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Contents contributed and discussions participated by dpurdy

dpurdy

Solar Energy and Energy Independence - 1 views

  • Science tells us that every square meter of the earth's surface, when exposed to direct sunlight, receives about 1000 watts (1 kilowatt) of energy from the sun's light.
dpurdy

War of Currents - Wikipedia, the free encyclopedia - 0 views

    • dpurdy
       
      use this picture for how generators work.
  • The advantage of AC for distributing power over a distance is due to the ease of changing voltages using a transformer. Available power is the product of current × voltage at the load. For a given amount of powe
dpurdy

Disadvantages of Geothermal Energy - It's All Location, Location, Location - 0 views

  • 3. You cannot transport geothermal energy. I used to live in the coal region of Pennsylvania. For years coal trucks used to drive by our front door hauling Anthracite coal to home and industries.
  • 4. There may be geothermal gases. Geothermal steam and hot water do contain naturally occurring traces of hydrogen sulfide (a gas that smells like rotten eggs) and other gases and chemicals that can be harmful in high concentrations.
dpurdy

Biomass Fuel - The Basics of Biomass Fuel - 1 views

  • Biomass fuel refers to anything that can either burn or decompose. Other terms are biomass energy or biofuel. The prefix "bio" refers to life.
  • Also utilizing the source of bioenergy reduces pollution, helps control carbon dioxide emissions ( Remember, plants take in CO2 which will offset emissions)
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    Biomass fuel refers to anything that can either burn or decompose. Other terms are biomass energy or biofuel. The prefix "bio" refers to life.
dpurdy

Solar Energy Facts - 0 views

  • Solar Cells or photovoltaic cells convert sunlight directly into electricity. When energy from the sun comes in contact with the cell, electrons in the two different semiconductors absorb the energy and use it to move around, creating an electrical current.
dpurdy

Define Wind Energy - Here are Wind Energy Facts - 0 views

  • In scientific terms, wind energy is the "force" of winds blowing across the earth’s surface ("Wind Energy"). Wind is caused by uneven heating on the earth’s surface. The equator region receives more heat than say, Antarctica.
  • That heat tries to move from hotter to colder regions. Wind energy was first harvested centuries ago, when early windmills were used to power millstones, pumps, and forges
  • The amount of kinetic energy within Earth's atmosphere is equal to about 10,000 trillion kilowatt-hours.
dpurdy

Hydrogen Fuel Alternative - 1 views

  • Just as solar, hydro and biomass energy has been utilized for thousands of years, hydrogen technology as a fuel source has also been known for over 150 years.
  • Hydrogen is a simple element - an atom with only one proton and one electron. It is 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 is always combined with other elements.
  • Water, for example, is a combination of hydrogen and oxygen. Hydrogen can be separated from hydrocarbons by applying heat, a process known as "reforming" hydrogen.
dpurdy

The Energy Challenge - Wind Energy Bumps Into Power Grid's Limits - Series - NYTimes.com - 2 views

  • The dirty secret of clean energy is that while generating it is getting easier, moving it to market is not.
  • While the United States today gets barely 1 percent of its electricity from wind turbines, many experts are starting to think that figure could hit 20 percent.
  • Achieving that would require moving large amounts of power over long distances, from the windy, lightly populated plains in the middle of the country to the coasts where many people live.
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  • “The windiest sites have not been built, because there is no way to move that electricity from there to the load centers,” he said
  • The basic problem is that many transmission lines, and the connections between them, are simply too small for the amount of power companies would like to squeeze through them
dpurdy

