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Wind Energy Basics - 5 views

windeis.anl.gov/...index.cfm wind convert
shared by pondalb98 on 13 Mar 12 - Cached
  • Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetative cover. This wind flow, or motion energy, when "harvested" by modern wind turbines, can be used to generate electricity.
  • The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity
  • The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power
  • ...19 more annotations...
  • Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current
  • Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model
  • wind farm, and generate bulk electrical power
  • Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts
  • Wind energy is very abundant in many parts of the United States. Wind resources are characterized by wind-power density classes, ranging from class 1 (the lowest) to class 7 (the highest). Good wind resources (e.g., class 3 and above, which have an average annual wind speed of at least 13 miles per hour) are found in many locations (see United States Wind Energy Resource Map)
  • free, renewable resource, so no matter how much is used today, there will still be the same supply in the future
  • clean, non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases
  • higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation.
  • 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
  • remote locations far from areas of electric power demand (such as cities)
  • alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming
  • Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetative cover. This wind flow, or motion energy, when "harvested" by modern wind turbines, can be used to generate electricity.
  • The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity to power homes, businesses, schools, and the like.
  • Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current. Simply stated, a wind turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.
  • Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor. Most large modern wind turbines are horizontal-axis turbines.
  • Wind is a form of solar energy
  • The terms "wind energy" or "wind power
  • describe the process by which the wind is used to generate mechanical power or electricity.
  • Wind turbines, like aircraft propeller blades, turn in the moving air and power an electric generator that supplies an electric current. Simply stated, a wind turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.
  • freeberntay99 on 08 Mar 13
     
    "Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetative cover. This wind flow, or motion energy, when "harvested" by modern wind turbines, can be used to generate electricity."
  • pondalb98 on 12 Mar 13
     
    "Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor. Most large modern wind turbines are horizontal-axis turbines."
9More

Energy Basics: Tidal Energy - 1 views

www.eere.energy.gov/...tidal_energy.html tidal current
shared by rascoekat00 on 08 Mar 13 - No Cached
  • 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.
  • albrechtjen99 on 08 Mar 13
     
    "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."
  • kramerjac99 on 11 Mar 13
     
