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Wind Program: Frequently Asked Questions about Wind Energy - 2 views

  • What is wind energy? Wind energy (or wind power) refers to the process by which wind turbines convert the movement of wind into electricity. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth's surface, and rotation of the earth. Humans use this wind flow for many purposes: sailing boats, pumping water, and also generating electricity. Wind turbines convert the kinetic energy of the moving wind into electricity.
  • Birds and bats are occasionally killed in collisions with wind turbines. Like any form of development, wind projects can also negatively impact wildlife by altering habitat. Over the past two decades, the impact of wind development on birds has been greatly reduced by improvements in turbine design and particularly through improved project and turbine siting.
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    How do wind turbines work? A wind turbine works like a fan, but in reverse: instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the turbine's blades, which spin a shaft connected to a generator to make electricity.
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    wind energy facts.
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NREL: Learning - Biomass Energy Basics - 0 views

  • The use of biomass energy has the potential to greatly reduce greenhouse gas emissions. Burning biomass releases about the same amount of carbon dioxide as burning fossil fuels. However, fossil fuels release carbon dioxide captured by photosynthesis millions of years ago—an essentially "new" greenhouse gas. Biomass, on the other hand, releases carbon dioxide that is largely balanced by the carbon dioxide captured in its own growth (depending How much energy was used to grow, harvest, and process the fuel).
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NREL: Learning - Geothermal Electricity Production - 0 views

  • Geothermal Electricity Production This geothermal power plant generates electricity for the Imperial Valley in California. Geothermal power plants use steam produced from reservoirs of hot water found a few miles or more below the Earth's surface to produce electricity. The steam rotates a turbine that activates a generator, which produces electricity.
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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.
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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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Energy Resources: Wave power - 1 views

  • Ocean waves are caused by the wind as it blows across the sea. Waves are a powerful source of energy.
  • How it works There are several methods of getting energy from waves. One of them works like a swimming pool wave machine in reverse. At a swimming pool, air is blown in and out of a chamber beside the pool, which makes the water outside bob up and down, causing waves.   At a wave power station, the waves arriving cause the water in the chamber to rise and fall, which means that air is forced in and out of the hole in the top of the chamber. We place a turbine in this hole, which is turned by the air rushing in and out. The turbine turns a generator.
  • Once you've built a wave power station, the energy is free, needs no fuel and produces no waste or pollution.
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  • Not expensive to operate and maintain.
  • Needs a suitable site, where waves are consistently strong.
  • Some designs are noisy. But then again, so are waves, so any noise is unlikely to be a problem.
  • Is it renewable? Wave power is renewable.
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EIA Energy Kids - Solar - 2 views

  • Energy from the Sun The sun has produced energy for billions of years.  Solar energy is the sun’s rays (solar radiation) that reach the Earth. This energy can be converted into other forms of energy, such as heat and electricity.
  • Photovoltaic (PV devices) or “solar cells” change sunlight directly into electricity. Individual PV cells are grouped into panels and arrays of panels that can be used in a wide range of applications ranging from single small cells that charge calculator and watch batteries, to systems that power single homes, to large power plants covering many acres.
  • Solar energy systems do not produce air pollutants or carbon-dioxide
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  • Solar energy is by far the Earth's most available energy source. Solar power is capable of providing many times the total current energy demand. But it is an intermittent energy source, meaning that it is not available at all times.
  • Photons Carry Solar Energy Sunlight is composed of photons, or particles of solar energy. These photons contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a photovoltaic cell, they may be reflected, pass right through, or be absorbed. Only the absorbed photons provide energy to generate electricity. When enough sunlight (energy) is absorbed by the material (a semiconductor), electrons are dislodged from the material's atoms. Special treatment of the material surface during manufacturing makes the front surface of the cell more receptive to free electrons, so the electrons naturally migrate to the surface.
  • Weather Affects Photovoltaics The performance of a photovoltaic array is dependent upon sunlight. Climate conditions (such as clouds or fog) have a significant effect on the amount of solar energy received by a photovoltaic array and, in turn, its performance.
  • History of the Photovoltaic Cell The first practical photovoltaic (PV) cell was developed in 1954 by Bell Telephone researchers examining the sensitivity of a properly prepared silicon wafer to sunlight. Beginning in the late 1950s, PV cells were used to power U.S. space satellites. PV cells were next widely used for small consumer electronics like calculators and watches and to provide electricity in remote or "off-grid" locations were there were no electric power lines. Technology advances and government financial incentives have helped to greatly expand PV use since the mid-1990s.
  • Using solar energy produces no air or water pollution and no greenhouse gases, but does have some indirect impacts on the environment.
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EIA Energy Kids - Geothermal - 3 views

