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wooddan99

Geothermal Energy - 3 views

www.renewableenergyworld.com/...geothermal-energy

geothermal sustainable

shared by wooddan99 on 08 Mar 13 - Cached
  • Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.
  • Hot water near the surface of Earth can be used directly for heat.
  • Wells can be drilled into underground reservoirs for the generation of electricity. Some geothermal power plants use the steam from a reservoir to power a turbine/generator, while others use the hot water to boil a working fluid that vaporizes and then turns a turbine.
  • ...3 more annotations...
  • Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.
  • Hot dry rock resources occur at depths of 3 to 5 miles everywhere beneath the Earth's surface and at lesser depths in certain areas.
  • of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely hig
  • brownale99 on 08 Mar 13
     
    "Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma."
  • ...3 more comments...
  • dittrichcai99 on 08 Mar 13
     
    "Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma."
  • faglejoh98 on 11 Mar 13
     
    "Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma."
  • vanierfel98 on 11 Mar 13
     
    Geothermal energy can be easily found close to the surface or far down in the core.
  • parkergar99 on 11 Mar 13
     
    "Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma."
  • glinbizzivic98 on 11 Mar 13
     
    "Geothermal energy is the heat from the Earth. It's clean and sustainable. Resources of geothermal energy range from the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma."
dpurdy

How do Photovoltaics Work? - NASA Science - 1 views

science.nasa.gov/...solarcells

solar history convert

shared by dpurdy on 08 Mar 13 - No Cached
  • 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.
  • bolendev99 on 08 Mar 13
     
    " 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"
  • dpurdy on 12 Mar 13
     
    "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."
cottonetar98

BP Alternative Energy - wind power - how it works - 0 views

www.bp.com/iframe.do

wind convert form

shared by cottonetar98 on 11 Mar 13 - No Cached
  • cottonetar98 on 11 Mar 13
     
    An interactive video about wind energy.
mannixjul00

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.
wellsann99

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

environment.about.com/...wind_power.htm

wind form

shared by wellsann99 on 11 Mar 13 - Cached
  • wind power as a better way to generate electricity than plants fueled by coal, hydro (water) or nuclear power.
  • willisjos98 on 11 Mar 13
     
    "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."
  • wellsann99 on 11 Mar 13
     
    what is wind power
bishophan00

Wind Power Information, Wind Power Facts - National Geographic - 1 views

environment.nationalgeographic.com/...wind-power-profile

wind form

shared by bishophan00 on 11 Mar 13 - No Cached
  • 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.
  • ...5 more annotations...
  • 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.
  • barnardnat99 on 11 Mar 13
     
