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Transcript of Electricity project
Renewable energy sources where coal comes from advantages how coal energy is collected
& made Non-Renewable Coal, the first fossil fuel exploited by humans for energy on a large scale, is a carbonaceous rock formed from buried plants in ancient forests or swamps. These plant materials are initially converted to peat—a loose, brown, organically rich soil. As more rock layers press down on the buried deposits, geothermal energy heats the peat and reduces its oxygen and hydrogen content, converting it to coal.
Currently coal is mined in over 100 countries in every continent except Antarctica. US, Russia, China and Australia hold more than half the world’s reserves.
First the coal is mined and taken to a power plant.
Then the coal is burned in a boiler which causes the water in the boiler pipes to become steam.
The steam travels through the pipes to the turbine.
The steam spins the turbine blades.
The spinning blades turn a shaft connected to the generator.
In the generator, big magnets spin close to coils of wire.
When this happens, electrical current is produced in the wires.
Then the electricity goes out through wires to homes, schools, and businesses etc. Energy Sources Fossil fuels- coal Coal is a combustible, sedimentary, organic rock, which is composed mainly of carbon, hydrogen and oxygen. It is formed from vegetation, which has been consolidated between other rock strata and altered by the combined effects of pressure and heat over millions of years to form coal seams. Coal is a fossil fuel and is far more plentiful than oil or gas, with around 112 years of coal remaining worldwide.
*Easily combustible, and burns at low temperatures, making coal-fired boilers cheaper and simpler than many others
*Widely and easily distributed all over the world;
Comparatively inexpensive to buy on the open market due to large reserves and easy accessibility
*Good availability for much of the world (i.e. coal is found many more places than other fossil fuels)
*Most coal is rather simple to mine, making it by far the least expensive fossil fuel to actually obtain
*Coal-powered generation scales well, making it economically possible to build a wide variety of sizes of generation plants.
*A fossil-fueled power station can be built almost anywhere, so long as you can get large quantities of fuel to it. Most coal fired power stations have dedicated rail links to supply the coal. disadvantages
*It is Non-renewable and fast depleting;
*Coal has the lowest energy density of any fossil fuel - that is, it produces the least energy per ton of fuel
*Has the lowest energy density per unit volume, meaning that the amount of energy generated per cubic meter is lower than any other fossil fuel
*High coal transportation costs due to the bulk of coal (as a result of the preceding two low energy density problems), especially for countries with no coal resources and hence will require special harbors for coal import and storage.
*Coal dust is an extreme explosion hazard, so transportation and storage must take special precautions to mitigate this danger
*Coal storage cost is high especially if required to have enough stock for few years to assure power production availability.
*Burning fossil fuels releases carbon dioxide, a powerful greenhouse gas, that had been stored in the earth for millions of years, contributing to global warming.
*It leaves behind harmful by-products upon combustion (both airborne and in solid-waste form), thereby causing a lot of pollution. In particular, air polution due to burning coal is much worse than any other form of power generation, and very expensive "scrubbers" must be installed to remove a significant amount of it; even then, a non-trivial amount escapes into the air.
*Mining of coal leads to irreversible damage to the adjoining environment;
*It will eventually run out.
*It cannot be recycled. Renewable Solar Energy Solar energy is very important to support life on earth, it helps to grow our food, light our days, influence weather patterns, provide heat, and can be used to generate solar electricity.
Solar electricity relies upon man-made devices such as solar panels or solar cells in order to provide a source of clean, and low cost renewable energy. Where Solar Energy come from Solar energy originates in the depths of our sun. The sun endures a continuous stream of thermonuclear explosions as hydrogen atoms are fused into helium atoms. We encounter the resultant energy as radiation that strikes the surface of the earth. Solar panels convert this solar radiation into useful electrical energy and store them in batteries for our use. Enough solar radiation strikes the earth every day to meet earth's energy needs for an entire year. Solar panels help us harvest this energy and convert it into usable energy to meet the everyday needs of modern life. How Solar Energy is collected
Solar Energy can be collected by using solar panels. These solar panels have PV cells which is short for photovoltaic. These cells are used to power your calculator and other solar powered items. The PV cells work as if the solar panels are a type of factory. The solar panels can be connected to a rooftop or on the ceiling. This is basically the machine absorbing the solar energy that you are collecting. advantages *Solar cells are long lasting sources of energy which can be used almost anywhere.
