, but the proportion or the percentage are nearly similar now. So, you can see the coal supplies about 23 percent of energy oil 35 percent and note that this is a primary energy it is not only electricity it is all forms of energy that we use in transportation in cooking in electricity any other form of energy that we use that is referred as a primary energy. So, I can see now that coal is 23 percent oil is 35 percent, gases 21 percent you put this together you are already talking about more than 75 percent of our energy is coming from the fossil fuel and then you have the biomass the biomass is very large because many developing nations use biomass for cooking and therefore, this is significant otherwise the use of biomass for electricity only is small and renewable is 1 percent and because of the many government initiatives now the contribution of other renewable energy sources is also increasing. So, world energy sources is predominantly by the fossil fuel based and this has to change in the later future why for many reasons. So, for example, when we start using energy so, we use energy for example, in our load our lights our computers or automobile or fans with the whole journey of the fuel start much earlier. So, the journey of fuel start from the mining for example, mining of the coal gas oil then you actually convert this fuel into the secondary fuel which is maybe a refined oil it may be a electricity at the power plant then you transmit and distribute this system this energy for example, you then you transmit and distribute the oil to the various petrol pump for example, so that it can then go into the your vehicles and be used or you generate electricity power plant in your transmit to the various substations and then finally, to your the house or industry so, that you can use it and finally, this is actually utilized by the loads. So, if you can look at the journey of the fuel it goes to the various processes various conversion before it is finally, utilized and as a result of this long process of conversion from the source to the final application there is a efficiency or not that high and we lose lot of energy in between. So, overall efficiency normally comes out to be about 15 to 16 percent only fine even if we think about the conventional energy sources how long we can use them, how long we can use coal, how long we can use oil, how long we can use gas and just to cut the story short I here what I have made a table which talks about how much is the overall reserves of the fuel. So, for example, oil in terms of the billion barrels there are 1047 billion barrels the gas is about 5500 standard cubic feet and the coal is about 984 billion tons these are the data about 2005 6 numbers might have been different little bit, but look at the production at that time. So, the production at that time is 26 billion barrels per year. So, this is our total reserve this is our per year consumption you divide this number by this number you will get this which means the availability of the fuel for that particular for number of years. You can do this exercise for the other fuel and you will find that you will find that the oil will only be available at 40 years and gas for 53 years coal is because the consumption is less it can be available for longer period, but which means the only point that want to emphasize here is this all this fossil fuel based sources are limited in the quantity they are not produced at the rate at which they are consumed and therefore we can say they are non-renewable in nature. What about India? So, India's coal consumption and production is here oil available reserves is 700 metric tons or consumption is very large and this shows the picture of the oil in terms of the million barrels per day MBD. What you can see here is our domestic production shown by yellow is very small as compared to what we consume and our imports are very large in 1997 our imports are 57 percent today's condition it is about 85 percent of oil that we import and in the years to come will even import more, but if you suppose we do not import and we consume whatever oil available in our country data shows that we will run out of the oil only within 6 to 7 years. So, we can survive with our own oil only for 6 to 7 years importing oil is lot of money that you have to pay and it is also related to the security. The suppose countries which are producing are supplying the oil to us if they stop giving oil to us then lot of our activities our economic activities will stop will suffer and we will suffer and therefore, there is a need for alternative energy options that we must find out. Now, let us look at the Indian electricity scenario what is happening so far we have been talking about the energy in general which includes other forms of energy, but let us look at the electricity because the photovoltaic technology is mainly used for electricity generation. So, if you look at our electricity scenario our total installed capacity is about 177,000 megawatts about 177 gigawatts that is what is there in the country right now out of which thermal power is 115 gigawatt out of which most of it is coming from the coal. So, about 54 percent of our electricity comes from the coal 10 percent from the gas small percentage from the oil because oil is mainly used for the transport application. Hydro is significant about 22 percent nuclear is small percentage and now we have the significant contribution of renewable energy sources about 10 percent of the installed capacity comes from the renewable energy sources of which wind is significant. So, predominantly our electricity scenario is 65 percent coming from thermal route and small percentage come from the renewable which is very significant