    where its used
  • butlerlei98 on 12 Mar 13
     
    "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."
9More

Wind Turbines - Kinetic wind energy generator technology - 0 views

www.alternative-energy-news.info/...wind-turbines wind turbines energy technology history current sustainable
shared by sankeyrya00 on 23 Sep 13 - No Cached
  • Though our scientists may claim that they are inventing something new by using wind as a source of generating energy, the truth is that wind is being used for centuries for this purpose. An example of this is an article published in 1838, which clearly shows that even in those times, wind was considered an important source of energy. Here are a few quotes that were recorded in the past, which prove that wind was always important in generating energy
  • Renewable energy production and demand growth is gaining momentum in many ways across the world. There is a booming demand of wind power today and all wind energy equipment manufacturers are gearing up to meet the demand and take advantage of it. Wind power capacity growth will be reaching 447GW in the next five years and by year 2014 end, Asia will lead the world in installed wind capacity.
  • Yes, the day is not far off when reaching for sky is the new motto for generating cost-effective renewable energy. Initially it was considered to be technically non-viable to tap high-altitude winds. But today, technically-advanced materials and innovative computer know-how are giving new life to this scheme with innovative autonomous aerial structures using wind energy to generate power
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  • It's an expert estimation that the total energy stored in wind is 100 times higher than actually needed by humans on this earth. The catch is that we have to learn and devise ways to trap this wind power blowing across the planet earth. Experts tell us one more thing that most of the wind energy is available at high altitude and we can’t manufacture turbines of that height. So we have to think of new ways to trap that wind power blowing at a significant height. Some experts estimate that the total energy contained in wind is 100 times the amount needed by everyone on the planet. However, most of this energy is at high altitudes, far beyond the reach of any wind turbine.
  • A research company in New Hampshire recently patented its bladeless wind turbine, which is based on a patent issued to Nikola Tesla in 1913. This wind turbine is christened as the Fuller Wind turbine. This turbine is developed by Solar Aero. The specialty of Fuller Wind turbine is it has only one rotating part, known as the turbine-driveshaft. The entire machinery is assembled inside a housing. Wind turbines are often disliked by environmentalists because they kill birds and bats and often generate noise for the residents living nearby
  • Presently Fluid Dynamics Expert, John Dabiri, is very much on the quest of improving designs of wind turbines. Spotting behaviours that may throw light on energy-related practices in biological system and trying to implement that in real-life situations is part of that quest and Mr.Dabiri is jubilant that he is learning lessons from a school of fish! Water-energy, and wind energy are both studied.
  • GE, the US industrial group, is promoting and showing confidence in offshore wind technology by buying ScanWind, which makes direct-drive turbine components. This move will help in generating thousands of new jobs in the field of designing and manufacturing turbines. This move will affirm the confidence of investors in the fledgling offshore wind industry, which has been weighed down by concerns about costs and reliability. GE is moving ahead with establishing turbine manufacturing facilities to serve the European markets at first. They have to make up their mind about the size of the investment and location
  • The Metropolis Magazine has been holding Next Generation Design Competition since 2003. They want to provide a platform for young designers to promote the spirit of activism, social involvement, and entrepreneurship. They offer prize money of $ 10,000. But the real attraction is the publicity given to the projects of winners and runners-up. This recognition helps abstract ideas take concrete forms. For 2009, the theme for the Next Generation Design Competition was: How do we fix our energy addiction? They offered some guidelines, "Think about how we live and work, what we use, how we get where we need to go, hidden costs to our pocket books and the environment, across the whole design spectrum. Focus on one area that needs fixing—products, interiors, buildings and landscape, communication systems, or anything else you can imagine—and develop your idea fully. And above all, think of our energy addiction as a design problem at all scales."
  • sector. Wind turbines generate clean and green power for us but they have certain precondition. One of it is the power unit has to be set up in strong wind area. But Green Energy Technologies has developed a brand new wind power generator known as the WindCube. It is smaller compared to the normal wind generator. WindCube is specially designed to set up on the roof of a building in urban and rural areas. WindCube carries a 22 x 22 x 12 feet framework and its single unit can produce a maximum of 60kW of power
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Wind Energy America - FAQs - 1 views

www.windenergyamerica.com/faqs.html wind
shared by bishophan00 on 19 Mar 12 - No Cached
  • 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
  • freeberntay99 on 08 Mar 13
     
    "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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  • wellsann99 on 12 Mar 13
     
    today's wind power
  • kurishkri00 on 24 Sep 13
     
    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.
  • kurishkri00 on 26 Sep 13
     
    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.
  • bishophan00 on 27 Sep 13
     
    , wind energy could provide 20% of America's electricity. Today's wind turbines are very different from the windmills of the past. Moder
15More

Energy Resources: Wave power - 3 views

www.darvill.clara.net/...wave.htm
shared by westkea00 on 08 Mar 13 - Cached
  • 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"
  • rodriguezjos99 on 08 Mar 13
     
    " 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."
  • gonzalezisa00 on 25 Sep 13
     