*They are particularly useful where there is no national grid and where there are no people such as remote site water pumping or in space.
*Solar cells provide cost effective solutions to energy problems in places where there is no mains electricity.
*Solar cells are also totally silent and non-polluting.
*They have no moving parts, they require little maintenance, and have a long lifetime.
*Rooftop power is a good way of supplying energy to a growing community.
*More cells can be added to homes and businesses as the community grows so that energy generation is in line with demand.
*Many large scale systems currently end up over generating to ensure that everyone has enough.
*Solar cells can also be installed in a distributed fashion, i.e. they don't need large scale installations.
*Solar cells can easily be installed on roofs which means no new space is needed and each user can quietly generate their own energy. Disadvantages *The main disadvantage of solar energy is the initial cost.
*Most types of solar cell require large areas of land to achieve average efficiency.
*Air pollution and weather can also have a large effect on the efficiency of the cells.
*The silicon used is also very expensive and the problem of nocturnal down times means solar cells can only ever generate during the daytime.
*Solar energy is currently thought to cost about twice as much as traditional sources (coal, oil etc).
*As fossil fuel reserves become depleted, their cost will rise until a point is reached where solar cells become an economically viable source of energy. When this occurs, massive investment will be able to further increase their efficiency and lower their cost.
The burning of fossil fuels for energy remains the world's No. 1 source of carbon dioxide emissions. Solar power is sometimes described as a zero emissions or emissions-free form of energy and it is true that greenhouse gas emissions from solar are negligible. However, the construction of new utility scale solar energy projects is bound to result in some greenhouse gas emissions. which results in both a negative and positive impact.
Creating energy is a water intensive process. In the U.S., electricity production accounts for more than 40 percent of all daily freshwater withdrawals. Solar photovoltaic systems do not require any water to generate electricity. Some solar thermal systems use water, but this water can be reused. Utility scale parabolic and central tower solar energy systems use steam plants to produce power, often relying on water for cooling. There is some concern that these types of systems, when located in arid environments, could put a strain on local water resources.
When placed on existing structured, such as the rooftop of a home or office building, solar energy systems require negligible amount of land space. Utility scale solar farms, on the other hand, do require large amounts of land to produce electricity on a commercial scale. This fact raises concerns about the potential impact of such projects on natural habitats, concerns the EPA is working to address by sitting renewable energy projects on contaminated lands and mine sites.
Solar photovoltaic panels may contain hazardous materials that could be released when a panel is damaged or disposed of improperly. Concentrating solar energy systems may also use potentially hazardous materials like oils and molten salts, creating the potential for spills. This would pose a negative impact on the environment. Environmental impact The economic impacts of solar power depend on how it is used. Although solar energy is not a new idea, its full economic impact is not yet certain. As renewable resources become more powerful, how extensively and in what manner communities use solar energy will effect how that energy impacts the economy. Large, centralized solar power plants and solar cell factories will effect the economy much differently than local factories and distributed solar power. Economic Impact Constructing large solar generating plants has a significant short term economic benefit in producing construction jobs, but once the plant is completed its employment advantage drops. A study by the National Renewable Energy Laboratory predicted that building a single 1,000 megawatt solar power plant in Nevada would generate over 2,000 jobs for three years as it was being built. After building, however, the job benefits dropped precipitously for the next four years, before slowly climbing to just over 200 new jobs. The advantages of building a series of electric plants every few years were predicted to be more lasting, with plentiful construction jobs for as long as new plants are built. The plants similarly produced large boosts in state product and average personal income while being built and more moderate increases in income once they were completed. Large Plants Big solar power plants are only a small part of the story. Solar power is a distributed energy: it is available everywhere and can be easily harvested by placing small batteries of solar cells on large numbers of local buildings, saving land that would otherwise be needed to operate big solar plants. Locally installing solar cells creates jobs installing those cells on houses, businesses and other buildings, stimulating local economies. If solar cells were manufactured locally in small factories as the solar movement occurs, it would provide another boost to the economy in the form of manufacturing jobs. Local Production environmental impact An average of 170 pounds of mercury is made by one coal plant every year. When 1/70 of a teaspoon of mercury is put in to a 50-acre lake it can make the fish unsafe to eat. Coal power also puts the lives of the people who dig the coal in danger, and it gives them poor lung quality.
