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murphymat98

Tidal Energy | Renewable Energy Development - 0 views

  • The cost of setting up a tidal power station can be very high, although once in place the operating costs are low. As an example of the cost of setting up, a proposed 8000 MW tidal power plant and barrage system on the Severn Estuary in the UK has been estimated to cost US$15 billion, while another in the San Bernadino strait which would produce 2,200 MW as a tidal fence in the Philippines will cost an estimated US$3 billion.
lemairenat98

Tidal stream systems - 0 views

shared by lemairenat98 on 12 Mar 13 - No Cached
tavarreskat99

What are the advantages and disadvantages of alternative tidal power as an energy source - 1 views

  • Advantages: Tidal energy is an alternative energy. The energy produced is clean and non polluting. There is no carbon dioxide or any other by-products released. It produces no greenhouse gases or other waste.It is a renewable energy that will help reduce our reliance on the burning of fossil fuels. There are two tides every day and they can be relied on. The energy is there for the taking.So the electricity supply is constant and efficient.Once you've built it, the energy is free because it comes from the ocean's powerIt needs no fuel.It produces electricity reliably.Not expensive to maintain.Tides are definitely predictable. There are two tides every day and they can be relied on. So the electricity supply is constant. Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact.A plant is expected to be in production for 75 to 100 yearsUses an abundant, inexpensive fuel source (water) to generate powerMay protect coastline against damage from high storm tides and provide a ready-made road bridge
  • Holding back the tide allows silt to build up on the river bed.The dams and barrages sometimes interfere with shipping. You will need to find a way to connect the electricity to the grid.Pose same threats as large dams, altering the flow of saltwater in and out of estuaries, which changes the hydrology and salinity and possibly negatively affects the marine mammals that use the estuaries as their habitatTurbidity decreases as a result of smaller volume of water being exchanged between the basin and the sea.The average salinity inside the basin decreases, also affecting the ecosystemA barrage across an estuary is very expensive to build, and affects a very wide area - the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed.There are few suitable sites for tidal barrages.Only provides power for around 10 hours each day, when the tide is actually moving in or out.
  • It only provides about 7% of the power needed for England and Wales that means that some people get their energy close to free and some pay a lot of moneyWater is not replenished, it cannot flow away so any dirt or pollution lingers around the coast much longerNeeds a very big piece of sea to be cost effectiveCannot be used inlandBarrage systems require salt resistant parts and lots of maintenanceAffects the lives of the people who rely on fishing for a means of livingLimited because the tide never speeds up or slows down, and occurs on 6 hour cycles. It is also dependent on the fetch distance. The fetch is the distance the tide rises and falls, so some beaches have a very small fetch, and others have a big fetch but hardly any have a large enough fetch to support tidal energy
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."
dylan purner

Solar Photovoltaics | Solar Energy - 0 views

  • What are photovoltaics? The word comes from “photo” (light) and “voltaic” (energy produced by a chemical reaction). Photovoltaic technology refers to the conversion of light into energy at the atomic level. Certain materials, such as silicon, cadmium, and selenium, have the ability to absorb light photons and release electrons. Solar photovoltaic technology harnesses these freed electrons and uses their electric current as DC electricity (NASA 2002). Fully powered by the sun, solar photovoltaics are a free, clean, and renewable source of energy that can be used independently of or in conjunction with conventional grid energy. Unlike solar thermal systems, solar energy panels require little maintenance, necessitate no moving parts, and last for 30-40 years.
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    " Photovoltaics: The Science Behind Solar Energy           What are photovoltaics? The word comes from "photo" (light) and "voltaic" (energy produced by a chemical reaction). Photovoltaic technology refers to the conversion of light into energy at the atomic level. Certain materials, such as silicon, cadmium, and selenium, have the ability to absorb light photons and release electrons. Solar photovoltaic technology harnesses these freed electrons and uses their electric current as DC electricity (NASA 2002). Fully powered by the sun, solar photovoltaics are a free, clean, and renewable source of energy that can be used independently of or in conjunction with conventional grid energy."
manzellaann99

Discover Solar Energy ADVANTAGES DISADVANTAGES | PROS and CONS of Solar Energy - 4 views

  • Solar Energy systems are virtually maintenance free and will last for decades.
wellsann99

Wind Turbines - How Long Have They Been Around? - 1 views

  • Essentially wind turbines were made first between 500-900 A.D. by the Persians and were used as a water pumping system
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    when it was first made 
mchughkon99

World's fist commercial scale tidal energy generator nears completion - 0 views

  • April 4, 2008 Bristol based renewable energy company Marine Current Turbines has completed the first installation phase of the 1.2MW SeaGen Tidal System at Northern Ireland’s Strangford Lough - a site chosen for its combination of fast tidal current and ability to provide shelter from bad weather which may hinder the construction process.
mcgarrdan98