by the way, but one thing we have to notice that this is the percentage of the power capacity the more important is the percentage of the energy capacity how much energy this renewable energy sources produce and because our supply of the fuel renewable energy fuel like solar radiation is not continuous the contribution to the energy from the renewable energy sources is less than 10 percent similar wind is not continuous 24 hours. So, the contribution of power is 10 percent, but the contribution of those power into the electricity generated is less and then we will come to that. So, this is the scenario of electricity generation earlier slide was about the power capacity now this is the electricity generation total generation. So, you can see that we have produced 771 billion units remember what is 1 unit 1 unit is 1 kilowatt hour. So, we have generated 771 billion units in 2019 811 billion units in 2010 11 do not worry about this number we will come to that. So, basically we our electricity generation in the countries in the range of 800 and now it this year it may be about 850 billion units is that large number of. So, it is a billion kilowatt hour is that large number of electricity probably not because our population is also very large. So, in the tutorial you will solve one of the problem which is related to that if this is our generation of electricity per year if we divide with our population then you will find how much electricity is available to us per capita. So, that is the problem that you will do in your tutorial now one important thing that you must learn here with the power with respect to the power plant is that is the capacity factor. So, the capacity factor is the ratio of energy generated by a power plant during a period this period can be one day one month one year divided by the energy generated that the plant would have generated if operated with 100 percent capacity in the same time. And we know that for example, a solar power plant if it is installed though it is let us have capacity 1 megawatt, but this 1 megawatt will not be produced in the night because in the night there is no radiation available, but a thermal power plant of 1 megawatt can operate almost 24 hours because the coal is kind of stored and it can be continuously supplied. So, the capacity factor gives us an idea how many percentage of the time a plant is operational. So, how many percentage of the time the plant is operational? So, in that way if I want to calculate the energy as I said energy generated is the power into the time. Suppose I have 1 megawatt plant and it is operating for 24 hours it will generate 24 megawatt hour of electricity. Now many times this power plant do not operate for 100 percent of time because of the maintenance schedule you have to stop for some time if it is a hydropower plant the availability of the water in the day will affect the operation. Therefore, that factor is how many percent of the time the plant is operational is actually captured by the capacity factor. So, normally instead of using this as expression for finding out how much energy a power plant will generate I should actually use the expression that energy from the power plant would be equal to the power capacity maybe 1 megawatt plant, 10 megawatt plant and the time normally let us say 1 day time if you are calculating it may be 1 month or 1 year and then the capacity factor C f let us say C f is the capacity factor and this capacity factor will then actually tell me the actual energy. Now this capacity factor can be small for a renewable energy technology and therefore just looking at the power capacity it does not give me the correct picture. I will give some numbers of the capacity factors for example the capacity factor for a coal based power plant is normally 70 to 80 percent it can be 85 percent 90 percent also similar for the hydro based power plant and for the nuclear power plant it can be again 70, 80, 80 percent but the capacity factor for wind the capacity factor for wind is only about 14 to 20 percent 14 to 20 percent similarly the capacity factor for PV is again only about 14 to 20, 22 percent. So, therefore it is important that if you take a right capacity factor then for a in order to calculate energy from a power plant you have to make sure that you take a capacity, the power, the time and the capacity factor that will give the true picture of how much energy a given power plant can generate. Therefore it is not the power capacity of the plant that is important it is the energy generated by the plant is that is more important fine. So these are the numbers that typically that you can get again you will do one problem in your tutorial about the capacity factor. So, suppose a plant capacity is given the energy produced by the plant is given in a given time it may be one day again or one month then you should be able to find out the capacity factor or if the capacity factor of the plant is given is sometime it is also called as a plant load factor sometime it is also called plant load factor also the plant load factor is given you should be able to calculate how much energy a given power plant will generate. Moving forward so we know that there are limitation of the conventional sources the quantity availability is limited the use of renewable energy, soil fuel based sources causes the environmental damage I will show you the slide for that it is a centralized energy source therefore the energy generation occurs at one place and it is distributed all over the places then there are related to that at the transmission and distribution losses. Energy security is also issue oil is not for example produced in the country and if other countries decide not to supply oil it