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kenyonlau99

chap15_pvcell.gif (300×324) - 0 views

shared by kenyonlau99 on 08 Mar 13 - No Cached
rascoekat00

Energy Basics: Tidal Energy - 1 views

  • Tidal turbines look like wind turbines. They are arrayed underwater in rows, as in some wind farms. The turbines function best where coastal currents run between 3.6 and 4.9 knots (4 and 5.5 mph). In currents of that speed, a 49.2-foot (15-meter) diameter tidal turbine can generate as much energy as a 197-foot (60-meter) diameter wind turbine. Ideal locations for tidal turbine farms are close to shore in water 65.5–98.5 feet (20–30 meters) deep
  • In currents of that speed, a 49.2-foot (15-meter) diameter tidal turbine can generate as much energy as a 197-foot (60-meter) diameter wind turbine. Ideal locations for tidal turbine farms are close to shore in water 65.5–98.5 feet (20–30 meters) deep.
  • A barrage or dam is typically used to convert tidal energy into electricity by forcing water through turbines, which activate a generato
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  • Some of the oldest ocean energy technologies use tidal power. All coastal areas experience two high tides and two low tides over a period of slightly more than 24 hours. For those tidal differences to be harnessed into electricity, the difference between high and low tides must be more than 16 feet (or at least 5 meters). However, there are only about 40 sites on Earth with tidal ranges of this magnitude.
  • Tidal Turbines Tidal turbines look like wind turbines. They are arrayed underwater in rows, as in some wind farms. The turbines function best where coastal currents run between 3.6 and 4.9 knots (4 and 5.5 mph). In currents of that speed, a 49.2-foot (15-meter) diameter tidal turbine can generate as much energy as a 197-foot (60-meter) diameter wind turbine. Ideal locations for tidal turbine farms are close to shore in water 65.5–98.5 feet (20–30 meters) deep.
  • Currently, there are no tidal power plants in the United States, but conditions are good for tidal power generation in the Pacific Northwest and the Atlantic Northeast regions.
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    "Tidal Turbines Tidal turbines look like wind turbines. They are arrayed underwater in rows, as in some wind farms. The turbines function best where coastal currents run between 3.6 and 4.9 knots (4 and 5.5 mph). In currents of that speed, a 49.2-foot (15-meter) diameter tidal turbine can generate as much energy as a 197-foot (60-meter) diameter wind turbine. Ideal locations for tidal turbine farms are close to shore in water 65.5-98.5 feet (20-30 meters) deep."
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    where its used
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    "Some of the oldest ocean energy technologies use tidal power. All coastal areas experience two high tides and two low tides over a period of slightly more than 24 hours. For those tidal differences to be harnessed into electricity, the difference between high and low tides must be more than 16 feet (or at least 5 meters). However, there are only about 40 sites on Earth with tidal ranges of this magnitude."
cottonetar98

GENERATION TO THE NATION - 0 views

  • Wind is created when the sun hits the earth. The air above water and the air above the ground heat at different rates. Since the air above the ground heats faster, the warm air from the ground hits the atmosphere first. It then is pushed out toward the sea. As the air heads toward the sea, it gets colder and sinks back down to the sea level. This creates a current pushing the sea air toward the land in the form of wind. The stronger the sun's energy on the land and water, the faster the wind will circulate.
  • As the gearbox turns, it feeds the RPM into the generator, which transfers the energy into usable electrical energy and stores it. Large cables are attached to the generator that feed the electrical currents from the generators of all the wind turbines on the farm into one electrical storage area. The energy can then be transported through power lines around the area for commercial and home usage.
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    What makes wind. 
faglejoh98

Geothermal Energy Information, Geothermal Power Facts - National Geographic - 0 views

