here's some pictures that we can use for the presentation. cause you know the turbines are used in the dams right? you realise that they're HUGE?!
here's the Nurek dam.
and i found this random map of relocation of people.
but according to the information that zhiyi found, they are perfectly happy!
Relocation of People “More than 1.05 million residents in the Three Gorges dam area have been successfully relocated over the past two decades,” an official in charge of operations said at a press conference on August 31. The number accounts for 82.6 percent of the 1.13 million people who were expected to be displaced from their homes in the water diversion project area, according to Cao Guangjing, deputy manager with China Yangtze Three Gorges Project Corporation (CTGPC), the company in charge of the development of the project. Cao said most of the resettled people are satisfied with their new homes and enjoy better living conditions. China began the eight-year trial resettlement exercise in 1985 in the Three Gorges area and launched official resettlement in 1993 when the construction of the 185-meter-high dam started on the middle reaches of China's longest river, the Yangtze.
and of course, a picture of the TGD.
Tuesday, 17 June 2008
this economical costs of the TGD is so shocking!
Economical Costs: Gorges area and launched official resettlement in 1993 when the construction of the 185-meter-high dam started on the middle reaches of China's longest river, the Yangtze. On July this year, nearly 42.9 billion yuan (US$ 5.3 billion) had been earmarked for relocation expenses, construction and rebuilding various infrastructural facilities. 21 billion yuan (US$ 2.6 billion) of the total amount was raised by 21 Chinese provinces and municipalities, more than10 large and medium-sized cities, and more than 50 government departments. At a cost of 203.9 billion yuan (about US$ 25.2 billion), the Three Gorges Project, scheduled for completion in 2009, is designed to help control flooding of the Yangtze River, at the same time generating hydroelectricity to meet China's power supply demands. China has injected an additional 121.6 billion yuan (US$ 14.9 billion) to the project so far, accounting for about 60 percent of the initial budget, according to CTGPC. But the plan is to keep costs within the 180 billion yuan (over US$ 22 billion) mark. However, in the long run, these expenses will be considered well used as no more capital will need to be posted to the Yangtze River as there would be no more floods after the completion of the TGD.
Wednesday, 28 May 2008
its MA KE HERE TO POST.
i've done the research already!
but then i dont want to come here and copy paste everything,
so just talk to me online if you want the URLs OKAY!
Sunday, 25 May 2008
here's more information that we can use for our project! i think using it for the introduction would be good(:
What are water dams? A water dam is a barrier that divides waters. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates, levees, and dikes are used to prevent water flow into specific land regions. The tallest dam in the world is the 300 meter high Nurek Dam in Tajikistan.
Three Gorges Dam The three Gorges dam, therefore, is the China Yangtze Three Gorges Project (TGP) as one of the biggest hydropower-complex project in the world. It ranks as the key project for improvement and development of Yangtze River. The dam is located in the areas of Xilingxia gorge, one of the three gorges of the river, which will control a drainage area of 1 million km 2 , with an average annual runoff of 451 billion m3 . The open valley at the dam site, with hard and complete granite as the bedrock, has provided the favorable topographical and geological conditions for dam construction.
As everybody here knows, energy cannot be created or destroyed, but it can be converted into other forms of energy.
Purpose of the dams in china The Three Gorges Dam was built for Flood Control. Floodgates are adjustable gates used to control water flow in reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge system. In the case of flood bypass systems, floodgates sometimes are also used to lower the water levels in a main river or canal channels by allowing more water to flow into a flood bypass or detention basin when the main river or canal is approaching a flood stage. Flood control standard of the middle and lower reaches of the Yangtze, especially the Jingjiang Section, will be largely upgraded from the present level of preventing under-10-year floods to that of preventing 100-year floods. So 15 million people and 1.5 million hectares of farmland in the Jianghan Plain are relieved from flood threats, and devastating plagues of massive death caused by big floods are avoided. The second reason is for Power Generation. The river water will generate electricity in the hydropower stations. The profits are considerable. With the Three Gorges Hydropower Plant (TGHP) containing twenty-six turbine-generator units, each with installed capacity of 700MW, not including the six more 700MW units in the Right Bank Underground Powerhouse under construction, the anticipated annual electricity generation is 84.6 billion kilowatt hours. It will be the number one in the world and will play an important role in the development of the economy and reduction of environmental pollution. This is linked to Tourism as the Three Gorges Dam Project will be the largest water conservancy in the world combined with the world-renowned natural beauty. It will become the "hottest" tourist and press attraction in recent years. Lastly, the 600km long waterway from Yichang to Chongqing will aid in Navigation. This waterway will be improved, making it possible for 10,000 tons of shipping to sail directly upstream to Chongqing. The river transport will be improved from 10 million to 50 million tons per year and the costs reduced by 35-37 percent. After the adjustment to the reservoir, navigation conditions both upstream and downstream on the Yangtze River will have been greatly improved in those seasons when water levels have been low.
