Hydropower and Thermal Energy
Today’s modern world is dependent on various types of advanced technological breakthroughs that are making our life more productive as well as comfortable. In simple terms, inexpensive and reliable electricity is critical to the sustained economic growth and security of any nation. Today’s world is dependent on reliable, low cost and abundant energy.
It is the power plant which provides this critical energy source. As an amazing fact, in the United Nations around 90% of the electricity is produced from the power plants that use steam as an energy source; with just 10% of the electricity produced from hydroelectric power plants. In other parts of the world as well, similar proportions are common for their electric production.
The power plant may be defined as a facility which transforms various types of energy into electricity or heat for some useful purpose. Based on the input mode to the power plant, the plant design will be drastically different for each energy source.
The forms of the input energy can be categorized as follows –
- The potential energy of an elevated body of water. In simple technical terms, it may be referred to as the hydroelectric power plant.
- The chemical energy that is relatively from the hydrocarbons which are contained in the fossil fuels such as coal, oil or natural gas, which can be referred to as a fossil fuel fired power plant.
- Now, comes the most amazing technology which is called as the Nuclear power plant. The energy developed is predominantly due to the separation or attraction of atomic particles.
- The growing concern for energy security is gradually becoming a major threat for a developing nation like INDIA. One of the most significant contributors to this has been the question of becoming self sufficient in power generation to meet the exponential demand of a growing nation. One of the most astonishing fact is that INDIA has been the 2nd best growing nation, even in the economic downslide of 2008-2009.Inspite of the current trend, one cannot overlook this fact that a regular supply of electricity is essential for a strong economic growth. An estimate shows that for every 1% economic growth, power generation capacity for INDIA needs to grow by 5-6 times to sustain the levels of growth for decades to come.
Nowadays most of the electricity produced throughout the world is from steam power plants. However electricity is being produced by some other power generation sources such as for example Hydropower, biogas power, solar cells etc. One newly developed method of electricity generation is the Magneto Hydro Dynamic Power Plant.
History of Hydropower Development:
Wind and running water were the only available sources of mechanical power from ancient times. In the past decades water wheels were used for milling, pumping and lifting water from a lower to a higher elevation for irrigation. Water wheels of various types are still being used in many countries. An attempt to improve the efficiency of the water wheel contributed to the development of hydroelectric plants. Aiming at the improvement of the turbine efficiency, which went up to 60-70% in the mid of 1850’s, extensive theoretical work was done by mathematician and engineers between 1750-1850.
However the utilization of water turbines in the production of electricity became extremely popular after the invention of Dynamo or Generator in 1880’s.The new birth of the electric power supply was marked by the opening of 12.5 kW plant on the Fox River near New York, USA.
The supply of electricity to a number of consumers in parallel had been mastered. Improved design of generator & motor were presented in rapid succession and multi phase motor proposed by Tesla in 1888 opened the practical use in the industry.
Nonetheless the use of Arc Lamps for lighting dates back to 1822 in USA, 1876 in Germany & 1879 in Switzerland.
Steam and its importance:
Steam is one of the most important critical resources in today’s industrial world. It is essential for the production of paper and other wood products, for the preparation and serving of foods for cooling and heating of large buildings, for driving equipments such as pumps and compressors and for powering ships. However the most important priority remains as the primary source of power for the production of electricity.
Steam is extremely valuable because it can be produced anywhere in the world by utilizing the heat that comes from the fuels that are available in the nearby area. Steam also has some unique properties that are extremely important in the production of energy. Steam is basically recycled, from steam to water and subsequently back to steam again in a manner which is non toxic in nature. The modern steam plants of today are a combination of some complex engineered system that work to produce steam in the most efficient manner that is economically feasible. In any kind of situation however the steam power plant must obtain the required amount of heat. This heat must come from an energy source which varies significantly based on the plant’s location in the world. The sources of heat could be the following:
- A fossil fuel-coal, oil or natural gas.
- A nuclear fuel such as uranium.
- Other forms of energy which includes waste heat from exhaust gases of the gas turbines by product fuels such as Carbon Monoxide (CO), blast furnace gas (BFG) or methane, geo thermal energy and solar energy.
Each of the fuels contains potential energy in the forms of a heating value and this is measured by terms of British thermal units (B tus) per each pound or cubic feet of the fuel, depending on whether the fuel is a solid or a gas. A British thermal unit is about equal to the quantity of heat required to raise one pound of water by one degree Fahrenheit. As the water is heated, it eventually changes its form by turning into steam. As the heat is continuously added, the steam reaches the desired temperature and pressure for the particular application.
Prof. Subhro Chakraborty,
Head, Department of Civil Engineering,
University of Engineering & Management (UEM), Jaipur