 Hello, I am Dr. Satish Kumar Kashid, Valshan Institute of Technology, Solapur presenting a topic, reservoir planning, estimating reservoir capacity of a dam reservoir by analytical method, learning outcomes of this session. At the end of the session, the students will be able to explain the characteristics of a hydropower plant and the students will be able to estimate required storage capacity of a dam and its reservoir for a particular inflow pattern by analytical method. One simple example we will take, now just observe this is a hydropower plant and spillway. So this is a barrier in form of a dam which is constructed. This is a spillway portion of a dam or overflow portion of a dam. We observe the gates here, the tenor gates are provided here. Whenever excess water comes in the reservoir and we need to release it, we open these gates and allow this water to flow. When we want to generate hydroelectricity, we allow the water to pass through the hydro power generation stations that turbines which are provided here. So whenever the reservoir is full and inflow is more than required, then hydro power generation will be there as well as there will be spill over the spillway. But when inflow is lesser than the required outflow, in that case we will be using water which is stored in the reservoir. Let us see, this is the dam, this is the reservoir form, here there is a control gate, this is the penstock, water enters, passes to this turbine, rotates the turbine, the vertical shaft rotates this particular coil in generator, electricity is generated and sent to the grid. This is the hydro power generation. Now let me discuss some important characteristics of hydro power plant. The system efficiency of hydro power plant is quite high. The installation cost of hydro power plant is very high. The running cost of hydro power plant is very low. The hydro generators give high efficiency or wide range of load. The hydraulic turbines take a very small time for putting off and on and the major hydro power generation in India is from storage type of hydro power plants. Small question, the only statement which is incorrect in regard to hydro power is the system efficiency of hydro power plant is quite high. The installation cost of hydro power plant is very high. The running cost of hydro power plant is very low. The hydraulic turbines take a lot of time in being put off and on. Obviously answer, the incorrect statement is the hydro power turbine takes a lot of time in being put off and on. This is not true but rather this is applicable to thermal plants which take a lot of time for putting on and off. Hydro power plants can be made off and on in relatively very short durations. Let us take one problem. The water turbines at hydroelectric store plant produce 7,360 kilowatt of power under head of 30 meter with an overall plant efficiency 80 percent. The inflow in the reservoir is given in the following table. In this table, find the minimum reservoir capacity required to satisfy the uniform demand of water. The uniform demand will be decided by the water discharge required to produce this 7,360 kilowatts. And we are also asked to find out the total quantity of water wasted during the year. Assume the reservoir to be full at beginning of November and you are asked to use the analytical method. So these are the months over a year. So at start of November, we are assuming reservoir full. And then monthly inflows in million cubic meters are given in this way. Now let us calculate what is the discharge required to generate 7,360 kilowatt continuously. Let P with the power in kilowatts, let Q is the discharge in Q mech, let H is head under which the turbines work. So power in kilowatt, this is the equation is 9.81 into efficiency into discharge Q in Q mech into head H in meter. So putting this value 7,360 efficiency 80 percent and head 30 meter, we can find out Q. So to generate continuously this 7,360 kilowatt, we need 31.29 meter cube per second as a continuous discharge. So we multiplied by 30 days, 24 hours into 60 minutes and 60 seconds. This term, this bracket will give you number of seconds and this is meter cube per second. So answer is 81 million cubic meter approximately. So we need 81 million cubic meter of water in every month to generate 7,360 kilowatt continuously. Now here inflow as it is given in our question, November, December, January, February, March, April you find it is varying and outflow we are assuming constant for generating 7,360 kilowatts of energy that is why it is same. Now as reservoir is full at start of November, in month of November inflow received is 100 whereas outflow used is 81. So naturally excess of this water excess over 81 will be wasted over spillway. Again by end of November the reservoir is full. When you come to December inflow is 75 and outflow is 81 it means outflow is more. So we will have to take 6 million meter cube of water from storage. That's why it is draft used from storage is 6 and by end of December 6 million meter cube will be the depletion in reservoir. In month of January we find that inflow is 90, outflow is 81. It means 9 million meter cube excess water has come. So this excess water will be used for refill first. So 6 million meter cube will be refill. That's why the 3 million meter cube of water will be wasted over the spillway. Here we come to February inflow is 80, outflow is 81. So draft used from storage is 1, reservoir depletion is 1. So we proceed with such calculations and ultimately we come to see that maximum depletion observed is minus 21. It means whenever there is excess water you can imagine that this is reservoir full condition indicated by hazard. Then when you come here in month of January spill is 19. But in month of December we are using 6 million meter cube from storage. In March we are using 9 million meter cube from storage and maximum we are using 21 million meter cube in month of May. So over a period of time we find that the maximum depletion from reservoir observed is 21 million meter cube. So if we provide 21 million meter cube as storage then every demand over a period of time will be satisfied. So this is the analytical method and the answers are shown by using this particular graph here. If the volume of water which is discharged over a spillway is shown in this way in particular months or so. So if you come here you will find these are the values of water wasted over spillway and these are the values of reservoir depletion. When you find some of all these you will be getting water wasted over spillway and maximum reservoir depletion will be the required reservoir capacity. So last question 400 cubic of water is being released from a dam storage to meet the downstream demand through turbines of the connected hydropower plant. The effective head of water acting on turbine is 50 meter. Efficiency of hydropower plant is 0.8, electrical power generated from this plant would be. So we will have to use this formula that power is 9.81 into efficiency into Q into H it will give this answer. So these are the references used. Thank you.