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Wind Power - What is Wind Power and How Does It Work? - 0 views

  • wind power as a better way to generate electricity than plants fueled by coal, hydro (water) or nuclear power.
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    "Wind power is actually a form of solar power, because wind is caused by heat from the sun. Solar radiation heats every part of the Earth's surface, but not evenly or at the same speed. Different surfaces-sand, water, stone and various types of soil-absorb, retain, reflect and release heat at different rates, and the Earth generally gets warmer during daylight hours and cooler at night. As a result, the air above the Earth's surface also warms and cools at different rates. Hot air rises, reducing the atmospheric pressure near the Earth's surface, which draws in cooler air to replace it. That movement of air is what we call wind."
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    what is wind power
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Tidal power (tidal energy) facts - Interesting energy facts - 1 views

  • Tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.
  • Tidal energy is a type of energy that produces electricity and other forms of power through the use of water.
  • The tide moves a huge amount of water twice each day and although the tidal energy supply is reliable and plentiful, converting it into useful electrical power is not easy.
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  • The first involves converting the power of the horizontal movement of the water into electricity. The second involves producing energy from the rise and drop of water levels
  • Although the technology required to harness tidal energy is well established, tidal power is expensive, and there is only one major tidal generating station in operation. This is a 240 megawatt station at the mouth of the La Rance river estuary in France.
  • There are three prototypes of tidal energy devices: horizontal axis turbine, vertical axis turbine, and oscillating devices
  • Tidal energy is not on the list of sustainable energy technologies the UN agencies even though for islanders it is our best hope for large amounts of affordable clean power.
  • Turbines, similar to wind turbines, can be anchored to the sea bed to generate electricity from tidal currents
  • Tidal energy has an efficiency of 80% in converting the potential energy of the water into electricity
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World of Wind Energy.com - The World's #1 Wind Energy Site! - News - WIND ECOLOGY AND P... - 1 views

  • Wind power is a renewable resource, which means using it will not deplete the earth's supply of fossil fuels. It also is a clean energy source, and operation does not produce carbon dioxide, sulfur dioxide, mercury, particulates, or any other type of air pollution, as do conventional fossil fuel power sources.
  • Wind power consumes no fuel for continuing operation, and has no emissions directly related to electricity production.
  • Wind power's ability to reduce pollution and greenhouse gas emissions will depend on the amount of wind energy produced, and hence scalability.
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  • Wind power may also have an indirect effect on pollution at other production facilities, due to the need for reserve and regulation, and may affect the efficiency profile of plants used to balance demand and supply, particularly if those facilities use fossil fuel sources. Compared to other power sources, however, wind energy's direct emissions are low, and the materials used in construction (concrete, steel, fiberglass, generation components) and transportation are straightforward.
  • Wind power's ability to reduce pollution and greenhouse gas emissions will depend on the amount of wind energy produced, and hence scalability.
  • Wind power may also have an indirect effect on pollution at other production facilities, due to the need for reserve and regulation, and may affect the efficiency profile of plants used to balance demand and supply, particularly if those facilities use fossil fuel sources. Compared to other power sources, however, wind energy's direct emissions are low, and the materials used in construction (concrete, steel, fiberglass, generation components) and transportation are straightforward.
  • carbon dioxide, sulfur dioxide, mercury, particulates, or any other type of air pollution, as do conventional fossil fuel power sources.
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    " United States, onshore and near-shore turbines kill 70,000 birds per year, compared to 57 million killed by cars and 97.5 million killed by collisions with plate glass."
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Wind Energy America - FAQs - 1 views

