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Thermal Power Plants
• Thermal power plants converts the heat energy of
primary fuels such as coal, to the electric power. In most of the thermal power
stations, combustion of primary fuels heats the water and transforms it to
steam. The steam drives steam turbines, which eventually generates electricity.
Subsequently, the steam is condensed and recycled back into the system. The
thermal power stations may use several different types of heat sources,
including fossil fuels, nuclear energy, biomass and waste.
• Types of thermal power plants (Wikipedia):
1. Subcritical. Operate at critical point of water with temperature
of 374 °C and pressure 22.12 MPa.
2. Supercritical. Operate at 500-600°C temperature and 24-26 Mpa Pressure.
3. Ultra Supercritical: Operate at 760°C temperature and 34 Mpa Pressure.
• Supercritical coal-fired power plants have higher
thermal efficiency than subcritical power plants due to their higher operation
temperature (500-600°C) and pressure (24-26 MPa) (Li & Wang, 2018).
• The thermal power plants using coal, lignite, diesel,
and natural gas, accounted for 69.25% (276,293 MW) share of total installed
capacity of conventional power plants in India (MOSPI, 2019). The total
installed capacity of coal and lignite based thermal power plants is
171,239 MW. The Vindhyachal Thermal Power Station in
Madhya Pradesh, operated by NTPC, is the largest coal-fired power plant in
India with an installed capacity of 4,760 MW, followed by the Mudra Thermal
Power Plant in Gujarat operated by Adani Power Ltd. with an installed capacity
of 4,620 MW.
• In a Combined Cycle Gas Turbines (CCGT) power plant,
the hot exhaust gas from a gas turbine is used for
generating steam in a waste heat steam generator, which is then used in a steam
turbine for generating additional electricity (Czisch,
2011). Natural gas based power plants are comparatively less polluting and more
efficient than other fossil fuel based power plants in general, and the coal
power plants in particular. The Pragati Combined
Cycle Gas Turbine (CCGT) – III, located in Delhi state, is the largest gas
based power plant in India with an installed capacity of 1,500 MW.
• Diesel-based power plants may use Diesel, Furnace Oil, Heavy Fuel Oil (HFO),
Low Sulfur Fuel Oil (LSFO) or Low Sulfur Heavy Stock (LSHS). The Basin Bridge
Diesel Generator Power Plant (DGPP) in Tamil Nadu is the largest diesel power
plant in India with an installed capacity of 200 MW.
• The installed capacity of nuclear power plants
in India is 6,780 MW with Kudankulam Nuclear Power
Plant in Tamil Nadu being the largest nuclear power plant with an installed
capacity of 2,000 MW. All nuclear power plants in India are
operated by Nuclear Power Corporation of India Ltd. (NPCIL).
• In addition to the conventional thermal power plants, biomass
and waste-to-energy (WTE) power plants are also being
promoted in India. The installed capacity of biomass-based power plants,
including bagasse (waste from distilleries) is 2,941 MW, while that of WTE
power plants is 272 MW.
References:
• Czisch, G., 2011, Scenarios for a Future Electricity Supply,
The Institution of Engineering and Technology, London,
United Kingdom.
• Li, D. and Wang, J., 2018, Study of supercritical
power plant integration with high temperature thermal energy storage for
flexible operation, Journal of Energy Storage, 20, pp. 140-152.
• MOSPI. (2019). Energy Statistics 2019. New Delhi:
Ministry of Statistics and Programme Implementation
(MOSPI).
• Wikipedia, Thermal power station, URL https://en.wikipedia.org/wiki/Thermal_power_station, Accessed: July 2020.