Skip to main content

Home/ Groups/ qmstech2
sconzomic99

Sustainable - Definition and More from the Free Merriam-Webster Dictionary - 0 views

  • of, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged
carpenteraut98

Fuel Cells for a Sustainable Future? | Tyndall°Centre for Climate Change Rese... - 0 views

  • >It is found that there are both technical and non technical barriers to the development of stationary fuel cells as a major component towards sustainable energy.
  • >It is found that there are both technical and non technical barriers to the development of stationary fuel cells as a major component towards sustainable energy.
  •  
    "It is found that there are both technical and non technical barriers to the development of stationary fuel cells as a major component towards sustainable energy"
olearydev99

What Is Hydrogen? (with picture) - 1 views

  •  
    "Hydrogen is a highly flammable chemical element that occurs in great abundance throughout the universe. In fact, this element 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."
lefebvrekat99

Where does biofuel come from - 0 views

  • Biofuel comes from petroleum products which come from below the ground. Ethanol, however, the "bio" part of biofuels, comes from corn.
brennantho98

Energy Resources: Wind power - 0 views

  • A good method of supplying energy to remote areas.
  • Wind is free, wind farms need no fuel.
  • The wind is not always predictable - some days have no wind.
  • ...1 more annotation...
  • Wind power is renewable. Winds will keep on blowing, it makes sense to use them.
lefebvrekat99

BIOFUELS: What are they? How can they be used as an energy source (either on-...(Q&A) - 0 views

  • ofuels can be derived from almost any type of "biomass," a broad term that refers to living or recently alive biological material. Because biomass is produced on a short time scale, it is considered a renewable resource. I will describe types of biofuels—ethanol, biodiesel, syngas, bio-hydrogen, biogas, and solid biofuel—and their use. I'll also identify the crops and wastes being used to produce biofuels, and some issues surrounding biofuel production. How are biofuels being used? Biofuels are already used to supply a small fraction of our energy needs, with significant opportunities to expand their use as infrastructure is developed. In addition to ethanol and biodiesel for transportation, biofuels are currently used for power production, heating and cooling of buildings, and the thermal needs of industry. Biomass is today the largest non-hydroelectric renewable source for electricity produced in the U.S. Most of this is produced in pulp and paper mills, which often generate electricity by burning wood chips, bark, or the sludges and "liquors" that are byproducts of the paper-making process. At the same time, they recover waste heat from electricity generation to meet the thermal needs of the mill. This highly efficient combination is referred to as combined heat and power (CHP) or cogeneration. The electricity generated may be used onsite and/or supplied to the local utility for distribution to the public.
conwayjam99

World of Wind Energy.com - The World's #1 Wind Energy Site! - News - WIND ECOLOGY AND P... - 1 views

  • Wind power is a renewable resource, which means using it will not deplete the earth's supply of fossil fuels. It also is a clean energy source, and operation does not produce carbon dioxide, sulfur dioxide, mercury, particulates, or any other type of air pollution, as do conventional fossil fuel power sources.
  • Wind power consumes no fuel for continuing operation, and has no emissions directly related to electricity production.
  • Wind power's ability to reduce pollution and greenhouse gas emissions will depend on the amount of wind energy produced, and hence scalability.
  • ...4 more annotations...
  • Wind power may also have an indirect effect on pollution at other production facilities, due to the need for reserve and regulation, and may affect the efficiency profile of plants used to balance demand and supply, particularly if those facilities use fossil fuel sources. Compared to other power sources, however, wind energy's direct emissions are low, and the materials used in construction (concrete, steel, fiberglass, generation components) and transportation are straightforward.
  • Wind power's ability to reduce pollution and greenhouse gas emissions will depend on the amount of wind energy produced, and hence scalability.
  • Wind power may also have an indirect effect on pollution at other production facilities, due to the need for reserve and regulation, and may affect the efficiency profile of plants used to balance demand and supply, particularly if those facilities use fossil fuel sources. Compared to other power sources, however, wind energy's direct emissions are low, and the materials used in construction (concrete, steel, fiberglass, generation components) and transportation are straightforward.
  • carbon dioxide, sulfur dioxide, mercury, particulates, or any other type of air pollution, as do conventional fossil fuel power sources.
  •  
    " United States, onshore and near-shore turbines kill 70,000 birds per year, compared to 57 million killed by cars and 97.5 million killed by collisions with plate glass."
conwayjam99

