Skip to main content

Home/ qmstech2/ Group items tagged _

Rss Feed Group items tagged

plattjak98

What is Hydrogen? - 0 views

  • Hydrogen is a highly flammable chemical element which occurs in great abundance throughout the universe. In fact, hydrogen makes up approximately 75% of the universe, by volume, and it appears in a very large number of compounds, especially those which make up various organic materials.
plattjak98

NOVA | How Fuel Cells Work - 0 views

  • Think of them as big batteries, but ones that only operate when fuel—in this case, pure hydrogen—is supplied to them.
rutaspe99

Hydrogen Power and Fuel Cells - Renewable Energy World - 3 views

  • Hydrogen Energy Hydrogen is the simplest element. An atom of hydrogen consists of only one proton and one electron. It's also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth - it's always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O).
  • Hydrogen Energy Hydrogen is the simplest element. An atom of hydrogen consists of only one proton and one electron. It's also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn't occur naturally as a gas on the Earth - it's always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H2O). Hy
  • Hydrogen is also found in many organic compounds, notably the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane.
  •  
    Hydrogen is also found in many organic compounds, notably the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane.
  •  
    A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. 
big_jerome

How do wind turbines transform the energy found in the wind - 1 views

  • A wind turbine is a rotating machine which converts the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by machinery, such as a pump or grinding stones, the machine is usually called a windmill.
  • wind t
bishophan00

Wind Energy America - FAQs - 1 views

  • Simply put, an average one megawatt wind turbine will produce enough energy for the annual needs of 350 average households. The amount of energy produced by a turbine varies depending on several factors, namely the size and reliability of the turbine, and the speed that the wind is blowing. These factors together produce the turbine’s capacity. Typically modern turbines range in size from 660 kilowatts to over 3 megawatts of capacity. They are placed in fairly windy locations with minimum wind speeds in the range of six meters per second (around 13 miles per hour). Wind turbines generally run at 30 to 40 percent capacity, so a 1 MW turbine could produce around 3 million KWh of electricity in a year.
  • , wind energy could provide 20% of America’s electricity.
  • According to the American Wind Energy Association, the total U.S. production of wind power is around 25 gigawatts
  •  
    "Simply put, an average one megawatt wind turbine will produce enough energy for the annual needs of 350 average households. The amount of energy produced by a turbine varies depending on several factors, namely the size and reliability of the turbine, and the speed that the wind is blowing. These factors together produce the turbine's capacity. Typically modern turbines range in size from 660 kilowatts to over 3 megawatts of capacity. They are placed in fairly windy locations with minimum wind speeds in the range of six meters per second (around 13 miles per hour). Wind turbines generally run at 30 to 40 percent capacity, so a 1 MW turbine could produce around 3 million KWh of electricity in a year."
  • ...2 more comments...
  •  
    today's wind power
  •  
    How much wind power is currently being produced in the United States? According to the American Wind Energy Association, the total U.S. production of wind power is around 25 gigawatts. New wind projects made up 42% of the U.S.'s total new power-producing capacity constructed in 2008, adding 8.4GW of new facilities into the grid.
  •  
    What is wind power? Wind power is the result of using the wind to generate electricity. In the past windmills were used to grind grain or pump water. Today, a large wind turbine can power all the electricity needs of at least 350 homes.
  •  
    , wind energy could provide 20% of America's electricity. Today's wind turbines are very different from the windmills of the past. Moder
dpurdy

The Future of Biofuels: A Global Perspective - Amber Waves-November 2007 - 2 views

  • Increased biofuel demand has contributed to higher world food and feed prices.
  • Global biofuel production has tripled from 4.8 billion gallons in 2000 to about 16.0 billion in 2007, but still accounts for less than 3 percent of the global transportation fuel supply.
  • Cellulosic ethanol could raise per acre ethanol yields to more than 1,000 gallons, significantly reducing land requirements. Cellulosic ethanol is made by breaking down the tough cellular material that gives plants rigidity and structure and converting the resulting sugar into ethanol. Cellulose is the world’s most widely available biological material, present in such low-value materials as wood chips and wood waste, fast-growing grasses, crop residues like corn stover, and municipal waste.
  • ...2 more annotations...
  • A key interest in developing or expanding biofuel production and use is the environmental benefits, including the potential to reduce emissions, such as greenhouse gases (GHG). An estimated 25 percent of manmade global carbon dioxide (CO2) emissions, a leading GHG, comes from road transport.
  • Biofuels are theoretically carbon neutral, releasing CO2 recently absorbed from the atmosphere by the crops used to produce them.
  •  
    Future costs and issue with biofuels.
smithree98

Fuel Cell Advantages and Disadvantages - 1 views

  • 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.
  •  
    advantages and disadvantages of hydrogen fuel cells
dpurdy

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

  • 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
  •  
    The article we read in class. Use the summary we wrote or refer to this.
dpurdy

