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tillmanash98

Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biof... - 0 views

  • Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels.
  • To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies.
  • Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol.
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  • Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels.
  • We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans.
  • These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies.
crandallchr98

Hydrogen Fuel Cells - Disadvantages - 0 views

  • Fuel cells are currently very expensive, but since they have a simple construction, mass production costs would become extremely low. 
  • Prototype fuel cells last only 1/5th as long as would be needed to make fuel cells cost-effective.
  • They are energy losers because it costs more to produce hydrogen than is earned by using hydrogen in fuel cells:  Electricity generated by fuel cells in cars costs thousands of dollars per kilowatt:  This would have to fall by a factor of 10 for fuel cells to become economically viable.
stamperdyl98

Environment « myFC - 0 views

  • Through the use of hydrogen together with fuel cell technology it is possible to achieve a radical decrease in local pollution of carbon dioxide, nitrogen oxides and particles from the transportation sector. Although the production of hydrogen from fossil fuels affects the environment it is an advantage that the carbon dioxide emissions can be separated already on the production site. This becomes evident when hydrogen is used as vehicle fuel, avoiding pollution from every individual vehicle.The only emission from a fuel cell reacting with hydrogen is pure water. The environmental gains are high, provided that pollution in the hydrogen production process is kept low. A fuel cell is approximately twice as energy efficient as a combustion engine if used in a regular car. The effect is that, using the same amount of energy, a fuel cell car can drive twice as far as a car with a combustion engine can.
dynesbri97

Renewable Solar Energy: How is Wind Formed - 0 views

  • Wind is formed by the indirect effect of the sun on the Earth’s surface. There is a reasonable explanation why is it so. As the sun shines, the Sun heats the Earth's surface; the air near ground level gets hot and rises up. Cold air at higher altitudes replaces it. At nighttime the process is reversed. This is  in principal how is wind formed on Earth.
  • This process of hot air rising and colder air sinking, causes high and low air pressure areas and results in wind formation. The more the pressure changes in an area, the faster the wind speed will be. If two areas are close to each other, pressure difference will cause higher wind speed to be produced compared to areas that are far apart from each other. This is how the wind is formed on Earth and this phenomena is known as vertical wind formation
dpurdy

Distributed Energy Resources Guide: Fuel Cells - Cost - 3 views

  • Price projections vary among fuel cell developers, but most are targeting costs below $1,500/kW
  • Maintenance costs of a fuel cell are expected to be comparable to that of a microturbine, ranging from $0.005-$0.010/kWh (based on an annual inspection visit to the unit).
  • At the current price, units are only used in high value, "niche" markets where reliability is premium, and in areas where electricity prices are very high and natural gas prices are low.
efana1

Long Island, New York City Offshore Wind Project - 0 views

  • Advantages of Wind Power
  • goal for the State to meet 45 percent of its electricity needs through improved energy efficiency and renewable sources by the year 2015
  • renewable resource that could provide a significant amount of clean energy to consumers
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  • Wind's relative low-energy density
sankeyrya00

The Energy Story - Chapter 16: Wind Energy - 2 views

    • shannonlan97
       
      inside of turbine picture
  • Farmers have been using wind energy for many years to pump water from wells using windmills like the one on the right
  • When a boat lifts a sail, it is using wind energy to push it through the water. This is one form of work.
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  • Wind is also used to turn large grinding stones to grind wheat or corn, just like a water wheel is turned by water power.
  • Wind can be used to do work. The kinetic energy of the wind can be changed into other forms of energy, either mechanical energy or electrical energy
  • n Holland, windmills have been used for centuries to pump water from low-lying areas.
  • Blowing wind spins the blades on a wind turbine – just like a large toy pinwheel.
  • If the wind gets too high, the turbine has a brake that will keep the blades from turning too fast and being damaged.
  • You can use a single smaller wind turbine to power a home or a school. A small turbine makes enough energy for a house.
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    "The blades of the turbine are attached to a hub that is mounted on a turning shaft. The shaft goes through a gear transmission box where the turning speed is increased. The transmission is attached to a high speed shaft which turns a generator that makes electricity."
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.
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  • 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.
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    Future costs and issue with biofuels.
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.
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.
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    " 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"
camptif97

Benefits of Fuel Cell Technology - 1 views

  • With low emissions of pollutants such as nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter as well as dramatically lower emissions of carbon dioxide (CO2),
crandallchr98

Fuel Cell Markets - Advantages & Benefits of Fuel Cell & Hydrogen Technologies - 2 views

