HYDROELECTRIC ENERGY
HOW DOES IT WORK
A hydraulic turbine converts the energy of flowing water into mechanical energy. A hydroelectric generator moves all of this mechanical energy into electricity. The operation of a generator is based on the principles discovered by Faraday. Faraday found out that when a magnet is moved past a conductor, it causes electricity to flow. In a large generator, electromagnets are made by circulating direct current through loops of wire wound around stacks of magnetic steel laminations. These are called field poles, and are mounted on the perimeter of the rotor. The rotor is attached to the turbine shaft, and rotates at a fixed speed. When the rotor turns, it causes the field poles (the electromagnets) to move past the conductors mounted in the stator. This, in turn, causes electricity to flow and a voltage to develop at the generator output terminals.
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ADVANTAGES OF HYDROELECTRIC ENERGY:
Electricity can be produced at a very constant rate. If electricity is not needed at the moment then the sluice gates can be shut to stop making electricity. Dams are designed to last many decades. The lake that forms behind the dam can be used for water sports, leisure and for irrigation purposes. The build up of water in the lake means that energy can be stored until needed. When in use, electricity produced by dam systems does not produce green house gases. They do not pollute the atmosphere. DISADVANTAGES OF HYDROELECTRIC ENERGY: Dams are extremely expensive to build and must be built to a very high standard. When a hydroelectric plant is built often times because so much room is needed to build the dam, people are forced to move and the people may have to leave their farm and loose their jobs to allow the plant to be built. The building of large dams can cause serious geological damage. For example, the building of the Hoover Dam in the USA triggered a number of earthquakes and has depressed the earth’s surface at its location. Building a large dam alters the natural water table level. For example, the building of the Aswan Dam in Egypt has altered the level of the water table. This is slowly leading to damage of many of its ancient monuments as salts and destructive minerals are deposited in the stonework from ‘rising damp’ caused by the changing water table level. GEOTHERMAL ENERGYHOW DOES IT WORKHeat from the earth can be used as an energy source in many different ways, from very large and complex power stations to very small and relatively simple pumping systems. This heat energy is known as geothermal energy it can be found almost anywhere in the world from as far away as in the remote deep wells in Indonesia and also as close as in the dirt in our backyards.
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WHAT ARE THE ADVANTAGES AND DISADVANTAGES
ADVANTAGES OF GEOTHERMAL ENERGY:
Geothermal energy generally involves low running costs. It saves about 80% the costs over fossil fuels and no fuel is used to generate the power. Since, no fuel is required, costs for purchasing, transporting and cleaning up plants it is quite low. As long as we don’t pump too much cold water into the earth -cooling off the hot rocks- the energy will just keep on coming! Geothermal energy doesn’t produce pollution, and at the same time, it doesn’t contribute to the greenhouse effect. The power stations for geothermal energy don’t take up a whole bunch of room, and because of this, they tend to have less of an impact on the surrounding environment. Because geothermal energy is energy in and of itself, no outside sources of fuel are needed to keep the power houses running. Even better, geothermal efficiency offers an even more exciting benefit for homeowners to safe money. Once you’ve built the geothermal power station, the energy is nearly, free!
DISADVANTAGES OF GEOTHERMAL ENERGY:
There is an unavailability of equipment, staff, infrastructure, training that makes it hard to install geothermal plants across the globe. Not enough skilled manpower and availability of suitable build location pose serious problem in adopting geothermal energy globally. There is a huge one time investment and skilled staff needs to be recruited and relocated to plant locations. Also electricity towers and stations need to be set up to move the power from geothermal plant to consumer. Geothermal sites can run out of steam over a period of time due to drop in temperature or if too much water is injected to cool the rocks and this may result in a huge loss for the companies which have invested heavily in these plants.
Geothermal energy generally involves low running costs. It saves about 80% the costs over fossil fuels and no fuel is used to generate the power. Since, no fuel is required, costs for purchasing, transporting and cleaning up plants it is quite low. As long as we don’t pump too much cold water into the earth -cooling off the hot rocks- the energy will just keep on coming! Geothermal energy doesn’t produce pollution, and at the same time, it doesn’t contribute to the greenhouse effect. The power stations for geothermal energy don’t take up a whole bunch of room, and because of this, they tend to have less of an impact on the surrounding environment. Because geothermal energy is energy in and of itself, no outside sources of fuel are needed to keep the power houses running. Even better, geothermal efficiency offers an even more exciting benefit for homeowners to safe money. Once you’ve built the geothermal power station, the energy is nearly, free!
