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Module 1: Basics of Energy Use and Environmental Impact

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Fuels and CO2 Emissions Relative to The Economy

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(Refer Slide Time: 31:33) So now let us look at any pollutant we would like to see what happens when you we have a fuel and that fuel is being used in a device, that device gives your useful energy and then we have some emissions. So if we look at a vehicle, these emissions will go in the place where the vehicle is moving. If we look at a power plant these emissions will be, there in the location of that power plant. These emission now this is one device in that area there will be other devices, D2, D3, Dn, there are different things. So, all of these emissions will come together and then you would basically get a concentration. So, if you look at for instance in the city of Delhi, you look at a number of vehicles at a traffic signal, each one is emitting some particulate matter. We will take all particulate matter which is there. Now depending on the air velocity some of it will defuse and move out, some of it will remain there and you will have a concentration. Now in that place, if there is a human and that human is you are in that place for a certain amount of time then you will get a dose of how much of that gets absorbed that will go toyour lungs and then that will have a health impact. So you see the change, it is about what kind of fuel we are using, what is the composition? As we use it for useful energy there are some adverse impact that emissions of course if it is in an area where it gets diffused out then it will not result in too much of a concentration.We can have a norm in terms of emissions cannot be more than this, we can also have a norm in terms of trying to see what is the concentration for instance in the case of Agra because of the Taj Mahal and the kind of discoloration which was happening to the Taj Mahal, several industries were asked to close down and not use fossil fuels in the location, so that you could reduce the emissions and do that. So we can look at concentration and concentration norms and if you see you will find that these norms are monitored by environmental stations at different locations, so that will be afunction of location. Then if you have people who are there depending on the amount of time you will have an intake and based on that intake then you can look at the impact which is there on respiration, it will have a health impact. (Refer Slide Time: 34:49) So, if you look at this on this slide you will see that this is illustrated in this his is in from the energy after Rio, so you have the fuel, you have the emission then you have concentration that concentration results in exposure and that exposure is dependent on how many peopleand how much time that results in a particular dose and then that dose results in an impact and that impact could be as there could be fatal or could be resulting in a other health impact. (Refer Slide Time: 35:14) Now depending on the percentage of the emissions which are taken in. So for instance active smoking is something where all the emissions are going in, so it is like one ton, per ton of pollutant almost all 100 percent is going in. If you look at second hand smoke, if you are near a smoker then you will take much less, in stove which is vented indoor you have this is indoor air pollution in a boiler, in a vehicle in a coal based power plant. So we can look at this and then we can see the impact and use it in our models to quantify safe levels, to quantify health impact. (Refer Slide Time: 36:00) The World Health Organisation has created a parameter called the disability adjusted lost years. So this is in order to, suppose we look at different kinds of impacts of different pollutants and what is the effect and why do we want to do that? Because we want to quantifyand see where we would like to put interventions, where we would like to put money, what kind of norms we need to have. So what is this is defined as disability adjusted lost year is thought of as one lost year of healthy life and then some of these DALYs across the population or the burden of disease is thought of as a measurement of the gap between a current health status and an ideal healthsituation, ideal health situation where the entire population lives to an advanced stage free of disease and disability. So when we want to make this calculation, this is calculated as a sum of two factors, the year of lost life. So for instance if due to pollution or if due to let us say tobacco, there is some person dies of cancer at a particular age, we have an expected age which the person would have lived to and the number of years that is lost is then computed into the number of deaths and this is summed up. And in a case where it is not fatal but because of that people have disability or they are unhealthy and they lose a number of days of healthy life and number of years so this is how it is added. This is then added by different categories and summed up and then this is one way in which you can compare for instance, indoor air pollution from stubs versus vehicle, impact of outdoor air pollution in vehicles versus diseases like tuberculosis or malaria and all of this can be used to see the impact and to then see what kind of norms we should do and then look at it. So, otherwise in many cases for instance if you look at smoke coming from chulas this the effect is seen over a long period of time, so people may not immediately appreciate the reason or the motivation to go for smokeless chulhas. So, this is a whole impact of energy and health and this is something which one needs to compute when you look at different kinds of policies and different kind of interventions. When we talked about the Kaya identity, one of the factors that we need to look at is what is the emission factor? So and this is something that we can do from first principle. So, whenever we look at, we are looking at a useful energy or a useful output that is being produced, for instance, tons of steel, kilowatt hour electricity how much electricity we are getting in a power plant. So we would like to see as we do that how much is the carbon dioxide emission. So this willdepend on the composition of the input or the fuel, the efficiency and the characteristics of the conversion device, similar calculations instead of CO2 can be also done for SOx particulate matter and this methodology is the same for all pollutants. The calculations are allpossible from a basic stoichiometry and understanding of the  process. (Refer Slide Time: 1:22) So, we will take an example. The same example that we took in the last class when we talked about in the previous lecture we talked about thermal power plant degraded at 500 megawatts and using coal and we calculated how much coal and how much energy is used. (Refer Slide Time: 1:32) So, let us just recast that question – If this thermal power plant has an efficiency of 38 % calculate the emission factor of the plant. So the input energy used is coal with net calorific value of 4500 kcal/kg and the percentage of carbon in the coal is 50 % by weight.  (Refer Slide Time: 2:02) So, let us start this calculation. 1 kwh = 1 kW joules/sec x 60 x 60 1kWh = 3600 kJ 1 mole of carbon = 12 kg 1 mole of oxygen = 32 kg So, 12 44  Now what you could do is you can see there is a Central Electricity Authorities – CEA, it gives norms of CO2 emission factors for different power plants in the country, I think you will have probably 2016 data is the latest which you can get, you can look at it and you will see many of these plants are in this kind of range. So this is something that you can calculate. Just like we have done this we can do a similar thing for a vehicle, we can do a similar thing for an industrial process, for any place where you are doing this you can get the emission factor. Emission factor into the activity level will give you the total emissions, sum it up overall all these and you get the cumulative, so this is a simple calculation and something that youshould be able to do on your own, please remember on the web you will find different emission factors for let us say power plants, they maybe for Australian coal in Australia, they maybe for European coal, the calorific value is different, the efficiencies are different so do not use emission factors from other context, for your context do the calculation yourself. (Refer Slide Time: 7:28) If you look at the different fuels when we will looked at coal, if you look at oil or natural gas you will see that the net calorific value is different, the percentage of carbon is different, you will find that all fuels have either have combinations of carbon and hydrogen and natural gashas more of hydrogen content so that on a per unit basis when we look at it the CO2 emission factors are lower. So this table shows you the kind of norms of emission CO2 per gram CO2 gram equivalentper kilowatt hour and you can see that for coal you have a whole range going up the average being of the around 0.9 to 1 kg. You can see that for natural gas it is about half that number. And when you look at renewables you see here all the renewables are in the range of 20 to 50 grams less than a hundred and almost since some cases biomass is neutral all of this is including the entire life cycle. So for instance if you look at a wind turbine it will be the steel which is there and what is been the CO2 emissions to produce that steel. (Refer Slide Time: 8:35) So, when we think in terms of managing the CO2, the options that we have are increased the sinks or reduce the sources, increase the sinks means we can do afforestation, in reducing the sources we can look at the fuel mix, changing from coal to oil to natural gas, we can look at the energy efficiency, we can look at renewables, we can look at nuclear, we can also look at carbon capture and storage and which technology will use depends on the kind of scale, depends on technology development, depends on cost. So in a sense as we go forward, we have the choices  between mitigation, adaptation and suffering and the decisions that we take today will decide the combination of this. So, either we can mitigate, if we do not mitigate and then there is some temperature rise and climate change we need to be able to adapt and we need to look at when that changes happen what will we do, and if you cannot adapt or mitigate then we will suffer. So this is a problemwhich is a global problem and this is a problem which needs all countries to get together and come up with solutions. (Refer Slide Time: 10:15) You can do as homework, you can look at check the IEA statistics for India for 2 years, I am suggesting 2005 and 2015, calculate the terms of the Kaya identity for both these years andsee and think how this factors can change in another 10 years or another 20 years. What are the possible futures scenarios, what interventions can we make to reduce the carbon intensity. As we go along in this course and we look at economics and policies towards the end we will discuss some of these. We will also have a recording of some of the country studies where some of our students will present some of the countries and what are they doing in terms ofthe Kaya identity and the policies. In Paris we had the Paris  agreement a couple of years back essentially where all countries got together and in the IPCC meetings there was the problem in this is that it is difficult to get a consensus. There are countries which are emitting much-much more than their global share but they are also highly develop, they do not want to change their trajectory. So even to decide whether we should have an emission norm which is CO2 per person and give a right to emit which is on a per capita basis was not agreed upon. (Refer Slide Time: 11:30) Several countries which have developed more want that CO2 emission to be based onhistorical numbers one that CO2 emission to be on a per GDP basis so that the increase level of GDP is taken care of. However, developing countries are not willing to do this and hence there could not be any binding mandatory agreements. Finally, what was decided was every country decided that this is a problem that we would like to tackle. So, there was a process by which there were voluntary commitments made by different countries and these was then ratified into the national commitments. In the case of India the commitments that we have made are: reducing the emissions intensity of GDP by about one third of the 2005 level in 2030, we are planning to create 40 % of cumulative non-fossil power bi installed capacity by 2030 and we expect that would get some finance from the International Green Climate Fund for this. We also plan to create an additional carbon sink of 2.5 to 3 billion tons of CO2 equivalent through additional tree cover and forest. (Refer Slide Time: 12:57) So we will discuss some of this and the economics of this and in the future lectures. In this lecture we have looked at the environment. We found that it is a key driver for future energy systems. We concluded that the existing patterns are not sustainable into the future and we have a real problem in terms of climate change. We also problems in terms of local emissions and urban air quality. We looked at the quantification through the Kaya identity and theemission factors. In future classes we will explore the interaction between energy economics and environment and carry on with same thread. Thank you. These are some of the references.