    where wind energy come from
  • conwayjam99 on 13 Mar 13
     
    ". 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. "
sconzomic99

What is tidal energy - How tidal works? - Tidal energy - 0 views

www.solarpowernotes.com/...tidal-energy.html

tide energy cost sustainable

shared by sconzomic99 on 11 Mar 13 - Cached
  • tidal energy uses tidal strength of water and back and forth movement  in seas, rivers or oceans. Tidal power exploits kinetic energy of water that power water turbines with its movement between the wings which rotate the turbine to produce electricity.
  • For producing significant amount of energy out of tidal water turbines, range of tides should be high and substantial amount of water should be there for pushing water through the turbine.
  • It is significantly important to spot the appropriate place which provide suitable and sustainable conditions to produce tidal energy, there are plenty of places around the globe which provide good conditions for installing water turbines and then produce electricity use tidal power of oceans in the location.
  • ...5 more annotations...
  • Once tidal power plant is built its’ electricity is free. It does not emit greenhouse gasses, carbon emission gasses which pollute environment. It does not have any dependency of any fossil fuel including furnace oil, gasses, etc; it needs no oil what so ever to produce electricity. Tidal power technology is renewable energy, which uses tidal and waves of same water for producing electricity over and over again. Tidal power technology like all renewable energy is clean energy and does not leave much impact on environment. Tidal power plants does not require much maintenance, therefore it is maintenance cost free. Tidal energy stations have about 80 % efficiency ratio, where as fossil fuel have approximately 30 % for efficiency levels. Tides in oceans are very predictable, its easy to judge when strong tides are going to show up from water consider weather and other conditions. The better tides and wave strengths of the oceans is, improved the efficiency of the station is. Electricity does not fluctuate on large scale using tidal energy as it happens in solar power technology.
  • Electricity can only be produced when tides are high in the sea, once ocean is calm and does not flow certain level of waves, it cannot produce electricity. Therefore electricity can be produced for only 10 hrs a day in presence of tides.
  • Tidal power plants are not cost effective. Millions of dollars are utilized for developing tidal power which could provide electricity in Megawatts.
  • Once tidal power plant is built its’ electricity is free. It does not emit greenhouse gasses, carbon emission gasses which pollute environment. It does not have any dependency of any fossil fuel including furnace oil, gasses, etc; it needs no oil what so ever to produce electricity. Tidal power technology is renewable energy, which uses tidal and waves of same water for producing electricity over and over again. Tidal power technology like all renewable energy is clean energy and does not leave much impact on environment. Tidal power plants does not require much maintenance, therefore it is maintenance cost free. Tidal energy stations have about 80 % efficiency ratio, where as fossil fuel have approximately 30 % for efficiency levels. Tides in oceans are very predictable, its easy to judge when strong tides are going to show up from water consider weather and other conditions. The better tides and wave strengths of the oceans is, improved the efficiency of the station is. Electricity does not fluctuate on large scale using tidal energy as it happens in solar power technology.
  • not appropriate to risk £15 millions worth of money. This is the main reason why this project is yet start
dpurdy

How does an electrical generator work? - 0 views

www.sommersgen.com/...about-generators.php

convert

shared by dpurdy on 25 Mar 13 - No Cached
  • Electric generators are essentially coils of electric conductors, usually copper wire, that are tightly wound onto a metal core and are mounted to spin around inside an array of large magnets
  • the copper conductor can spin at very high speeds through the magnetic field, producing a powerful flow of electricity. The same principle applies whether the generator is driven by a bicycle wheel, a tractor engine or a steam turbine.
dpurdy

Tidal Power - Costs - Pros & Cons - How it Works - Green Energy - 0 views

clean-future.com/...tidal-power

tide form convert

shared by dpurdy on 06 Apr 13 - No Cached
  • 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.
dpurdy

How much CO2 does one solar panel create? | MNN - Mother Nature Network - 2 views

www.mnn.com/...o2-does-one-solar-panel-create

solar co2 fossil fuels

shared by dpurdy on 06 Apr 13 - Cached
  • solar panels are at least 20x better on the climate than coal, kWh for kWh.
  • Based on that study, solar PV works out to about 50g of CO2 per kWh compared to coal's 975g of CO2 per kWh, or about 20x "cleaner."
  • dpurdy on 06 Apr 13
     
    Comparison of CO2 from photovoltaics and coal. 
dpurdy

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."
dpurdy

Tidal stream generators - Brightside - 0 views

www.brightknowledge.org/...tidal-stream-generators

tidal how

shared by dpurdy on 03 Nov 12 - No Cached
  • Tidal stream generators look and work like underwater wind turbines. As opposed to using the rising and falling movement of the tides, tidal stream generators take advantage of the fast moving sea currents (tidal streams), which flow when tides are moving in and out. These tidal streams cause the turbines to rotate, turning the generators which generate electricity. Tidal stream generators have the advantage of being much cheaper to build, and do not have as much of an environmental impact as a tidal barrage. The turbines turn relatively slowly, hence do not affect sea life. This is different to tidal barrages which can disrupt fish migrating up rivers from the sea.
dpurdy