Cost of hydrogen from different sources - 0 views

  • Estimated cost of hydrogen per kilogram in a variety of scenarios With all of this in mind, here are the cost estimates per kilogram (which each include $1.25 for taxes): Hydrogen from natural gas (produced via steam reforming at fueling station) $4 – $5 per kilogram of hydrogen Hydrogen from natural gas (produced via steam reforming off-site and delivered by truck) $6 – $8 per kilogram of hydrogen Hydrogen from wind (via electrolysis) $8 – $10 per kilogram of hydrogen Hydrogen from nuclear (via electrolysis) $7.50 – $9.50 per kilogram of hydrogen Hydrogen from nuclear (via thermochemical cycles – assuming the technology works on a large scale) $6.50 – $8.50 per kilogram of hydrogen Hydrogen from solar (via electrolysis) $10 – $12 per kilogram of hydrogen Hydrogen from solar (via thermochemical cycles – assuming the technology works on a large scale) $7.50 – $9.50 per kilogram of hydrogen As mentioned above, a cost of hydrogen of $4 to $12 per kilogram is equivalent to gasoline at $1.60 to $4.80 per gallon.
olearydev99

Hydrogen Fuel - 0 views

  • Fuel Cost & Availability. Hydrogen is currently expensive to produce and is only available at a handful of locations, mostly in California. Vehicle Cost & Availability. Fuel cell vehicles are currently far too expensive for most consumers to afford, and they are only available to a few demonstration fleets.
  •  
    "It is an environmentally friendly fuel that has the potential to dramatically reduce our dependence on imported oil, but several significant challenges must be overcome before it can be widely used."
dpurdy

The Fuel Cell: Is it Ready? - 0 views

  • The fuel cell is being considered as an eventual replacement for the internal combustion engine for cars, trucks and buses. Major car manufacturers have teamed up with fuel cell research centers or are doing their own development. There are plans for mass-producing cars running on fuel cells. Because of the low operating cost of the combustion engine, and some unresolved technical challenges of the fuel cell, however, experts predict that a large scale implementation of the fuel cell to power cars will not occur before 2015, or even 2020.
  • Most fuel cells are still handmade and are used for experimental purposes. Fuel cell promoters remind the public that the cost will come down once the cells are mass-produced and lower cost material are found. While an internal combustion engine requires an investment of $35 to $50 to produce one kilowatt (kW) of power, the equivalent cost in a fuel cells is still a whopping $3,000 to $7,500. The goal is a fuel cell that would cost equal or less than diesel engines.
dpurdy

How Fuel Cells Work - 0 views

  • Most fuel cells designed for use in vehicles produce less than 1.16 volts of electricity—far from enough to power a vehicle. Therefore, multiple cells must be assembled into a fuel cell stack.
  •  
    great pic on how fuel cells look. 
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%
  • ...6 more annotations...
    • 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]
  •  
    Fuel cell cars are expensive.  The fuel cell costs a lot
geczyluk99

Fuel Cell Vehicles: Challenges - 1 views

  • Fuel cell system costs have decreased significantly over the past several years but are still nearly twice as high as those for internal combustion engines. Likewise, onboard hydrogen storage costs are currently $15–$18/kWh for high-pressure gaseous storage, while the commercialization target is $2/kWh. There is potential to reduce this cost using lower-cost carbon fiber tanks or materials-based storage technologies, such as metal hydrides.
    • dpurdy
       
      as noted in the graph. the cost has been coming down. If it keeps on dropping it will be a good system in the future.
    • dpurdy
       
      Just click on the more link. 
  • FCVs will have to offer consumers a viable alternative, especially in terms of performance, durability, and cost, to survive in this ultra-competitive market.
  •  
    Cost per kilowat to generate/
  •  
    today hindi news,today news talmi,hindi news www.killdo.de.gg
sconzomic99

Today's Climate Change | A Student's Guide to Global Climate Change | US EPA - 2 views

  • Burning fossil fuels releases carbon dioxide, a heat-trapping gas, into the atmosphere, which is the main reason why the climate is changing.
  •  
    What is climate change
dpurdy

Learn the Basics | A Student's Guide to Global Climate Change | US EPA - 0 views

  • The Earth is getting warmer because people are adding heat-trapping gases to the atmosphere, mainly by burning fossil fuels. These gases are called greenhouse gases. Warmer temperatures are causing other changes around the world, such as melting glaciers and stronger storms. These changes are happening because the Earth's air, water, and land are all linked to the climate
  •  
    The basics of climate change.
wellsann99

Wind Power History - 0 views

  • It development of technology have been well proven over the years of time. When the sun emit heat to warm of the Earth it would be unbearable without wind. Wind widely disperses the heat making it bearable for all living things to survive. Without wind nothing would exist, it would just like all the other planets uninhibited by human nature or any living things for that matter.
  • A wind turbine is a machine that transforms kinetic energy from the wind into mechanical energy.
  • Wind power was first used in ancient times with the sail boat.
  • ...2 more annotations...
  • When windmills were first developed they were used to assist man with the chores of pumping and grinding.
  • Well wind power is the transformation of energy from wind to electricity or other forms of energy
  •  
    what wind power is
« First ‹ Previous 661 - 680 of 936 Next › Last »
Showing 20 items per page