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streetscor99

Fuel cells, what is a fuel cell, disadvantages, benefits - 0 views

www.altenergy.org/...fuel_cells.html

fossil fuels fuel cell disadvantages

shared by streetscor99 on 11 Mar 13 - Cached
  • * Because there is no combustion in a fuel cell, fuel is converted to electricity more efficiently than any other electrical generating technology available today. * There are no moving parts in a fuel cell stack, making them more reliable and quieter than generators. Even the ancillary systems (fans, pumps, controls, etcetera) in a complete fuel cell unit are relatively mature and simple technologies that should prove extremely reliable.
  • In the past, fuel cells were large and extremely expensive to manufacture, just as the first calculators and computers were. But, just like these products, the cost of fuel cells will quickly come down to consumer-affordable levels with mass production. We are currently in a transition period now, where many fuel cell companies are investing literally hundreds of millions of dollars to gear up for mass manufacturing at the same time they are trying to begin to develop a variety of markets for their product.
knightoli99

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
hardingmar00

Geothermal energy in the United States - Wikipedia, the free encyclopedia - 0 views

en.wikipedia.org/...al_energy_in_the_United_States

current geothermal

shared by hardingmar00 on 12 Mar 13 - No Cached
  • knightoli99 on 12 Mar 13
     
    "eothermal energy in the United States continues to be an area of considerable activity. In 2012, the United States led the world in geothermal electricity production with 3,386 megawatts (MW) of installed capacity;[1][2] the largest group of geothermal power plants in the world is located at The Geysers, a geothermal field in California.[3] The United States generates an average of 15 billion kilowatt hours of geothermal power per year, comparable to burning some 25 million barrels (4,000,000 m3) of oil or 6 million short tons of coal per year.[4] Geothermal power plants are largely concentrated in the western states. They are the fourth largest source of renewable electricity, after hydroelectricity, biomass, and wind power. A geothermal resource assessment shows that nine western states together have the potential to provide over 20 percent of national electricity needs.[4][5]"
gazdiknic99

Energy Resources: Geothermal power - 2 views

www.darvill.clara.net/...geothermal.htm

geothermal sustainable pollution

shared by gazdiknic99 on 12 Mar 13 - No Cached
  • Geothermal energy does not produce any pollution, and does not contribute to the greenhouse effect.
  • No fuel is needed.
dextereli99

SOLAR POWER BENEFITS - 0 views

www.vivasolar.com/solarpowerbenifits.html

solar sustainable cost pollution

shared by dextereli99 on 12 Mar 13 - No Cached
  • Advantages of solar power are many. Although solar power is an energy source that we have only recently tapped into, it may easily become the most important energy source of the future. • Solar power is a renewable and natural resource. • Solar power is non-polluting. Unlike oil, solar power does not emit greenhouse gases or carcinogens into the air. • Light and energy from the sun costs nothing. Once you purchase the equipment to collect and convert energy from the sun, it costs you nothing to run. • Solar cells require little maintenance. • Solar cells can last a lifetime. • Solar power is silent.
  • • Solar energy can be used to heat water, dry clothes, heat swimming pools, power attic fans, power small appliances, produce light for both indoors and outdoors, and even to power cars, among other things.
  • • Solar energy products can be very expensive. The initial cost is, perhaps, the main disadvantage of solar energy. • To reach maximum level of efficiency you need a relatively large area to install solar panels. • Depending where you live (Arizona vs. Alaska, around many shady trees or in the desert, etc.), you will get different results with solar energy systems.
  • ...3 more annotations...
  • • If you have a really good solar energy system, one that produces even more energy than you use, your utility company might buy that extra energy from you. • When you use solar energy, you and your home become independent on foreign or other sources of energy which raise costs quickly. • To run solar water pumps, you do not even need to connect to a gas or power grid. • Solar energy cannot be produced at night or if there is a lot of pollution in the air or clouds over the sun.
  • • Of course, realize you can have a battery backup system for your solar energy system that will take care of the problems that could arise when the sun does not. • You can install solar energy in remote locations. • If there is a power outage, but you run on solar, you will still have electricity! • As your energy needs grow, you can add more solar panels
  • • Technology for solar energy is constantly improving.
mchughkon99