    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.  
14More

Wind power - Wikipedia, the free encyclopedia - 1 views

en.wikipedia.org/Wind_power power
shared by rutalil00 on 13 Mar 12 - Cached
  • Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships
  • Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships.
  • The total amount of available power from the wind is considerably more than present human power use from all sources.[3] At the end of 2011, worldwide nameplate capacity of wind-powered generators was 238 gigawatts (GW), growing by 41 GW over the preceding year.[4] Wind power now (2010 data) has the capacity to generate 430 TWh annually, which is about 2.5% of worldwide electricity usage.[5][6] Over the past five years (2010 data) the average annual growth in new installations has been 27.6 percent. Wind power market penetration is expected to reach 3.35 percent by 2013 and 8 percent by 2018.[7][8] Several countries have already achieved relatively high levels of wind power penetration, such as 21% of stationary electricity production in Denmark,[5] 18% in Portugal,[5] 16% in Spain,[5] 14% in Ireland[9] and 9% in Germany in 2010.[5][10] As of 2011, 83 countries around the world are using wind power on a commercial basis
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  • A large wind farm may consist of several hundred individual wind turbines which are connected to the electric power transmission network. Offshore wind power can harness the better wind speeds that are available offshore compared to on land, so offshore wind power’s contribution in terms of electricity supplied is higher.[11] Small onshore wind facilities are used to provide electricity to isolated locations and utility companies increasingly buy back surplus electricity produced by small domestic wind turbines. Although a variable source of power, the intermittency of wind seldom creates problems when using wind power to supply up to 20% of total electricity demand, but as the proportion rises, increased costs, a need to use storage such as pumped-storage hydroelectricity, upgrade the grid, or a lowered ability to supplant conventional production may occur.[12][13][14] Power management techniques such as excess capacity, storage, dispatchable backing supply (usually natural gas), exporting and importing power to neighboring areas or reducing demand when wind production is low, can mitigate these problems.
  • Wind power, as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation, and uses little land. In operation, the overall cost per unit of energy produced is similar to the cost for new coal and natural gas installations.[15] The construction of wind farms is not universally welcomed, but any effects on the environment from wind power are generally much less problematic than those of any other power source
  • Wind is the movement of air across the surface of the Earth, affected by areas of high pressure and of low pressure.[35] The surface of the Earth is heated unevenly by the Sun, depending on factors such as the angle of incidence of the sun's rays at the surface (which differs with latitude and time of day) and whether the land is open or covered with vegetation. Also, large bodies of water, such as the oceans, heat up and cool down slower than the land. The heat energy absorbed at the Earth's surface is transferred to the air directly above it and, as warmer air is less dense than cooler air, it rises above the cool air to form areas of high pressure and thus pressure differentials. The rotation of the Earth drags the atmosphere around with it causing turbulence. These effects combine to cause a constantly varying pattern of winds across the surface of the Earth.[35]
  • Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electrical power, windmills for mechanical power, wind pumps for water pumping or drainage, or sails to propel ships.
  • Compared to the environmental impact of traditional energy sources, the environmental impact of wind power is relatively minor in terms of pollution
  • Wind energy is the kinetic energy of air in motion, also called wind
  • ind power, as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation and uses little land.[2] The effects on the environment are generally less problematic than those from other powe
  • Wind power is very consistent from year to year but has significant variation over shorter time scales. The intermittency of wind seldom creates problems when used to supply up to 20% of total electricity demand,[5] but as the proportion increases, a need to upgrade the grid, and a lowered ability to supplant conventional production can occur.
  • krolnik98 on 13 Mar 12
     
    wind turbine stuff
  • pondalb98 on 11 Mar 13
     
    "Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electrical power, windmills for mechanical power, wind pumps for water pumping or drainage, or sails to propel ships."
  • rutalil00 on 24 Sep 13
     
    Wind power, as an alternative to fossil fuels, is plentiful, renewable, widely distributed, clean, produces no greenhouse gas emissions during operation and uses little land.[2] The effects on the environment are generally less problematic than those from other power sources. As of 2011, Denmark is generating more than a quarter of its electricity from wind and 83 countries around the world are using wind power on a commercial basis.[3] In 2010 wind energy production was over 2.5% of total worldwide electricity usage, and growing rapidly at more than 25% per annum. The monetary cost per unit of energy produced is similar to the cost for new coal and natural gas installations.[4]
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Wind Program: Frequently Asked Questions about Wind Energy - 2 views

www1.eere.energy.gov/...faqs.html Wind cons
shared by jack wells on 03 Nov 11 - No Cached
  • What is wind energy? Wind energy (or wind power) refers to the process by which wind turbines convert the movement of wind into electricity. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Humans use this wind flow for many purposes: sailing boats, pumping water, and also generating electricity. Wind turbines convert the kinetic energy of the moving wind into electricity.
  • Birds and bats are occasionally killed in collisions with wind turbines. Like any form of development, wind projects can also negatively impact wildlife by altering habitat. Over the past two decades, the impact of wind development on birds has been greatly reduced by improvements in turbine design and particularly through improved project and turbine siting.
  • dpurdy on 03 Nov 11
     