will become a difficult scenario for us. So considering this we should actually look for the alternative energy sources how much is the environmental damage that is caused there is lot of news especially after this IPCC that intergovernmental committee for the climate change report has come out and it has linked that the increase in the CO2 in our atmosphere has resulted in a increase in the temperature and it will continue to do so if you do not take care of it. So if you look at the pre industrial era the CO2 percentage was about 280 parts per million the CO2 concentration is given in terms of the PPM PPM is parts per million. How does after the industrialization how is the part how the CO2 is increasing and now when the current industrial rate the CO2 increases very high and we have already about 390 to 400 parts per million and if it continues like this people have estimated that the earth's temperature could actually increase by 456 degree centigrade by 2050 and you can imagine that is not acceptable or it will not be sustainable life on earth and therefore we have to some do something to minimize the CO2. What we can do we can use alternative energy sources which does not cause the pollution which does not emit the CO2 and this alternative sources can be solar it can be wind it can be biomass it can be small hydro it can be tidal energy it can be ocean thermal geothermal or anything in this particular course our interest is on solar photovoltaics. So we will just focus on the solar photovoltaic itself one good thing about the solar photovoltaic is very direct way of energy conversion. So if you for example look at the thermal way of energy conversion solar thermal then you actually have the sunlight then you have to concentrate light because all the solar thermal power plant use concentrated lights you have to concentrate the light you generate high temperature using that high temperature you generate steam and then use this steam to drive the turbine use the turbine output to fade into the generator and get the electricity. So this is a long process if you come to the wind turbine for example you have the sunlight which causes the wind flow wind flow result in the motion of the rotor of the blade of the wind turbine and that is fade to the generator and then the generator gives the electricity. So this is the path for solar to electricity using wind look at the path for the solar cells you get the sunlight you put the solar cell and you get the electricity very simple direct there is no part that is moving therefore the maintenance is very low and it is so simple that you can actually make a solar PV very small as per your need you can take a 1 watt of power 1 milli watt of power 1 micro watt of power but also you can actually get a mega watt of power or even gigawatt of power. So energy conversion through solar cell is very simple and that is what you are learning in this course. How much percentage of our energy requirement can be supplied by solar PV technology that is the final question that we want to answer in this lecture how much percentage of our energy requirement can be supplied by solar PV technology. You have any answer to that any idea any guess? So the answer is yes we can actually supply the whole energy requirement by using very small portion of the fraction of the solar radiation. Let us look at the world solar radiation map the world solar radiation map is having a radiation energy so it is given in terms of energy radiation energy is again here we are giving in terms of the kilowatt hour remember kilowatt hour is unit of energy and 1 kilowatt hour is 1 electricity unit. The amount of solar radiation falling on a given surface at a given location given country is also given in terms of kilowatt hour but we talk about how many kilowatt hour per meter square. So the energy unit is given in terms of kilowatt hour per meter square per year. So this map is the world map of solar radiation kilowatt hour per meter square per year. So the blue is actually 400 500 kilowatt hour you see none of the areas blue except few but most of the area is red and orange and yellow which means that most part of the world receives the solar radiation I hope you can see this number but here we have 1000 here we have 1500 and here we have 2000 and here we have 2500. So most of the part receives lot of sunlight by the way 2000 kilowatt hour is a very large amount of solar radiation. So look at the India most of the India is about yellow color yellow and bright orange color and which means that we receive lot of amount of solar radiation. What I have done a very simple calculation here that India electricity consumption density what I have done I have taken the energy produced in India electricity produced in India sorry how much electricity we produce I have given you the earlier number per year then electricity produce is 800 billion units per year in India. If I divide that number by the area of India so if I divide the 800 billion unit I have converted into the kilowatt hour so that is a common unit I am using here also and here also. So if I divide if I convert that electricity produced in India and if I divide by the area area the surface area of India then actually the electricity density of the country is only 0.35 kilowatt hour per meter square per meter square per year how much is available 2000 kilowatt hour per meter square per year. So 2000 kilowatt hour per meter square per year is available while we are consuming only 0.35 kilowatt hour per meter square per year. So let me repeat the question again can we generate all our electricity from solar PV modules answer should be emphatically yes because the area that we are going to use is very small. So then