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osikatho97

Biofuels, Biodiesel and Ethanol - The New York Times - 0 views

topics.nytimes.com/...index.html

new york times biofuels biodiesel

shared by osikatho97 on 13 Mar 12 - No Cached
  • In the early days of motorized transport, fuels derived from plants lost out to fuels refined from crude oil
  • first-generation biofuels -- chiefly, ethanol made from corn or sugar cane, or biodiesel made from vegetable oil
  • The source plants absorb carbon dioxide from the air as they are growing, and consequently, the carbon dioxide that is released when biofuels are burned does not represent a net addition of that greenhouse gas to the atmosphere.
  • ...1 more annotation...
  • second-generation biofuels made from plant wastes
smithree98

Fuel Cell Advantages and Disadvantages - 1 views

www.futurecars.com/...hydrogen_fuellcell_cars2.html

hydrogen fuel benefit advantages disadvantages cell

shared by smithree98 on 19 Mar 12 - No Cached
  • Conceptually, replacing the current oil-based infrastructure with hydrogen would cost billions, maybe trillions, of dollars. Although abundant in the universe, hydrogen is fairly rare in our atmosphere, meaning that it has to be extracted (for example through electrolysis, as explained above) and currently, the process is cost prohibitive and inefficient. Its production at energy plants creates excessive carbon dioxide. When it burns, a hydrogen flame is virtually invisible; coupled with the gas’s propensity for escaping, in small amounts, almost any tank, there are concerns about explosions. On the plus side, hydrogen is so light it typically is dispersed in the air very quickly. On-board storage is a major issue; a hydrogen tank would currently be too large for a car. It is a very flammable gas (think of the Hindenburg), which further adds to the on-board storage problems.
  • smithree98 on 24 Oct 12
     
    advantages and disadvantages of hydrogen fuel cells
dpurdy

The Hidden Cost of Fossil Fuels | Union of Concerned Scientists - 2 views

www.ucsusa.org/...the-hidden-cost-of-fossil.html

Fossil fuels pollution

shared by dpurdy on 19 Mar 12 - Cached
  • Fossil fuels—coal, oil, and natural gas—are America's primary source of energy, accounting for 85 percent of current US fuel use.
  • Many of the environmental problems our country faces today result from our fossil fuel dependence. These impacts include global warming, air quality deterioration, oil spills, and acid rain.
  • Over the last 150 years, burning fossil fuels has resulted in more than a 25 percent increase in the amount of carbon dioxide in our atmosphere.
  • ...8 more annotations...
  • limate scientists predict that if carbon dioxide levels continue to increase, the planet will become warmer in the next century.
  • Several important pollutants are produced by fossil fuel combustion: carbon monoxide, nitrogen oxides, sulfur oxides, and hydrocarbons. In addition, total suspended particulates contribute to air pollution, and nitrogen oxides and hydrocarbons can combine in the atmosphere to form tropospheric ozone, the major constituent of smog.
  • Finally, fossil fuel use also produces particulates, including dust, soot, smoke, and other suspended matter, which are respiratory irritants.
  • Oil spills, for example, leave waterways and their surrounding shores uninhabitable for some time.
  • Production, transportation, and use of oil can cause water pollution.
  • Sulfur oxides are produced by the oxidization of the available sulfur in a fuel. Utilities that use coal to generate electricity produce two-thirds of the nation's sulfur dioxide emissions. Nitrogen oxides and sulfur oxides are important constituents of acid rain
  • Hydrocarbons are emitted from human-made sources such as auto and truck exhaust, evaporation of gasoline and solvents, and petroleum refining.
  • Two oxides of nitrogen--nitrogen dioxide and nitric oxide--are formed in combustion. Nitrogen oxides appear as yellowish-brown clouds over many city skylines
  • dpurdy on 19 Mar 12
     
    The article we read in class. Use the summary we wrote or refer to this.
dpurdy

Hydrogen cars ready to roll - for a price - US news - Environment - Green Machines - ms... - 0 views

www.msnbc.msn.com/...hydrogen-cars-ready-roll-price

hydrogen cost

shared by dpurdy on 21 Mar 12 - No Cached
  • The cost varies too, from $1 to $20 a kilo. A gallon of gasoline has the same energy content as a kilo of hydrogen, but vehicles using the latter get two to three times higher mileage.
dpurdy