    How do wind turbines work? A wind turbine works like a fan, but in reverse: instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the turbine's blades, which spin a shaft connected to a generator to make electricity.
  • jack wells on 11 Mar 13
     
    wind energy facts.
15More

Tidal Energy | Pros for Wave and Tidal Power - 3 views

www.oceanenergycouncil.com/...Tidal-Energy.html pollution tide
shared by tavarreskat99 on 03 Nov 11 - Cached
  • Tidal energy is one of the oldest forms of energy used by humans. Indeed, tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.. Tide mills consisted of a storage pond, filled by the incoming (flood) tide through a sluice and emptied during the outgoing (ebb) tide through a water wheel. The tides turned waterwheels, producing mechanical power to mill grain. We even have one remaining in New York- which worked well into the 20th century.
  • Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • A tidal range of at least 7 m is required for economical operation and for sufficient head of water for the turbines
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  • Currently, 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 (1 megawatt = 1 MW = 1 million watts) at the mouth of the La Rance river estuary on the northern coast of France
  • Tidal electricity can be used to displace electricity which would otherwise be generated by fossil fuel (coal, oil, natural gas) fired power plants, thus reducing emissions of greenhouse and acid gasses.
  • There is a high capital cost for a tidal energy project, with possibly a 10-year construction period.
  • Electricity can be generated by water flowing both into and out of a bay. As there are two high and two low tides each day, electrical generation from tidal power plants is characterized by periods of maximum generation every twelve hours, with no electricity generation at the six hour mark in between.
  • Tidal energy is a renewable source of electricity which does not result in the emission of gases responsible for global warming or acid rain associated with fossil fuel generated electricity. Use of tidal energy could also decrease the need for nuclear power, with its associated radiation risks. Changing tidal flows by damming a bay or estuary could, however, result in negative impacts on aquatic and shoreline ecosystems, as well as navigation and recreation.
  • Indeed, tide mills, in use on the Spanish, French and British coasts,
  • date back to 787 A.D..
  • Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • idal energy is one of the oldest forms of energy used by humans. Indeed, tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.. Tide mills consisted of a storage pond, filled by the incoming (flood) tide through a sluice and emptied during the outgoing (ebb) tide through a water wheel. The tides turned waterwheels, producing mechanical power to mill grain. We even have one remaining in New York- which worked well into the 20th century. Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • butlerlei98 on 08 Mar 13
     
    "Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable."
  • kramerjac99 on 11 Mar 13
     
    when it started to be used and who it was used by.
7More

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

environment.nationalgeographic.com/...geothermal-profile geothermal sustainable
shared by faglejoh98 on 08 Mar 13 - No Cached
  • 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
  • behanjos99 on 08 Mar 13
     
    good info.
  • vanierfel98 on 11 Mar 13
     
    Geothermal energy doesn't release much CO2
  • faglejoh98 on 12 Mar 13
     
    "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."
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Tidal power - Wikipedia, the free encyclopedia - 0 views

en.wikipedia.org/...Tidal_power tide form
shared by lemairenat98 on 11 Mar 13 - No Cached
  • 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
  • lemairenat98 on 11 Mar 13
     
    "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 - Wikipedia, the free encyclopedia - 0 views

en.wikipedia.org/...Tidal_power
shared by dpurdy on 03 Nov 12 - No Cached
  • 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. Likewise, “tidal bridging” is a relatively new advancement that is gaining recognition as a more practical and beneficial way to generate tidal power.
    • dpurdy
      dpurdy on 03 Nov 12
       