A coal plant generates about 3,700,000 tons of carbon dioxide every year; this is one of the main causes of global warming. A single coal plant creates 10,000 tons of sulfur dioxide, which causes acid rain that damages forests, lakes, and buildings. When people dig for coal, they cut down many trees. A coal plant also creates 720 tons of carbon monoxide; which causes headaches and place additional stress on people with heart disease.
A 500-megawatt coal- fired plant draws about 2.2 billion gallons of water from near by bodies of water. This is enough water to support approximately 250,000 people. Some people have said that coal power is good, because coal power is reliable and affordable. It may be reliable and affordable, but in the future the damage that coal power would cause, would be much more expressive. see link below.
Coal slurry (a mix of rock and coal products left over after the mined coal has been treated for use as a fuel) is a severe environmental problem around coal mines. The slurry itself is a semi-liquid, and is generally stored in a pond or small lake near the mine exit. The slurry contains a whole host of nasty chemicals, mostly benzene relatives and derivatives, and is categorized as low-level toxic waste. Storing is a significant problem, as it has a tendency to leech into the local environment, contaminating groundwater and nearby croplands. The major problem is that the volume of coal slurry is quite high, relative to the amount of usable coal produced. economical impact Fossil fuels—coal, oil, and natural gas—are America's primary source of energy. Some of the costs of using these fuels are obvious, such as the cost of labor to mine for coal and materials to build energy-generating plants, and of transportation of coal to the plants. These costs are included in our electricity bills.
But some energy costs are not included in gas bills, nor are they paid for by the companies that produce or sell the energy. These include human health problems caused by air pollution from the burning of coal and oil; damage to land from coal mining and to miners from black lung disease; environmental degradation caused by global warming, acid rain, and water pollution; and national security costs, such as protecting foreign sources of oil.
Since such costs are indirect and difficult to determine, they have traditionally remained external to the energy pricing system, and are thus often referred to as externalities. And since the producers and the users of energy do not pay for these costs, society as a whole must pay for them. But this pricing system masks the true costs of fossil fuels and results in damage to human health, the environment, and the economy. social -When you burn coal the sulfur in it burns as well and produces H2S which goes up into the clouds, mixes with water and creates acid rain which destroys lakes, rivers and water bodies. Fishing, recreational activities as well as the food supply of humans will be affected. Acid rain also affects peoples health.
-Electricity from coal is cheap so, people will have more money to spend on other activities rather than their electricity bill.
-Many jobs are created- mining coal, power plants, transportation of coal -Creates high tech jobs both in engineering and manufacturing
-Replacing a high pollution energy source with a zero pollution energy source (solar)
-Solar electricity is very expensive, people may not be able to pay off their electricity bill in a few years if they use them
-Can be put anywhere, and uses otherwise wasted space leaving useable land for other development Social Long Lasting http://curriculum.cna.ca/curriculum/cna_world_energy_res/fossil_fuels-eng.asp?bc=Fossil%2520Fuels&pid=Fossil%2520Fuels