Fuel Cells 2000 : Hydrogen : Basics - 1 views

www.fuelcells.org/...basics.html

Hydrogen cost

shared by dpurdy on 03 Nov 11 - Cached
  • How much will Hydrogen fuel cost? The U.S. Department of Energy's Hydrogen, Fuel Cells & Infrastructure Technologies Program is working to achieve the following goals: By 2005, the technology will be available to produce hydrogen at the pump for $3.00 per gallon gasoline equivalent, and DOE wants to validate this technology by 2008.  By 2010, the price goal is $1.50 per gallon of gasoline equivalent (untaxed) at the station. Even $3 a gallon would save most of us money, since FCVs will be two to three times more efficient than internal combustion engine (ICE) vehicles.  If all the goals are met, FCVs offer the promise of energy at $1 a gallon - or less! 
gaworeckilog99

Cheap fuel cells real soon? - Democratic Underground - 0 views

www.democraticunderground.com/10023006104

fuel cell sustainable

shared by gaworeckilog99 on 20 Sep 13 - No Cached
  • Scientists have come up with a more efficient way to split ocean water and turn it into sustainable, clean hydrogen fuel. They created a flexible plastic film that acts as the catalyst to begin splitting ocean water, without requiring the high energy input that current methods need.
gonzalezisa00

Science of Summer: How Do Ocean Waves Form? | LiveScience - 0 views

www.livescience.com/1-how-do-ocean-waves-form.html

wave form

shared by gonzalezisa00 on 20 Sep 13 - No Cached
  • Presnell explained that wind speed and duration help in determining the size and frequency of ocean waves. Another factor is called "fetch," referring to the span of water over which a breeze blows, and the longer a fetch, the more energy a wave can build up.
bondycal00

Solar power - Wikipedia, the free encyclopedia - 0 views

en.wikipedia.org/Solar_power

solar pollution cost co2 sustainable convert history form current

shared by bondycal00 on 20 Sep 13 - Cached
  • The Life-cycle greenhouse-gas emissions of solar power are in the range of 22 to 46  g/kWh depending on if solar thermal or solar PV is being analyzed, respectively. With this potentially being decreased to 15 g/kWh in the future.[71] For comparison (of weighted averages), a combined cycle gas-fired power plant emits some 400-599 g/kWh,
  • bondycal00 on 26 Sep 13
     
    Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect.
sopranodan99

What Causes Ocean Waves? - EnchantedLearning.com - 0 views

www.enchantedlearning.com/...Waves.shtml

wave form

shared by sopranodan99 on 20 Sep 13 - Cached
  • The winds cause waves on the surface of the ocean (and on lakes). The wind transfers some of its energy to the water, through friction between the air molecules and the water molecules. Stronger winds (like storm surges) cause larger waves.
nassiveradom00

Geothermal Energy | A Student's Guide to Global Climate Change | US EPA - 0 views

www.epa.gov/...geothermal.html

shared by nassiveradom00 on 23 Sep 13 - No Cached
  • Geothermal power plants, which use heat from deep inside the Earth to generate steam to make electricity. Geothermal heat pumps, which tap into heat close to the Earth's surface to heat water or provide heat for buildings.
  • At a geothermal power plant, wells are drilled 1 or 2 miles deep into the Earth to pump steam or hot water to the surface.
  • hot springs, geysers, or volcanic activity, because these are places where the Earth is particularly hot just below the surface.
  • ...3 more annotations...
  • Hot water is pumped from deep underground through a well under high pressure. When the water reaches the surface, the pressure is dropped, which causes the water to turn into steam. The steam spins a turbine, which is connected to a generator that produces electricity. The steam cools off in a cooling tower and condenses back to water. The cooled water is pumped back into the Earth to begin the process again.
  • Geothermal heat pumps can do all sorts of things—from heating and cooling homes to warming swimming pools.
  • heat by pumping water or a refrigerant (a special type of fluid) through pipes just below the Earth's surface, where the temperature is a constant 50 to 60°F.
thibodeaueth00

