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.
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
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
Mettur dam

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