Theory:

Thermal power station:
  • In thermal power stations, thermal or heat energy is generated by burning fuels like coal, diesel or gas.
  • This heat or thermal energy is used to boil the water; thereby, we can produce steam. The steam thus produced is made to rotate the turbine.
  • The turbine is connected to a coil which is placed between a strong electromagnet. When the turbine rotates, the coil of wire also rotates.
  • Thus, an electric current is produced in the coil due to electromagnetic induction. Here, we use heat energy to produce electricity.
1200px-Trypilska_Thermal_Power_Plant_inside_(1).jpg
Interior view of thermal power plant
  
Do you know what is mean by electromagnetic induction?
Electromagnetic induction is a process that produces voltage or emf (electromotive force) across a conductor when it is exposed to a varying magnetic field.
We can also produce voltage or emf by placing a moving coil in the fixed magnetic field.
It was Michael Faraday who discovered Electromagnetic induction.
The thermal power station in Tamilnadu are
  • Neyveli in Cuddalore District
  • Ennore in Thiruvallur District
Ennore_Thermal_Power_Plant.jpg
Thermal power plant, Ennore
 
Hydel power plant:
 
The hydel power plant is similar to the thermal power plant, but we make use of water from the dam to rotate the turbine.
Why do we use dam water
  • Due to the higher altitude of the dam, the water reaches the turbine with high pressure. When this water is allowed to fall on the turbine, it rotates at a high speed. When the turbine rotates, the current is produced in the coil by electromagnetic induction.
  • Thus, the hydel power plant uses the kinetic energy of falling water to generate electricity. Therefore, kinetic energy is converted into electric energy.
The hydel power plants in Tamilnadu are
  • Mettur in Salem District
  • Papanasam in Tirunelveli District
1200px-16_gate_Bridge_at_Mettur_dam.jpg
Mettur dam
  
1200px-ServalarDam_-_Mundanthurai.jpg
Servalar dam - Papanasam
Reference:
https://commons.wikimedia.org/wiki/File:Ennore_Thermal_Power_Plant.jpg
https://commons.wikimedia.org/wiki/File:16_gate_Bridge_at_Mettur_dam.jpg
https://commons.wikimedia.org/wiki/File:ServalarDam_-_Mundanthurai.jpg
https://commons.wikimedia.org/wiki/File:Trypilska_Thermal_Power_Plant_inside_(1).jpg