      Good pic of tidal stream generator working
  • dpurdy on 03 Nov 12
     
    "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. Likewise, "tidal bridging" is a relatively new advancement that is gaining recognition as a more practical and beneficial way to generate tidal power."
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Tidal power - Wikipedia, the free encyclopedia - 1 views

en.wikipedia.org/...Tidal_power tidal power history
shared by rascoekat00 on 03 Nov 11 - No Cached
  • The first tidal power station was the Rance tidal power plant built over a period of 6 years from 1960 to 1966 at La Rance, France.[8] It has 240 MW installed capacity.
  • Historically, tide mills have been used, both in Europe and on the Atlantic coast of North America. The incoming water was contained in large storage ponds, and as the tide went out, it turned waterwheels that used the mechanical power it produced to mill grain. [1] The earliest occurrences date from the Middle Ages, or even from Roman times.[2][3] It was only in the 19th century that the process of using falling water and spinning turbines to create electricity was introduced in the U.S. and Europe.[
  • Tides are more predictable than wind energy and solar power.
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  • relatively high cost and limited availability of sites with sufficiently high tidal ranges or flow velocities, thus constricting its total availability. However, many recent technological developments and improvements, both in design (e.g. dynamic tidal power, tidal lagoons) and turbine technology (e.g. new axial turbines, cross flow turbines), indicate that the total availability of tidal power may be much higher than previously assumed
  • 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. Likewise, “tidal bridging” is a relatively new advancement that is gaining recognition as a more practical and beneficial way to generate tidal power. Blue Energy Canada is a company that is focused on building bridges to match today's demands. [9]
  • The first study of large scale tidal power plants was by the US Federal Power Commission in 1924 which if built would have been located in the northern border area of the US state of Maine and the south eastern border area of the Canadian province of New Brunswick, with various dams, powerhouses and ship locks enclosing the Bay of Fundy and Passamaquoddy Bay (note: see map in reference). Nothing came of the study and it is unknown whether Canada had been approached about the study by the US Federal Power Commission.[10] There was also a report on the international commission in April 1961 entitled " Investigation of the International Passamaquoddy Tidal Power Project" produced by both the US and Canadian Federal Governments.
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Wind Turbine Syndrome | Wind energy: The "least sustainable energy option" - 0 views

www.windturbinesyndrome.com/...east-sustainable-energy-option wind energy cost sustainable pollution co2
shared by mcdermottaar99 on 12 Mar 13 - No Cached
  • Wind turbine installations impact vast amounts of land, far more than traditional power plants.
  • Raptors, bats and other beautiful flying creatures continue to be sliced and diced by wind turbines.
  • Principal health issues are associated with noise – not just annoying audible noise, but inaudible, low-frequency “infrasound” that causes headache, dizziness, “deep nervous fatigue” and symptoms akin to seasickness. “Wind turbine syndrome” also includes irritability, depression, and concentration and sleep problems. Others include “shadow flicker” or “strobe effect” from whirling blades, which can trigger seizures in epileptics, “vibroacoustic” effects on the heart and lungs, and non-lethal harm to animals. Serious lung, heart, cancer and other problems have been documented from rare earth mining, smelting and manufacturing in China, under its less rigorous health, workplace and environmental regulations.
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  • Wind turbine installations require vast amounts of steel, copper, rare earth metals, fiberglass, concrete, rebar and other materials for the turbines, towers and bases.
  • Wind turbines are supposed to reduce pollution and carbon dioxide emissions. But because backup generators must repeatedly surge to full power and back to standby, as wind speed rises and falls, they operate inefficiently, use more fuel and emit more – much like cars forced to stop repeatedly on freeways.
  • Even huge subsidies cannot cure wind power’s biggest defects: its electricity costs far more than coal, gas or nuclear alternatives – and its intermittent nature wreaks havoc on power grids and consumers.
    • dpurdy
      dpurdy on 21 Mar 13
       