What are the advantages and disadvantages of wind power - 0 views

  •  
    "Wind power will become cheaper than fossil fuel in the next few years (when the price of carbon is added to coal and oil), and in many places already is."
stewartlas97

Wind - 0 views

  •  
    "This movement is complicated by several other factors that means wind does not always flow from the equator in the direction of either pole. The rotation of the earth creates a force known as the Coriolis force and this factor along with the temperature differences create winds at high altitudes above the earth on a large scale. These Geostrophic winds play a part in the wind's that affect us in everyday life, but local winds are largely affected by the surface of the earth - which is neither uniform or smooth. The earth has large flat plains (desert regions), areas covered with plant life (rainforests), very uneven regions (mountain ranges) and very smooth regions (seas and oceans), all of which affect the wind near the surface of the earth to varying degrees. These areas of the earth all have different values of roughness, which can impeded the flow of air. Obviously the lower the value of roughness the less the air is impeded."
bonnjos98

My Library - 0 views

  •  
    ""It may surprise you to know that the ancient Romans had central heating. They used geothermal energy - in the form of hot springs - to heat their homes. Geothermal heating wasn't used in an organized fashion since until the late 19th century when Boise, Idaho, piped in water from local hot springs to warm buildings. Now, geothermal energy is used globally. Reykjavik, Iceland, leads the world in use of geothermal energy, heating 95 percent of its buildings with heat from below the Earth's surface." more from curiosity.discovery.com - Not Cached - Edit - Delete - Share▼ - Preview"
kenyonlau99

How much power is generated in the United States by solar power? - 2 views

  • just over 843,000 kilowatt-hours of electricity were provided by solar power. The vast majority of that, more than 666,500 kWh, were produced in California. Roughly 14 percent of the total renewable energy generated in the U.S. in 2008 was solar energy. And remember that these numbers continue to grow each year. The solar industry has been growing on an average of 30-40 percent each year, and as the industry grows, so will the amount of clean, renewable power it puts out. Interested in Home Solar Energy? Fill in your details below and certified solar contractors will give you FREE estimates. What type of Solar Energy services are you interested in? * Please Select Solar Electrical Solar Thermal First Name * Last Name * Zipcode *
    • kenyonlau99
       
      GOOD INFO!
  • The EIA states that just over 843,000 kilowatt-hours of electricity were provided by solar power. The vast majority of that, more than 666,500 kWh, were produced in California. Roughly 14 percent of the total renewable energy generated in the U.S. in 2008 was solar energy. And remember that these numbers continue to grow each year. The solar industry has been growing on an average of 30-40 percent each year, and as the industry grows, so will the amount of clean, renewable power it puts out.
  •  
    how much solar energy is being converted in the USA?
  •  
    "How much power is generated in the United States by solar power? ted-vollgraff According to the Energy Information Administration (EIA), renewable energy accounted for 7 percent of U.S. energy consumption in 2008. Solar power accounted for only one percent. But, considering how much energy is consumed each year in the United States, that is still a decent bit of power. The EIA states that just over 843,000 kilowatt-hours of electricity were provided by solar power. The vast majority of that, more than 666,500 kWh, were produced in California. Roughly 14 percent of the total renewable energy generated in the U.S. in 2008 was solar energy. And remember that these numbers continue to grow each year. The solar industry has been growing on an average of 30-40 percent each year, and as the industry grows, so will the amount of clean, renewable power it puts out. "
labrumbra99

