INTRODUCTION • The cheapest source which is to generating power is water. • Hydro-electric power plant main aim was to generate power in flowing water. • The energy which is from hydel plant is utilized to drive turbine. • In India during 1987, the first hydro-electric power station was started near Darjeeling.
COMPONENTS • Water reservoir. • Dam. • Penstock. • Fore bay. • Surge tank. • Water turbine..
WATER RESERVOIR • In hydel electric power plant, there must be continuous supply of water. • Water reservoirs main functions are to store a net amount of water in it during rainy season and supply it throughout the year.
DAM • The dam is used in hydro power plants to increase the capacity of reservoir. • It also helps to increase the working head of the power plant.
PENSTOCK • A pipeline fixed between the surge tank and prime mover is known as penstock. • It is commonly made of reinforced concrete or steel.
FOREBAY • The main function is to regulating the reservoir. • In the plant when the load is decreased initially then water provided for increasing load.
SURGE TANK • Surge tank is introduced in between the power house and dam to avoid sudden rise in the penstock. • As the load is reduced then there will be a backflow of water inside the penstock. • The back flow of water is known as water hammer.
WATER TURBINE • Water turbine converts kinetic energy into mechanical energy to produce electrical energy. • Pelton turbine, Francis and Kaplan turbine are the prime mover. • The energy in the turbine shaft is mechanical energy and this is used to run electric generator.
WORKING PRINCIPLE • There is supply of energy cycle in hydroelectric power plant. • The mechanical energy converted into kinetic energy.
In other words, at first the potential energy is derived from water it is converted into kinetic energy to derive the turbine in which the electric generated coupled from the turbine shaft, the mechanical energy is derived. • The mechanical energy is converted into electrical energy and used to run electric generated and thus the mutual energy transformation is performed.
ADVANTAGES • Water is cheapest source of energy. The fuels needed for the thermal, diesel and nuclear plants are exhaustive and expansive. • Water is renewable source of energy. • The fuel cost is totally absent. • There is no problem of handling the fuel ash and fuel.
The installation of hydel power plant is easy. • Maintenance cost is low.
DISADVANTAGE • Hydel power projects are capital intensive with a low rate of return. • Initial cost of the plant is high. • Power generation is dependent on the quantity of water available, which may vary from season-to-season and year-to-year.