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pros_and_cons_of_energy_sources

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What are the pros and cons of different sources of energy?
The three different kinds of energy-sources have their own pros and cons. In this
part we give a few of them.

       Nuclear power
        For the generation of nuclear power, a little bit of uranium (an element) from
        the earth can be used to make a whole lot of energy. This is a very good
        thing. It’s an advantage because the earth has enough uranium to last a long
        time. A very big disadvantage is that the uranium, is very radio-active. Also
        the used rods and other materials used in nuclear power plants stay radio-
        active for hundres of years. The nuclear power plant Chernobyl exploded
        leaking radioactive material to the surrounding city polluting the environment
        and making the entire city a waste zone. People could no longer live there.

       Fossil energy
        The big advantage of fossil energy is that, to generate the energy from the
        raw material is easy and cheap. Disadvantage is that during the process of
        combustion a lot of toxic materials comes into the air which causes extra
        pollution of the atmosphere, these materials also increase the effect of global
        warming. Another disadvantage of fossil energy is that the supply of fossil
        fuels is not endless. The current supply is for approximately 50 years. That is
        why the USA wants to trail for oil and natural gas in Alaska. If the USA does
        this, there are big consequences for the environment.

       Alternative energy
        The advantage of alternative energy is that the energy source is endless and
        doesn't give any pollution. Wind, biomass, geothermal, solar and
        hydroelectric are some examples. Still, there are not many alternative
        energy forms, because for instance the technique to transform sun-beams
        into electric energy is very expensive.

Wind Power
Wind energy harnesses the power of the wind to propel the blades of wind turbines. The
rotation of turbine blades is converted into electrical current by means of an electrical
generator. In the older windmills, wind energy was used to turn mechanical machinery to do
physical work, like crushing grain or pumping water.Wind towers are usually built together on
wind farms. Now, electrical currents are harnessed by large scale wind farms that are used by
national electrical grids as well as small individual turbines used for providing electricity to
isolated locations or individual homes. In 2005, worldwide capacity of wind-powered
generators was 58,982 megawatts, their production making up less than 1 of world-wide
electricity use.
                 Pros

            Wind power produces no pollution that can contaminate the environment, Since
             no chemical processes take place, like in the burning of fossil fuels, in wind power
             generation, there are no harmful by-products left over.
            Since wind generation is a renewable source of energy, we will never run out of
             it.
            Farming and grazing can still take place on land occupied by wind turbines which
             can help in the production of biofuels.
           Wind farms can be built off-shore.

            Cons

           Wind power is intermittent. Consistent wind is needed for continuous power
            generation. If wind speed decreases, the turbine lingers and less electricity is
            generated.
           Large wind farms can have a negative effect on the scenery.

            Solar Power
            Solar energy is used commonly for heating, cooking, the production of electricity,
            and even in the desalination of seawater. works by trapping the sun's rays into
            solar cells where this sunlight is then converted into electricity. Additionally, solar
            power uses sunlight that hits solar thermal panels to convert sunlight to heat
            water or air. Other methods include using sunlight that hits parabolic mirrors to
            heat water (producing steam), or simply opening a rooms blinds or window
            shades to allow entering sunlight to passively heat a room.

            Pros

           Solar power is a renewable resource. As long as the Sun exists, its energy will
            reach Earth.
           Solar power generation releases no water or air pollution, because there is no
            chemical reaction from the combustion of fuels.
           Solar energy can be used very efficiently for practical uses such as heating and
            lighting.
           The benefits of solar power are seen frequently to heat pools, spas, and water
            tanks all over.

            Cons

           Solar power does not produce energy if the sun is not shining. Nighttime and
            cloudy days seriously limit the amount of energy produced.
           Solar power stations can be very expensive to build.

            Geothermal Energy
            Literally, geothermal means, "earth heat." Geothermal energy harnesses the heat
            energy present underneath the Earth. Hot rocks under the ground heat water to
            produce steam. When holes are drilled in the region, the steam that shoots up is
            purified and is used to drive turbines, which power electric generators.

            Pros

           If done correctly, geothermal energy produces no harmful by-products.
           Once a geothermal plant is build, it is generally self-sufficient energy wise.
           Geothermal power plants are generally small and have little effect on the natural
            landscape.

            Cons

           If done incorrectly, geothermal energy can produce pollutants.
           Improper drilling into the earth can release hazardous minerals and gases.
           Geothermal sites are prone to running out of steam.

Hydroelectric Energy
Hydroelectric power comes from the potential energy of dammed water driving a water turbine
and generator. Another variation is to make use of water's kinetic energy or undammed
sources such as tidal power. Hydro power works by harnessing the gravitational descent of a
river that is compressed from a long run to a single location with a dam or a flume. This
creates a location where concentrated pressure and flow of water can be used to turn turbines
or water wheels. These can then drive an electric generator. This can be compared to past
days when a water wheel would drive a mill. Electric generators powered by hydro power can
be run backwards as a motor to pump water back up for later use.

               Pros

           Water can be accumulated above the dam and released to coincide with peaks in
            demand. So, unlike other types of power stations, hydroelectric power stations
            can promptly increase to full capacity.
           Electricity can be generated constantly, because there are no outside forces,
            unlike other forms of alternative energy, which affect the availability of water.
           Hydroelectric power produces no waste or pollution since there is no chemical
            reaction to produce power.
           Water used for hydro power can be reused.

            Cons

           Dams can be very expensive to build.
           There needs to be a sufficient, and powerful enough, supply of water in the area
            to produce energy.

				
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posted:9/24/2011
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