Hydro-Electric Power Generation

Hydro-Electric Power Generation

• Hydro-electric power stations are used where water resources are available in an ample quantity at sufficient head 
• Such plants are built along with the dam
• Low energy cost due to low operating cost
• The potential energy of the water stored at a height is converted into mechanical energy by using water turbine
• A generator coupled to the water turbine converts the mechanical energy into electrical energy

Diesel Electric Station

Diesel Electric Station

• The diesel engine coupled with generator uses diesel oil as fuel
• It is used where plant capacity is not large 
• A diesel station can be started and stopped quickly as and when required
• It does not require large quantity of water for cooling
• A diesel station may be used as a standby plant to supply part of the load in a power system when required

Gas Turbine

Gas Turbine

• In a gas turbine, the working medium for transforming thermal energy into rotating mechanical energy is the hot combustion gas, hence the term "gas turbine." 
• Gas turbine generators are self-contained packaged power plants.
• Early utility applications of gas turbine-generators were strictly for peak load operation
• Improvements in efficiency and reliability and the application of combined cycles have made it possible to use gas turbine power plants for a wider range of application on electric systems.

Steam Turbine

Steam Turbine

• The thermal energy is used in the steam generators/ boilers to convert water into steam
• The energy in the steam is converted into mechanical energy of a rotating shaft by a steam turbine
• The steam is passed through the high pressure (HP) turbine
• The exhaust steam of the HP turbine is passed through the low pressure (LP) turbine after removing its moisture through the moisture separator
• The mechanical energy of the steam turbine is converted into electrical energy by means of a generator

Power Stations

An electric power station is a factory in which energy is converted from one form to electrical energy.

Types of Power Stations;

There are mainly three types of power stations:

• Thermal
• Hydro-electric
• Nuclear

Thermal Power Stations:

• In a conventional thermal power station, the thermal energy is generated from coal, gas or oil.

Hydro-Electric Power:

• Hydro-electric power stations are used where water resources are available in an ample quantity at sufficient head 
• Such plants are built along with the dam
• Low energy cost due to low operating cost

Nuclear Power Stations:

• The reserves of fossil fuel (coal, oil and gas) are gradually depleting, thus, there is a need to seek alternate sources of energy
• In a nuclear power station, like Karachi Nuclear Power Plant, instead of a furnace there is a nuclear reactor, in which heat is generated by splitting the atoms of the nuclear fuel, known as Uranium. 
• It reduces the demand for coal, oil and gas

Sources of Energy

• Thermal
• Hydro
• Nuclear
• Other 

Thermal Power:

• Coal: Coal energy is one of the types of fossil fuels and non-renewable energy
• Oil: Oil is a natural substance 
• Natural Gas: Natural gas is present in the earth along with other natural resources like coal and oil.

Hydro electric Power:
Hydro-electricity is the production of electricity from the falling water

Nuclear Power:

Nuclear power is the production of electricity with the use of controlled nuclear reactions. Nuclear power provided about 2.1% total energy and 15% of electricity production.

Other Source of Energy:

• Wind: Wind power or wind energy falls in the category of renewable energy source. It can be used again and again without the fear of it being diminished or become scarce. 
• Solar: Sunlight reaches to earth in the form of photons which are energy packets that contain light in it.
• Geo-thermal: This energy is present into the earth due to the decay of minerals and absorption of sunlight by earth. 
• Tidal: The energy of the tides which is transformed into useful electricity and other power sources is known as tidal energy or tidal power. It is more efficient and reliable way of generating electricity as compared to wind mills and solar energy systems.
• Wave Power: When the power of the waves, present on the surface of the ocean, is used to convert it into useful form of energy it is known as wave power. Wave power is different from tidal power and ocean currents. 

Main Parts of Electrical Power System

• Power stations 
• Transmission systems
• Distribution network

Power Stations:

A complex of structures, machinery, and associated equipment for generating electric energy from another source of energy, such as nuclear reactions or a hydroelectric dam. Also called powerhouse, power station.

Transmission Systems: