Pros And Cons Of Electric Power Engineering Environmental Sciences Essay

Pros And Cons Of Electric Power Engineering Environmental Sciences Essay Electric power has becoming a necessity in our daily lives. As the use of fossil fuels are slowly running out and phasing out, the use of environmentally friendly energy is now becoming popular and cheaper too. Electrical power is then transmitted after an electric charge has been generated and converted into electricity. It is then distributed to substations then to the homes at a level of voltage, which is safe for us to use. And that is how scientists and engineers have made electricity such as a success to date. Electric power is the use of electric energy to do work. Through electric power, machines are run, and through the running of machines electricity can be generated. Electric power is used in all industries and therefore become an essential tool in our lives. No-one is certain as to where the future of transmission and distribution of electric power lies, but scientists are certain that the energy sources of the future definitely lie in the emission-free sources. Over the years of electric power production various energy sources have been used to produce electric power across the world. These energy sources have been used according to its availability in that specific area, the cost to build and maintain the station, how it will be transmitted and distributed and lastly its affect on the environment. Engineers are trying to find an alternative of clean and cost effective energy to produce electric power. These are some of the electric power used from the past, to date. Hydro-electric power Hydroelectric power is the conversion of energy from free falling water into electrical energy. It uses the water stored in dams. The water flows through a tunnel pipe to the power plants hydraulic turbine. As water rushes through the turbine, it spins the turbine, which drives the electric generator.[1,2] [see figure 3.1 and 3.2]. Pro: It costs less to operate than fossil-fueled stations. There are no emissions produced. Cons: There is generally a deterioration of fish spawning in the areas when dams are used. This process of producing hydro electric power is limited to availability of water and suitable locations for dams and reservoirs [1,2,3] Nuclear power Nuclear power uses a device called nuclear reactor to produce enormous amount of heat by fissioning the nuclei of atoms of a heavy element like Uranium. The heat converts water into steam, which drives the turbine that runs the electric generator. After the steam has turned the turbine, it is left to be condensed in the cooling towers and then later recycled in the plant [4]. Pros: It is carbon-free electricity as it hardly emits any carbon dioxide. It requires much less fuel than fossil-fueled stations to produce an equal amount of electricity. Cons: It produces tons of radioactive waste annually, which is a health hazard to all living organisms. Uranium mining scars the land and pollutes the water supplies as all types of mining do [4,5,6]. Geothermal power Geothermal energy is generated wherever water comes into contact with hot rocks below the Earths surface. The rocks give off heat that makes the water hot enough to turn it into steam. The energy is captured by tapping into earths crust through a process called hydrothermal convection, where a cooler water seeps into the Earths crust, is heated up and then rises to the surfaces. When the water is heated it turns into steam. The steam is then captured and used to drive electric generators [7]. Pros: It releases no harmful emissions as it is a natural source of energy. It is far more efficient than heating and cooling and can move 3-5 times more energy Cons: Geothermal heat pumps have higher up-front costs. Theres a risk that while trying to drill into earths crust, it might trigger seismic activity fracture rock stability, thus resulting in the collapsing of infrastructures.[7,8] And now it is rumored that the use of biofuels might be the energy source for the future as they are the third generation biofuels (made from algae and other microbes). Despite the type of energy source used, the bottom line is they all have to create enough force to turbine a turn a turbine that will then run a generator. The generator has a rotating electromagnet called a rotor and a stator. A separate generator called an excitor powers the rotor creating a magnetic field that produces an electric charge in the stator. The charge is transmitted as electricity [1,7].[see Figure 3.3 and figure 3.4] Electric power transmission There are mainly two ways electric power can be transmitted either overhead or underground. As electric current moves along transmission lines, the lines resist the current flow. The resistance within the lines causes the current to lose energy. Power stations therefore limit energy losses by transmitting electricity at high voltages. As the voltage is increased, the amount of current needed to transmit a particular amount of electric power decreases. Because there is less energy lost due to the resistance. Electric current may either be DC or AC. Direct current flows in only one direction. Alternating current is therefore easier to transmit than direct current [1].[see Figure 5]. The history behind the way electric power is transmitted today. In 1878, Thomas Edison [see Figure 6:] developed and sold commercially viable replacement for gas lighting and heating locally generated and generated direct current electricity. He opened the worlds first public electricity supply in the late 1881.this system was powered from a water wheel , which drove a Siemens alternator that supplied a number of arc lamps with electricity within the town as well as shops and premises. As the years went by Edison opened more power stations in various parts o the world. All his methods of supplying electricity were using direct current (DC). Later on that year it was discovered that there was a demand for electricity, so Edison decided to increase the voltage so that the high demand for electricity could be supplied, and also because the increase in voltage reduced the resistive losses in the cable. But it was after a series of fatal accidents that he also realized that increasing the voltage increases the danger from direct contact and also incre ases the required insulation thickness. Furthermore some loads were difficult or impossible to make for higher voltages. Nikola Tesla, who worked for Edison for a short period of time and appreciated electricity in a way that Edison did not, devised a alternative system using alternating current. Tesla realized that while doubling the voltage would halve the current and reduce losses by three quarters, only an alternating current system allowed the transformation between voltage levels in different part of the systems. This allowed efficient high voltages for distribution where their risks could be easily migrated by good design while still allowing fairly safe voltages to be supplied to the loads. He went on to develop alternative for DC appliances. In 1888, Tesla worked with George Westinghouse, who owned a patent for type of transformer that could deal with high voltages and was easy to make. They both built a power system for a gold mine in Colorado. Almarian Decker finally inve nted the whole system of the three-power generating in California. Edison was force to sell his deal with General Electric to Teslas new system. Thus Teslas alternating current system remains the primary means of delivering electric power to consumers throughout the world. While high-voltage direct current is increasingly being used to transmit large quantities of electricity over long distances.[9] Electrical power distribution Some large industries require high voltage current and receive it directly from transmission lines. But high voltages are unsafe in homes, offices and most factories. The voltage must therefore be decreased before the electricity is distributed to them. High voltages are carried by the transmission line to sub transmission substations near the substations to 12500 to 138000 volts. The voltage is then further reduced at the distribution substations to 2,000 to 34,000 volts. Distribution lines may carry this medium voltage current voltage to commercial, industrial or institutional users. Distribution lines may also carry electric power to distribution transformers on poles , on the grounds , or in under ground vaults. Distribution transformers are what reduce the voltage to the levels needed by most users. Wires from the transformers run to homes, stores, offices, and other users. Nearly all consumers receive electric power at a level of 110-240 volts. And we use it to run our daily li ves [1] [see Figure 7:] . Conclusion Electricity has evolved over the years for it to be where it is today. The electric power demand continues to grow. Power companies as well as engineers must plan carefully for expansion to meet the ever-increasing demand. However, construction of new power plants is costly and takes several years. Many planned nuclear power have been cancelled due to the soaring construction costs and public concern over safety and nuclear waste [see Figure 8 ] :. Extensive research is being carried out into nuclear fusion, but it may take decades to succeed. If the consumption of fossil fuels continues as at present, then the supply will eventually run out. However, many scientists believe that energy from the sun, earth, wind and oceans can be used more extensively to produce electric power cheaply and efficiently in the future [1]. References : electric power. The World Book Encyclopedia. International edition. 6th vol. 1995, 1994, 1993, 1992 pp 159. Hydro electric power. The World Book Encyclopedia. International Edition. 6th vol. 1995,1994,1993,1992 .pp 159. United States geological Survey. (n.d.). Retrieved 11 09,2010, from Water Science for Schools: http://ga.water.usgs.gov/edu/hyhowworks.html nuclear power stations. The World Book Encyclopedia. International edition. 6th vol.1995,1994,1993,1992.pp159. Pros and Cons of nuclear power http://www.greenenergyhelpfiles.com Pros and Cons of nuclear power http:// timeforchange.org. Geothermal energy. The World Book Encyclopedia. International edition. 6th vol.1995, 1994, 1993,1992.pp 245. Department of energy-Oak Ridge National Laboratory (ORNL).2008. Geothermal (Ground-Source) Heat Pumps: Market status, Barriers to Adoption, and Actions to Overcome Barrers. Report ORNL/TM-2008/232. http://en.wikipedia.org./wiki/electric_power_industry.

