What is the good source of energy?
- We can choose the fuel which is good and which would satisfy the following requirements:
- The fuel we have chosen would do a large amount of work per unit volume or mass.
- That fuel would be easily accessible.
- The fuel must be easy to store and transport.
- And most importantly that fuel must be economical.
Conventional sources of energy:
- Conventional energy sources are also called as non-renewable energy sources which are having high energy efficiency.
- These sources are not eco-friendly.
- After using conventional energy sources for long time, they may get exhausted.
For example:
The fossil fuels like coal, oil, wood water, petrol etc all are the conventional energy sources.
Fossil fuels:
- Fossil fuels were formed millions of years ago and hence they are available in limited quantities. As fossil fuels are non renewable energy sources, hence we have to conserve them. To conserve them we have to use the alternate energy sources.
- But, burning of fossil fuels also has many disadvantages.
- Now a days, lot of factories, vehicles are using fossil fuels in huge amount and after burning of this fossil fuels there is a evolution of tremendous amount of gases in air which are responsible for air pollution.
- In order to avoid this, we have to use pollutant free energies and have to plant more trees for better environmental conditions.
- We have to use vehicles, machines which works in the electricity or energy stored from the sun so that air pollution will be avoided.
- We have to ban on deforestation and have to plant more trees which will produce pollution free environment in future.
Thermal power plant:
- Now a days large number of fuels are used to generate heat and thereby to produce steam which helps in generation electricity. It is easy to transmit the electricity rather then transporting coal or petroleum over the same distance.
- For this purpose, many thermal power plants are developed near the coal or oil fields.
- Thermal power plants are developed to produce heat energy and again which is converted into electrical energy.
Hydropower plant:
- Also, we can use the kinetic energy of flowing water or potential energy of water falling from more height to generate electricity.
- Hydropower plants converts mainly potential energy of falling water into electricity.
- For this purpose, hydropower plant are associated with the dams due to very few water falls availability.
- There are also some problems associated with the construction of dams. They can be constructed only in limited areas like hilly terrains.
- Due submerging of dams large land of farmers and human habitation may be get sacrificed.
Improvements in the technology for using conventional sources of energy:
Biomass:
- The biomass uses the animal and plant waste material as a form of fuel. The main source of fuel used is biogas. From decades ago, we are using bio mass.
- The cow dung, plant waste or residue, vegetable waste is decomposed in the absence of oxygen to produce biogas.
- The starting material used is only the cow dung.
Principal:
The biogas is produced only because of anaerobic fermentation of organic and inorganic waste in the presence of water and absence of oxygen.
Fig. Schematic diagram of Biomass
Wind energy:
- Due to unequal heating if landmass and water bodies due to solar radiation produces air movement and leads to wind to blow.
- This high kinetic energy of the wind is used to to do work. In the past windmills are used to do mechanical work using kinetic energy of blowing wind.
- Windmill construction is similar like that to large electric fans and they are erected to some height with the help of rigid support.
- The number of windmills is constructed over a area called as wind energy farms. Wind energy is the eco-friendly and efficient source of renewable energy. But there some limitations to harness wind energy also.
Following are the disadvantages to produce wind energy:
- In case of producing wind energy, we must have large area for wind mills. The speed of wind blowing should be constant but in actual it does not remain constant.
- Also, we have to maintain the blades of the wind mills properly because they are exposing to all environmental conditions such as rain, cyclone and sometimes high speed of wind also.
- Wind energy is produced only in those areas where the speed of blowing wind is high in order to generate electricity in more form.
Alternative or non-conventional sources of energy:
- The non -conventional energy sources are eco-friendly and if we use them continuously, they will not exhaust.
- Non conventional energy sources are solar power, hydroelectric power, ocean wave energy, tidal energy, wind energy, solar cell, ocean thermal power energy, biomass etc.
Solar energy:
- The sun is radiating tremendous amount of solar energy from billions of years ago and the solar energy reaching to earth is in very small content. So, every person on the earth can use solar energy for its daily purposes.
- Solar cooker, solar cell, solar panels are all working using solar energy.
- Solar cooker or solar heaters absorbs the heat energy due to black coating and achieve high temperature in order to cook food easily and also to heat water.
Solar cells:
- Solar cell is also called as photovoltaic cell which is used to convert solar energy into electrical energy. And it is based on the working of PN junction diode in a semiconductor.
- The solar cell has vast of advantages because it works on the basis of solar energy which is easily available and does not create any kind of pollution.
- The solar cell is a pollution free device and safe to use. Also, it has no movable parts, so easy to handle and work. And the solar energy used is in tremendous form which is available to every person on the earth equally and daily.
- So, we have to only work on it, to produce electricity by using solar cell without giving any harm to environment.
Energy from the sea:
Tidal energy:
- Tidal energy is harnessed due to the difference in sea levels. The gravitational force of moon on the spinning earth leads to rise and fall in the sea water.
- The rising and falling of water level is called as high tide and low tide. The dam is constructed near the sea and at its opening a turbine is rotating which converts tidal energy into electrical energy.
- Tidal energy is the pollution free energy.
Wave energy:
- Wave energy is also the form of energy harnessed from ocean, which is due to the huge waves in the sea level. These waves are trapped somewhere and used for producing wave energy.
- The wave energy is formed due to the strong winds blowing on the sea level which are due to the temperature difference and pressure difference in the atmosphere.
- In this way from tidal energy and wave energy we can produce electrical energy. The above discussed energies are the two forms of energy harnessed from ocean.
Ocean thermal energy:
- The temperature difference in the upper level and deep level in the sea is used to produce thermal energy called as Austin thermal energy and it is converted into electrical energy.
Geothermal energy:
Due to geological changes, there are hot spots are formed in the earth crust due to molten rocks formed. When such hot spots come in contact with hot water then steam get generated and some hot springs on the earth’s surface are produced. And this steam is used to generate electricity using turbines.
Nuclear energy:
Nuclear power plant uses nuclear energy to generate electricity.
- These days the nuclear power plants, which are using the heat energy produced during nuclear fission reaction mostly. The heat energy evolved during nuclear fission reaction in the core of nuclear reactor is used to boil steam water and which rotates the blades of turbine and helps in producing electricity.
- The main reaction is nuclear fission reaction in which heavy atomic nuclei are bombarded with low energy neutron. In this reaction, fission of reactant nuclei takes place and most of the mass is converted into energy and it is evolved out after reaction.
- The difference between mass of reactant nuclei and mass of product nuclei is the amount of energy evolved during the reaction.
- The nuclear fission reaction is based on Einstein mass energy relation. The amount of energy evolved which takes main role in generating electricity.
- But in a nuclear fission reaction, most of the radioactive waste are generated which are more hazardous to the human life and creates water pollution.
- The nuclear fission reaction is also used in atom bomb. After explosion of atom bomb huge amount of energy is evolved and radioactive waste are also emitted.
Environmental consequences:
- Burning of fossil fuels causes air pollution.
- Solar cells are pollution free devices but operation of solar cell may cause environmental damages.
- So, there are some disadvantages of non conventional energy sources also.