  • Simply put, an average one megawatt wind turbine will produce enough energy for the annual needs of 350 average households. The amount of energy produced by a turbine varies depending on several factors, namely the size and reliability of the turbine, and the speed that the wind is blowing. These factors together produce the turbine’s capacity. Typically modern turbines range in size from 660 kilowatts to over 3 megawatts of capacity. They are placed in fairly windy locations with minimum wind speeds in the range of six meters per second (around 13 miles per hour). Wind turbines generally run at 30 to 40 percent capacity, so a 1 MW turbine could produce around 3 million KWh of electricity in a year.
  • , wind energy could provide 20% of America’s electricity.
  • According to the American Wind Energy Association, the total U.S. production of wind power is around 25 gigawatts
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    "Simply put, an average one megawatt wind turbine will produce enough energy for the annual needs of 350 average households. The amount of energy produced by a turbine varies depending on several factors, namely the size and reliability of the turbine, and the speed that the wind is blowing. These factors together produce the turbine's capacity. Typically modern turbines range in size from 660 kilowatts to over 3 megawatts of capacity. They are placed in fairly windy locations with minimum wind speeds in the range of six meters per second (around 13 miles per hour). Wind turbines generally run at 30 to 40 percent capacity, so a 1 MW turbine could produce around 3 million KWh of electricity in a year."
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    today's wind power
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    How much wind power is currently being produced in the United States? According to the American Wind Energy Association, the total U.S. production of wind power is around 25 gigawatts. New wind projects made up 42% of the U.S.'s total new power-producing capacity constructed in 2008, adding 8.4GW of new facilities into the grid.
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    What is wind power? Wind power is the result of using the wind to generate electricity. In the past windmills were used to grind grain or pump water. Today, a large wind turbine can power all the electricity needs of at least 350 homes.
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    , wind energy could provide 20% of America's electricity. Today's wind turbines are very different from the windmills of the past. Moder
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Tidal Power: Nature's renewable hydro electric engine: Additional info - 2 views

  • Tidal power energy is still being studied and developed, but in the future it could be a major renewable hydropower energy source.
  • England, for example, could supply over 10 percent of its electricity in this way.
  • . Wind and solar energy generators convert much less.
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  • They can convert about 80 percent of the energy into electricity
  • Another disadvantage is that the start-up costs involved are very high and a lot of time is required for the construction projects, which can cost millions of dollars and take up to 10 years to build
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    Tidal hydropower energy has various advantages. The first of these is reliability and consistency. Other alternative energy sources like wind and solar can have varying amounts of energy generated depending on the weather conditions. Tidal power energy can generate electricity by the clock and indefinitely. This means that shortages can be easily avoided. In addition, tidal turbines are efficient when it comes to generating energy. They can convert about 80 percent of the energy into electricity. Wind and solar energy generators convert much less. Of course, another great benefit of tidal power renewable energy is that it is environmentally friendly. There are no CO2 emissions that are damaging to the atmosphere or Sulfur Dioxide emissions responsible for acid rain.
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Tidal power - Wikipedia, the free encyclopedia - 0 views

  • Tidal stream generators (or TSGs) make use of the kinetic energy of moving water to power turbines, in a similar way to wind turbines that use wind to power turbines. Some tidal generators can be built into the structures of existing bridges, involving virtually no aesthetic problems. [edit] Tidal barrage
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    "Tidal stream generator Main article: Tidal stream generator Tidal stream generators (or TSGs) make use of the kinetic energy of moving water to power turbines, in a similar way to wind turbines that use wind to power turbines. Some tidal generators can be built into the structures of existing bridges, involving virtually no aesthetic problems."
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Tidal Power - Costs - Pros & Cons - How it Works - Green Energy - 0 views

  • Tidal power is a predictable source of energy unlike that of wind power and solar power because the tides follow the gravitational pull of the moon. The general production of tidal energy is similar to other forms of hydroelectric power where the force of water flow spins a turbine which generates energy.
  • he tidal stream generator uses the kinetic energy of the flowing tide to spin windmill like turbines. It is also often referred to as a tidal energy converter (TEC).
  • Tidal power is the production of electricity by the utilization of tidal energy.
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Haldor Topsoe - Fuel cells for sustainable energy - 0 views

  • What is a fuel cell?A fuel cell produces electricity from fuel and air. The simplest fuel cell produces electricity from hydrogen and air with water as the only by-product.
  • Where can fuel cells be used?Fuel cells in general can be used in many different circumstances, depending on the type of fuel cell. Topsoe Fuel Cell focuses on SOFC fuel cells, which can be used in:Auxiliary power units (APUs) provide electricity where there is no access to grid power. Fuel cell based APUs can be used on, for instance, long-haul trucks to generate power during breaks.Micro combined heat and power units may be scaled to meet the electricity demand in single family households. Combined heat and power generation for households is one of the most efficient ways to meet residential energy requirements.Distributed generation using SOFC technology offers efficient power generation, for example hospitals, shopping malls, in apartment buildings and in areas with low power capacity.
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How much greenhouse gas does a solar power system replace? | Solar Powered in Toronto - 1 views