      Be cautious as this site is obviously anti wind power. The points might be valid though.
  • mcdermottaar99 on 12 Mar 13
     
    wind turbine impacts 
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Energy Source: Tidal Power | Renewable Energy & Efficiency | Pembina Institute - 0 views

www.pembina.org/tidal tidal energy
shared by kramerjac99 on 11 Mar 13 - No Cached
  • idal power can be harnessed using a barrage (dam) built across an estuary that captures the potential energy generated by the change in height (or head) between high and low tides. As the tide goes in and out, the water flows through tunnels in the dam. The ebb and flow are used to either turn a water turbine or compress air through a pipe that then turns a turbine, which generates electricity. Tidal Fences and turbines Tidal fences and turbines can also be used to capture tidal power. Tidal fences are turbines that operate like giant turnstiles, while tidal turbines are similar to wind turbines. In both cases, electricity is generated when the turbines are turned by the tidal currents that occur in coastal waters. Ocean currents generate relatively more energy than wind (air currents) because ocean water has a higher density than air and therefore applies greater force on the turbines.
  • kramerjac99 on 11 Mar 13
     
    how we use it.
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Geothermal Electricity Production - Geothermal Energy - Renewable Energy World - 0 views

www.renewableenergyworld.com/...geoelectricity geothermal convert
shared by knightoli99 on 12 Mar 13 - No Cached
  • knightoli99 on 12 Mar 13
     
    " Geothermal Electricity Production Most power plants need steam to generate electricity. The steam rotates a turbine that activates a generator, which produces electricity. Many power plants still use fossil fuels to boil water for steam. Geothermal power plants, however, use steam produced from reservoirs of hot water found a couple of miles or more below the Earth's surface. There are three types of geothermal power plants: dry steam, flash steam, and binary cycle. Dry steam power plants draw from underground resources of steam. The steam is piped directly from underground wells to the power plant, where it is directed into a turbine/generator unit. There are only two known underground resources of steam in the United States: The Geysers in northern California and Yellowstone National Park in Wyoming, where there's a well-known geyser called Old Faithful. Since Yellowstone is protected from development, the only dry steam plants in the country are at The Geysers. This geothermal power plant generates electricity for the Imperial Valley in California. Credit: Warren Gretz Flash steam power plants are the most common. They use geothermal reservoirs of water with temperatures greater than 360°F (182°C). This very hot water flows up through wells in the ground under its own pressure. As it flows upward, the pressure decreases and some of the hot water boils into steam. The steam is then separated from the water and used to power a turbine/generator. Any leftover water and condensed steam are injected back into the reservoir, making this a sustainable resource. Binary cycle power plants operate on water at lower temperatures of about 225°-360°F (107°-182°C). These plants use the heat from the hot water to boil a working fluid, usually an organic compound with a low boiling point. The working fluid is vaporized in a heat exchanger and used to turn a turbine. The water is then injected back into the ground to be reheated. The water and the working fluid are
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Wind Energy Basics - 1 views

windeis.anl.gov/basics wind how what location cost pollution infrastructure
shared by dpurdy on 15 Apr 12 - No Cached
  • 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.
  • 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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  • Cost Issues Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation. If wind generating systems are compared with fossil-fueled systems on a "life-cycle" cost basis (counting fuel and operating expenses for the life of the generator), however, wind costs are much more competitive with other generating technologies because there is no fuel to purchase and minimal operating expenses.
    • dpurdy
      dpurdy on 03 Nov 12
       
      Good point for how we will need to change in future! To get more wind energy.
  • Wind energy is very abundant in many parts of the United States. Wind resources are characterized by wind-power density classes, ranging from class 1 (the lowest) to class 7 (the highest). Good wind resources (e.g., class 3 and above, which have an average annual wind speed of at least 13 miles per hour) are found in many locations
  • Wind speed is a critical feature of wind resources,
  • In other words, a stronger wind means a lot more power.
  • Horizontal turbine components include: blade or rotor, which converts the energy in the wind to rotational shaft energy; a drive train, usually including a gearbox and a generator; a tower that supports the rotor and drive train; and other equipment, including controls, electrical cables, ground support equipment, and interconnection equipment. Wind turbine diagram - click for enlarged image.
  • Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Wind flow patterns are modified by the earth's terrain, bodies of water, and vegetative cover.
  • How Wind Power Is Generated The terms "wind energy" or "wind power" describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power.
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EIA Energy Kids - Wind - 1 views

