1. GENERATION CONVENTIONAL SOURCES STRUCTURE OF POWER SYSTEM Power system owned by state electricity boards. Private sector utilities operate in Mumbai, Kolkata, Ahmedabad Regional electricity boards – Northern, Southern, Eastern, Western, North-eastern. Power Grid corporation- Central. Introduction India is one of the world’s largest consumer of energy Installed capacity – 1,67,317 MW  Thermal = 1,08,602 MW  Nuclear = 4,780 MW  Hydro = 37,367 MW  RES = 16,787 MW Per capita power consumption – 612KWH Annual power production – 680 billion KWH
2. Break up of Power  Thermal power Plants : 65.34%[  Hydro Electric Power Plants : 21.53%  Nuclear Power Plants : 2.70%  Renewable energy sources : 10.42%  30% to 40% of electrical power is lost in transmission and distributionThermal Power Plants  Installed Capacity – 65% of total installed capacity.  Coal based –54% of total installed capacity.  Gas Based –10% of total installed capacity.  Oil Based –1% of total installed capacity.Main Components  Fuel Handling Unit  Ash Handling Unit  Boiler Unit  Feed Water Unit  Cooling Water Unit  Generator Unit
3.  Turbine UnitMain Circuit  Fuel And Ash Circuit  Air And Gas Circuit  Feed Water And Steam Circuit  Cooling Water CircuitFuel And Ash Circuit  Fuel stored and fed to the boiler through conveyor belts. Broken down into proper shape for complete burning.  Ash thus generated after burning is removed from the boiler through ash handling equipmentAir And Gas Circuit  Air is required for combustion of fuel and is supplied through fans  Air is passed through air preheater to extract energy from flue gases for proper burning of the fuel  Flue gases have ash and several gases which are passed through the precipitator(dust collector) and go to atmosphere through chimney.Feed Water And Steam Circuit  Steam Converted to water by condenser.  Water is demineralized & hence not wasted to have better economic operation of the plant.  Some part of steam and water is lost while passing through different parts.  Boiler feed pump feeds water into the boiler drum where it is heated to form steam.  Wet steam is again heated in super heater before passing through the turbine  Steam is expanded in the turbine to run it. After which again it goes to boiler for reheatingCooling Water Circuit  To condensate the steam, large quantity of cooling water is required which is taken from river or pondage  After passing through the condenser, it is fed back to the river or Pondage
5. Selection Of site  Availability of cheap land.  Availability of water.  Availability of fuel.  Possibility of future expansion of the plant.  Away from the urban areas due to pollution.  The initial cost of plant.  Magnitude and nature of load to be handled. Hydro Power Plant  India is Pioneer in HEP  Darjeeling(1898) and Shivanasamudra (1902) one of the first in Asia.  Installed Capacity – 37,367MW
6. Advantages of Hydro Power Plant  Water is self – replenishing, non wasting.  Water reaches the powerhouse site on its own.  Water after producing electricity can be used for drinking or irrigation.  Efficiency of HEP is high(about 80%).  HEP has very long life.  Maintenance is easy and less expensive.  The percentage outage is low.  Benefits of recreation, fisheries etc. Selection of sites  Availability of water  Storage of water  Head of water  Distance of power station to the load centres  Accessibility of site
7. Classification of HEP based on Capacity Very low-capacity plants – up to 0.1MW Low capacity plants – up to 1.0 MW Medium-capacity plants – up to 10 MW High-capacity plants – more than 10 MW Classification of HEP based on Capacity Micro Hydro plants : < 100KW Mini Hydro plants : 100KW to 1MW Small Hydro plants : 1MW to few MW Hydro plants : More than a few MW Super Hydro plants : More than 1000MW Classification of HEP based on Head Low-head Plants < 15m Medium-head Plants 15 – 70m High-head Plants 71 – 250m Very High-head Plants > 250m Nuclear Power Plants Twenty Nuclear Reactors Production – 4780 MW Energy from atomic nuclei via controlled nuclear reactions(Fission) Uranium-235 and plutonium-239. Nuclear Fission
8. NPP Using A Heat Exchanger PWR – Pressurized Water Reactor(Nuclear Furnace or Pile) Main Components Of A Reactor Fuel Rods – Tube filled with pellets of Uranium Shielding - Protection against alpha, beta and Gamma Rays Moderator - Slow down the neutron release(Heavy water, Beryllium, Graphite) Control Rods - neutron absorbing material(boron Carbide, cadmium) Coolant - To transfer the heat generated inside the reactor to a heat exchanger for utilization of power generation(CO2, H2, He, heavy water, liquid metal-Sodium or Potassium) Steam Separator - steam from the heated coolant is fed to the turbines to produce electricity from generator.
9.  Containment - concrete lined cavity acting as a radiation shield Boiling Water Reactor (BWR) Heavy Water Reactor(CANDU) Gas-Cooled Reactor
10. Selection of Site Availability of water - NPP requires ample amount of water for cooling and steam generation. Disposal of Waste – Dangerous waste/residue obtained It needs to be disposed deep under the ground in sea so that radioactive effect is eliminated. Away from populated area – For health safety Nearest to the load centre Other Factors – Accessibility to the road and rail are general considerations. Advantages of NPP Fuel is easy to transport. Energy generated is very efficient and the remaining waste is compact. Nuclear reactors need little fuel. Amount of waste produced is much smaller than that produced in coal burning plant Chance of a nuclear accident is 1 in 250 years. Clean source of energy. Disadvantages Actual cost of producing energy is more because of containment, radioactive waste storage system The mining of the fuel itself can cause serious problems The meltdown of reactor can cause serious disaster. GAS POWER PLANT
11. Axial Compressor Air is taken from the atmosphere , compressed, heated (usually by combustion of fuel in the air) and expanded in the turbine. Gases coming out of the turbine are exhausted in the air. Used in emergency and when there is peak demand. Fossil fuels such as gasoline, natural gas etc are used as fuel Diesel Engine It is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber. Diesel engines are manufactured in two stroke and four stroke versions. Used to drive the prime mover of electric generators Used as a stand-by set for start up of auxiliaries in steam and gas power plants
12.  Used for emergency supply to hospitals, hotels, factories and in other commercial units. Advantages: High operating efficiency. Need very little water for cooling. Quick start and stop is possible. Easier handling of fuel.