Saturday, 24 May 2008
Hello people!;D here's some info on how the dam works based on hydro energy!
How it works A dam is built to trap water, usually in a valley where there is an existing lake. Water is allowed to flow through tunnels in the dam, to turn turbines and thus drive generators. Notice that the dam is much thicker at the bottom than at the top, because the pressure of the water increases with depth.
Hydro-electric power stations can produce a great deal of power very cheaply. When it was first built, the huge "Hoover Dam", on the Colorado river, supplied much of the electricity for the city of Las Vegas; however now Las Vegas has grown so much, the city gets most of its energy from other sources.
There's a good explanation of how hydro power works at www.fwee.org. Although there are many suitable sites around the world, hydro-electric dams are very expensive to build. However, once the station is built, the water comes free of charge, and there is no waste or pollution.
The Sun evaporates water from the sea and lakes, which forms clouds and falls as rain in the mountains, keeping the dam supplied with water. More details Gravitational potential energy is stored in the water above the dam. Because of the great height of the water, it will arrive at the turbines at high pressure, which means that we can extract a great deal of energy from it. The water then flows away downriver as normal. In mountainous countries such as Switzerland and New Zealand, hydro-electric power provides more than half of the country's energy needs.
An alternative is to build the station next to a fast-flowing river. However with this arrangement the flow of the water cannot be controlled, and water cannot be stored for later use. See also: www.fuelfromthewater.com
Advantages Once the dam is built, the energy is virtually free. No waste or pollution produced. Much more reliable than wind, solar or wave power. Water can be stored above the dam ready to cope with peaks in demand. Hydro-electric power stations can increase to full power very quickly, unlike other power stations. Electricity can be generated constantly.
thereeee(: hope this will help in our SIA! O: since it's about the whatever whatever china dam, LOL.
Monday, 19 May 2008
okay so righttt. here's a summary of what our meeting was about.
1. ma ke, you're in charge of mainly research! make sure you go find relavant information constantly kay!xD like. hmmm. we decided on once every 2 weeks right?
2. wandong, you're finding nice pictures of the dam! and water running. LOL. for our physics poster(:
3. zhi-yi! design the posterrrr. O:
4. im here to make sure you all are on time! HAHHA. and to keep this blog alive luh, basically. and do the physics presentation. o.o
datelines: try to finish up this blog by june hols, poster by week 2 of term 3, and presentation materials by week 5(:
its do-able people! we give ourselves too much time actually, HAHAH. okay jiayouuu<3
Saturday, 26 April 2008
Hydropower Basics Flowing water creates energy that can be captured and turned into electricity. This is called hydropower. Hydropower is currently the largest source of renewable power, generating nearly 10% of the electricity used in the United States. The most common type of hydropower plant uses a dam on a river to store water in a reservoir. Water released from the reservoir flows through a turbine, spinning it, which, in turn, activates a generator to produce electricity. But hydropower doesn't necessarily require a large dam. Some hydropower plants just use a small canal to channel the river water through a turbine.
Another type of hydropower plant—called a pumped storage plant—can even store power. The power is sent from a power grid into the electric generators. The generators then spin the turbines backward, which causes the turbines to pump water from a river or lower reservoir to an upper reservoir, where the power is stored. To use the power, the water is released from the upper reservoir back down into the river or lower reservoir. This spins the turbines forward, activating the generators to produce electricity.