Pakistan :: essays research papers fc

Pakistan   Ã‚  Ã‚  Ã‚  Ã‚  Pakistan is a country that, since its creation, has been rooted in turmoil. The recent years are no exception to this. Since 1988, power has been divided among the president, the prime minister and the military. Tensions between the three, however, have led to eight changes of government and three elections. No elected leader has ever completed a full term in office. Benazir Bhutto, who was dismissed by the president in August 1990 after only twenty-one months in office, is the only Pakistani leader to be given a second chance at ruling (Newberg 19). On October 6, 1993 a general election was held in Pakistan. The Pakistan People's Party (or PPP) received a majority of the vote and as a result Benazir Bhutto once again became prime minister. This time however, she has a pliant president in the form of an old friend. On November 13, 1993, Farooq Leghari was elected the country president. Yet even with this unique opportunity for agreement within the ruling circle reforms have not taken place (The Europa World Year Book 2460). Despite the PPP's success in the 1993 election they still faced uncertainty. They lack not only a parliamentary majority but unity within their own ranks. One of the biggest problems was a bitter family feud between Benazir Bhutto and her mother, Begum and brother, Murtaza. Murtaza had returned from exile to claim a seat in the Sind provincial assembly, but was immediately arrested for alleged terrorist activity. In late December 1993, Benazir removed her mother as PPP co-chair after she had endorsed Murtaza's claim that he was the rightful heir to his father's political legacy. However, in September 1994, the family feud seemed to end during a visit of the prime minister to her mother (Banks 717).   Ã‚  Ã‚  Ã‚  Ã‚  In Pakistan the end of the cold war had not brought on new, pragmatic thinking on foreign policy that could make Pakistan less reliant on Western support and allow it to develop closer ties with its neighbors. After the cold war, many third world countries were abandoned by their protectorates- the U.S. or the former soviet Union. However Pakistan's elite has yet to fend for itself (Rashad 158). Pakistan's relations with India worsened. Since the creation of Pakistan, relations with India have dominated foreign affairs. These relations reflect a centuries old rivalry between Hindus and Muslims. The reason for the tensions today is allegations that each side was on the verge of conducting nuclear tests (Year Book 2462).   Ã‚  Ã‚  Ã‚  Ã‚  Much of Pakistan's problems stem from a legacy of rule by a small group of around 300 families. Through blood ties, marriage, and business, they have

