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dpurdy

World_energy_consumption_by_type_2006.png (763×277) - 4 views

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    about 6.27% of energy is generated by hydrogen fuel cells
coreyemi99

How Do PV Solar Panels Work - Solar - 0 views

  • When a visible light photon strikes a solar cell it can do one of three things: pass straight through, be reflected, or be absorbed. If the photon is absorbed, its energy is absorbed by an electron in an atom of the solar cell enabling it to escape from its normal position (photon excitation), cross the junction and fill a hole. Since electrons are physically moving across the PN junction, the positive charge carrying holes are effectively moving in the opposite direction around the load circuit (a rechargeable battery or light bulb etc). This completes the circuit providing more holes for the electrons to combine with and providing usable electricity.
dpurdy

Hydrogen vehicle - Wikipedia, the free encyclopedia - 2 views

  • As of October 2009, Fortune magazine estimated the cost of producing the Honda Clarity at $300,000 per car
  • by 2010, the Department of Energy estimated that the cost had fallen 80% and that such fuel cells could be manufactured for $51/kW,
  • When compared to ICE vehicles using gasoline, however, fuel cell vehicles using hydrogen produced from natural gas reduce greenhouse gas emissions by 60%
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    • dpurdy
       
      so an internal combustion engine releases more co2 than a fuel cell that uses natural gas as its hydrogen source. 
  • Hydrogen fuel does not occur naturally on Earth and thus is not an energy source, but is an energy carrier. Currently it is most frequently made from methane or other fossil fuels. However, it can be produced from a wide range of sources (such as wind, solar, or nuclear) that are intermittent, too diffuse or too cumbersome to directly propel vehicles. Integrated wind-to-hydrogen plants, using electrolysis of water, are exploring technologies to deliver costs low enough, and quantities great enough, to compete with traditional energy sources.[1]
  • While methods of hydrogen production that do not use fossil fuel would be more sustainable
  • The challenges facing the use of hydrogen in vehicles include production, storage, transport and distribution.
  • The hydrogen infrastructure consists mainly of industrial hydrogen pipeline transport and hydrogen-equipped filling stations like those found on a hydrogen highway. Hydrogen stations which are not situated near a hydrogen pipeline can obtain supply via hydrogen tanks, compressed hydrogen tube trailers, liquid hydrogen tank trucks or dedicated onsite production.
  • Hydrogen fuel does not occur naturally on Earth and thus is not an energy source, but is an energy carrier. Currently it is most frequently made from methane or other fossil fuels. However, it can be produced from a wide range of sources (such as wind, solar, or nuclear) that are intermittent, too diffuse or too cumbersome to directly propel vehicles. Integrated wind-to-hydrogen plants, using electrolysis of water, are exploring technologies to deliver costs low enough, and quantities great enough, to compete with traditional energy sources.[2]
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    Fuel cell cars are expensive.  The fuel cell costs a lot
dpurdy

Energy Resources: Wave power - 1 views

  • Ocean waves are caused by the wind as it blows across the sea. Waves are a powerful source of energy.
  • How it works There are several methods of getting energy from waves. 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.   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.
  • Once you've built a wave power station, the energy is free, needs no fuel and produces no waste or pollution.
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  • Not expensive to operate and maintain.
  • 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.
  • Is it renewable? Wave power is renewable.
dpurdy

EIA Energy Kids - Biomass - 1 views

  • Biomass is organic material made from plants and animals (microorganisms). Biomass contains stored energy from the sun. Plants absorb the sun's energy in a process called photosynthesis. The chemical energy in plants gets passed on to animals and people that eat them. Biomass is a renewable energy source because we can always grow more trees and crops, and waste will always exist. Some examples of biomass fuels are wood, crops, manure, and some garbage. When burned, the chemical energy in biomass is released as heat. If you have a fireplace, the wood you burn in it is a biomass fuel. Wood waste or garbage can be burned to produce steam for making electricity, or to provide heat to industries and homes.
  • Crops like corn and sugar cane can be fermented to produce ethanol. Biodiesel, another transportation fuel, can be produced from left-over food products like vegetable oils and animal fats.
  • Ethanol and biodiesel were the fuels used in the first automobile and diesel engines, but lower cost gasoline and diesel fuel made from crude oil became the dominant vehicle fuels. The Federal government has promoted ethanol use in vehicles to help reduce oil imports since the mid-1970s.
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  • Compared to petroleum diesel, biodiesel combustion produces less sulfur oxides, particulate matter, carbon monoxide, and unburned and other hydrocarbons, but more nitrogen oxide.
  • Biofuels may be considered to be carbon-neutral because the plants that are used to make biofuels (such as corn and sugarcane for ethanol, and soy beans and palm oil trees for biodiesel) absorb CO2 as they grow and may offset the CO2 produced when biofuels are made and burned.
  • Growing plants for biofuels is controversial however, as the land, fertilizers, and energy used to grow biofuel crops could be used to grow food crops instead. Also, in some parts of the world, large areas of natural vegetation and forests have been cut down to grow sugar cane for ethanol and soybeans and palm-oil trees to make biodiesel.
  • Biomass — Renewable Energy from Plants and Animals Source: The National Energy Education Project (Public Domain) Source: The National Energy Education Project (Public Domain) Biomass is organic material made from plants
  • Biomass fuels provided about 4% of the energy used in the United States in 2010. Of this, about 46% was from wood and wood-derived biomass, 43% from biofuels (mainly ethanol),
dpurdy