Geothermal energy - Wikipedia, the free encyclopedia - 0 views

  • Drilling and exploration for deep resources is very expensive. Forecasts for the future of geothermal power depend on assumptions about technology, energy prices, subsidies, and interest rates. Pilot programs like EWEB's customer opt in Green Power Program [6] show that customers would be willing to pay a little more for a renewable energy source like geothermal. But as a result of government assisted research and industry experience, the cost of generating geothermal power has decreased by 25% over the past two decades.[7] In 2001, geothermal energy cost between two and ten cents per kwh.[8]
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    "Hot springs have been used for bathing at least since paleolithic times[9] The oldest known spa is a stone pool on China's Lisan mountain built in the Qin dynasty in the 3rd century BC, at the same site where the Huaqing Chi palace was later built. In the first century AD, Romans conquered Aquae Sulis, now Bath, Somerset, England, and used the hot springs there to feed public baths and underfloor heating. The admission fees for these baths probably represent the first commercial use of geothermal power. The world's oldest geothermal district heating system in Chaudes-Aigues, France, has been operating since the 14th century.[10] The earliest industrial exploitation began in 1827 with the use of geyser steam to extract boric acid from volcanic mud in Larderello, Italy."
dpurdy

Wave Hub wave energy hydropower infrastructure project on track for summer 2011 deploym... - 0 views

  • Hartlepool-based JDR Cable Systems is constructing the armored 25- kilometer subsea cable that will connect Wave Hub to the grid and the hub structure that will sit on the seabed. Work also is progressing on the hub assembly, which will provide a connection between the main cable from the shore and the tails leading to the wave energy devices.
logansar99

Wave Energy - 2 views

  • northwestern coasts of the United States.
  • Positive or negative impacts on marine habitat (depending on the nature of additional submerged surfaces, above-water platforms, and changes in the seafloor);
  • Toxic releases from leaks or accidental spills of liquids used in those systems with working hydraulic fluids;
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  • Conflict with other sea space users, such as commercial shipping and recreational boating;
  • Visual and noise impacts (device-specific, with considerable variability in visible freeboard height and noise generation above and below the water surface)
  • Wave power varies considerably in different parts of the world, and wave energy can't be harnessed effectively everywhere
demboskiemm00

Solar power in the United States - Wikipedia, the free encyclopedia - 0 views

  • Solar potential from very large scale solar power plants State Land used (sq mi) Potential (GWp) Annual generation (TWh) Arizona 19,279 2,468 5,837 California 6,853 877 2,075 Colorado 2,124 272 643 Nevada 5,589 715 1,692 New Mexico 15,156 1,940 4,588 Texas 1,162 149 351 Utah 3,564 456 1,079
  • 6,877
  • Total generation in the United States is about 3,800 TWh.[11]
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  • ) systems. This was double the 435 MW installed in 2009 around the U.S.[16] According to a 2011 survey conducted by independent polling firm Kelton Research, nine out of 10 Americans support the use and development of solar technology. Eight out of 10 respondents indicated that "the federal government should support solar manufacturing in the U.S. and should give federal subsidies for solar energy".[17] According to the Energy Information Administration, in 2010, subsidies to the solar power industry amounted to 8.2% ($968 million) of all federal subsidies for electricity generation.[18] Solar Energy Industries Association and GTM Research found that the amount of new solar electric capacity increased in 2012 by 76 percent from 2011, raising the United States’ market share of the world’s installations above 10 percent, up from roughly 5 to 7 percent in the last seven years. [19]
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    "Total: 42,554 MW - 76,577 MW, depending on the technology used"
geczyluk99

Benefits and Challenges - 0 views

  • Fuel cell systems are not yet as durable as internal combustion engines, especially in some temperature and humidity ranges.
  • FCVs are currently more expensive than conventional vehicles and hybrids. Manufacturers must bring down production costs, especially the costs of the fuel cell stack and hydrogen storage, to compete with conventional technologies.
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    "FCVs are currently more expensive than conventional vehicles and hybrids. Manufacturers must bring down production costs, especially the costs of the fuel cell stack and hydrogen storage, to compete with conventional technologies."
rutaemi98

How Fuel Cells Work | ClearEdge Power - 1 views

  • About the size of a refrigerator, the ClearEdge Plus fuel system hooks up to your natural gas supply and through its fuel processor, draws the hydrogen molecules out. Then, through an electrochemical process that combines the hydrogen molecules with oxygen, the unit generates up to 5kW of electricity for use throughout your entire home and allows you the control to select specific critical circuits you want to remain "up" even when the grid is "down."
handste99

Revolution Green: A True Story of Biodiesel in America - 0 views

  • There are over 180,000 fueling stations nationwide. About 40% of those service petroleum diesel fuel, and less than 1% service biodiesel.
  • Biodiesel is simple to use and requires no costly engine conversions or infrastructure changes to the current delivery system of diesel fuel.
hughesacam99

Wave Energy: Pros and Cons - 0 views

  • wave power is one of the most researched areas of renewable energy.
  • Wave power results from the transport of energy by ocean surface waves and its capture into systems that can be therefore used for useful applications
  • Some of these applications include electricity generation, the pumping of water, or water desalination.
labrumbra99