A Basic Overview of Fuel Cell Technology - 0 views

  • they generate electricity with very little pollution—much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water.
  • Scientists and inventors have designed many different types and sizes of fuel cells in the search for greater efficiency, and the technical details of each kind vary
  • in general terms, hydrogen atoms enter a fuel cell at the anode where a chemical reaction strips them of their electrons. The hydrogen atoms are now “ionized,” and carry a positive electrical charge. The negatively charged electrons provide the current through wires to do work. If alternating current (AC) is needed, the DC output of the fuel cell must be routed through a conversion device called an inverter.
  • ...6 more annotations...
  • But in general terms, hydrogen atoms enter a fuel cell at the anode where a chemical reaction strips them of their electrons. The hydrogen atoms are now �ionized,� and carry a positive electrical charge. The negatively charged electrons provide the current through wires to do work. If alternating current (AC) is needed, the DC output of the fuel cell must be routed through a conversion device called an inverter.
  • A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode. The reactions that produce electricity take place at the electrodes.
  • Every fuel cell also has an electrolyte, which carries electrically charged particles from one electrode to the other, and a catalyst, which speeds the reactions at the electrodes. Hydrogen is the basic fuel, but fuel cells also require oxygen. One great appeal of fuel cells is that they generate electricity with very little pollution–much of the hydrogen and oxygen used in generating electricity ultimately combine to form a harmless byproduct, namely water.
  • fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode.
  • One detail of terminology:
  • Oxygen enters the fuel cell at the cathode and, in some cell types (like the one illustrated above), it there combines with electrons returning from the electrical circuit and hydrogen ions that have traveled through the electrolyte from the anode. In other cell types the oxygen picks up electrons and then travels through the electrolyte to the anode, where it combines with hydrogen ions. The electrolyte plays a key role. It must permit only the appropriate ions to pass between the anode and cathode. If free electrons or other substances could travel through the electrolyte, they would disrupt the chemical reaction. Whether they combine at anode or cathode, together hydrogen and oxygen form water, which drains from the cell. As long as a fuel cell is supplied with hydrogen and oxygen, it will generate electricity. Even better, since fuel cells create electricity chemically, rather than by combustion, they are not subject to the thermodynamic laws that limit a conventional power plant (see "Carnot Limit" in the glossary). Therefore, fuel cells are more efficient in extracting energy from a fuel. Waste heat from some cells can also be harnessed, boosting system efficiency still further
  •  
    "A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode. The reactions that produce electricity take place at the electrodes."
  •  
    "A fuel cell is a device that generates electricity by a chemical reaction. Every fuel cell has two electrodes, one positive and one negative, called, respectively, the anode and cathode."
bonnjos98

How long have people been using geothermal energy? - Curiosity - 1 views

  •  
    "It may surprise you to know that the ancient Romans had central heating. They used geothermal energy - in the form of hot springs - to heat their homes. Geothermal heating wasn't used in an organized fashion since until the late 19th century when Boise, Idaho, piped in water from local hot springs to warm buildings. Now, geothermal energy is used globally. Reykjavik, Iceland, leads the world in use of geothermal energy, heating 95 percent of its buildings with heat from below the Earth's surface."
  •  
    "It may surprise you to know that the ancient Romans had central heating. They used geothermal energy - in the form of hot springs - to heat their homes. Geothermal heating wasn't used in an organized fashion since until the late 19th century when Boise, Idaho, piped in water from local hot springs to warm buildings. Now, geothermal energy is used globally. Reykjavik, Iceland, leads the world in use of geothermal energy, heating 95 percent of its buildings with heat from below the Earth's surface."
coreyemi99

How is solar energy converted into electrical energy - 0 views

  • Solar energy is very easyto change to electric energy. All you have to do is to take a solar cell. Put it in sunlight or other such source of light. It will use this light energy and will convert it into electric energy.
  •  
    how solar energy is converted into electricity
brownale99

How much more expensive is solar energy than fossil fuels - 0 views

  •  
    "Fossil fuel power stations typically cost about $2.1 dollars per watt to build solar stations around $7 at present. The efficiency is increasing and costs are falling. This of course does not represent the cost to the consumer. In addition it does not take into account all the various other costs and the advantages and disadvantages of each. Fuel (fossil stations), poor sunlight (solar stations). Maintenance costs are similar for single plants but solar stations do not have the capacity of fossil fuel stations."
careyeth99

Fuel Cells & Hydrogen | Fuel Cells 2000 - 0 views

  •  
    A fuel cell is an electrochemical device that combines hydrogen and oxygen to produce electricity, with water and heat as its by-product.
dittrichcai99

How long has geothermal energy been around - 0 views

  •  
    "In some countries geothermal energy has been around for thousands of years and has been used for cooking and heating."
kennedyeri98

Climate Change: Evidence - 0 views

  • evidence that atmospheric CO2 has increased since the Industrial Revolution.
  • been seven cycles of glacial advance and retreat, with the abrupt end of the last ice age about 7,000 years ago
  • proceeding at a rate that is unprecedented in the past 1,300 years.1
« First ‹ Previous 361 - 380 of 816 Next › Last »
Showing 20 items per page