The paper explores the technology of hydroelectric power generation. It throws light on how the technology works, brief historical viewpoint, its benefits and shortcomings, the transmission aspect of the technology, its future potential. Hydroelectricity is the largest source of renewable energy throughout the planet. We will learn how it provides a double benefit of energy and water management provisions leading to accelerated growth and development. Though initial costs related to a hydroelectric project are high, they provide a long term source of energy with considerably low running and maintenance costs. This paper also highlights how water resources have been utilized by mankind for centuries for making their tasks easier and quicker and how it has broad futuristic prospects.
Hydroelectric power is generated by transforming the kinetic energy of falling water into mechanical energy of rotating turbines, which is then converted to electrical energy using dynamos. This process is a part of the water cycle, which consist of solar energy converting water from seas and oceans to vapors resulting in rain and snow which lead to the formation of rivers and the flow of these rivers, from high altitude to low, can be harnessed as hydro energy. .
In earlier times, Greeks used water wheels to grind wheat into flour, and similar concept was used around 1700s for milling and pumping. First Hydroelectric power plant was set up in England and United States in 1870 and 1882 respectively. For Hydroelectric power generation, power plants can be established over rivers and other watercourses etc. Generally dams are built to ensure a reliable flow of water to the power plant. The water collected in the dam can be channelized through canals and propellers to fulfill water needed for irrigation, industrial, household etc. in areas that don’t have a steady supply of water. This proves to be an added advantage that is not possible with other types of power plants like thermal, nuclear power plants, which use heating of water to generate steam to rotate the turbine. Normally a hydro power plant consists of a dam which creates a head connected to the penstock or pipe that carries the water to the turbine blades resulting in its circular motion which in turn moves the rotor of the electric generator, and thus electricity is produced. This concept of electricity generation using motion of a rotor inside a stationary coil called stator was discovered by Michael Faraday in 1831.
After generation of hydroelectric power, it needs to be delivered to consumers, which is done by the use of network of transmission lines and transformers. Electricity is first stepped up (voltage is raised) using transformers to be transmit over large distances. Transmission lines carry it to various stations and substations, established in consumer inhabitation. It is finally delivered to homes, offices, factories etc. after stepping it down (voltage level lowered) to appropriate levels for direct use in appliances and instruments.
Apart from huge advantages, there are some disadvantages’ of hydropower generation. Firstly, this technology is based at remote locations that causes huge transportation costs of material during setup and then huge cost of transmission lines during operation. Secondly the operation requires a steady flow of water which gets impacted during a drought. Although dam is created to maintain an adequate supply but as the water flow decreases during summers and more water is stored in the dam and the water flow gets affected after the dam. Thirdly, Water coming out of turbines contains very less sediment resulting in washing of rivers beds and loss of riverbanks. Fourthly, establishment of reservoir behind the dam leads to displacement of human and aquatic wildlife inhabitation. Mainly fish is the organism that gets largely affected due to change in flow of water, change in temperature and water levels. Lastly, in a comparatively warmer areas, creation of large water bodies leads to increase in water borne diseases like malaria, yellow fever etc.
Advancements and innovations in hydro power technologies is resulting in better options to utilize this resource like creating of upper reservoir where water is pumped up to the upper reservoir during off peak hours and later on used it to generate additional power during peak hours or at other times of need. Other technologies like Variable Speed technology, Matrix Technology, Fish Friendly Turbines, Hydrokinetic turbines are being explored for betterment of the technology.
Total worldwide potential capacity of hydropower generation is 3721 GW that is approximately four times the current installed hydropower capacity. With examples of large projects like Itaipu in Brazil of 14000 MW and Three Gorges in China of 22400 MW. There exists a huge possibility of exploring this natural source of energy all across the world. In conclusion, hydroelectric power is an important, efficient and flexible source of energy, which is based on natural water cycle available to the world without any expense.
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