A Basic Overview of Fuel Cell Technology - 0 views

  • they generate electricity with very little pollution—much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water.
  • Scientists and inventors have designed many different types and sizes of fuel cells in the search for greater efficiency, and the technical details of each kind vary
  • in general terms, hydrogen atoms enter a fuel cell at the anode where a chemical reaction strips them of their electrons. The hydrogen atoms are now “ionized,” and carry a positive electrical charge. The negatively charged electrons provide the current through wires to do work. If alternating current (AC) is needed, the DC output of the fuel cell must be routed through a conversion device called an inverter.
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  • But in general terms, hydrogen atoms enter a fuel cell at the anode where a chemical reaction strips them of their electrons. The hydrogen atoms are now �ionized,� and carry a positive electrical charge. The negatively charged electrons provide the current through wires to do work. If alternating current (AC) is needed, the DC output of the fuel cell must be routed through a conversion device called an inverter.
  • Every fuel cell also has an electrolyte, which carries electrically charged particles from one electrode to the other, and a catalyst, which speeds the reactions at the electrodes. Hydrogen is the basic fuel, but fuel cells also require oxygen. One great appeal of fuel cells is that they generate electricity with very little pollution–much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water.
  • A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode. The reactions that produce electricity take place at the electrodes.
  • fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode.
  • One detail of terminology:
  • Oxygen enters the fuel cell at the cathode and, in some cell types (like the one illustrated above), it there combines with electrons returning from the electrical circuit and hydrogen ions that have traveled through the electrolyte from the anode. In other cell types the oxygen picks up electrons and then travels through the electrolyte to the anode, where it combines with hydrogen ions. The electrolyte plays a key role. It must permit only the appropriate ions to pass between the anode and cathode. If free electrons or other substances could travel through the electrolyte, they would disrupt the chemical reaction. Whether they combine at anode or cathode, together hydrogen and oxygen form water, which drains from the cell. As long as a fuel cell is supplied with hydrogen and oxygen, it will generate electricity. Even better, since fuel cells create electricity chemically, rather than by combustion, they are not subject to the thermodynamic laws that limit a conventional power plant (see "Carnot Limit" in the glossary). Therefore, fuel cells are more efficient in extracting energy from a fuel. Waste heat from some cells can also be harnessed, boosting system efficiency still further
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    "A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode. The reactions that produce electricity take place at the electrodes."
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    "A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode."
dpurdy

Fuel Cells 2000 : Fuel Cell Basics : Applications - 0 views

  • There are many uses for fuel cells — right now, all of the major automakers are working to commercialize a fuel cell car. Fuel cells are powering buses, boats, trains, planes, scooters, forklifts, even bicycles. There are fuel cell-powered vending machines, vacuum cleaners and highway road signs. Miniature fuel cells for cellular phones, laptop computers and portable electronics are on their way to market. Hospitals, credit card centers, police stations, and banks are all using fuel cells to provide power to their facilities. Wastewater treatment plants and landfills are using fuel cells to convert the methane gas they produce into electricity. Telecommunications companies are installing fuel cells at cell phone, radio and 911 towers. The possibilities are endless.
  • Stationary
  • More than 2500 fuel cell systems have been installed all over the world
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  • Telecommunications
  • Landfills/Wastewater Treatment Plants/Breweries/Wineries-
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    Current Applications for fuel Cells
gillinghammic98

TLC Home "How many solar cells would I need in order to provide all of the electricity ... - 0 views

  • Because solar electricity is so expensive, you would normally go to great lengths to reduce your electricity consumption. Instead of a desktop computer and a monitor you would use a laptop computer. You would use fluorescent lights instead of incandescent. You would use a small B&W TV instead of a large color set. You would get a small, extremely efficient refrigerator­. By doing these things you might be able to reduce your average power consumption to 100 watts. This would cut the size of your solar panel and its cost by a factor of 6, and this might bring it into the realm of possibility.
  • From our calculations and assumptions abo­ve, we know that a solar panel can generate 70 milliwatts per square inch * 5 hours = 350 milliwatt hours per day. Therefore you need about 41,000 square inches of solar panel for the house. That's a solar panel that measures about 285 square feet (about 26 square meters). That would cost around $16,000 right now. Then, because the sun only shines part of the time, you would need to purchase a battery bank, an inverter, etc., and that often doubles the cost of the installation.If you want to have a small room air conditioner in your bedroom, double everything.
  • A "typical home" in America can use either electricity or gas to provide heat -- heat for the house, the hot water, the clothes dryer and the stove/oven. If you were to power a house with solar electricity, you would certainly use gas appliances because solar electricity is so expensive. This means that what you would be powering with solar electricity are things like the refrigerator, the lights, the compute­r, the TV, stereo equipment, motors in things like furnace fans and the washer, etc. Let's say that all of those things average out to 600 watts on average. Over the course of 24 hours, you need 600 watts * 24 hours = 14,400 watt-hours per day.
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  • The thing to remember, however, is that 100 watts per hour purchased from the power grid would only cost about 24 cents a day right now, or $91 a year. That's why you don't see many solar houses unless they are in very remote locations. When it only costs about $100 a year to purchase power from the grid, it is hard to justify spending thousands of dollars on a solar system.
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