Impact of Power Generation on Environment Research (Essay Sample)

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Impact of Power Generation on Environment
Introduction
Energy resources throughout the world are scarce in nature. Physics as a branch of science has made great progressions over the years. Some of the fundamental laws of physics such as Faraday’s Laws of Electromagnetic Induction lead to the generation of electricity. Electricity has become an integral part of everyone’s life in the 21st century, and gadgets that run on electricity have become ubiquitous. Electricity generation requires energy sources, and some experimentation has been done in this front. However, since the dawn of civilization, power generation has been dependent on fossil fuels in order to meet people’s daily requirements. At one point of time there was abundant fossil fuel resources on earth, which has fueled the growth of civilization. The United States is one of the most industrialized and urbanized countries in the world, and therefore, the demand for power is the highest in the USA. However, use of fossil fuel has taken its toll on the environment and created massive pollution in the form of greenhouse gases, which has led to global warming. Hence, this has resulted the execution of several experimentation in the US and discovery of various new methods for power generation. However, two most popular raw materials for power generation still remain to be coal and natural gas. The USA is making a calculated and informed move to shift all of its coal plants into natural gas based plants. The different aspects such as economic, environmental, and technological advancement in power generation through these two raw material sources will be discussed in the following sections.
Coal Based Power Plant
Coal based thermal power plants are the most basic power plants and are widely used throughout the world to produce power. Nearly half of world’s electricity production is done through coal plants. Power generation from coal consists of several complex processes, and the basic principal is conversion of chemical energy of coal into the electrical energy. The first step involves burning coal in the boilers, which produces heat. The carbon from coal and oxygen in air gets mixed to produce carbon dioxide, which then heats up the water that flows through tubes on the body of boilers. Steam is generated through this process under high pressure and temperature (Mardon and Hower). The steam produced is then allowed to be carried through insulated pipelines to the turbines where it expands. Hence, this expansion of high pressure steam leads to the release of kinetic energy, which is utilized to rotate the shaft of the turbine. The turbine in turn rotates the rotor of the generator, and it leads to the generation of electricity based on Faraday’s Laws of electromagnetic induction. However, this is a broad overview of the process, and there are several auxiliary processes which impact different elements of the environment, for example, the burning of coal creates huge amount of ash. The ash is collected in electronic precipitators in order to reduce pollution and use the ash for some meaningful purpose. The amount of coal that is required for 500MW plant is almost 2 million tons annually. It leads to the production of 200,000 tons of ash per year (Mardon and Hower). It also results in the generation of carbon dioxide, which is the most abundant greenhouse gas. Carbon dioxide is the primary cause for global warming, which has a disastrous impact on the flora and fauna of the world. Moreover, the steam that leaves the turbine is condensed and recirculated back to the turbine, which requires 50,000 cubic meter of water per hour. The water is mostly procured from nearby lakes or rivers, which leads to a depletion of the water table. However, these are some of the environmental and natural resources that are depleted due to thermal power plants. Apart from that there are other economic impacts as well. Thermal power plants require huge upfront investment for the construction of the plant. Land is another pre-requisite for thermal power plant, which is a scarce resource. Huge amount of land acquisition leads to eviction of native people, and it may make them homeless. Moreover, coal based power plant being an older technology, there are several processes which lead to energy loss. Study has revealed that the efficiency of a thermal power plant can only be up to 32-40%. Technologically also there has been not much advancement in the domain of thermal power plants (Dr A. R. Tyagi et al.). These are some of the aspect of coal based power plant which is making it an unpopular mode of power generation.
Natural Gas Based Power Plant
The principal of operation of a natural gas turbine based power plant is almost similar to that of internal combustion engine. The principal is based on the fact that the compressor will suck in air from the atmosphere and then compress it under high pressure. The design of a compressor is basically a series of fans mounted on a shaft so that the air passes from one blade to other getting further compressed (McKenzie). There is also a combustor, which is in the form of an annular chamber that lets the natural gas burn at a temperature of 1400 to 1500º C, which leads to the generation of high energy levels. The high energy natural gas is then passed through the shaft of the turbine to rotate the rotor of the generator. The only difference between the internal combustion engine and a natural gas turbine is that the energy is utilized to create a rotary motion rather than a reciprocating motion (Hope). Natural gas based power plants are also a type of fossil fuel but the efficiency is considered to be better than other types of fossil fuel based power plant. It also leads to generation of carbon dioxide and other harmful gases, but the magnitude is much lower. Apart from that, there are no requirements of water for its power generation process (McKenzie). Therefore, it helps to conserve water and utilize for other useful purpose. The capital required for setting up a natural gas based thermal power plant is also lower than coal based thermal power plant. All these aspects put together make a natural gas turbine based power plant a better option than coal based power plant. The comparison between the two types of power generation process has been done in the following section.
Comparison of Coal and Natural Gas Power Plants
Coal based thermal power plants have several deficiencies, which have restricted their use in developing countries. The USA being one of the most industrialized country has a huge requirement for power, but slowly and steadily it is shifting towards natural gas based power generation from coal power based, which is because of the ill effects of coal power plants. Some of the negative impacts of coal power plants have already been discussed. The most significant of which is production of carbon dioxide and sulfur dioxide in the boiler. It leads to greenhouse gas emission and adversely affects the environment. Ash generated is also another concern and the ill effects are coupled with the usage of fresh water, which depletes the water table. All these problems are not that much significant in case of natural gas power plants. Economically also natural gas power plants are better than coal based power plants. Natural gas power plants can clock an efficiency of up to 35-42% with reduced pollution (Bright Hub). The investment for natural gas power plants is also less (Corradetti and Desideri). Another important aspect of natural gas turbines is that they can be used to supply peak loads. Therefore, it can be started in less time and achieve its rated capacity, whereas a thermal power plant has to run its auxiliaries constantly even if it is not producing any electricity. The main reason for this is that it cannot be started immediately, and as such if the plant is shut down for some reason, it takes time to restart. Coal based thermal power plants are based on the principal of modified Rankine thermodynamic cycle, which leads to a maximum efficiency of 38%. Natural gas based power p...