  • kilowatt system will replace around 2.5 tonnes of greenhouse gases, possibly more. It depends on what your annual output is, and what the local mix of power sources is in your province/state/country.
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    So a 3 kilowatt system will replace around 2.5 tonnes of greenhouse gases, possibly more. It depends on what your annual output is, and what the local mix of power sources is in your province/state/country.
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Cost of Geothermal Energy - 0 views

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    "Certain studies have shown that a geothermal power plant that could be considered as economically competitive would cost at around $3400/kw installed. Yes, the cost of the construction of a geothermal power plant is much higher compared to a facility producing natural gas, however, the cost of electricity production of the two in the long run would be similar. Initially, the construction cost of the geothermal plant would be 2/3 of the total cost. On the other hand, with a natural gas facility, the cost of the fuel is 2/3 while construction cost is just 1/3 of the total cost.  So this is where geothermal power plant and natural gas energy come into a standoff. In the long run, production rates stabilize and the cost of production for both plants become competitive. One good thing about the pric"
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Mapping US Tidal Power Potential | Climate Central - 0 views

  • It’s estimated that tidal power in Alaska could generate as much as 16 TWh/yr of energy (about four times more than what Hoover Dam generates in an average year). In the Lower 48, the potential energy from tidal power is just a fraction of that (just 0.6 TWh/year from Puget Sound, for example). Considering that no tidal power plants in these areas have even been approved yet, it’s going to be several years, or even decades, before Americans can rely on tidal power for their electricity. But for some regions, DOE says the energy from tidal currents will help meet the goal of generating 80 percent of America's electricity from clean sources by 2035.
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Wind Energy - 0 views

  • Wind Energy, like Solar Energy is fully sustainable, being generated by natural wind flows, which in the U.K. are reliable enough to guarantee a stable, near constant supply of energy. Wind Power can be easily set up, either at home (see related article) or on a larger scale, by energy suppliers keen to meet government targets to reduce carbon emissions that are produced by conventional power stations.
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    "Wind Energy, like Solar Energy is fully sustainable, being generated by natural wind flows, which in the U.K. are reliable enough to guarantee a stable, near constant supply of energy. Wind Power can be easily set up, either at home (see related article) or on a larger scale, by energy suppliers keen to meet government targets to reduce carbon emissions that are produced by conventional power stations."
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How do Photovoltaics Work? - NASA Science - 1 views

  • Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.
  • When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current -- that is, electricity. This electricity can then be used to power a load, such as a light or a tool.
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    " Solar cells are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current -- that is, electricity. This electricity can then be used to power a load, such as a light or a too"
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    "The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. It was billed as a solar battery and was mostly just a curiosity as it was too expensive to gain widespread use. In the 1960s, the space industry began to make the first serious use of the technology to provide power aboard spacecraft. Through the space programs, the technology advanced, its reliability was established, and the cost began to decline. During the energy crisis in the 1970s, photovoltaic technology gained recognition as a source of power for non-space applications."
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Wind Power Information, Wind Power Facts - National Geographic - 1 views

  • Wind is a clean source of renewable energy that produces no air or water pollution.
  • Wind is the movement of air from an area of high pressure to an area of low pressure. In fact, wind exists because the sun unevenly heats the surface of the Earth. As hot air rises, cooler air moves in to fill the void. As long as the sun shines, the wind will blow. And as long as the wind blows, people will harness it to power their lives.
  • The wind spins the blades, which turn a shaft connected to a generator that produces electricity. Other turbines work the same way, but the turbine is on a vertical axis and the blades look like a giant egg beater.
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  • At the end of last year, global capacity was more than 70,000 megawatts.
  • And since the wind is free, operational costs are nearly zero once a turbine is erected.
  • Globally, generation more than quadrupled between 2000 and 2006.
  • n the energy-hungry United States, a single megawatt is enough electricity to power about 250 homes.
  • ndustry experts predict that if this pace of growth continues, by 2050 the answer to one third of the world's electricity needs will be found blowing in the wind.
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    where wind energy come from
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    ". At the end of last year, global capacity was more than 70,000 megawatts. In the energy-hungry United States, a single megawatt is enough electricity to power about 250 homes. "
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Tidal Power - Generating electricity from tidal currents - 1 views

