Skip to main content

Home/ Groups/ qmstech2
fieldingbry99

Ch 12 Page 73: Sustainable Energy - without the hot air | David MacKay - 0 views

  • In open water, waves are generated whenever the wind speed is greater than about 0.5 m/s.
  • First, let’s clarify where waves come from: sun makes wind and wind makes waves.
  •  
    "First, let's clarify where waves come from: sun makes wind and wind makes waves."
freedenjoh99

Hydrogen Basics - Fuel Cells - 1 views

  • A fuel cell converts the chemical energy in hydrogen and oxygen into direct current electrical energy by electrochemical reactions. Fuel cells are devices that convert hydrogen gas directly into low-voltage, direct current electricity. The cell has no moving parts.
  • The process is essentially the reverse of the electrolytic method of splitting water into hydrogen and oxygen. In the fuel cell, the cathode terminal is positively charged and the anode terminal is negatively charged. These electrodes are separated by a membrane. Hydrogen gas is converted into electrons and protons (positive hydrogen ions) at the anode. The protons pass through the membrane to the cathode, leaving behind negatively charged electrons. This creates a flow of direct current electricity between the terminals when connected with an external circuit. This current can power an electric motor placed in this circuit. The hydrogen ions, electrons, and oxygen combine at the cathode to form water, the only byproduct of the process.
  •  
    " 13kW PEM fuel cell (Photo: Ballard Power Systems, Inc.) The process is essentially the reverse of the electrolytic method of splitting water into hydrogen and oxygen. In the fuel cell, the cathode terminal is positively charged and the anode terminal is negatively charged. These electrodes are separated by a membrane. Hydrogen gas is converted into electrons and protons (positive hydrogen ions) at the anode. The protons pass through the membrane to the cathode, leaving behind negatively charged electrons. This creates a flow of direct current electricity between the terminals when connected with an external circuit. This current can power an electric motor placed in this circuit. The hydrogen ions, electrons, and oxygen combine at the cathode to form water, the only byproduct of the process"
kennedyeri98

Inverter Noise Emissions from a solar PV application - 2 views

  • Electrical interference is a problem that might be encountered with solar power system electronics
  • produces at least some noise and nearly all equipment now used in PV systems is digital.
  • digital electronic
  • ...2 more annotations...
  • charge controllers and many inverters (particularly modified sine wave inverters)
  • high power digital pulses are one of the worst interference sources.
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."
stewartlas97

Wind - 0 views

shared by stewartlas97 on 13 Mar 13 - No Cached
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. "
ricciardellinick

How Fuel Cells Work - 0 views

shared by ricciardellinick on 13 Mar 13 - No Cached
« First ‹ Previous 381 - 400 of 927 Next › Last »
Showing 20 items per page