Wave Energy: an Overview (Oxfordshire Climate Exchange) - 1 views

climatex.org/...wave-energy-overview

wave potential future how form history

shared by dpurdy on 30 Oct 12 - No Cached
  • Waves are generated by winds blowing over the ocean surface.  Wave energy is effectively a stored and concentrated form of solar energy since the winds that produce them are caused by pressure differences in the atmosphere caused by the sun's differential heating of the earth's surface. Waves can efficiently transport energy for thousands of miles and retain their energy long after the winds that first created them have died down, which makes waves one of the most concentrated and consistent sources of renewable energy. 
  • Globally, the potential use of wave power is, unsurprisingly, limited to areas of the world where there are waves. On a global scale, this is dictated by global wind patterns, with the result that waves are more prevalent in the mid-latitudes (40-60(N/S), than nearer the equator where the lack of ocean wind is referred to as the 'doldrums'.  Interestingly, this potential for wave power contrasts with that of solar power, which is more effective in lower latitudes
    • dpurdy
      dpurdy on 30 Oct 12
       
      Location of wave power.
  • ...5 more annotations...
  • it is widely anticipated that other types of renewable resources, including wave energy, will need to be developed in order to meet more challenging targets beyond 2020. 
  • As with most renewable energy sources, wave devices have no emissions during generation but the energy associated with the construction of the device does have small associated emissions.
    • dpurdy
      dpurdy on 30 Oct 12
       
      What do we need to do in the future to make this work.
  • it is essential that the current demonstration schemes are successful, to reassure future investors. The most important objective is to deploy full-size demonstration schemes in order to gain greater confidence in the most developed technologies (as in the EU's Atlas project). 
  • it will be necessary to significantly improve the network connections to the electricity suppliers.
dpurdy

Wave Hub wave energy hydropower infrastructure project on track for summer 2011 deployment - HydroWorld - 0 views

www.hydroworld.com/...wave-hub-wave-energy.html

infrastructure wave

shared by dpurdy on 31 Oct 12 - No Cached
  • 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

ocsenergy.anl.gov/...index.cfm

wave location

shared by logansar99 on 22 Oct 12 - Cached
  • 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;
  • ...3 more annotations...
  • 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
handste99

Biofuels | BP - 0 views

www.bp.com/sectiongenericarticle800.do

future change

shared by handste99 on 22 Oct 12 - No Cached
  • Biofuels
  • We are working to produce biofuels that are low cost, low carbon, sustainable and able to fulfil the world’s transportation fuel needs on a large scale without compromising food production
pettitmat99

Biofuels - 0 views

www.voxsolaris.com/biofuels.html

cost

shared by pettitmat99 on 22 Oct 12 - No Cached
  • Biofuels are basically any fuel that can be burned in air to produce heat that is produced by biological means, normally by plant growth. Currently the most prominant biofuels are ethanol and bio-deisel because these can be burned in existing internal combustion engines and are thus a direct replacement for oil. The most important biofuel historically is wood with oth
  • Biofuels are currently cheaper than oil although this is only because we are seeing very high oil prices at the moment. Under what might be termed more 'normal' market conditions, biofuels lack any meaningful price advantage. Biofuel production is very labor intensive and very land intensive. Production of ethanol from sugar cane was pioneered by the Brazilians in the 1970's as a solution to an oil import bill they could ill afford. It worked for them as they have plenty of land they can convert to growing sugar cane and at the time, plenty of cheap labor with which to harvest it.
  • he simple truth is the world does not have enough land to produce anywhere near the quantity of biofuels we need to make any dent in our oil consumption. They are only in fashion now oil prices are high and it is cost effective to produce them. Sooner or later food prices will rise to such a point that biofuel production will cease to be economic.
  • ...2 more annotations...
  • In any case the current price of oil is unlikely to be sustained. Much of today's oil prices can be attributed to the geopolitical situation in the Middle East and the hording of oil both for security of supply and more recently as a hedge against the falling dollar.
  • e they cheaper than oil? That depends how you calculate the cost!
  • pettitmat99 on 22 Oct 12
     
    "But herein lies the first problem with biofuels. They may be carbon nuetral but they are certainly not as green as they might be. Not if the land to grow sugar is coming from cutting down the Amazon jungle and not if vast quantities o"
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