EIA Energy Kids - Biofuels - 0 views

  • "Biofuels" are transportation fuels like ethanol and biodiesel that are made from biomass materials.
  • Ethanol and biodiesel are usually more expensive than the fossil fuels that they replace, but they are also cleaner-burning fuels, producing fewer air pollutants.
  • What Is Ethanol? Ethanol is an alcohol fuel made from the sugars found in grains, such as:
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  • Most of the ethanol used in the United States today is distilled from corn
  • As a transportation fuel, ethanol can be used as a total or partial replacement for gasoline
  • Unlike gasoline, pure ethanol is nontoxic and biodegradable; it quickly breaks down into harmless substances if spilled.
  • Ethanol and ethanol-gasoline mixtures burn cleaner and have higher octane than pure gasoline, but have higher "evaporative emissions" from fuel tanks and dispensing equipment. These evaporative emissions contribute to the formation of harmful, ground-level ozone and smog.
  • Ethanol may be considered to be carbon-neutral because the plants that are used to make fuel ethanol (such as corn and sugarcane) absorb CO2 as they grow and may offset the CO2 produced when ethanol is made and burned.
  • However, in some parts of the world, large areas of natural vegetation and forests have been cleared and burned to grow soybeans and palm oil trees to make biodiesel
  • Fueling engines with biodiesel has just started to catch on, but it isn't a new idea. Before petroleum diesel fuel became popular, Rudolf Diesel, the inventor of the diesel engine in 1897, experimented with using vegetable oil (biodiesel) as fuel.
  • Biodiesel as a Transportation Fuel A Bus Powered by Soybean Oil Source: Stock photography (copyrighted) Most trucks, buses, and tractors in the United States use diesel fuel.
  • Using a gallon of biodiesel produced in the United States avoids the CO2 emissions that result from burning about a gallon of petroleum diesel. Biodiesel may be considered to be carbon-neutral because the plants that are used to make it, such as soy beans and palm oil trees, absorb carbon dioxide (CO2) as they grow and may offset the CO2 produced when biodiesel is made and burned.
  • Biodiesel is a renewable fuel that can be used instead of diesel fuel, which is made from petroleum. Biodiesel can be made from vegetable oils, animal fats, or greases. Most biodiesel today is made from soybean oil. About half of biodiesel producers are able to make biodiesel from used oils or fats, including recycled restaurant grease.
dpurdy

EIA Energy Kids - Renewable - 0 views

    • dpurdy
       
      Graphic showing US energy production and consumption for all energy sources, fossil fuel and renewable. 
dpurdy

Wind Program: Advantages and Challenges of Wind Energy - 1 views

  • Challenges Wind power must compete with conventional generation sources on a cost basis. Depending on how energetic a wind site is, the wind farm may or may not be cost competitive. Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Good wind sites are often located in remote locations, far from cities where the electricity is needed. Transmission lines must be built to bring the electricity from the wind farm to the city. Wind resource development may compete with other uses for the land and those alternative uses may be more highly valued than electricity generation. Although wind power plants have relatively little impact on the environment compared to other conventional power plants, there is some concern over the noise produced by the rotor blades, aesthetic (visual) impacts, and sometimes birds have been killed by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.
dpurdy

Wind Program: History of Wind Energy - 2 views

  • Since early recorded history, people have been harnessing the energy of the wind. Wind energy propelled boats along the Nile River as early as 5000 B.C. By 200 B.C.,
  • Commonly called wind turbines, these machines appeared in Denmark as early as 1890. In the 1940s the largest wind turbine of the time began operating on a Vermont hilltop known as Grandpa's Knob. This turbine, rated at 1.25 megawatts in winds of about 30 mph, fed electric power to the local utility network for several months during World War II.
dpurdy

Fuel Cells - Electrochemical Power - 1 views

  • Hydrogen as the Main Fuel of the Future Over the last decades hydrogen, (H2) has gained more and more attention as an environmentally friendly fuel and storage medium. Combustion of pure hydrogen produces only water as exhaust. Hydrocarbon and carbon oxide emissions can only come from motor oil in the combustion chamber. Nitrous oxide emissions result from the nitrogen content in the air and increase exponentially with the combustion temperature. By using H2 in fuel cells, practically no pollution occurs. In this respect, hydrogen offers emission levels that are much lower than existing and future standards.
  • Hydrogen is the most common of all elements in the universe.
  • The desire for a long-term transition to a hydrogen society is mainly based on the need to reduce polluting and climate-affecting emissions and the concern about depletion of fossil fuel resources. Today about 90 % of the world's energy consumption is covered by fossil fuels, and most of this comes from a limited number of regions in the world. Even if hydrogen will be used on a large scale in the future, there is still a need for an energy source to produce it. Renewable energy technology such as hydro electricity, wind, wave and solar power are in principle available, but are not yet mature for mass production and/or fully developed. 
dpurdy

Fuel Cells - Electrochemical Power - 0 views

  • Fuel Cell Principle A fuel cell is an electrochemical energy converter. It converts chemical energy into electrical energy by two separated electrochemical reactions. In a hydrogen-fuelled polymer electrolyte membrane fuel cell (PEMFC), hydrogen is oxidised to protons and electrons at the anode. Protons migrate through the membrane electrolyte to the cathode. As the membrane is an electric insulator, electrons are forced to flow in an external electric circuit. At the cathode, oxygen reacts with protons to produce water, which is the only waste product
dpurdy