  • Geothermal energy has been used for thousands of years in some countries for cooking and heating. It is simply power derived from the Earth's internal heat.This thermal energy is contained in the rock and fluids beneath Earth's crust. It can be found from shallow ground to several miles below the surface, and even farther down to the extremely hot molten rock called magma.These underground reservoirs of steam and hot water can be tapped to generate electricity or to heat and cool buildings directly.A geothermal heat pump system can take advantage of the constant temperature of the upper ten feet (three meters) of the Earth's surface to heat a home in the winter, while extracting heat from the building and transferring it back to the relatively cooler ground in the summer
  • There are three types of geothermal power plants: dry steam, flash, and binary. Dry steam, the oldest geothermal technology, takes steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants pull deep, high-pressure hot water into cooler, low-pressure water. The steam that results from this process is used to drive the turbine. In binary plants, the hot water is passed by a secondary fluid with a much lower boiling point than water. This causes the secondary fluid to turn to vapor, which then drives a turbine. Most geothermal power plants in the future will be binary plants.
  • It can be extracted without burning a fossil fuel such as coal, gas, or oil. Geothermal fields produce only about one-sixth of the carbon dioxide that a relatively clean natural-gas-fueled power plant produces.
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  • wer plants: dry steam, flash, and binary. Dry steam, the oldest geothermal technology, takes steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants
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    good info.
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    Geothermal energy doesn't release much CO2
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    "There are three types of geothermal power plants: dry steam, flash, and binary. Dry steam, the oldest geothermal technology, takes steam out of fractures in the ground and uses it to directly drive a turbine. Flash plants pull deep, high-pressure hot water into cooler, low-pressure water. The steam that results from this process is used to drive the turbine. In binary plants, the hot water is passed by a secondary fluid with a much lower boiling point than water. This causes the secondary fluid to turn to vapor, which then drives a turbine. Most geothermal power plants in the future will be binary plants."
dpurdy

EIA Energy Kids - Geothermal - 1 views

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    "Geothermal energy is generated in the Earth's core. Temperatures hotter than the sun's surface are continuously produced inside the Earth by the slow decay of radioactive particles, a process that happens in all rocks."
dextereli99

solar-power.jpg (430×354) - 3 views

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    process of solar energy
westkea00

Wave Power - Energy from ocean surface waves - 1 views

  • Wave energy is produced when electricity generators are placed on the surface of the ocean
  • Energy output is determined by wave height, wave speed, wavelength, and water density.
  • The energy provided is most often used in desalination plants, power plants and water pumps.
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  • The energy provided is most often used in desalination plants, power plants and water pumps.
  • Just like wind mills and wind turbines that generate power and electricity from the wind, scientists are now working to generate power from the sea
  • Wave energy is among the impressive list of renewable energy resources that is being developed in the United States.
  • Ocean wave energy can be captured directly from surface waves. Blowing wind and pressure fluctuations below the surface are the main reasons for causing waves.
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    Controlling factor of electric power.
westkea00

Energy Resources: Wave power - 3 views

  • Waves are a powerful source of energy.
  • The problem is that it's not easy to harness this energy and convert it into electricity in large amounts.
  • wave power stations are rare
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  • Once you've built a wave power station, the energy is free, needs no fuel and produces no waste or pollution
  • The energy is free - no fuel needed, no waste produced.
  • Not expensive to operate and maintain.
  • Can produce a great deal of energy.
  • Some designs are noisy. But then again, so are waves, so any noise is unlikely to be a problem.
  • Ocean waves are caused by the wind as it blows across the sea. Waves are a powerful source of energy.
  • Some designs are noisy. But then again, so are waves, so any noise is unlikely to be a problem
  • At a wave power station, the waves arriving cause the water in the chamber to rise and fall, which means that air is forced in and out of the hole in the top of the chamber. We place a turbine in this hole, which is turned by the air rushing in and out. The turbine turns a generator. A problem with this design is that the rushing air can be very noisy, unless a silencer is fitted to the turbine. The noise is not a huge problem anyway, as the waves make quite a bit of noise themselves.
  • At a wave power station, the waves arriving cause the water in the chamber to rise and fall, which means that air is forced in and out of the hole in the top of the chamber. We place a turbine in this hole, which is turned by the air rushing in and out. The turbine turns a generator. A problem with this design is that the rushing air can be very noisy, unless a silencer is fitted to the turbine. The noise is not a huge problem anyway, as the waves make quite a bit of noise themselves.
  • A company called Pelamis Wave Power are developing a method of offshore wave energy collection, using a floating tube called "Pelamis"
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    " Advantages   The energy is free - no fuel needed, no waste produced. Not expensive to operate and maintain. Can produce a great deal of energy. Disadvantages Depends on the waves - sometimes you'll get loads of energy, sometimes almost nothing. Needs a suitable site, where waves are consistently strong. Some designs are noisy. But then again, so are waves, so any noise is unlikely to be a problem. Must be able to withstand very rough weather."
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    One of them works like a swimming pool wave machine in reverse. At a swimming pool, air is blown in and out of a chamber beside the pool, which makes the water outside bob up and down, causing waves.  
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