Hydro Power Plant


Hydro Power Plant

  • By using hydro power plant we can generate electrical power .
  • Energy neither be created nor be destroyed. it can transfer in one form of energy another form of energy.

In hydro power plant energy conversation in form of followings are :

  1. Potential to Kinetic (Potential of water)
  2. Kinetic to Mechanical (by Turbine)
  3. Mechanical to Electrical (by Alternator)
  • In hydro power station we can generate electrical energy by using potential energy.

Classification of Hydro Power Plant:

  • According to head
  1. High head (above 300 meter)
  2. Medium head (60 to 300 meter)
  3. Low head (less than 60 meter)
  • According to Operation
  1. Manual control
  2. Automatic control
  • According to types of Load
  1. Base load
  2. Peak load
  • According to head Turbine are selected.
  1. Impulse and Pelton wheel( for  High head)
  2. Francis and Reaction (for medium head)
  3. Propeller and Kaplan (for low head )

Different scheme of Hydro Power Plant:-

hydro power plant
fig: basic hydro power plant
  • High head scheme :

                 This type of scheme is established at where high head can achieve, make the dame across the river, Hence it make big reservior at one side, pen-stock is connect with the dam,by using valve house water can be injected in pen-stock, by using penstock water is supplied to the turbine,and its rotate turbine, turbine is connected with the alternator. which is convert mechanical energy in to electrical energy. In high head scheme head is above 300 meter.

  • Medium head scheme:-

                Construction of medium head scheme is same like high head scheme. head is between 60 to 300 meter. its deffer from high head scheme by the type of turbine. in this type Reaction or Francis turbine are used.

  • Low head scheme

                   In these scheme water head is less than 60 meter. propeller or Kaplan turbine are used for low head scheme.

Different element are used in Hydro Power Station :-

  1. Reservoir: make the dam across the river hence it make a big reservoir at one side the capacity of power station can be increase by increasing capacity of reservoir.
  2. Dam: dam is a barrier which stores water and creates water head dam is made by concrete. the arrangement is depends upon the topographic of the site. there are three type of dam concrete, rock or earth fill ,stone masonary.
  3. Spillways : there are times when the river flow exceeds the storage capacity of the reservoir. spillways are made of concrete piers of top of the dam.
  4. Penstock: penstock are one type of conduit which is open or close and its carry water to the turbines . its made from steel or reinforce concrete . concrete penstock are suitable or low head line.
  5. Surge tank: Surge tank is located near the penstock conduit .Surge tank is a small storage tank or reservoir required in the hydro power plants for regulating the water flow during load reduction and sudden increase in the load on the hydro generator and thus reducing the pressure on the penstock. This is the advantage of surge tank.
  6. Turbine: Turbine are use to convert kinetic energy into mechanical energy. There are different type of turbine which can be use according to head of water. Turbine is connected to alternator which is convert mechanical energy into electrical energy.
  7. Tailrace: The water that has been used to rotate the turbine blades and turbines shaft leaves the power generation unit entering the pipeline called as the tailrace. From here the water flows into the main river. The height of water in the tailrace is much below the height of water in the water reservoir behind the dam.
Selection of site:-
  • Availability of huge quantity of water. it  is primary requirement of hydro power plant
  • Storage of water : water is stored by constructing dam across the river,  in order to ensure the generation of power throughout the year,storage helps in equalizing the flow of water so that any excess quantity of water at a certain period of a year can be made available during time of very low flow in river.
  • Cost :- water is store by making the dam across the river hence the cost of construction of dam is high.
  • Transportation facilities :- site selection of hydro power plant should be accessible by rail or road so that necessary equipment and machinery can be easily transport.
  • Land area :- space is require more because future expansion can do easily.
  • Catchment area :- catchment area is require more because huge quantity of water is necessary, it stored by that area.
Advantages :-
  • It has longest life.
  • No fuel are require, because water is used to generate electrical energy.
  • It is neat and clean, no ash produced.
  • Require less maintenance ,simple constructed.
  • Less no of equipment hence stand by loss are less.
  • Plant operation is easy ,can be easily turn ON-OFF.
  • No atmospheric pollution.
  • Less running cost compare to other power station.
Disadvantages :-
  • Necessary to make the dam to storage of water, hence Capital cost is high.
  • Transmission line cost is high (because plant is located away to the consumer).
  • Transportation cost is high.
  • Skilled and experience person is require to make this plant.


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