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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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Solar power - Wikipedia, the free encyclopedia - 0 views

  • The Life-cycle greenhouse-gas emissions of solar power are in the range of 22 to 46  g/kWh depending on if solar thermal or solar PV is being analyzed, respectively. With this potentially being decreased to 15 g/kWh in the future.[71] For comparison (of weighted averages), a combined cycle gas-fired power plant emits some 400-599 g/kWh,
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    Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect.
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Where Does Wind Power Come From? - 0 views

  •  Wind power is an interesting renewable energy source as wind turbines can essentially be placed anywhere geographically where there is ample wind to turn the wind blades.
  • One thing that we haven't written about extensively on the MyEnergySolution.com blog is wind power.  Wind power is an interesting renewable energy source as wind turbines can essentially be placed anywhere geographically where there is ample wind to turn the wind blades.
  • o put this in context, an average U.S. household uses about 10 megawatt-hours (MWh) of electricity each year. One megawatt of installed wind energy from a single large turbine can generate from 2,400 to more than 3,000 MWh annually – enough to power about 250 homes.
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Solar power - Sustainable green energy to protect our economy and environment | PARTHA ... - 2 views

  • A Solar Energy system can operate entirely independently, not requiring a connection to a power or gas grid at all. Systems can therefore be installed in remote locations, making it more practical and cost-effective than the supply of utility electricity to a new site.
  • A Solar Energy system can operate entirely independently, not requiring a connection to a power or gas grid at all. Systems can therefore be installed in remote locations, making it more practical and cost-effective than the supply of utility electricity to a new site.
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    "It offers much more self-reliance than depending upon a power utility for all electricity."
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Tidal power - Wikipedia, the free encyclopedia - 0 views

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    "tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power."
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Tidal Power: Pros and Cons - 0 views

  • Day and night, the vast waters of the ocean press and recede along the shorelines of Earth’s every continent in accordance to the celestial movements of our planet in relation to the sun and the moon
  • ay and night, the vast waters of the ocean press and recede along the shorelines of Earth’s every continent in accordance to the celestial movements of our planet in relation to the sun and the moon
  • Records of ocean power conversion date back to 900A.D. where the power of tidal movement was used to grind grains. The first modern commercial tidal power was installed off the coast of St. Malo, in Northern France. Installed in 1965, it has been operating continuously since then, producing 240 MW with every tide.
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    how the tides move to create energy
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What are the advantages and disadvantages of alternative tidal power as an energy source - 1 views

  • Advantages: Tidal energy is an alternative energy. The energy produced is clean and non polluting. There is no carbon dioxide or any other by-products released. It produces no greenhouse gases or other waste.It is a renewable energy that will help reduce our reliance on the burning of fossil fuels. There are two tides every day and they can be relied on. The energy is there for the taking.So the electricity supply is constant and efficient.Once you've built it, the energy is free because it comes from the ocean's powerIt needs no fuel.It produces electricity reliably.Not expensive to maintain.Tides are definitely predictable. There are two tides every day and they can be relied on. So the electricity supply is constant. Offshore turbines and vertical-axis turbines are not ruinously expensive to build and do not have a large environmental impact.A plant is expected to be in production for 75 to 100 yearsUses an abundant, inexpensive fuel source (water) to generate powerMay protect coastline against damage from high storm tides and provide a ready-made road bridge
  • Holding back the tide allows silt to build up on the river bed.The dams and barrages sometimes interfere with shipping. You will need to find a way to connect the electricity to the grid.Pose same threats as large dams, altering the flow of saltwater in and out of estuaries, which changes the hydrology and salinity and possibly negatively affects the marine mammals that use the estuaries as their habitatTurbidity decreases as a result of smaller volume of water being exchanged between the basin and the sea.The average salinity inside the basin decreases, also affecting the ecosystemA barrage across an estuary is very expensive to build, and affects a very wide area - the environment is changed for many miles upstream and downstream. Many birds rely on the tide uncovering the mud flats so that they can feed.There are few suitable sites for tidal barrages.Only provides power for around 10 hours each day, when the tide is actually moving in or out.
  • It only provides about 7% of the power needed for England and Wales that means that some people get their energy close to free and some pay a lot of moneyWater is not replenished, it cannot flow away so any dirt or pollution lingers around the coast much longerNeeds a very big piece of sea to be cost effectiveCannot be used inlandBarrage systems require salt resistant parts and lots of maintenanceAffects the lives of the people who rely on fishing for a means of livingLimited because the tide never speeds up or slows down, and occurs on 6 hour cycles. It is also dependent on the fetch distance. The fetch is the distance the tide rises and falls, so some beaches have a very small fetch, and others have a big fetch but hardly any have a large enough fetch to support tidal energy
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How long has wind power been used? - Curiosity - 0 views