EIA Energy Kids - Hydrogen - 2 views

  • Like electricity, hydrogen is a secondary source of energy. It stores and carries energy produced from other resources (fossil fuels, water, and biomass).
  • ydrogen is the simplest element. Each atom of hydrogen has only one proton. It is also the most plentiful gas in the universe. Stars like the sun are made primarily of hydrogen. The sun is basically a giant ball of hydrogen and helium gases. In the sun's core, hydrogen atoms combine to form helium atoms. This process — called fusion — gives off radiant energy.
  • Hydrogen gas is so much lighter than air that it rises fast and is quickly ejected from the atmosphere. This is why hydrogen as a gas (H2) is not found by itself on Earth. It is found only in compound form with other elements. Hydrogen combined with oxygen, is water (H2O). Hydrogen combined with carbon forms different compounds, including methane (CH4), coal, and petroleum.
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  • Hydrogen has the highest energy content of any common fuel by weight
  • Like electricity, hydrogen is an energy carrier and must be produced from another substance. Hydrogen is not currently widely used, but it has potential as an energy carrier in the future. Hydrogen can be produced from a variety of resources (water, fossil fuels, or biomass) and is a byproduct of other chemical processes.
  • Steam reforming is currently the least expensive method of producing hydrogen and accounts for about 95% of the hydrogen produced in the United States. This method is used in industries to separate hydrogen atoms from carbon atoms in methane (CH4). But the steam reforming process results in greenhouse gas emissions that are linked with global warming.1
  • Electrolysis Creates No Emissions but Is Costly Electrolysis is a process that splits hydrogen from water. It results in no emissions, but it is currently an expensive process. New technologies are currently being developed.
  • Hydrogen fuel cells make electricity. They are very efficient, but expensive to build. Small fuel cells can power electric cars. Large fuel cells can provide electricity in remote places with no power lines.
  • Portable fuel cells are being sold to provide longer power for laptop computers, cell phones, and military applications.
dpurdy

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
dpurdy

HowStuffWorks "How the Hydrogen Economy Works" - 3 views

  • In the hydrogen economy, there is no storehouse to tap into. We have to actually create the e­nergy in real-time.
  • There are two possible sources for the hydrogen: Electrolysis of water - Using electricity, it is easy to split water molecules to create pure hydrogen and oxygen. One big advantage of this process is that you can do it anywhere. For example, you could have a box in your garage producing hydrogen from tap water, and you could fuel your car with that hydrogen. Reforming fossil fuels - Oil and natural gas contain hydrocarbons -- molecules consisting of hydrogen and carbon. Using a device called a fuel processor or a reformer, you can split the hydrogen off the carbon in a hydrocarbon relatively easily and then use the hydrogen. You discard the leftover carbon to the atmosphere as carbon dioxide.
  • To have a pure hydrogen economy, the hydrogen must be derived from renewable sources rather than fossil fuels so that we stop releasing carbon into the atmosphere. Having enough electricity to separate hydrogen from water, and generating that electricity without using fossil fuels, will be the biggest change that we see in creating the hydrogen economy.
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  • In the future, barring some technological breakthrough, it seems likely that one of two things will happen to create the hydrogen economy: Either nuclear-power or solar-power generating capacity will increase dramatically.
  • The electrical-generation problem is probably the biggest barrier to the hydrogen economy
dpurdy

HowStuffWorks "How the Hydrogen Economy Works" - 0 views

  • The elimination of pollution caused by fossil fuels - When hydrogen is used in a fuel cell to create power, it is a completely clean technology. The only byproduct is water. There are also no environmental dangers like oil spills to worry about with hydrogen. The elimination of greenhouse gases - If the hydrogen comes from the electrolysis of water, then hydrogen adds no greenhouse gases to the environment. There is a perfect cycle -- electrolysis produces hydrogen from water, and the hydrogen recombines with oxygen to create water and power in a fuel cell. The elimination of economic dependence - The elimination of oil means no dependence on the Middle East and its oil reserves. Distributed production - Hydrogen can be produced anywhere that you have electricity and water. People can even produce it in their homes with relatively simple technology.
dpurdy

Fuel Cells 2000 : Hydrogen : Basics - 1 views

  • 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! 
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