Good Source of Energy:
Good source of energy should have following qualities:
1. Optimum heat production per unit of volume/mass used
2. Easy to transport
3. Least Polluting
Earlier coal was used to run trains, but given its bulk it was difficult to transport. Hence now world over trains are run on either diesel or electricity. This example shows how petroleum is better against coal on all the above parameters.
Conventional Sources of Energy
Fossil Fuel: Plants and animals which were buried under the earth millions of years ago, have transformed into petroleum because of high heat and high pressure in the inner layers of earth. As petroleum is made from fossilized plants and animals that is why this is called as fossil fuel. Petroleum is refined into huge refineries to produce various fuels like petrol and diesel. Petroleum requires low temperature to catch fire, is easy to transport and is affordable to the masses. Hence, it is one of the widely used fuel. Coal is also made of plant fossils. Nowadays coal is primarily used in thermal power plants to generate electricity.
Hydro-energy: Water is very powerful. Its power is harnessed by building dams, where water’s potential energy is used to run dynamo to produce electrical energy.
Steam: Coal is used to heat water to generate steam. Earlier steam’s power was used to run train engines. At present steam is used to run dynamo to produce electricity.
Bio-Mass: Cow dung and plant residues are left to decompose in a huge tank. The decomposition results in production of methane gas, which is used as fuel.
Nuclear Energy: Fission of an atom creates huge amount of energy. This property is used to produce energy in nuclear power plants.
Risks and Ecological Problems of Conventional Energy:
1. Fossil fuel is also called as non-renewable energy resource. Fossil take millions of years to get converted into energy source. The speed at which humankind is using these resources, will extinguish all fossil fuel sources on earth. Moreover, they produce CO2 and other pollutants which are harmful for our environment.
2. Most of the major rivers are past their prime, so their water reservoir is about to finish. High dams often cause massive earthquakes.
3. Nuclear power plants always carry the risk of leaking harmful radiation into the environment.
Non-Conventional or Renewable Energy Resources:
Risks associated with conventional energy sources have forced scientists world over to think of finding non-polluting and renewable energy sources. Some of them are as follows:
Wind Energy: Wind’s power is being used to run windmills to produce energy. They are non-polluting and wind cannot be finished.
Solar Energy: Sun is the main source of energy for all life forms on this earth. Solar panels are being used to trap sun’s heat energy to convert it into electrical energy. At present they are very costly, but further research will make solar energy affordable in near future.
Bio-Diesel: Some wild plants like Jathropa is now being cultivated to produce oil, which is being used as bio-diesel. Drawback of this is the fear of agricultural land being shifted for Jathropa plantations. This is now being blamed for rising food prices around the world.
Hydrogen Fuel Cells: Hydrogen is available in abundance in the environment. When hydrogen is combined with oxygen, energy is produce and the byproduct of such reaction is water. Research is going on for this source of energy on a large scale. This will be the safest, since the byproduct water is non-polluting for environment.
Tidal Energy: Tides come with great force. In some countries dams are built and dynamo is placed near small opening in the dam. When tide comes it helps turn the dynamo, which in turn produces electrical energy.
Wave Energy: High hollow tubes are built near seashore. When a wave comes, it pushes the air up inside the tube with great force. This air helps run the dynamo.
Geothermic Energy: Inside of earth is filled with molten lava, which turns underground water into vapour. In certain countries turbines are placed strategically to harness the energy of steam from underground water reservoir.
Most of the renewable energy resources are still in experimental stage. Wind energy is somewhat developed compared to others. Hopefully all these research will bring great relief to the mankind.