 Hello, I am Dr. Sitesh Kumar Kashin presenting a topic, a reservoir planning for runoff river type hydro power plants. I work as a professor in civil engineering at Valshan Institute of Technology, Solapur. The learning outcomes, at the end of this session, the students will be able to compare different types of hydroelectric plants, discuss suitability of runoff river type hydroelectric plants, calculate pondage required in the reservoir used for runoff river plant to satisfy inflow and power generation pattern. This is a typical hydro power generation plant. Here there is a reservoir, which is formed by this stamp. This is a control gate. When we open the gate, water enters through the spine stock to this turbine, turbine rotates and after transferring energy to turbine, water further moves to the downstream channel. The rotating turbine has a shaft. The shaft is rotated and then electricity is generated in electric generator and then it is transmitted. Now, let us very briefly discuss different types of hydro power plants. Hydro power plants can be of storage type hydro power plant, runoff river type hydro power plant, pumped storage type hydro power plant and also tidal water hydro power plant. Now, this is a well-known storage type hydro power plant from USA. That is the hydro power plant with Hoover Dam. This is Hoover Dam, a very big storage reservoir formed on the upstream side of the stamp and it is utilizing a very big head available here and this is the hydro power generation station at the foot of the dam. In this season of high flows, the reservoir will be filled in and water will be used over the year for hydro power generation. So, this is a speciality of storage type hydro power plants. Now, this is an example of Chief Joseph Dam from USA. This is runoff river type hydro power plant. Now, the speciality of runoff river hydro power plant is such that major flow is passed through the hydro power plant and excess water which is available is passed over the spillways. So, here you find the water passing through the hydro power generation plant as well as the additional water flowing through the channel. The reservoir which is formed here is comparatively very small as compared to storage type of hydro power plants. This is a power plant which is called as pumped storage power plant. In pumped storage power plant, you will find there are two reservoirs. One is reservoir at higher elevation and another is the reservoir at the lower elevation. When your peak hours of demand are there, water from the upper reservoir is passed through the penstock through the hydro power generation plants and electricity is generated. The electricity generated is fed to the grid and sold at the higher rates as compared to off peak hours. The water which is released from the upper reservoir will be stored in the lower reservoir and will not be allowed to go further in the river. And in off peak hours, the water which was released at the time of generation will be again pumped up and thrown in this upper reservoir. This steam does not have 100% efficiency but the difference is managed by the rates at which power is sold. That's why you will find that pumped storage type hydro power plants are also useful whenever we can manage the demand and supply of electricity in peak and off peak hours. At off peak hours, excess energy available in the grid is taken and it is used to pump the water from the lower reservoir to upper reservoir. This is La Rance tidal type hydro power plant in France. So here we find that here there is history and here there is a power plant. A reservoir is formed on this side. The level difference in between the reservoir and open sea at the time of high tide and low tide is used here for generation of electricity. So this plant side features the tidal range of 8.2 m. This is the highest range in France. The capacity of this power plant that it can generate up to 540 gigawatt hours annually. It consists of 145 m long barrage with 6 fixed wheel gates and 163 m long dike and the basin area which is covered is 22 square km. Power produced through this particular plant is generated by using 24 reversible bulb turbines of capacity 10 MW each. This is the another picture of the same hydro power plant. This is the open sea and this is the stream and the level difference in between the open sea and the reservoir is used here. So here you find this particular reservoir is storing this water. It is at higher level whereas there is low tide in sea and the water is released to generate. Now let us discuss in details about the runoff of your plant. The same example I am giving. So the characteristics of runoff of your plant can be summarized like this. A small damage is usually built to create a head point ensuring enough water entering the penstock pipes. Water led to the turbines which are at low elevation. Projects with pondage as opposed to those without pondage can store water for daily load demands. Many larger runoff of your plant projects are now designed to a scale which have their generation capacity comparable to the traditional hydro dams. Let us compare the source plant and runoff of your plant. These are different in design. The traditional hydro dams store enormous quantities of water in the reservoirs and sometimes it causes flooding. In contrast runoff of your plants do not have the disadvantage associated with big reservoirs. That is why they have less environmental impact. Advantage of runoff of your plants they can create sustainable energy minimizing the impact of surrounding environment and nearby communities. These plants give cleaner power, fewer greenhouse gases less flooding due to big reservoirs. Without a reservoir flooding of upper part of the river does not take place and as a result people remain living or near the river and in existing habitations and these habitations are not flooded. Whereas there are some disadvantages also of this runoff of your plants. The runoff of your plant is considered as a uniform source of power. It has little or no capacity for energy storage and hence cannot effectively coordinate the output of electricity generation to match the consumer demand. It means these are not as flexible as the storage plants because their storage is limited and they largely depend upon the runoff of the river. It thus generates much more power during times when river has high floors but it generates much less power during drier summer months that is the disadvantage. The sites are also not available in great number for this type of plants. Let us take few questions. A runoff of your plant for hydro power generation is essentially a head scheme, a low head scheme, medium head scheme or none of these. Second question. Pondage requirement in hydro power plant includes the need to balance the varying demand to compensate for wastage and spillage to balance short term fluctuations in the flow Let us see the answer. A runoff of your plant for hydro power generation is essentially a low head scheme. Pondage requirement in hydro power plant includes the need to balance the varying demand to compensate for wastage and spillage to balance short term fluctuations in the flow. Let us take one problem. A runoff of your plant is to be constructed across river at a site where net head of 22 m is available on the turbines. The river carries a sustained minimum flow of 26 km as drive other flow. Behind the power station sufficient pondage is to be provided to supply daily peak load of demand with a load factor of 70%. Assuming the plant efficiency of 58% determine maximum generation capacity of the generators to be installed at powerhouse and the volume of pondage to be provided to supply the daily demand Assuming daily demand pattern consists of average load for 21 hours and peak load for 3 hours. Let us go to the solution. Let P be a power in kW. Let H be the head in m and it has the efficiency. Power P is given by P is equal to 9.81 into efficiency into discharge Q into head H. Here efficiency we are given as 0.58 and Q is 26 km. With the head 22 m one can calculate power P generated in kW that is 9.81 into 0.58 into 26 into 22 that is 3251 kW. However we are given the load factor as 0.75 load factor is average load by peak load. So we equate this average load 3251 and then we find out the peak load. So it gives you peak load as 4645 kW. Now hence assuming there is no reserve capacity we have maximum capacity of generators to be installed as 4645 kW which matches with the peak. So from point H is drawn in order to meet excess demand for 3 hours when we need the excess power. So let us find the difference between the peak demand and average demand. It is 4645 minus 3252 So we need to generate additional 1394 kW of power for 3 hours. So let us find out excess discharge required for developing excess power. So power P is 9.81 into Q into H. Now we want to generate 1394 kW. So additional discharge required is 11.15 kW. So this discharge has to be there for 3 hours. So let us multiply it by the seconds of 3 hours and then we get this as 120400 cubic meters. So in this way we calculate the reserve storage capacity required for a rough plan. So these are the references which are used for drafting this presentation. Thank you.