Types of Hydropower Impoundment An impoundment facility, typically a large hydropower system, uses a dam to store river water in a reservoir. The water may be released either to meet changing electricity needs or to maintain a constant reservoir level.
Diversion A diversion, sometimes called run-of-river, facility channels a portion of a river through a canal or penstock. It may not require the use of a dam.
Pumped Storage When the demand for electricity is low, a pumped storage facility stores energy by pumping water from a lower reservoir to an upper reservoir. During periods of high electrical demand, the water is released back to the lower reservoir to generate electricity.
Sizes of Hydropower Plants Facilities range in size from large power plants that supply many consumers with electricity to small and micro plants that individuals operate for their own energy needs or to sell power to utilities.
Large Hydropower Although definitions vary, DOE defines large hydropower as facilities that have a capacity of more than 30 megawatts.
Small Hydropower Although definitions vary, DOE defines small hydropower as facilities that have a capacity of 0.1 to 30 megawatts.
Micro Hydropower A micro hydropower plant has a capacity of up to 100 kilowatts (0.1 megawatts).
Turbine Technologies There are many types of turbines used for hydropower, and they are chosen based on their particular application and the height of standing water—referred to as "head"—available to drive them. The turning part of the turbine is called the runner. The most common turbines are as follows: Pelton Turbine A Pelton turbine has one or more jets of water impinging on the buckets of a runner that looks like a water wheel. The Pelton turbines are used for high-head sites (50 feet to 6,000 feet) and can be as large as 200 megawatts. Francis Turbine A Francis turbine has a runner with fixed vanes, usually nine or more. water enters the turbine in a radial direction with respect to the shaft, and is discharged in an axial direction. Francis turbines will operate from 10 feet to 2,000 feet of head and can be as large as 800 megawatts. Propeller Turbine A propeller has a runner with three to six fixed blades, like a boat propeller. The water passes through the runner and drives the blades. Propeller turbines can operate from 10 feet to 300 feet of head and can be as large as 100 megawatts. Kaplan Turbine A Kaplan turbine is a type of propeller turbine in which the pitch of the blades can be changed to improve performance. Kaplan turbines can be as large as 400 megawatts.
How Hydropower Works Most hydropower projects use a dam and a reservoir to retain water from a river. When the stored water is released, it passes through and rotates turbines, which spin generators to produce electricity. Water stored in a reservoir can be accessed quickly for use during times when the demand for electricity is high. Dammed hydropower projects can also be built as power storage facilities. During periods of peak electricity demand, these facilities operate much like a traditional hydropower plant — water released from the upper reservoir passes through turbines, which spins generators to produce electricity. However, during periods of low electricity use, electricity from the grid is used to spin the turbines backward, which causes the turbines to pump water from a river or lower reservoir to an upper reservoir, where the water can be stored until the demand for electricity is high again. A third type of hydropower project, called "run of the river", does not require large impoundment dams (although it may require a small, less obtrusive dam). Instead, a portion of a river's water is diverted into a canal or pipe to spin turbines.
How Hydropower is Used Hydropower is currently the largest and least expensive source of renewable electricity produced in the United States. Large and small-scale hydropower projects are most commonly used by clean power generators to produce electricity. Our Buying Clean Electricity section provides information on buying electricity generated from hydro and other renewable resources in your state. Many large-scale dam projects have been criticized for altering wildlife habitats, impeding fish migration, and affecting water quality and flow patterns. As a result of increased environmental regulation, the National Hydropower Association forecasts a decline in large-scale hydropower use through 2020. Research and development efforts have succeeded in reducing many of these environmental impacts through the use of fish ladders (to aid fish migration), fish screens, new turbine designs, and reservoir aeration. Although funding has been limited, current research focuses on the development of a "next generation turbine, which is expected to further increase fish survival rates and improve environmental conditions. A very small hydropower (called microhydro) project can also be installed to meet the electricity needs of a single home or small business, and is especially useful for those in remote areas.