Tidal Power - 0 views

www.surviveclimatechange.com/tidal-power.html

tide cost current

shared by mchughkon99 on 12 Mar 13 - No Cached
  • Although this source of energy shows some promise in terms of "clean", renewable energy there have been some roadblocks to widespread use of energy from the tides. This type of energy should not be put on the back burner even though there appears to be limited opportunities at this time
  • mchughkon99 on 12 Mar 13
     
    can be cost effective
fieldingbry99

Ocean Wave Energy - Pros and Cons - 1 views

www.energy-consumers-edge.com/ocean_wave_energy.html

current convert pollution

shared by fieldingbry99 on 12 Mar 13 - No Cached
  • But, on shore ocean wave energy generators will occupy extended lengths of coastline. And most of the coastlines of the world that have significant wave activity are either highly desired residential areas, or they are pristine wilderness.
  • Ocean wave energy is still in the development stages but it is already apparent that its impact on the environment could be relatively high compared to other renewable energies.
  • It is noteworthy that even these environmental impacts are far less than those of most fossil fuel plants.
  • ...1 more annotation...
  • electrical charges of less than $.05 per KWh; which makes it competitive with fossil fuel generators.
  • fieldingbry99 on 12 Mar 13
     
    " wave energy is very close to being competitive with installed costs that suggest electrical charges of less than $.05 per KWh; which makes it competitive with fossil fuel generators. But that figure doesn't take into account the fact that wave energy is intermittent and variable. Even in the most active wave areas, there are many days with little wave activity."
westkea00

Energy Basics: Wave Energy - 0 views

www.eere.energy.gov/...wave_energy.html

shared by westkea00 on 12 Mar 13 - No Cached
  • Offshore Systems Offshore systems are situated in deep water, typically of more than 131 feet (40 meters). Sophisticated mechanisms—such as the Salter Duck—use the bobbing motion of the waves to power a pump that creates electricity. Other offshore devices use hoses connected to floats that ride the waves. The rise and fall of the float stretches and relaxes the hose, which pressurizes the water, which, in turn, rotates a turbine. Specially built seagoing vessels can also capture the energy of offshore waves. These floating platforms create electricity by funneling waves through internal turbines and then back into the sea. Onshore Systems Built along shorelines, onshore wave power systems extract the energy of breaking waves. Onshore system technologies include: Oscillating Water Columns: Oscillating water columns consist of a partially submerged concrete or steel structure that has an opening to the sea below the waterline. It encloses a column of air above a column of water. As waves enter the air column, they cause the water column to rise and fall. This alternately compresses and depressurizes the air column. As the wave retreats, the air is drawn back through the turbine as a result of the reduced air pressure on the ocean side of the turbine. Tapchans: Tapchans, or tapered channel systems, consist of a tapered channel that feeds into a reservoir constructed on cliffs above sea level. The narrowing of the channel causes the waves to increase in height as they move toward the cliff face. The waves spill over the walls of the channel into the reservoir, and the stored water is then fed through a turbine. Pendulor Devices: Pendulor wave-power devices consist of a rectangular box that is open to the sea at one end. A flap is hinged over the opening, and the action of the waves causes the flap to swing back and forth. The motion powers a hydraulic pump and a generator.
  • Wave energy technologies extract energy directly from surface waves or from pressure fluctuations below the surface. Renewable energy analysts believe there is enough energy in ocean waves to provide up to 2 terawatts of electricity. (A terawatt is equal to a trillion watts.)
wellsann99

Wind Energy: Facts - 1 views

www.mass.gov/...wind-energy-facts.html

wind current

shared by wellsann99 on 12 Mar 13 - No Cached
  • Over 8,500 MW were installed in the US in 2008 (just beating out China with 6,300 MW). This represents: 50 percent increase from 200742 percent of all new generating capacity installed in 2008$17 billion investment44 million tons of carbon emissions avoided (equivalent of 7 million cars)35,000 new jobs
  • wellsann99 on 12 Mar 13
     
    wind power today
sconzomic99

Tidal energy extraction: renewabl... preview & related info | Mendeley - 0 views

www.mendeley.com/...ewable-sustainable-predictable

cost tide sustainable

shared by sconzomic99 on 12 Mar 13 - No Cached
  • The tidal flow of sea water induced by planetary motion is a potential source of energy if suitable systems can be designed and operated in a cost-effective manner
murphymat98

Tidal Energy | Renewable Energy Development - 0 views

renewableenergydev.com/tidal-energy

cost tide

shared by murphymat98 on 12 Mar 13 - No Cached
  • 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.
stockmanchl99

Information about Biofuel, what is Biofuel, renewable energy solutions, Ethanol uses - 0 views

www.biofuelwatch.org

biofuel

shared by stockmanchl99 on 12 Mar 13 - No Cached
  • Basically biofuel is produced by using ethanol from naturally grown plant matter which allows for a more sustainable and environmentally friendly earth.
  • Bio fuel is a natural alternative from other fossil fuels and is attained from living or biological material that has just died. Basically biofuel is produced by using ethanol from naturally grown plant matter which allows for a more sustainable and environmentally friendly earth. To assist in the manufacturing of biofuel, the plants and plant-derived materials that contribute to its formation includes corn, corn cob, sugar cane, soybeans, flaxseed, rapeseed, vegetable oils, waste cooking oils, animal fats, tall oil and even cow manure. However, at present the most widely used source of bioeenergy is of course wood.
lemairenat98