  • Geothermal Basics What Is Geothermal Energy? The word geothermal comes from the Greek words geo (earth) and therme (heat). So, geothermal energy is heat from within the Earth. We can recover this heat as steam or hot water and use it to heat buildings or generate electricity. Geothermal energy is a renewable energy source because the heat is continuously produced inside the Earth.
  • Geothermal energy is generated in the Earth's core. Temperatures hotter than the sun's surface are continuously produced inside the Earth by the slow decay of radioactive particles, a process that happens in all rocks. The Earth has a number of different layers:
  • Where Geothermal Energy is Found The ring of fire goes around the edges of the Pacific. The map shows that volcanic activity occurs around the Pacific rim.Source: National Energy Education Development Project (Public Domain) Naturally occurring large areas of hydrothermal resources are called geothermal reservoirs. Most geothermal reservoirs are deep underground with no visible clues showing above ground. But geothermal energy sometimes finds its way to the surface in the form of: Volcanoes and fumaroles (holes where volcanic gases are released) Hot springs Geysers
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  • U.S. Geothermal Is Mostly in the West Most of the geothermal reservoirs in the United States are located in the western States and Hawaii.
  • Electricity generation power plants require water or steam at very high temperature (300° to 700°F). Geothermal power plants are generally built where geothermal reservoirs are located within a mile or two of the surface.
  • The United States Is the Leader in Geothermal Power Generation The United States leads the world in electricity generation with geothermal power.  In 2009, U.S. geothermal power plants produced 15 billion kilowatt-hours (kWh), or 0.4% of total U.S. electricity generation.  In 2009, five States had geothermal power plants:
  • Geothermal power plants use hydrothermal resources that have two common ingredients: water (hydro) and heat (thermal). Geothermal plants require high temperature (300°F to 700°F) hydrothermal resources that may come from either dry steam wells or hot water wells.
  • high-pressure hot water from deep inside the Earth and convert it to steam to drive the generator turbines. When the steam cools, it condenses to water and is injected back into the ground to be used over and over again. Most geothermal power plants are flash steam plants.
  • Geothermal Power Plants Have Low Emission Levels Geothermal power plants do not burn fuel to generate electricity, so their emission levels are very low. They release less than 1% of the carbon dioxide emissions of a fossil fuel plant. Geothermal plants use scrubber systems to clean the air of hydrogen sulfide that is naturally found in the steam and hot water. Geothermal plants emit 97% less acid rain-causing sulfur compounds than are emitted by fossil fuel plants. After the steam and water from a geothermal reservoir have been used, they are injected back into the Earth.
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Connecting renewable energy to the grid - 2 views

  • Big cities need large amounts of electricity to function. Often, this is transported from generating sites located in remote areas hundreds or even thousands of kilometers away. The question is how to move as much electricity as possible from renewable generation sites like hydro plants and wind parks without impairing the function of the power networks that need it.
  • One of the challenges of renewable power generation like wind and solar power is that it can be interrupted, and this variability affects the stability of the power produced
  • The "smart grid" will create a power network that is more reliable, flexible, secure and efficient
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  • Power grids are facing a major transformation, driven by the need to integrate renewable energy
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Hydropower: Generate Energy with Rivers and Ocean Tides - For Dummies - 0 views