Biofuel Guide - Introduction to Ethanol and Biodiesel - 0 views

  • First generation biofuel are those fuel derived from vegetable or animal fats/oils, starch or sugar with the use of modern technology.
    • dpurdy
       
      Gallons per acre In the perspective of land use and agricultural efficiency, ethanol seems to be a good choice. The reason is that about 420 gallons of ethanol can be generated per acre in contrast to 60 gallons of biodiesel per acre soybeans. Consequently, the cost of soybean oil would significantly increase if biodiesel production is increased as well.
  • 1. Let the base organic material (corn, sugarcane, wheat, etc) pass through a grinding meal to pulverize the selected material. 2. Then, liquefy it by placing the blend of water, grain powder and an enzyme that facilitates the breakdown of the grain compound into a high-heat cooker. 3. Cool it afterwards. Add another enzyme that will facilitate the conversion of starch into sugars which are then fermented, producing alcohol from the cooled mash. 4. Start the fermentation by adding yeast to the sugar mixture. The sugars will be broken down to ethanol (a form of alcohol) and carbon dioxide. 5. Distill the fermented mixture in order for the ethanol to separate from the solids. 6. Get rid of the water from the separated ethanol through a dehydration process.
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    "Cellulose ethanol production is newly discovered experimental processes which can breakdown cellulose in woody fibers. This would only mean that through this method, ethanol from crop wastes, trees and grasses can be derived. It is significantly better since trees and grasses require small amount of energy in comparison to grains that must be replanted annually. "
dpurdy

Biodiesel Performance, Costs, and Use - 0 views

  • Unless soybean oil prices decline dramatically, it does not appear that biodiesel can be produced in large quantities at a cost that is competitive with petroleum diesel
dpurdy

The Biofuels FAQs: The Facts About Biofuels: Biodiesel - 0 views

  • Biodiesel from soybeans costs an estimated $2 to $2.50 per gallon to produce. Biodiesel from yellow grease is about $1 a gallon cheaper, but the available supply in the U.S. is much smaller – enough to make 100 million gallons per year. Producers of biodiesel from pure vegetable oil are eligible for a federal excise tax credit of $1 for every gallon blended with conventional diesel. Biodiesel from used cooking oil earns a credit of 50 cents per gallon.
  • Another promising technology captures smokestack emissions of carbon dioxide for use in an “algae farm,” where the gas stimulates the rapid growth of algae that can be converted into biodiesel and ethanol.
dpurdy

HowStuffWorks "Mechanics of Hand-powered Generators" - 1 views

  • A generator is basically an electric motor working in reverse.
  • By spinning a coil of wire around a magnet, he found that he could create a steady current. Thus, he could convert energy used to spin the coil into electrical energy.
  • This principle powers generators that run on gasoline or diesel fuel, as well as the massive turbines in modern power plants, where the coils are turned by falling water or steam generated by burning coal or igniting nuclear reactions.
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    How a generator works
dpurdy

Wind - Energy Explained, Your Guide To Understanding Energy - Energy Information Admini... - 1 views

  • 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.
  • Wind is a renewable energy source because the wind will blow as long as the sun shines.
dpurdy

How do fossil fuels cause pollution - 1 views

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    "Fossil fuels, even when burned perfectly (natural gas, or methane, burns the best) release carbon dioxide which is a greenhouse gas causing dangerous global warming. Most fossil fuels also release smoke (leading to smog), and they may also release sulfur oxides and nitrogen oxides which contribute to acid rain."
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    "Fossil fuels, even when burned perfectly (natural gas, or methane, burns the best) release carbon dioxide which is a greenhouse gas causing dangerous global warming. Most fossil fuels also release smoke (leading to smog), and they may also release sulfur oxides and nitrogen oxides which contribute to acid rain."
mcgarrdan98

Geothermal energy environmental impact | Earth's Heat - 0 views

  • First of all, harnessing geothermal energy does not have the devastating impact on climate change like burning of the fossil fuels does. It is true that fluids drawn from the earth's core include greenhouse gases such as carbon dioxide and methane, but the amount of released greenhouse gas emissions is negligible compared to those from fossil fuel fired power plants.
  • One of the reasons for this is the fact that geothermal power plants are equipped with emission-control systems that reduce the exhaust.
  • geothermal power plants are connected with minimal freshwater and land requirements. This means that geothermal energy commonly has minimal impact on nearby ecosystems.
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  • Geothermal fluids contain elevated levels of certain toxic elements such as arsenic, mercury, lithium and boron, which means that geothermal plants need to be equipped with proper waste disposal units in order to ensure that the waste is disposed back into geothermal fields
    • dpurdy
       
      pollution from geothermal
  • constructing geothermal plant (which includes deep drilling) can affect land stability, and in some cases even trigger earthquakes (especially enhanced geothermal systems).
  • Geothermal power plants operate quietly meaning that they do not cause noise pollution.
  • It is often relatively easy to incorporate them into the existing environment without the obvious visual pollution because of their modest land requirements.
  • This natural source of energy provides efficient way to harness energy from with minimal impact on its surrounding environment.
dpurdy

What makes geothermal energy clean? - Curiosity - 0 views

  • The water that creates the energy ultimately returns to the Earth, where it can be used again.
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