  • Windmills were first used to grind grain anywhere from 2000 to 4000 years ago in ancient Persia or Babylon;
  • The initial use of wind power was by Egyptians in 3000 B.C. to move their sailboats.
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    "The initial use of wind power was by Egyptians in 3000 B.C. to move their sailboats. Windmills were first used to grind grain anywhere from 2000 to 4000 years ago in ancient Persia or Babylon; crusaders brought the windmill idea back to Europe with them in the 11th century A.D. In the 1930s, windmills in rural areas of the U.S. pumped water and generated electricity."
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    In the 1930s, windmills in rural areas of the U.S. pumped water and generated electricity.
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    The initial use of wind power was by Egyptians in 3000 B.C. to move their sailboats. Windmills were first used to grind grain anywhere from 2000 to 4000 years ago in ancient Persia or Babylon; crusaders brought the windmill idea back to Europe with them in the 11th century A.D.
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Tidal Power - 1 views

  • Tidal power is a means of electricity generation achieved by capturing the energy contained in moving water mass due to tides. Two types of energy can be extracted: kinetic energy of currents between ebbing and surging, and potential energy from the difference in height (or head) between high and low water marks.
  • Tidal power schemes do not produce energy 24 hours a day. A conventional design, in any mode of operation, would produce power for 6 to 12 hours in every 24 and will not produce power at other times
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List of Tidal Power Plants and Future Tidal Stations- Facing Difficult Times | Green Wo... - 0 views

  • Except for South Korea,not other government in the world is really pushing Tidal Wave Energy which needs massive government support at this stage of development.
  • Tidal Technology is still in the baby phase
  • Most of the tidal power plants using the modern tidal turbine technology are still in the pilot phase and generate negligible power.However tidal power stations have the potential to generate large amounts of energy in a non-polluting way
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Photovoltaic power station - Wikipedia, the free encyclopedia - 0 views

  • A photovoltaic power station, also known as a solar park, is a large-scale photovoltaic system designed for the supply of merchant power into the electricity grid. They are differentiated from most building-mounted and other decentralised solar power applications because they supply power at the utility level, rather than to a local user or users. They are sometimes also referred to as solar farms or solar ranches, especially when sited in agricultural areas.
  • Most stations are sited within a few kilometres of a suitable grid connection point. This network needs to be capable of absorbing the output of the solar park when operating at its maximum capacity. The project developer will normally have to absorb the cost of providing powerlines to this point and making the connection; in addition often to any costs associated with upgrading the grid, so it can accommodate the output from the plant.
  • Income is therefore affected not only by the reliability of equipment within the plant, but also by the availability of the grid network to which it is exporting
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Solar Electricity and how it works - Photovoltaic Systems and Components, Grid-Connecte... - 0 views

  • A valuable feature of photovoltaic systems is the ability to connect with the existing power grid which allows owners to sell excessive electricity back to the utility with a plan known as (5) Net Metering. At times when you are not using all of the electricity produced by your system, your meter will spin backwards selling the electricity back to the (6) utility power grid at retail rate.
  • (1) Solar Electric or PV modules convert sunlight to electricity. The PV modules generate DC electricity - or direct current - sending it to the inverter. (2) The inverter transforms the DC power into AC electricity for ordinary household needs. (3) Existing electrical panel distributes solar electricity and utility power to (4) loads (appliances). For systems with a battery backup (optional), the inverter also regulates the charge of batteries. The electricity stored in the batteries can be used at night or during blackouts.
    • dpurdy
       