DISADVANTAGES OF GEOTHERMAL ENERGY:
There is an unavailability of equipment, staff, infrastructure, training that makes it hard to install geothermal plants across the globe. Not enough skilled manpower and availability of suitable build location pose serious problem in adopting geothermal energy globally. There is a huge one time investment and skilled staff needs to be recruited and relocated to plant locations. Also electricity towers and stations need to be set up to move the power from geothermal plant to consumer. Geothermal sites can run out of steam over a period of time due to drop in temperature or if too much water is injected to cool the rocks and this may result in a huge loss for the companies which have invested heavily in these plants.
WIND ENERGY
HOW DOES IT WORK
A wind
turbine works the opposite of a fan. Instead of using electricity to
make wind, like a fan does wind turbines use wind to make electricity. The
wind turns the blades, which spin a shaft, which connects to a generator
and makes electricity. View the wind turbine animation to see how a
wind turbine works.
Wind is a form of solar energy and it is a result of the uneven heating
of the atmosphere by the sun the irregularities of the earth's surface
and the rotation of the earth. Wind flow patterns and speeds vary greatly across the United States
. Humans use this wind flow, or motion energy for all of these purposes like
sailing, flying a kite, and even generating electricity!
WHAT ARE THE ADVANTAGES AND DISADVANTAGES
ADVANTAGES OF WIND POWER:
The wind is
free and also with all of the modern technology it can be captured efficiently. Once the wind turbine is built and
the energy it produces does not cause green house gases or other
pollutants. Although wind turbines can be
very tall each takes up only a small plot of land. This means that the
land below it can still be used. Many people find wind farms an
interesting feature of the landscape. Remote areas that are not
connected to the electricity power grid can use wind turbines to produce
their own electricity supply. Wind turbines have a role to play
in both the developed and third world. Wind turbines are available in many different sizes which means a vast range of people and businesses can use
them. Single households to small towns and villages can make good use of
range of wind turbines available today.
DISADVANTAGES OF WIND POWER: The strength of the wind is not very constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity at every moment in time. There will be times when they produce no electricity at all. Many people feel that the countryside should be left untouched, without these large structures being built. The landscape should left in its natural form for everyone to enjoy. Wind turbines are very noisy. Each one can generate the same level of noise as a family car traveling at 70 mph. Many people see large wind turbines as unsightly structures and not pleasant or interesting to look at. They disfigure the countryside and are generally pretty erugly. When wind turbines are being manufactured some pollution is produced. Therefore wind power does produce some pollution. Large wind farms are needed to provide entire communities with enough electricity. For example, the largest single turbine available today can only provide enough electricity for 475 homes, when running at full capacity. |
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SOLAR ENERGY
HOW DOES IT WORK
The sun is a power plant in the sky that bathes Earth in ample energy to fulfill all the world's power needs many times over. It doesn't give off any carbon dioxide emissions. It won't run out and it's free. The sun's light contains energy. Usually, when light hits an object the energy turns into heat, like when you are sitting in the sun and it becomes warm. But when light hits certain materials the energy turns into an electrical current instead, which we can then harness for power.
WHAT ARE THE ADVANTAGES AND DISADVANTAGES
ADVANTAGES OF SOLAR ENERGY
Solar energy is very clean and renewable energy source. Once a solar panel is installed, solar energy can be produced for free. Solar energy will last forever. Solar energy causes no pollution. Solar cells make absolutely no noise at all. Very little maintenance is needed to keep solar cells running. There are no moving parts in a solar cell which makes it impossible to damage them at all. In the long term, there can be a high return on investment due to the amount of free energy a solar panel can produce.
DISAVANTAGES OF SOLAR ENERGY
Solar panels can be very expensive to install resulting in a time-lag of many years for savings on energy bills to match initial investments. Electricity generation depends entirely on a countries' exposure to sunlight. This could be limited by the climate. Solar power stations do not match the power output of similar sized conventional power stations; they can also be very expensive to build. Solar power is used to charge batteries so that solar powered devices can be used at night. The batteries can often be very large and also very heavy, taking up space and needing to be replaced from time to time.
Solar energy is very clean and renewable energy source. Once a solar panel is installed, solar energy can be produced for free. Solar energy will last forever. Solar energy causes no pollution. Solar cells make absolutely no noise at all. Very little maintenance is needed to keep solar cells running. There are no moving parts in a solar cell which makes it impossible to damage them at all. In the long term, there can be a high return on investment due to the amount of free energy a solar panel can produce.
DISAVANTAGES OF SOLAR ENERGY
Solar panels can be very expensive to install resulting in a time-lag of many years for savings on energy bills to match initial investments. Electricity generation depends entirely on a countries' exposure to sunlight. This could be limited by the climate. Solar power stations do not match the power output of similar sized conventional power stations; they can also be very expensive to build. Solar power is used to charge batteries so that solar powered devices can be used at night. The batteries can often be very large and also very heavy, taking up space and needing to be replaced from time to time.