considering the potential for the solar energy our electricity by the way this is the world electricity I am considering the total world energy sorry the electricity consumed is 56.7 extra joules remember 1 excise stands for 18 joules. The solar radiation falling on earth surface is 3.8 million extra joules much much much higher than what is being produced. So this point is again just to emphasize that this point is again just to emphasize that whatever we are using right now the solar energy received by the earth is much much higher and therefore it is a big big potential to fulfill all our energy requirement using solar remember one earlier number that I told you that all the energy that we consume is equivalent to a 15.7 terawatt plant operating full time in the world. Look at the solar radiation that is coming to us 90 times transferred 12. So it is a much much much higher several thousand times higher than what is what is actually needed by the way this should be the transferred 15. So it is a petawatt 19 petawatt so 1 petas transfer 15 so there is a mistake here this is not transferred 12 it should be transferred 15. So our current power is in the range of 15 terawatt that is transferred 12 and what is reaching on the earth surface is petawatt so about 10,000 times more than what is consumed or what is required. Again re-emphasizing the fact that both in terms of the energy and the power the amount of solar radiation received on earth is much much higher than what we are generating and consuming. So this is very interesting graph that shows that the amount of solar radiation but it also shows that this dots this dot here in the North America, South America, Africa Middle East, Asia, Australia. What it says is that this is the land area that is available the land area where the water is not there. If you install a solar power solar photovoltaic only of this area which is the size of the dot if you only consume this area and if you install your solar photovoltaic module on this dots covering the area exactly equal to the dot size then that should be sufficient to generate all the energy requirements of the world. So in terms of the area required to install a photovoltaic module is again very very small as compared to the area available to us again re-emphasizing the fact that yes it is possible that by using only very small area we can generate all the energy required in the world. For India I have again done a small calculation and you can also do this calculation yourself and this is part of assignment also one of the tutorial problem is this that if you use up modules of only 10 percent efficiency if you use a solar PV module of only 10 percent efficiency and if you cover 100 by 50 kilometer square area in the country in India. So take 10 percent modules cover 100 by 50 kilometer square which is very small as compared to 3000 by 2000 kilometer square that is available. So if you do this then India will generate enough electricity to produce what we are producing by other power plants today. So we will generate enough electricity which we are producing by other power plant today. So basically you can fulfill all our electricity requirement by using very small portion of the country above the land area available. So in conclusion coming to the end of the first lecture then in conclusion solar energy is a huge potential to meet our energy requirement I guess all of you must be convinced by the slides that I have shown you. And now we should understand how much we can make use of the solar energy using solar photovoltaic and therefore with this background about the solar photovoltaic and the solar energy with this background this course will provide you the fundamentals, technologies, fabrication and application and we have designed the lectures toward that. So if there are any questions please ask thank you very much for your attention. This was the background lecture and after this we will start learning about little bit more about the solar radiation and how to install your photovoltaic module so that you can collect the best radiation possible. So we will little bit learn about the sun and earth moment with respect to each other and how much solar radiation is available. Thank you very much. If you have any questions please ask we have couple of minutes for this lecture. VNIT Nagpur. Yes sir, good afternoon. What is the yearly increase in solar power generation in India? What is the increase in solar power generation in India? Well India have done very good in the last 2 years in 2009 our installed power capacity was only about 10 megawatt but as of now we have as the secretary told in the morning in inaugural session that there is about 150 megawatt of solar power installed in the country and as per the national solar mission we are targeting 20,000 megawatts by year 2022 and my personal belief is that I think when the year 2022 will come we will install much much more than 20,000 megawatt and that is why all this manpower is required and that is where all of you can play a very important role. Jaipur college. Yes sir, my question is very simple I just want to ask that you have told we can achieve the energy as was required today with this technology then sir why we are not using this technology, what is the main problem behind all these things, what are the main problems that we are not using this technology, whether we can achieve all the energy which is required today. Right. So, good question so if it is so nice if it is you know clean technology if we can actually produce large amount of energy why we are not using it and the one reason is the economy. The cost of installation of solar energy technology is very high right now but I mean let me tell you