  • When water flows toward the shore with the incoming tide, it flows through a tidal energy system, turning a turbine that generates electricity. When the tide shifts and flows in the opposite direction, away from shore, the tidal energy system again captures the energy with a turbine and converts it into electricity.
  • An important source of alternative energy is hydropower: converting the flow of rivers and ocean waves and tides into electricity through dams and turbines. The best part about both of these water sources is that they’re 100 percent renewable.
  • The main advantage of using ocean tides for energy is that tides and waves are a constant, unchanging, clean source of energy. The main disadvantage is that tidal energy systems may impact the environment by changing the flow of water into shoreline and estuarine ecosystems.
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HowStuffWorks "How Geothermal Energy Works" - 0 views

  • t's called geothermal energy -- from the Greek words geo, or "earth," and therme, meaning "heat."
  • The core, about 4,000 miles (6,437 kilometers) beneath the surface, can reach temperatures of 7,600 degrees Fahrenheit
  • (4,204 degrees Celsius).
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  • Part of that heat is left over from the Earth's formation, about 4 billion years ago. The rest comes from the constant decay of radioactive isotopes inside the Earth.
  • ometimes that water escapes through cracks in the Earth to form pools of hot water (hot springs) or bursts of hot water and steam (geysers). The rest of the heated water remains in pools under the Earth's surface, called geothermal reservoirs.
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It is said that rotation of the earth causes wind.But how? - 0 views

  • Wind speed and direction is a result of high and low pressure areas in the atmosphere.
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    Wind speed and direction is a result of high and low pressure areas in the atmosphere.
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Voith | Wave power plants - 0 views

  • With this technology, sea water turbines do not come into contact with water
  • Instead, a column of air is set in motion which drives the machines. In detail, this works in the following manner: The waves spill into a hollow container which is open to the sea. This compresses and calms the air column in a so-called collector in a similar way to how an air pump works. The power plant "breathes" in and out. The pressure difference is then turned into rotary energy in a so-called Wells turbine (named after its inventor). This is in turn passed to a generator where electricity is produced. This means that the turbine has the air periodically flow through it from both sides, depending on whether the device is "breathing" in or out. Because of the special rotor geometry, there is no need to either periodically change the blade angles or the direction of rotation. If you consider the fact that an average of some 3 million waves break on to the coast every year, it is clear that only this simple turbine design can offer maximum reliability.
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Solar Energy Facts - 0 views

  • hen a modern day person hears the term “solar energy” they often think about solar panels that are mounted on roofs in sunny neighborhoods. Find out how to slash your electric bill by 75% with little out of pocket expense. Although this is a part of solar energy, there is much more to it.
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DOE - Fossil Energy: How Fossil Fuels Were Formed - 1 views

  • They were formed from prehistoric plants and animals that lived hundreds of millions of years ago.
  • Some coal deposits, however, were formed from freshwater swamps which had very little sulfur in them. These coal deposits, located largely in the western part of the United States, have much less sulfur in them
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Wind energy has been around for thousands of years. But man is now finding ever more in... - 0 views

  • Wind Energy The answer is blowin’ in the wind How is man going to keep up with increasing energy demand while the amount of available fossil fuel diminishes? The answer could be wind power, the capturing of the energy contained in gusts of wind. What is wind Energy?
  • Man has been using wind energy for thousands of years. Windmills, sails and even kites are all devices designed to harness the awesome power produced when the wind blows. Even modern aircraft benefit from wind power. Pilots flying westward usually expend much effort trying to make sure they place themselves in the jet stream, the hundred mile per hour wind caused by the earth spinning. Now engineers are able to convert such power into electricity, pump it into grids and provide energy for homes.
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HowStuffWorks "How Biodiesel Works" - 0 views

  • Lost in the mix are the biofuels, fuels made from biological ingredients instead of fossil fuels. These starting ingredients can range from corn to soybeans to animal fat, depending on the type of fuel being made and the production method.
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How Geothermal Energy Works - 0 views

  • The amount with in the earth’s surface contains 50,000 times more energy than all the oil and natural gas resources in the world.
  • To get that heat, water is pumped down an “injection well”. Then it filters through the cracks in the rocks where they are at a high temperature. The water then returns via the “recovery well” under pressure in the form of steam. That steam is captured and is used to drive electric generators.
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