  • Tidal energy is produced through the use of tidal energy generators. These large underwater turbines are placed in areas with high tidal movements, and are designed to capture the kinetic motion of the ebbing and surging of ocean tides in order to produce electricity. Tidal power has great potential for future power and electricity generation because of the massive size of the oceans. These articles explore the potential energy of tidal power technologies.
  • We can use slow moving ocean and river waves for a new, reliable and affordable alternative energy source. A University of Michigan engineer has developed a device that acts like a fish that turns the potentially destructive vibrations in water into clean, renewable energy.
  • It will generate one of the most environmentally-friendly forms of energy - it makes no noise
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  • "But if we could harness 0.1 percent of the energy in the ocean, we could support the energy needs of 15 billion people
  • Tidal energy is produced through the use of tidal energy generators. These large underwater turbines are placed in areas with high tidal movements
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    This is how tidal energy is converted into useful form of power. 
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First Tidal Power in U.S. Starts Flowing to the Grid - IEEE Spectrum - 0 views

  • An offshore turbine is finally spinning in the United States!
  • Bay of Fundy, off the Maine coast. The TidGen has a peak power output of 180 kilowatts, enough to power around 25 to 30 homes
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    The ONLY tidal power plant connected to the grid in the US is online.
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Group items tagged pollution - qmstech2 | Diigo Groups - 0 views

    • filionmar99
       
      read this
  • The major challenge to using wind as a source of power is that it is intermittent and does not always blow when electricity is needed. Wind cannot be stored (although wind-generated electricity can be stored, if batteries are used), and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities).
  • Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.
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  • A Renewable Non-Polluting Resource Wind energy is a free, renewable resource, so no matter how much is used today, there will still be the same supply in the future. Wind energy is also a source of clean, non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases. According to the U.S. Department of Energy, in 1990, California's wind power plants offset the emission of more than 2.5 billion pounds of carbon dioxide, and 15 million pounds of other pollutants that would have otherwise been produced. It would take a forest of 90 million to 175 million trees to provide the same air quality.
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Renewable Energy, Other sources of Renewable Energy - 0 views

  • "Worldwide, approximately 3000 gigawatts (1 gigawatt = 1 GW = 1 billion watts) of energy is continuously available from the action of tides.
  • The best areas are on the eastern sides of the oceans (western side of the continents) between the 40 and 60 latitudes in both the northern and southern hemispheres.
  • While the "wave power at deep ocean sites is three to eight times the wave power at adjacent coastal sites," constructing and mooring the site and transmitting the electricity to shore would be prohibitively costly.
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  • There is a handful of wave energy demonstration plants operating worldwide, but none produces a significant amount of electricity.
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    While the "wave power at deep ocean sites is three to eight times the wave power at adjacent coastal sites," constructing and mooring the site and transmitting the electricity to shore would be prohibitively costly.
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Wind Power History - 0 views

  • It development of technology have been well proven over the years of time. When the sun emit heat to warm of the Earth it would be unbearable without wind. Wind widely disperses the heat making it bearable for all living things to survive. Without wind nothing would exist, it would just like all the other planets uninhibited by human nature or any living things for that matter.
  • A wind turbine is a machine that transforms kinetic energy from the wind into mechanical energy.
  • Wind power was first used in ancient times with the sail boat.
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  • When windmills were first developed they were used to assist man with the chores of pumping and grinding.
  • Well wind power is the transformation of energy from wind to electricity or other forms of energy
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    what wind power is
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NREL: Learning - Solar Photovoltaic Technology Basics - 1 views

  • The PV effect was discovered in 1954, when scientists at Bell Telephone discovered that silicon (an element found in sand) created an electric charge when exposed to sunlight.
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    "The PV effect was discovered in 1954, when scientists at Bell Telephone discovered that silicon (an element found in sand) created an electric charge when exposed to sunlight. Soon solar cells were being used to power space satellites and smaller items like calculators and watches. Today, thousands of people power their homes and businesses with individual solar PV systems. Utility companies are also using PV technology for large power stations. "
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