Hydropower Plants Worldwide, hydropower plants produce about 24 percent of the world's electricity and supply more than 1 billion people with power. The world's hydropower plants output a combined total of 675,000 megawatts, the energy equivalent of 3.6 billion barrels of oil, according to the National Renewable Energy Laboratory. There are more than 2,000 hydropower plants operating in the United States, making hydropower the country's largest renewable energy source.
Hydropower plants harness water's energy and use simple mechanics to convert that energy into electricity. Hydropower plants are actually based on a rather simple concept -- water flowing through a dam turns a turbine, which turns a generator.
Here are the basic components of a conventional hydropower plant:
1. Dam - Most hydropower plants rely on a dam that holds back water, creating a large reservoir. Often, this reservoir is used as a recreational lake, such as Lake Roosevelt at the Grand Coulee Dam in Washington State.
2. Intake - Gates on the dam open and gravity pulls the water through the penstock, a pipeline that leads to the turbine. Water builds up pressure as it flows through this pipe.
3. Turbine - The water strikes and turns the large blades of a turbine, which is attached to a generator above it by way of a shaft. The most common type of turbine for hydropower plants is the Francis Turbine, which looks like a big disc with curved blades. A turbine can weigh as much as 172 tons and turn at a rate of 90 revolutions per minute (rpm), according to the Foundation for Water & Energy Education (FWEE).
4. Generators - As the turbine blades turn, so do a series of magnets inside the generator. Giant magnets rotate past copper coils, producing alternating current (AC) by moving electrons. (You'll learn more about how the generator works later.)
5. Transformer - The transformer inside the powerhouse takes the AC and converts it to higher-voltage current.
6. Power lines - Out of every power plant come four wires: the three phases of power being produced simultaneously plus a neutral or ground common to all three. (Read How Power Distribution Grids Work to learn more about power line transmission.)
7. Outflow - Used water is carried through pipelines, called tailraces, and re-enters the river downstream.
Pumped Storage The majority of hydropower plants work in the manner described above. However, there's another type of hydropower plant, called the pumped-storage plant. In a conventional hydropower plant, the water from the reservoir flows through the plant, exits and is carried down stream. A pumped-storage plant has two reservoirs:
1. Upper reservoir - Like a conventional hydropower plant, a dam creates a reservoir. The water in this reservoir flows through the hydropower plant to create electricity.
2. Lower reservoir - Water exiting the hydropower plant flows into a lower reservoir rather than re-entering the river and flowing downstream.
Using a reversible turbine, the plant can pump water back to the upper reservoir. This is done in off-peak hours. Essentially, the second reservoir refills the upper reservoir. By pumping water back to the upper reservoir, the plant has more water to generate electricity during periods of peak consumption.
Inside the Generator The heart of the hydroelectric power plant is the generator. Most hydropower plants have several of these generators.
The generator, as you might have guessed, generates the electricity. The basic process of generating electricity in this manner is to rotate a series of magnets inside coils of wire. This process moves electrons, which produces electrical current.
The Hoover Dam has a total of 17 generators, each of which can generate up to 133 megawatts. The total capacity of the Hoover Dam hydropower plant is 2,074 megawatts. Each generator is made of certain basic parts: 1. Shaft 2. Excitor 3. Rotor 4. Stator As the turbine turns, the excitor sends an electrical current to the rotor. The rotor is a series of large electromagnets that spins inside a tightly-wound coil of copper wire, called the stator. The magnetic field between the coil and the magnets creates an electric current.
In the Hoover Dam, a current of 16,500 volts moves from the generator to the transformer, where the current ramps up to 230,000 volts before being transmitted.
Sunday, 13 April 2008
hello people!:D instead of using that incomprehendable wetpaint, lets just use blogger! since everybody knows how to use it anw(: i'm going to do up the blogskin and profile and everything now, so yea, please constantly blog and tag and everything!
xoxo, qiaohui. [edited] the tagboard's darn sucky, but whatever, we've got our WEBSITE!:D
to threeohseven's physics SIA blog(:
we're a bundle of nanyang girls :D
studying in 3ohseven.
this blog is set up for our PHYSICS SIA
=Zhi-yi= =Qiao Hui= =Wandong= =Ma Ke=