Thermal energy comes from heat and motion of atoms and molecules. Thermal energy is used to generate electricity from sources like coal, nuclear, and geothermal. Coal is a main fuel source for thermal power plants. Coal is pulverized and blown into a boiler to burn and heat water into high pressure steam. This steam spins a turbine connected to a generator to produce electricity. The steam is then condensed back into water to repeat the process. While coal is a cheap fuel, it pollutes the atmosphere with greenhouse gases, acid rain, and mercury.

1. Thermal energy
• Thermal means heat
• It means production of energy from heat

2. Thermal energy
– Thermal energy is the energy a substance or system has related to its
temperature, i.e., the energy of moving or vibrating molecules. Atoms
and molecules, the smallest particles of any substance, are always in
motion. The motion of thermal energy is usually not visible, but we
can feel or see its effects. We use thermal energy to cook our food
and heat our homes, and we use it to generate electricity.

3. There are many types which come
under Thermal energy
• Preparation of energy from coal
• Geothermal energy
• Nuclear energy is also come under thermal
energy

4. • Main fuel source is coal
– Let us consider the power generation through coal

6. Generation of power from coal
• Thermal power plant contain mainly
Feedwater:-
Feedwater used in a steam boiler to transfer heat energy from the fuel burning
area to mech. Energy of spinning steam turbine
Boiler:-
Rectangular furnace, pulverized coal is blown in from fuel nozzles at 4 corners.
The coal then burns quickly and forms a fireball at the center
Steam Turbine Generator:-
Is a series of steam turbines interconnected to each other and then a
generator

7. Steam Condenser:-
Steam enters from the turbine generator and is pumped into the bottom
of the condenser, where pumps recycle the condensed steam from the
feedwater
Stack:-
Releases process emissions.

8. Brief Explanation of generation of
power from coal
• Coal is delivered from the coal wash plant to the power plant where
it is placed in a large
• coal storage facility.
• A conveyor transports the coal to a pulverizer where it is ground
into a fine powder.
• The fine, powdery coal is blown into the boiler where it is burned.
Water passes through
• tubes in the boiler walls where it is heated to produce high
temperature and pressure
• steam.
• Waste (flue) gases and small particles of non combustible materials
(fly ash) produced in
• the coal burning process are contained and treated before exiting
up a chimney or stack.

9. • The high temperature and pressure steam created in the
boiler turns the turbine blades.
• The spinning turbine blades drive the generator to create
electricity. The electricity
• generated is stepped up by a transformer to 240 kilovolts
and transmitted, through a
• substation into the high voltage Alberta electric grid.
• The exhaust steam from the turbine is routed through a
condenser which serves to
• advance the conversion of the steam back to its liquid state.
The exhaust steam is
• recycled as water to the boiler to repeat the process.

10. • The condenser is cooled either by an air-cooled
or water-cooled system.
• Solids within the water that is used for steam
generation is treated before it enters the
• Boiler. The treated, de-mineralized water helps to
reduce pipe corrosion within the boiler
• and condenser.
• Heavier non combustible materials (bottom ash)
produced in the coal burning process fall
• to the bottom of the boiler where they are
extracted.

11. Advantages
The fuel used is quite cheap.
• Less initial cost as compared to other generating
plants.
• It can beinstalled at any place iirespective of the
existence of coal. The coal can be transported to
the site of the plant by rail or road.
• It require less space as compared to Hydro power
plants.
• Cost of generation is less than that of diesel
power plants.

12. Disadvantages
• It pollutes the atmosphere due to production
of large amount of smoke and fumes.
• It is costlier in running cost as compared to
Hydro electric plants.

13. Share of coal in generation of power

14. Effects on the
environment and Human health
• CO2 ~ carbon dioxide pollution, making energy use the single largest
source of greenhouse gases
• Sulfur dioxide combined with nitrogen oxide react with water and oxygen in the atmosphere
to form acidic compounds, which can mix with natural precipitation and fall to the earth as
acid rain.
• Mercury One of the most dangerous pollutants released into the air through the
exhaust system when coal is burned.