      Great video showing solar cell (photovoltaic) in action.
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    Solar is not always connected to grid. Sometimes there are batteries, otherwise your system is connected to grid to share excess electricity.
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TLC Home "How many solar cells would I need in order to provide all of the electricity ... - 0 views

  • Because solar electricity is so expensive, you would normally go to great lengths to reduce your electricity consumption. Instead of a desktop computer and a monitor you would use a laptop computer. You would use fluorescent lights instead of incandescent. You would use a small B&W TV instead of a large color set. You would get a small, extremely efficient refrigerator­. By doing these things you might be able to reduce your average power consumption to 100 watts. This would cut the size of your solar panel and its cost by a factor of 6, and this might bring it into the realm of possibility.
  • From our calculations and assumptions abo­ve, we know that a solar panel can generate 70 milliwatts per square inch * 5 hours = 350 milliwatt hours per day. Therefore you need about 41,000 square inches of solar panel for the house. That's a solar panel that measures about 285 square feet (about 26 square meters). That would cost around $16,000 right now. Then, because the sun only shines part of the time, you would need to purchase a battery bank, an inverter, etc., and that often doubles the cost of the installation.If you want to have a small room air conditioner in your bedroom, double everything.
  • A "typical home" in America can use either electricity or gas to provide heat -- heat for the house, the hot water, the clothes dryer and the stove/oven. If you were to power a house with solar electricity, you would certainly use gas appliances because solar electricity is so expensive. This means that what you would be powering with solar electricity are things like the refrigerator, the lights, the compute­r, the TV, stereo equipment, motors in things like furnace fans and the washer, etc. Let's say that all of those things average out to 600 watts on average. Over the course of 24 hours, you need 600 watts * 24 hours = 14,400 watt-hours per day.
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  • The thing to remember, however, is that 100 watts per hour purchased from the power grid would only cost about 24 cents a day right now, or $91 a year. That's why you don't see many solar houses unless they are in very remote locations. When it only costs about $100 a year to purchase power from the grid, it is hard to justify spending thousands of dollars on a solar system.
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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: 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 - Wind - 1 views

