Towards green energy class 10 short notes 2020

Chapter - 5.0

Towards Green Energy

Energy and use of energy:-

• We need energy in different for forms diverse types of works.
• Energy that we need may be in form of mechanical energy, chemical energy, sound energy, Fight energy  or Heat energy.

Generation of electrical energy:-

• Most of the electric power plants are based on the principle of electro magnetic in wanted by Michael faraday  .
• The field around a conductor can be changed in two ways.
• It conductor is stationary and magnet is nothing
• Thus in both these cases , a potential difference is created across the conductor
• The  electrical power generating machine based on this principle is called electric generator.

• Such large generators are used in commercial power generation plants.

Thermal energy based electric power station:-

• Turbine is rotated using steam
• Water is heated is a boiler .
• Thermal energy released due to bowing of coal.
• Theme of very high temperature  and pressure is generated .
• The energy in the steam drivers the turbine .
• Generator connected to the to the turbine rotates and electrical energy is produced.
• Steam is converted back into water and the water is recirculated to the boiler.

Power  plant based on nuclear energy:-

• Steam turbine is used to rotate the generator.
• Energy released by fission of nuclei of atoms like uranium as plutonium
• Energy in the steam rotates the turbine it drives the generator producing Electricity

• Nuclear energy is converted into thermal energy .
• Thermal energy is converted into kinetic energy of the turbine converted into electrical energy.

• Nuclear power plant does not use fossil fuel like coal.
• Problems like are pollution do not arise .
• Sufficient nuclear fuel is available .
• This can be good source of electrical energy.

Power generation plant based an energy of natural gas:-

• Turbine is run by gas at very high temperature and pressure generated by combustion of natural gas .

• Three main sections type of plant .
• Combustion chamber using a compressor .
• The natural gas burns in presence of the air.
• Turbine then drives the generator to produce electricity .

• Efficiency is higher than plant based on coal.
• Burning of natural gas results in less pollution.

• Electricity energy generation and environment.
• Electricity generation based on fossils fuels like coal , natural gas and nuclear fuels like uranium and plutonium are not environment friendly .
• It can lead to environmental degradation .
• Burning of fossil fuels like coal and natural gas leads to emission of certain gases and soot particles
• Increase in percentage of carbon dioxide
• Nitrogen dioxide generated due to burning of fuels like coal, diesel, petrol etc.
• Problem like acid – rain occur
• Soot particles are generated
• Problems related to respiratory system, like asthama.
• Millions of years for formation of fossil fuels like coal, Crude oil and natural gases (LPG and CNG)

Hydroelectric Energy:-

• Hydroelectric power plant the potential energy in water stored in dam is converted into kinetic energy of water.
• The kinetic energy of the flowing water drives the turbine
• The turbine in turn drives the generator to generate electricity.

Electricity Generation using wind – energy:-

• The wind energy can also be used for electricity generation.
• The machine which converts the kinetic energy of wind to electrical energy is called wind turbine.
• The axel of turbine connected to electric generator through a gear-box. It increases the rotations per unit time.
• Turbine in turn drives the generator to generate electricity

• Wind velocity is high on sea- shores
• Wind energy is clean energy source.
• Wind energy is not available every where

Electric Energy generation using solar energy:-

• Using the energy in the sunlight Electric energy can be generated in two way-
• Solar photovoltaic cell:-
• Solar photovoltaic cell converts the solar radiation energy directly into electric energy.
• These solar cells are made of a special type of material called semiconductor.
• (eg silicon)
• P E
• Energy in sunlight    =====> D C Electric power

Solar thermal power plant:-

• Thermal energy generated from coal and nuclear fuel can be used to generate electricity.
• It can also be generated from solar radiation and can be for electricity production