  • Advantages by Application Telecoms CHP Fuel Cell Generators Electric Vehicles - APU's and Range Extenders Fuel Cell Forklifts Marine Power Portable Power
  • Low Emissions – Using hydrogen, PEM fuel cells only emit water at the point of use. Even when using hydrocarbon fuels, fuel cells emit considerably less emissions than other combustion based technologies, this is for two reasons. Firstly their higher efficiency means they require less fuel to generate the same energy and secondly because there is no combustion, there are negligible NOx or SOx emissions and no particulate emissions.
  • Reliability & Maintenance – The only moving parts in fuel cells are involved with water, heat and air management (pumps, blowers, compressors). When compared to internal combustion engines, there are considerably less moving parts and these require less maintenance (no oil changes every 150 hours). Less maintenance means less site visits or trips to the garage and reduced operating costs. Fuel cells can be monitored remotely and any problems dealt with quickly.
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  • Few moving parts means all you will ever hear of a fuel cell is either a compressor, blower or pump
  • Hydrogen is the lightest of all gases and disperses very quickly, it is also non-polluting and hazardous to the surrounding environment (unlike gasoline a spillage / leak will not cause an environmental disaster). Hydrogen, like natural gas and petrol, is a fuel and will burn when ignited. Hydrogen is only explosive when it is able to build up in a enclosed space, which is very difficult as it has a habit of escaping (hydrogen is the smallest of all elements). As long as appropriate safety procedures are followed, as they should with any fuel, hydrogen is a safe fuel.
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    Advantages & Benefits of Hydrogen and Fuel Cell Technologies High Efficiency - Like generators and other engines, fuel cells are energy conversion devices - they convert stored energy within a fuel into usable energy. A fuel cell uses an electrochemical reaction to extract energy directly in the form of heat and electricity, both of which can be utilised at the point of generation.
dpurdy

Energy Resources: Solar power - 0 views

  • Advantages
  • Solar energy is free - it needs no fuel and produces no waste or pollution.
  • Handy for low-power uses such as solar powered garden lights and battery chargers, or for helping your home energy bills.
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  • Disadvantages
  • Very expensive to build solar power stations, although the cost is coming down as technology improves. In the meantime, solar cells cost a great deal compared to the amount of electricity they'll produce in their lifetime.
  • Is it renewable? Solar power is renewable. The Sun will keep on shining anyway, so it makes sense to use it.
dpurdy

Energy Resources: Wind power - 0 views

  • The Sun heats our atmosphere unevenly, so some patches become warmer than others. These warm patches of air rise, other air blows in to replace them - and we feel a wind blowing. We can use the energy in the wind by building a tall tower, with a large propellor on the top. The wind blows the propellor round, which turns a generator to produce electricity.
  • he best places for wind farms are in coastal areas, at the tops of rounded hills, open plains and gaps in mountains - places where the wind is strong and reliable. Some are offshore.
  • The best places for wind farms are in coastal areas, at the tops of rounded hills, open plains and gaps in mountains - places where the wind is strong and reliable. Some are offshore.
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  • Advantages Wind is free, wind farms need no fuel. Produces no waste or greenhouse gases. The land beneath can usually still be used for farming
  • Suitable areas for wind farms are often near the coast, where land is expensive.
  • Can be noisy. Wind generators have a reputation for making a constant, low, "swooshing" noise day and night, which can drive you nuts.
  • Wind power is renewable. Winds will keep on blowing, it makes sense to use them.
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tavarreskat99

Tidal Energy | Pros for Wave and Tidal Power - 3 views

  • Tidal energy is one of the oldest forms of energy used by humans. Indeed, tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.. Tide mills consisted of a storage pond, filled by the incoming (flood) tide through a sluice and emptied during the outgoing (ebb) tide through a water wheel. The tides turned waterwheels, producing mechanical power to mill grain. We even have one remaining in New York- which worked well into the 20th century.
  • Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • A tidal range of at least 7 m is required for economical operation and for sufficient head of water for the turbines
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  • Currently, although the technology required to harness tidal energy is well established, tidal power is expensive, and there is only one major tidal generating station in operation. This is a 240 megawatt (1 megawatt = 1 MW = 1 million watts) at the mouth of the La Rance river estuary on the northern coast of France
  • Tidal electricity can be used to displace electricity which would otherwise be generated by fossil fuel (coal, oil, natural gas) fired power plants, thus reducing emissions of greenhouse and acid gasses.
  • There is a high capital cost for a tidal energy project, with possibly a 10-year construction period.
  • Electricity can be generated by water flowing both into and out of a bay. As there are two high and two low tides each day, electrical generation from tidal power plants is characterized by periods of maximum generation every twelve hours, with no electricity generation at the six hour mark in between.
  • Tidal energy is a renewable source of electricity which does not result in the emission of gases responsible for global warming or acid rain associated with fossil fuel generated electricity. Use of tidal energy could also decrease the need for nuclear power, with its associated radiation risks. Changing tidal flows by damming a bay or estuary could, however, result in negative impacts on aquatic and shoreline ecosystems, as well as navigation and recreation.
  • Indeed, tide mills, in use on the Spanish, French and British coasts,
  • date back to 787 A.D..
  • Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • idal energy is one of the oldest forms of energy used by humans. Indeed, tide mills, in use on the Spanish, French and British coasts, date back to 787 A.D.. Tide mills consisted of a storage pond, filled by the incoming (flood) tide through a sluice and emptied during the outgoing (ebb) tide through a water wheel. The tides turned waterwheels, producing mechanical power to mill grain. We even have one remaining in New York- which worked well into the 20th century. Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
  • Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable.
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    "Tidal power is non-polluting, reliable and predictable.Tidal barrages, undersea tidal turbines - like wind turbines but driven by the sea - and a variety of machines harnessing undersea currents are under development. Unlike wind and waves, tidal currents are entirely predictable."
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    when it started to be used and who it was used by.
wooddan99

Geothermal Basics - Environment - 0 views

  • Unlike fossil fuel power plants, no smoke is emitted from geothermal power plants, because no burning takes place; only steam is emitted from geothermal facilities. Emissions of nitrous oxide, hydrogen sulfide, sulfur dioxide, particulate matter, and carbon dioxide are extremely low, especially when compared to fossil fuel emissions. The binary geothermal plant, which currently represents around 15% of all geothermal plant capacity, along with the flash/binary plant, produce nearly zero air emissions. Even dry steam plants, which are considered to have the highest levels of air emissions, are considered environmentally benign compared with fossil fuels. For example, Lake County, California, downwind of The Geysers, has met all federal and state ambient air quality standards for almost 25 years. There are 21 power plants at The Geysers, comprising a significant complex of electric generation facilities, yet even despite this, air quality is excellent. At The Geysers, air quality has even improved as a result of geothermal development because hydrogen sulfide, which would ordinarily be released naturally into the atmosphere by hot springs and fumaroles, instead now passes through an abatement system that reduces hydrogen sulfide emissions by 99.9%. (1) See also Myth #2.
charlesjos00

How Solar Works in 4 Steps « Energy4Home - 0 views

  • 1) Individual silicon based (most commonly) cells called photovoltaics (PV) make up the modern day solar panel. These PV cell clusters perform the task of converting incoming sunlight directly into electricity. 2) Wires attached to the panels transport the converted electricity to a piece of equipment called an inverter. The job of the inverter is to convert the solar generated Direct Current (DC) electricity into the type of power your home can use, which is called Alternating Current (AC). 3) After the electricity travels through the inverter, the AC electricity is then transported via wire to your breaker panel to meet your home’s electric demands. 4) The process doesn’t end there, though. There are times when your panels will generate more power than you consume and times when you aren’t generating enough electricity (night times and periods of low light). When your panels are not generating enough solar electricity, you will continue to get power from your local utility. However, when you’re generating a surplus of solar electricity, that excess clean energy will be “net metered” to your local utility grid and you may earn a credit on your power bill for that net metered electricity.
westkea00

Waves - Photography by David Orias | Ecology Global Network - 0 views

  • Waves are generated by low pressure weather systems sometimes thousands of miles from where they will break on the shore. Waves are born from high winds pushing the surface of the ocean
kurishkri00

Wind Energy - 0 views

  • The wind turns the blades, which spin a shaft connected to the generator and produces electricity. Turbine blades are designed in such a way that wind causes them to rotate, which rotates the shaft at low speed, with a gear at the end that itself is connected to small gear on high speed shaft that runs through alternator housing.
  • he generator produces electricity using the same principle as a generator of your car (depending on the turbine). Magnetic Rotor inside the generator on high speed shaft spins inside loops of copper wire that are wound around an iron core. The rotor creates “electromagnetic induction” as it spins around the inside of the core through the coils, which generates electrical power. The current is regulated and transmission network (or home network system connection), after some changes, so it can use in our homes or sent to a battery bank for storage.
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    Most wind turbines turn in the moving air like blades of propeller aircraft and supply power to an electric generator that produces electricity. Wind turbines, rather than working as a fan in your house that uses electricity to generate wind, use wind power to generate electricity. - See more at: http://www.conserve-energy-future.com/Wind_Into_Energy.php#sthash.MFQJ5BOI.dpuf
kirkpatrickcon99

Articles about Solar Energy - Los Angeles Times - 0 views

  • with $25 million set aside for low-income customers. An additional $100.8 million will be used to swap out water heaters powered by electricity.
  • NATIONALHawaii sets 'breakthrough' framework for new solar power
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