Bishop’s “The Fish” Poetry Response Essay

In the poem â€Å"The Fish,† Elizabeth Bishop uses a fish as a symbol to express the theme of life and experience. The poem by itself has little structure to it. There are no apparent rhyme schemes, nor any clear meters. However, Bishop uses very powerful diction and ideas in the poem, forcing the reader to think and relate it to a greater aspect of his/her own life. The persona has a very mature and serious tone, and some gloomy element to his/her mood. The poem uses a significant amount of imagery. Descriptions like â€Å"brown skin hung in strips† and â€Å"fresh and crisp with blood† are common throughout the poem. The reader can almost see the fish on the boat, waiting for its life to end. Bishop also uses a plethora of colors in the poem. Colors include: â€Å"brown skin,† â€Å"green weed,† â€Å"dramatic reds and blacks,† â€Å"yellowed,† â€Å"green line,† and it also contains the combination of all the colors in the sp ectrum as â€Å"rainbow, rainbow, rainbow!† was repeated in the poem. The Colors are there to enhance the imagery and also work archetypically to express the mood of the poem. When the persona states that the â€Å"oil had spread a rainbow,† it should indicate that tears has formed in her eyes, splitting the light into its spectrum, as she also mentions â€Å"sun-cracked thwarts.† At the end where â€Å"everything was rainbow,† tears had flooded her eyes, blurring every sight and showing only splashes of colors all around. At the beginning of the poem, the persona notes that the fish did not fight at all. She describes the fish as â€Å"battered,† â€Å"homely,† but yet â€Å"venerable.† Later she discovers that the fish has fought many battles, and the broken lines are signs of victory. She realizes the fish is not just something that gives up without a fight, but it is something that has just fought too long and is tired of it. The persona realizes what the fish has gone through and instantly gains respect and condemnation for it. She lets it go. For writing this poem, the author might have a family member that was suffering from a disease. After a long time of painful struggle, that member finally gives up because he/she saw through the value of life, just like the fish. However, there is one thing that I disagree with the persona, because she states the fish has â€Å"a five-haired beard of wisdom.† In my opinion it should be â€Å"five-haired beard of stupidity† since the fish cannot learn from its past.

Communication Disorders Type Of Disorder - 2396 Words

Communication Disorders: This type of disorder is connected with speech or language disorders and it represents at least 1.7% of students ages 6-21. Speech disorders deal with difficulty in producing and pronouncing specific sounds or words and language disorders deal with difficulty in putting words together correctly in order to get their ideas across to everyone else. Usually the causes for communication disorders are not known but other times students obtain a communication disorder as a result of another disability like TBI or cerebral palsy. When it comes to identifying this disorder, parents are usually the ones to notice first if their child is already 3, for example, and still does not talk. When the disability has been identified†¦show more content†¦However, this disability is not necessarily bad because it could mean that the student has difficulty with their school work but still has either average or even above average intelligence like mentioned in the book. T hese students are very bright but just have a problem with obtaining the knowledge and information. Maybe they have a problem with listening, thinking, or even writing and that is why they have this disability and because there are many issues that come from learning disabilities it is very difficult to identify this issue on a student. As far as the characteristics of this disability, those students have reading problems because they often don’t understand some grammar, they show difficulties in learning math such as the rules or equations, their attention span is very limited and their memory is also very limited when it comes to learning new concepts, they have trouble thinking and solving problems, and they also tend to lack social skills because of how frustrated they might get in the classroom. Some strategies for students with learning disabilities might be seating that student near other classmates or teaching assistant who may help them focus in school, avoid distractions, show organization and set schedules that way the student can get used to the daily routine and avoid confusion, or