Wave & Tidal Energy | Market | BioPower Systems - 0 views

www.biopowersystems.com/market.html

wave sustainable

shared by thibodeaueth00 on 23 Sep 13 - No Cached
  • The growth of the waves depends on the strength of the wind, its duration, and the open ocean distance (fetch) over which it blows
  • Ocean waves are created by surface winds.
rascoekat00

BBC News - UK tidal power has huge potential, say scientists - 0 views

www.bbc.co.uk/...science-environment-20983645

renewable tidal energy UK

shared by rascoekat00 on 23 Sep 13 - No Cached
  • Despite high costs, experts say tidal power is more reliable than wind.
  • The UK is underestimating the amount of electricity that could be generated from tidal sources, new research says.
  • rascoekat00 on 23 Sep 13
     
    Despite high costs, experts say tidal power is more reliable than wind.
levendosjoh99

History of Tidal Energy in Europe - 0 views

www.tidalenergy.eu/tidal_energy_history.html

tide history

shared by levendosjoh99 on 23 Sep 13 - No Cached
  • Europe has a long history of employing tidal forces to generate power, and tide mills dating back to the Middle Ages can be found across the continent. A dam with a sluice was constructed spanning a tidal inlet, or a section of a tidal estuary was turned into a reservoir.
demboskiemm00

Converting Sunlight into Electricity | Solar Power by KYOCERA | SOLAR POWER EXPO | KYOCERA - 0 views

global.kyocera.com/...mechanism.html

solar convert

shared by demboskiemm00 on 23 Sep 13 - No Cached
  • Light striking a silicon semiconductor causes electrons to flow, creating electricity. Solar power generating systems take advantage of this property to convert sunlight directly into electrical energy.
geczyluk99

HowStuffWorks "Hydrogen Fuel Economy" - 0 views

auto.howstuffworks.com/...hydrogen-vehicle-benefit3.htm

hydrogen fuel economy fuel cell sustainable pollution

shared by geczyluk99 on 23 Sep 13 - No Cached
  • If hydrogen extraction is performed using electricity from a coal-driven power plant, it doesn't matter that the fuel cell doesn't pollute because the pollution occurred when the hydrogen was extracted. If hydrogen is to be a true nonpolluting power source, the electricity used to extract the hydrogen will need to be produced by a nonpolluting method such as solar power.
geczyluk99

A Pollution-Free Hydrogen Economy? Not So Soon | MIT Technology Review - 0 views

www.technologyreview.com/...e-hydrogen-economy-not-so-soon

hydrogen economy co2 pollution

shared by geczyluk99 on 24 Sep 13 - No Cached
  • There’s a much cheaper way to produce hydrogen: spray steam on white-hot coals and out comes mostly hydrogen gas (40 percent) and carbon monoxide (50 percent), a mixture known appropriately as “water gas.” It’s the least expensive way to make hydrogen. Unfortunately, the carbon monoxide produced along with it is highly poisonous. To extract the last bit of energy, the carbon monoxide can be burned, and that turns it into the greenhouse gas carbon dioxide.
  • Electric cars powered by hydrogen fuel cells don’t produce greenhouse-enhancing carbon dioxide. But producing hydrogen does-and if we want to reduce our petroleum dependence, we’re going to have to reconcile ourselves to that fact.
sokolkyl00

Towards a Just and Sustainable Solar Industry - Silicon Valley Toxics Coalition - 0 views

svtc.org/solar

solar sustainable

shared by sokolkyl00 on 24 Sep 13 - No Cached
  • Although solar panels provide clean energy while in use, a variety of factors during the manufacturing and disposal of these panels have the potential to greatly damage the environment.
  • The most commonly used solar panels are silicon-based panels that share many of the same materials and manufacturing processes as semiconductors. Solar panels have the potential to create an e-waste burden if the proper infrastructure is not developed before the first wave of panels begins to come down.
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