that as the secretary also mentioned in the morning two years back the cost of electricity that company were quoting was about 17 rupees per kilowatt hour. Today there is a smallest code that one company has come is 7.5 rupees only per kilowatt hour. So, with the advancement in the technology and the volume of production is increasing the cost of solar energy is also decreasing. So, there is a one presentation that I have attended yesterday that there is always talk about the grid parity. Grid parity means at what time the cost of the solar electricity becomes equal to the cost of the grid electricity and the presenter showed that there are already eight countries where the grid parity has been achieved by the solar power and I am sure in the couple of years more there will be many other countries where the grid parity will be achieved. And because of this increase in the technology decrease in the cost increase in the efficiency now it is becoming more and more viable for the countries to afford solar power, but it was not possible five years ago. And I will also want to give example of IIT Bombay itself at IIT we are installing one megawatt of solar photovoltaic power because the cost of electricity that we pay is actually higher than the cost of solar electricity. Now five years back this was not the case, but now because the electricity grid electricity prices are going up, solar prices are going down, so it is becoming more and more viable now. KJ Somaya college? Sir, you rightly said in the previous slide that with the installing the power plant solar power at dots which is mentioned in the world map, but sir will you think that what is the cost of transmission and what is the loss? Right, cost of transmission. Okay, very good point that you know the whole advantage of a renewable energy technology that it is distributed and because all our users are also distributed, so it will not make a sense to actually put all your power plant at one point and then distribute. That idea was only to convince you that by using small amount of power, sorry small amount of area, we can actually fulfill all our energy requirement, but by no means it suggests that we should actually put all power plant at the same place. Definitely renewable energy is distributed, all users and all our applications are distributed and therefore we should not go for all the concentrated plant at one place. Okay, go ahead for the next question. Sir, in India particularly we have a monsoon over fixed period of time, so during which the solar radiation is poor, but the wind is significant. So is India planning to have a hybrid technology of solar and wind energy in future? Yes, definitely solar photovoltaic may not be the only solution and in the future energy scenario of the country, I am sure there will be a coal based power plant, there will be a PV power plant, there will be a hydro, there will be nuclear, there will be thermal. So we have to actually combine all the technologies and then make the best use of whatever is available, but definitely the only one technology will not be our solution, we have to rely on many technologies. One last question from Bhopal. Sir, my question is the in world energy scenario, the contribution of renewable energy is only one percent as you saw in your presentation. So what are the possible reasons and how it can be improved, situation how can be improved? One way to improve the situation is actually train thousand teachers which we are doing right now. So basically it requires the technology development, it requires government policies, it requires trained manpower, it requires user awareness, public awareness about the renewable energy technology. And I would like to quote the example of a Germany. Germany actually receives much less solar radiation than what we do, but still the solar power installed in Germany is the highest in the world and being a very small country, why it is possible? Because government is very receptive, the public is actually wanting to do that. So in order for a technology to be successful, there are many factors that are involved and one of the factor is for example policies, finances, technological development, trained manpower and so on. And in India we are trying to create that ecosystem, the government has already done a significant job by having a good policy in place, technological development is happening in the country and worldwide also, but there is a shortage of manpower. So I think you people, all the teachers I am requesting again and again that there is a huge requirement of the people and I request all of you to actually learn this PV technology and teach as many students as possible, so that you know we can contribute to the growth of this technology not only in our country, but let us say we can lead this moment in all the developing countries. So therefore as I mentioned that we were conducting the quizzes, this quizzes will be conducted please pay attention and those who are those will score very good mark will issue about 100 certificates of excellence. I would like to ask what is the life of a PV solar panel and the after the life it has completed life, is it harmful for the when many worried or is it harmful for the environment? So first question life of the solar PV modules is about 25 years and there is people have already used it for 25 years, so that is proven. So solar cell for example is solar module is made of a glass, aluminum frame, silicon metals including silver, aluminum all these materials are actually recyclable. So once the life is over it will not cause any damage to the environment, so that aspect is taken care. Thank you very much to all of you, let me stop here for this particular lecture.