Energy can be transformed to a range of states. Energy in different states can be used for various physical works. Energy can be utilized in natural processes or in supplying services to the community. For instance, an inner combustion engine transfers the latent chemical energy present in petrol and oxygen into heat, which is next changed to kinetic energy for use by automobiles and a solar cell changes solar energy into electrical energy which can be used to power television or light a bulb.
Fossil fuels are products of decayed residues of ancient animals and plants. They consist of oil, natural gas and coal. Currently, they provide more than 90 percent of the world’s sum energy (Vas, 1998). Fossil fuels remain attractive for use today since they are cheap, easily distributed, easily available, and can directly generate heat and electricity. However, they emit hazardous substances to the environment. As a result, alternative sources like wind and hydro electricity which are less harmful to the environment are being explored.
Hydro electricity is produced by streaming water through turbines. In generation of hydro electric power, water is bunged up in dams. Big pipes run through the dam construction directing water to the turbines which are turned round by the power of water. The power stations then control the level of the water by opening and closing water gates that ferry water into the turbine quarters.
Hydropower has several benefits over other energy sources. It does not pollute the environment since water is a clean source of fuel. It is also a renewable source that is easily available. Impoundment hydropower builds dams and pools that offer various leisure opportunities, particularly boating, swimming and fishing. Hydropower installations are supposed to offer public access to the reservoir. Other benefits of using hydropower as a source of energy include: flood management and water supply.
On the other hand, hydropower has several limitations. Dams can be a cause of soil erosion and may cause threats to downstream animals and plants in case of floods. Also, developing hydro electricity power plants is really expensive.
The other alternative source of energy is wind energy. Wind energy is a reproducible source of energy that is fueled by the sun so as to produce electricity. Since the earth is enclosed by almost 70 percent water, there is a difference in the manner of heating between the land and the sea (Muljadi & Wang, 2004).
During the night, the air on top of water cools less fast than the air above land. The temperate air over the sea inflates and mounts up while the heavier, cooler air hurries in to replace it, generating winds. During the day, the opposite occurs. The land heats up quicker than the seas. The temperate air over the land inflates and goes up while the heavier, cooler air hurries in to replace it, generating winds.
Wind Energy produces electricity by utilizing blades on wind turbines to amass the kinetic energy of the wind. Wind turbines hold back the wind which streams above the airfoil formed blades causing lift, and making them to revolve. The blades are linked to a drive ray that revolves an electric generator thus generating electricity.
Wind energy is the most rapidly growing energy source in the world as it has several advantages (Farret & Simoes, 2006). The fact that it is fueled by wind makes it a clean source of fuel. It does not emit harmful substances in the environment and it is a renewable source of energy. Wind energy is cheap and easily available. Wind turbines can be constructed on agricultural estates or ranches, thus promoting the rural economy.
On the other hand, wind energy has some demerits. Despite the fact that wind power plants have somewhat less impact on the surroundings weighed against other common power plants, there is much distress over the noise created by the rotor blades. In other instances, birds have lost their lives by soaring into the rotors. However, these issues have been significantly reduced through technological upgrading and by locating wind plants appropriately.
From the above discussion, it is clear that the two alternative sources of energy, the wind and hydropower, compare with fossil fuels in many ways. First, all of them are sources of energy that are available in the world today. However, while the wind and hydropower are renewable sources of energy, fossil fuels are not renewable.
This is the major difference between them. Fossil fuels also emit greenhouse gases that are harmful to the atmosphere. There is also a difference in the way these sources are obtained. While wind energy and hydropower are obtained from the wind and water respectively, fossil fuels are obtained from decayed remains of ancient plants and animals.
In conclusion, energy is convertible to different states. Currently, the world is exploring alternative sources of energy that can suitably replace the common use of fossil fuels as the chief source of energy. This has been motivated by the fact that fossil fuel emits greenhouse gases which are harmful to the environment. Wind energy and hydropower are some of the alternative sources of energy that have been explored. However, each of these sources of energy has its own merits and demerits.
References
Farret, F.A. & Simoes, M.G. (2006). Integration of alternative sources of energy. New York: Oxford University Press
Muljadi, E. & Wang, C. (2004). Parallel operation of wind, turbine, fuel cell, and diesel. Melboume: Generation Sources.
Vas, G. (1998). Sources of energy. London: Sage