Skip to main content

Home/ Groups/ qmstech2
kramerjac99

Tidal energy | Alstom - 0 views

shared by kramerjac99 on 11 Mar 13 - No Cached
wellsann99

Wind Power - What is Wind Power and How Does It Work? - 0 views

  • wind power as a better way to generate electricity than plants fueled by coal, hydro (water) or nuclear power.
  •  
    "Wind power is actually a form of solar power, because wind is caused by heat from the sun. Solar radiation heats every part of the Earth's surface, but not evenly or at the same speed. Different surfaces-sand, water, stone and various types of soil-absorb, retain, reflect and release heat at different rates, and the Earth generally gets warmer during daylight hours and cooler at night. As a result, the air above the Earth's surface also warms and cools at different rates. Hot air rises, reducing the atmospheric pressure near the Earth's surface, which draws in cooler air to replace it. That movement of air is what we call wind."
  •  
    what is wind power
sconzomic99

Sea Power - Tidal Power 1 - 0 views

shared by sconzomic99 on 11 Mar 13 - No Cached
leonardsar99

The Energy Story - Chapter 15: Solar Energy - 1 views

  • We have always used the energy of the sun as far back as humans have existed on this planet. As far back as 5,000 years ago, people "worshipped" the sun. Ra, the sun-god, who was considered the first king of Egypt.
  • We have always used the energy of the sun as far back as humans have existed on this planet. As far back as 5,000 years ago, people "worshipped" the sun.
  • Ra, the sun-god, who was considered the first king of Egypt
  • ...1 more annotation...
  • When sunlight strikes the solar cell, electrons (red circles) are knocked loose. They move toward the treated front surface (dark blue color). An electron imbalance is created between the front and back. When the two surfaces are joined by a connector, like a wire, a current of electricity occurs between the negative and positive sides. These individual solar cells are arranged together in a PV module and the modules are grouped together in an array. Some of the arrays are set on special tracking devices to follow sunlight all day long.
  •  
    the sun
kramerjac99

The Physics of Tidal Energy - NYTimes.com - 0 views

  • a tidal energy project is moving ahead in Maine, with high costs but high hopes too. But the 180-kilowatt unit that the Ocean Renewable Power Company hopes to put under water next week is really just a first step. The big question is, how well will it withstand the force of the rushing water?
  • The region, the Bay of Fundy, is famous for strong tides, but the company has picked a spot called Cobscook Bay, where the current is relatively slow, an average of 5.8 knots, or 6.7 miles an hour. That is the speed at which the hardware will produce 180 kilowatts.
  •  
    How it works, how fast the waves are
behanjos99

What are geothermal energy advantages and disadvantages? - 0 views

  • Advantages: Geothermal energy cost is extremely low compared to many other energy sources. It has low pollution compared to fossil fuels and nuclear energy. Geothermal energy is a renewable energy source. Almost no environmental impact when using geothermal heat from nuclear decay. Geothermal heat pump systems can reduce your energy use storing heat from the summer/sun and makes use of it in the night and winter. Low maintenance systems.
  • Disadvantages: The most important disadvantage is absolutely the geological problem.  The heat source is mostly close to volcanic activity of some sort. Chemicals are byproducts of the production electricity with hot ground water. Some geothermal plants use a lot of water and it needs to go somewhere its after use. Some of the poluting chemicals in that water and steam are sulfur, mercury, hydrogen sulfide, arsenic, ammonia. Earth is a changing creature.  A drilled hole in the ground could supply thousands of homes heat and one earthquake could change that in a second.  It can also change gradually over time. Location, location, location.  That is certainly true of geothermal energy.  It cannot be transported over vast distances.  If used to heat up houses or for hot tap water it is only the quality of the pipe that delivers the water that determines how far it can go and if it will be of any use when it arrives. If the heat is used for electrical production it helps to have plants close so the energy loss is not too great. 
  • Corrosion is a big problem.  Composition of the chemicals can vary but it is always a problem.  It is among other the reason they need to heat up clean water to use and do not use it directly in to heating of houses.  In cases it has been used directly it causes pipes to corrode. In nuclear heating rock the rock cools down over few decades and hundreds of years are needed to get initial heating back.  Power stations of that sort are therefore not considered as profitable. Geothermal Heat pump systems do have high installation cost. Some areas run out of water or run low on ground water during seasonal dry spells. Less water means less heat and less energy to produce. Some drilling sites are too hot to handle.  Yea. Drillers have actually tried and tried some holes and they just can’t get the needed equipment in because the holes shoot it out like guns.   With workers running to stay alive while steel rains down on them. 
cottonetar98

GENERATION TO THE NATION - 0 views

  • Wind is created when the sun hits the earth. The air above water and the air above the ground heat at different rates. Since the air above the ground heats faster, the warm air from the ground hits the atmosphere first. It then is pushed out toward the sea. As the air heads toward the sea, it gets colder and sinks back down to the sea level. This creates a current pushing the sea air toward the land in the form of wind. The stronger the sun's energy on the land and water, the faster the wind will circulate.
  • As the gearbox turns, it feeds the RPM into the generator, which transfers the energy into usable electrical energy and stores it. Large cables are attached to the generator that feed the electrical currents from the generators of all the wind turbines on the farm into one electrical storage area. The energy can then be transported through power lines around the area for commercial and home usage.
  •  
    What makes wind. 
lemairenat98