ScienceDirect.com - Renewable Energy - Initial evaluation of tidal stream energy resour... - 0 views

www.sciencedirect.com/...S0960148105002193

tide current

shared by lemairenat98 on 12 Mar 13 - No Cached
  • Portland Bill (Dorset, UK) is a promising site for tidal stream energy exploitation; it combines high tidal stream velocities around the headland with a location closer to population centres than other proposed sites.
  • lemairenat98 on 12 Mar 13
     
    "Portland Bill (Dorset, UK) is a promising site for tidal stream energy exploitation; it combines high tidal stream velocities around the headland with a location closer to population centres than other proposed sites."
dextereli99

Solar Power and Climate Change - 2 views

solar.calfinder.com/...solar-power-and-climate-change

solar co2

shared by dextereli99 on 12 Mar 13 - No Cached
  • Solar power and its partners in the renewable energy movement are our best bet toward curbing our part in climate change.
crandallmad00

How Tidal Power is Riding the Crest of a Wave - 1 views

www.renewableenergyworld.com/...-is-riding-the-crest-of-a-wave

tide wave

shared by crandallmad00 on 12 Mar 13 - No Cached
  • The argument for tidal power is overwhelming: it’s a practically infinite supply of clean energy and has one of the smallest carbon footprints of any power source; it’s reliable, cost-efficient, has minimal effect on the marine environment and virtually zero effect on sea-gazing aesthetics. Most importantly, The World Energy Council estimates that the energy that can be harvested from world’s oceans is equal to twice the electricity that the world produces now
  • A reason many energy experts are looking at what tidal may be able to contribute, compared to other renewable sources like wind power, is that the amount of energy generated from a power-generating turbine is proportional to the density of the fluid that flows back and forth – meaning a water turbine has several hundred times the power of an air turbine.
  • Seawater is denser than air; a lot denser – 832 times to be exact, meaning an 8 knot tidal current has more energy than a 380kph wind. This means a wave farm of ‘sea snakes’ – devices built by Scotland’s Pelamis Wave Power – covering half a square mile of ocean could produce 30 MWh of power, which is estimated to be enough for 20,000 homes. A wave farm covering 472 square miles could supply 24 million households – enough for the entire UK.
  • ...1 more annotation...
  • Partly this has been due to the uncertainty of how to harness all this abundant marine energy. While it’s great that there’s the potential to harness up to 153 GW of tidal power in the UK alone,
tavarreskat99

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

wiki.answers.com/...idal_power_as_an_energy_source

tidal energy

shared by tavarreskat99 on 12 Mar 13 - No Cached
  • 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
jack wells

Yale Environment 360: Wind Energy Now Cheaper Than Fossil Fuel Power Plants in Australia - 0 views

e360.yale.edu/...3762

wind cost

shared by jack wells on 12 Mar 13 - No Cached
  • Unsubsidized wind power is now cheaper than electricity produced from new coal- and natural gas-fired power stations in Australia, according to an analysis by Bloomberg New Energy Finance. The study said that electricity can be supplied from a new wind farm at a cost of 80 Australian dollars per megawatt hour, compared to 143 Australian dollars from a new coal plant and 116 Australian dollars from a new natural gas plant.
faglejoh98

Renewable Energy Sources in the United States - 0 views

www.nationalatlas.gov/...a_energy.html

geothermal current

shared by faglejoh98 on 12 Mar 13 - No Cached
  • Flash steam plants are the most common type of geothermal power plants in operation today. They use extremely hot water (above 300 degrees F (149 degrees C)), which is pumped under high pressure to the generation equipment at the surface. The hot Estimated subterranean temperatures at a depth of 6 kilometers.water is vaporized and the vapor in turn drives turbines to generate electricity
  • While geothermal energy use is efficient, reliable, and environmentally friendly, it currently meets less than 1% of U.S. power needs.
  • While geothermal energy use is efficient, reliable, and environmentally friendly, it currently meets less than 1% of U.S. power needs.
lefebvrekat99

Biodiesel as a Transportation Fuel - 0 views

www.consumerenergycenter.org/...biodiesel.html

biodiesel form

shared by lefebvrekat99 on 12 Mar 13 - No Cached
  • Biodiesel is an alternative fuel produced from renewable resources, such as soybeans or used restaurant grease. Biodiesel contains no petroleum, but it can be blended with petroleum diesel to create a biodiesel blend. It can be used in diesel engines with no major modifications. Biodiesel is simple to use, biodegradable, nontoxic, and essentially free of sulfur and aromatics.
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