  • Wind is simply air in motion. It is caused by the uneven heating of the Earth's surface by the sun. Because the Earth's surface is made of very different types of land and water, it absorbs the sun's heat at different rates. One example of this uneven heating can be found in the daily wind cycle.
  • The Daily Wind Cycle During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises, and the heavier, cooler air rushes in to take its place, creating wind. At night, the winds are reversed because the air cools more rapidly over land than over water. In the same way, the atmospheric winds that circle the earth are created because the land near the Earth's equator is heated more by the sun than the land near the North and South Poles. Wind Energy for Electricity Generation Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source because the wind will blow as long as the sun shines
  • Like old fashioned windmills, today’s wind machines (also called wind turbines) use blades to collect the wind’s kinetic energy. The wind flows over the blades creating lift, like the effect on airplane wings, which causes them to turn. The blades are connected to a drive shaft that turns an electric generator to produce electricity. With the new wind machines, there is still the problem of what to do when the wind isn't blowing. At those times, other types of power plants must be used to make electricity.
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  • Wind Production In 2010, wind turbines in the United States generated about 2% of total U.S. electricity generation. Although this is a small fraction of the Nation's total electricity production, it was equal to the annual electricity use of about 8.7 million households.
  • Operating a wind power plant is not as simple as just building a windmill in a windy place. Wind plant owners must carefully plan where to locate their machines. It is important to consider how fast and how much the wind blows at the site
  • As a rule, wind speed increases with altitude and over open areas that have no windbreaks. Good sites for wind plants are the tops of smooth, rounded hills, open plains or shorelines, and mountain gaps that produce wind funneling.
  • Conditions are well suited along much of the coasts of the United States to use wind energy. However, there are people who oppose putting turbines just offshore, near the coastlines, because they think the wind turbines will spoil the view of the ocean. There is a plan to build an offshore wind plant off the coast of Cape Cod, Massachusetts.
  • Wind is a renewable energy source that does not pollute, so some people see it as a good alternative to fossil fuels.
  • 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.
  • As late as the 1920s, Americans used small windmills to generate electricity in rural areas without electric service. When power lines began to transport electricity to rural areas in the 1930s, local windmills were used less and less,
  • In the early 1980s, wind energy really took off in California, partly because of State policies that encouraged renewable energy sources.
  • Wind is a clean source of energy, and overall, the use of wind for energy has fewer environmental impacts than using many other energy sources. Wind turbines (often called windmills) do not release emissions that pollute the air or water (with rare exceptions), and they do not require water for cooling. They may also reduce the amount of electricity generated from fossil fuels and therefore reduce the amount of air pollution, carbon dioxide emissions, and water use of fossil fuel power plants.
  • Modern wind turbines are very large machines, and some people do not like their visual impact on the landscape.
  • Some people do not like the sound that wind turbine blades make. Some types of wind turbines and wind projects cause bird and bat deaths. These deaths may contribute to declines in species that are also being affected by other human-related impacts.
  • Most wind power projects on land also require service roads that add to their physical impact on the environment.
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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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Solar Power - Advantages and Disadvantages - Sustainable Development Information - 0 views

  • By converting the power of the sun into electricity, solar energy is clean, green, will never run out and, after the initial cost of the solar panels, is entirely free
  • The sun is constant – it will always be there and is therefore a reliable, utterly renewable source of energy.
  • As it does not rely on the burning of harmful fuels to generate electricity, solar power is non-polluting – it does not contribute to global warming or greenhouse gas emissions.
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Why Solar Powered Energy Is Better Than Fossil Fuels - 2 views

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    In only one hour, the amount of energy that shines on the Earth equates to the amount used by the world's population in an entire year. Mankind has developed a way to utilize the sun's vast energy by converting its sunlight into electricity via photovoltaics and other solar power methods.
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Tidal Energy : Advantages and Disadvantages - 0 views

  • Advantages of Tidal Energy1)  It is an inexhaustible source of energy. 2)  Tidal energy is environment friendly energy and doesn't produce greenhouse gases. 3)  As 71% of Earth’s surface is covered by water, there is scope to generate this energy on large scale. 4)  We can predict the rise and fall of tides as they follow cyclic fashion. 5) Efficiency of tidal power is far greater as compared to coal, solar or wind energy. Its efficiency is around 80%. 6)  Although cost of construction of tidal power is high but maintenance costs are relatively low. 7)  Tidal Energy doesn’t require any kind of fuel to run. 8)  The life of tidal energy power plant is very long. 9)  The energy density of tidal energy is relatively higher than other renewable energy sources.
  • Disadvantages of Tidal Energy 1)  Cost of construction of tidal power plant is high. 2)  There are very few ideal locations for construction of plant and they too are localized to coastal regions only. 3)  Intensity of sea waves is unpredictable and there can be damage to power generation units. 4)  Influences aquatic life adversely and can disrupt migration of fish. 5)  The actual generation is for a short period of time. The tides only happen twice a day so electricity can be produced only for that time. 6)  Frozen sea, low or weak tides, straight shorelines, low tidal rise or fall are some of the obstructions. 7)  This technology is still not cost effective and more technological advancements are required to make it commercially viable. 8)  Usually the places where tidal energy is produced are far away from the places where it is consumed. This transmission is expensive and difficult. Tidal Energy is thus a clean source of energy and doesn’t require much land or other resources as in harnessing energy from other sources. However, the energy generated is not much as high and low tides occur only twice a day and continuous energy production is not possible.
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    Lets now discuss the advantages and
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