Tidal stream power - Simple English Wikipedia, the free encyclopedia - 0 views

  • Tidal stream systems need to be located in areas with fast currents where natural flows are concentrated between obstructions, for example at the entrances to bays and rivers, around rocky points, headlands, or between islands or other land masses.
  •  
    "Tidal stream systems need to be located in areas with fast currents where natural flows are concentrated between obstructions, for example at the entrances to bays and rivers, around rocky points, headlands, or between islands or other land masses."
Connor Wiggins

HowStuffWorks "How Fuel Cells Work" - 0 views

  • This initiative, supported by legislation in the Energy Policy Act of 2005 (EPACT 2005) and the Advanced Energy Initiative of 2006, aims to develop hydrogen, fuel cell and infrastructure technologies to make fuel-cell vehicles practical and cost-effective by 2020
  • Why are governments, private businesses and academic institutions collaborating to develop and produce them? Fuel cells generate electrical power quietly and efficiently, without pollution. Unlike power
  • that use fossil fuels, the by-products from an operating fuel cell are heat and water
  • ...5 more annotations...
  • With a fuel cell, chemicals constantly flow into the cell so it never goes dead -- as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the chemicals.
  • If you want to be technical about it, a fuel cell is an electrochemical energy conversion device. A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity.
  • polymer electrolyte membrane fuel cells (PEMFC)
  • United States has dedicated more than one billion dollars to fuel cell research and development so far.So what exactly is a fuel cell,
  • With a fuel cell, chemicals constantly flow into the cell so it never goes dead -- as long as there is a flow of chemicals into the cell, the electricity flows out of the cell. Most fuel cells in use today use hydrogen and oxygen as the chemicals.
  •  
    "In 2003, President Bush announced a program called the Hydrogen Fuel Initiative (HFI) during his State of the Union Address."
  •  
    It shows how its sustainable 
warneraus98

Tidal power - Wikipedia, the free encyclopedia - 0 views

  • idal power is taken from the Earth's oceanic tides; tidal forces are periodic variations in gravitational attraction exerted by celestial bodies. These forces create corresponding motions or currents in the world's oceans
  • Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource
  • Because the Earth's tides are ultimately due to gravitational interaction with the Moon and Sun and the Earth's rotation, tidal power is practically inexhaustible and classified as a renewable energy resource
  •  
    ware tide energy comes from     
rainwateremi99

HowStuffWorks "Biofuels vs. Fossil Fuels" - 0 views

  • The U.S. currently produces 9.2 billion gallons of ethanol a year and consumes 9.6 billion gallons.
adamsaub98

How long has the concept of tidal power been around? | GreenAnswers - 0 views

  • Mills using tidal power can be dated back to 12th century Europe,
adamsaub98

How does tidal energy generate electricity - 0 views

  • Tidal BarragesA tidal barrage is basically a huge dam that is built across a river or estuary. Tunnels are built throughout the dam, and when the tide rises and falls it turns a turbine that generates power. Tidal FencesTidal fences are giant turnstiles that have vertical axis turbines mounted on a fence. The water passes through the fence and powers the turbines. Tidal TurbinesTidal turbines are the latest water power technology used in tidal areas. They look like wind turbines that are lined together underwater. They are used to capture strong tidal flows, so they have to be built extra strong.
Connor Wiggins

Fuel Cells Information, Fuel Cells Facts, Fuel Cells Technology - National Geographic - 0 views

  • A fuel cell is a device that uses a source of fuel, such as hydrogen, and an oxidant to create electricity from an electrochemical process.
  • Most fuel cells in use today, however, use hydrogen and oxygen as the chemicals.
  • Although hydrogen is the most abundant element in the universe, it is difficult to store and distribute. Canisters of pure hydrogen are readily available from hydrogen producers, but as of now, you can't just fill up with hydrogen at a local gas station.
  • ...2 more annotations...
  • All fuel cells have the same basic configuration; an electrolyte and two electrodes. But there are different types of fuel cells, based mainly on what kind of electrolyte they use.
  • All fuel cells have the same basic configuration; an electrolyte and two electrodes. But there are different types of fuel cells, based mainly on what kind of electrolyte they use.
  •  
    According to many experts, we may soon find ourselves using fuel cells to generate electrical power for all sorts of devices we use every day
dpurdy

What is wave energy? | Pelamis Wave Power - 4 views

  • What is wave energy? Waves are generated by the passage of wind across the surface of the sea.  Energy is transferred from the wind to the waves.  Waves travel vast distances across the ocean and at great speed and the energy is concentrated near the water surface.  The energy within a wave is proportional to the square of the wave height.  Therefore a two-meter high wave has four times the power of a one-meter high wave. The longer and stronger the wind blows over the surface of the sea, the higher, longer, faster and more powerful the sea is.
  • Although wave energy is a form of concentrated wind energy, as it has often travelled over large distances it is regularly out of phase with the local wind conditions.  Wave energy can therefore help to balance output variability from other renewable sources and maximise the efficient use of the electricity networks.   Wave energy is also more predictable than many other forms of renewable energy, such as wind or solar, and can be forecast accurately up to five days in advance.
  • Wave energy is clean and renewable!  It is one of the last renewable energy forms which mankind has yet to harness, and its potential is huge.
  • ...1 more annotation...
  • Wave energy could play a major part in the world’s efforts to combat climate change, potentially displacing 1 – 2 billion tonnes of CO2 per annum from conventional fossil fuel generating sources.
« First ‹ Previous 601 - 620 of 927 Next › Last »
Showing 20 items per page