www.eia.gov/...energy.cfm Wind what history pollution
shared by dpurdy on 03 Nov 11 - No Cached
  • Wind is simply air in motion. It is caused by the uneven heating of the Earth's surface by the sun. Because the Earth's surface is made of very different types of land and water, it absorbs the sun's heat at different rates. One example of this uneven heating can be found in the daily wind cycle.
  • The Daily Wind Cycle During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air rushes in to take its place, creating wind. At night, the winds are reversed because the air cools more rapidly over land than over water. In the same way, the atmospheric winds that circle the earth are created because the land near the Earth's equator is heated more by the sun than the land near the North and South Poles. Wind Energy for Electricity Generation Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source because the wind will blow as long as the sun shines
  • Like old fashioned windmills, today’s wind machines (also called wind turbines) use blades to collect the wind’s kinetic energy. The wind flows over the blades creating lift, like the effect on airplane wings, which causes them to turn. The blades are connected to a drive shaft that turns an electric generator to produce electricity. With the new wind machines, there is still the problem of what to do when the wind isn't blowing. At those times, other types of power plants must be used to make electricity.
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  • Wind Production In 2010, wind turbines in the United States generated about 2% of total U.S. electricity generation. Although this is a small fraction of the Nation's total electricity production, it was equal to the annual electricity use of about 8.7 million households.
  • Operating a wind power plant is not as simple as just building a windmill in a windy place. Wind plant owners must carefully plan where to locate their machines. It is important to consider how fast and how much the wind blows at the site
  • As a rule, wind speed increases with altitude and over open areas that have no windbreaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.
  • Conditions are well suited along much of the coasts of the United States to use wind energy. However, there are people who oppose putting turbines just offshore, near the coastlines, because they think the wind turbines will spoil the view of the ocean. There is a plan to build an offshore wind plant off the coast of Cape Cod, Massachusetts.
  • Wind is a renewable energy source that does not pollute, so some people see it as a good alternative to fossil fuels.
  • Since early recorded history, people have been harnessing the energy of the wind. Wind energy propelled boats along the Nile River as early as 5000 B.C.
  • As late as the 1920s, Americans used small windmills to generate electricity in rural areas without electric service. When power lines began to transport electricity to rural areas in the 1930s, local windmills were used less and less,
  • In the early 1980s, wind energy really took off in California, partly because of State policies that encouraged renewable energy sources.
  • Wind is a clean source of energy, and overall, the use of wind for energy has fewer environmental impacts than using many other energy sources. Wind turbines (often called windmills) do not release emissions that pollute the air or water (with rare exceptions), and they do not require water for cooling. They may also reduce the amount of electricity generated from fossil fuels and therefore reduce the amount of air pollution, carbon dioxide emissions, and water use of fossil fuel power plants.
  • Modern wind turbines are very large machines, and some people do not like their visual impact on the landscape.
  • Some people do not like the sound that wind turbine blades make. Some types of wind turbines and wind projects cause bird and bat deaths. These deaths may contribute to declines in species that are also being affected by other human-related impacts.
  • Most wind power projects on land also require service roads that add to their physical impact on the environment.
  • anonymous on 02 Oct 13
     
    Most quality online stores. Know whether you are a trusted online retailer in the world. Whatever we can buy very good quality. and do not hesitate. Everything is very high quality. Including clothes, accessories, bags, cups. Highly recommended. This is one of the trusted online store in the world. View now www.retrostyler.com
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Environment for Kids: Wave and Tidal Energy - 0 views

www.ducksters.com/...wave_and_tidal_energy.php history
shared by gonzalezisa00 on 12 Mar 13 - No Cached
  • There are also three main ways that tidal energy is harnessed: Tidal Barrages - A tidal barrage works like a dam. When the tide goes high, the reservoir fills up. When the tide drops the dam lets the water out. In both directions the moving water can spin the blades of turbines to create electricity. Tidal Fences - These are smaller structures than a barrage. A number of vertical turbines form a fence between two land masses. When the tide moves in or out, the turbines spin and generate electricity. Tidal turbines - These are individual turbines placed anywhere there is a strong tidal flow.
  • Tidal power to turn water wheels and grind grains was used as far back as Roman times and the Middle Ages. The idea of using tidal power for electricity is fairly recent, but the costs have been too high to make it a major energy source. Recent technological advances have shown that it could become a competitive and viable source
  • Tidal turbines are more expensive to build and maintain than wind turbines, but produce more energy. They also produce energy more consistently as the tide is continuous while the wind doesn't always blow.
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  • Concepts for wave energy have existed since the 1800s, however modern wave technology began in the 1940s with the experiments of scientist Yoshio Masuda
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Tidal Energy | Marine Current Turbines - 0 views

www.marineturbines.com/Tidal-Energy tidal tide
shared by mannixjul00 on 11 Mar 13 - No Cached
  • idal turbines are very much like an underwater windmill where the blades are driven by consistent, fast-moving currents.  The submerged rotors harness the power of the tidal streams to drive generators, which in turn produce electricity. Water is 832 times denser than air so consequently tidal turbine rotors can be are much smaller than wind turbine rotors generate equivalent  amounts of electricity, and they can be deployed much closer together. Devices that harness tidal stream energy present a unique set of engineering challenges in terms of design, installation and maintenance. During operation, the force of the tidal flow in Strangford Lough is equivalent to a 345 mph wind generating a 100 tonnes of thrust on the rotors. The unique SeaGen design allows capture of the maximum amount of tidal energy whilst keeping maintenance and connectivity costs low.
  • Tidal turbines are very much like an underwater windmill where the blades are driven by consistent, fast-moving currents.  The submerged rotors harness the power of the tidal streams to drive generators, which in turn produce electricity. Water is 832 times denser than air so consequently tidal turbine rotors are much smaller than wind turbine rotors generate equivalent  amounts of electricity, and they can be deployed much closer together. Devices that harness tidal stream energy present a unique set of engineering challenges in terms of design, installation and maintenance. During operation, the force of the tidal flow in Strangford Lough is equivalent to a 345 mph wind generating a 100 tonnes of thrust on the rotors.
  • kramerjac99 on 11 Mar 13
     
    How it works.
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The Energy Story - Chapter 16: Wind Energy - 2 views

www.energyquest.ca.gov/...chapter16.html energy windenergy current history sustainable wind
shared by sankeyrya00 on 13 Mar 12 - Cached
    • shannonlan97
      shannonlan97 on 13 Mar 12
       
      inside of turbine picture
  • Farmers have been using wind energy for many years to pump water from wells using windmills like the one on the right
  • When a boat lifts a sail, it is using wind energy to push it through the water. This is one form of work.
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  • Wind is also used to turn large grinding stones to grind wheat or corn, just like a water wheel is turned by water power.
  • Wind can be used to do work. The kinetic energy of the wind can be changed into other forms of energy, either mechanical energy or electrical energy
  • n Holland, windmills have been used for centuries to pump water from low-lying areas.
  • Blowing wind spins the blades on a wind turbine – just like a large toy pinwheel.
  • If the wind gets too high, the turbine has a brake that will keep the blades from turning too fast and being damaged.
  • You can use a single smaller wind turbine to power a home or a school. A small turbine makes enough energy for a house.
  • freeberntay99 on 08 Mar 13
     
    "The blades of the turbine are attached to a hub that is mounted on a turning shaft. The shaft goes through a gear transmission box where the turning speed is increased. The transmission is attached to a high speed shaft which turns a generator that makes electricity."
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