Иностранный язык (английский яз)

RENEWABLE SOURCES OF ENERGY

Answer the following questions and read the text below to check your answer.

1)        What is the difference between renewable and non –  renewable energy sources?

2)   Why is it so important to develop alternative energy sources?

 The pros and cons of alternative energy

Oil and oil products make the world go round, some would say. Just about every piece of equipment or type of machinery uses oil to run. Oil, however, is a «non-replenishable» resource, and when it runs out, how will we run our equipment and machinery? In response to this question, many are trying to develop alternative sources of energy. Hopefully, these alternative sources will make the world less dependent on the limited supply of oil.

There are a number of types of alternative energy sources which have already been developed. They include:

Energy from the sun. Known as solar energy, this powerful and unlimited source of energy would offer us a very efficient alter­native to oil, and it is a free resource.

If solar power were properly developed, it could easily become our primary power source. The use of solar power is especially at­tractive in areas that have long days and not much cloud cover. It is therefore ideal for less developed areas which may be far from the more traditional power sources.

The problem is that capitalizing on this powerful resource is not as simple as it seems. Locations with limited daylight hours or consistently overcast skies do not receive the amount of light re­quired to store the energy, in addition, locations that do not have wide expanses of land available will not be able to tap this re­source, since the photocells necessary to collect and store the sun­light require large tracts of land.

Wind. The power of the wind was harnessed hundreds of years ago to run windmills, which directly ran mills on farmlands. The same principle can now be used, with the addition of storage capacity, to supply as much as 20 % of our energy needs. In loca­tions with strong winds, such as along the seashore, or in the moun­tains, wind can easily be harnessed to run generators to create elec­tricity. This is an energy alternative that is safe and clean: no harm­ful carbon dioxide or other gases are produced in the creation of electricity through wind power. However, there are many areas that don't receive enough wind to make it a reliable source.

Hydroelectric energy. A powerful surge of water sluicing over a cliff creates a tremendous source of energy. This is the con­cept behind the construction of the many dams in the world today. Hydroelectric energy is another clean alternative to oil, since it does not produce waste or pollution. Energy produced by a dam is cheap and adaptable, but the cost of building a dam is very high and, with­out destroying entire potentially habitable areas, it is difficult to find locations for dams. Tidal energy –  the power of water can also be harnessed on a smaller scale by the use of tidal flow. This alter­native is very limited, however, since not every area has bodies of water with strong tidal flows, and the concern over the effect on fish and birds in the area raise many concerns. It is also not a steady source of energy, since tides move in twice daily movements. For this reason there are only nine workable sites for this type of power and only two being used.

Biomass. Biomass can be considered a nice way of speaking of waste. Animal waste, rotten crops and grains, residues from wood mills and aquatic waste can all be fermented to form an alco­hol that is comparable to coal in its energy producing powers. It also produces greenhouse gases, making it one of the less attractive alternative energy sources. In addition to these more «natural» sources of energy produc­tion, fusion, fuel cells, nuclear, geothermal and hydrogen energies can be used for our future needs for power. These have negative environmental effects and so are questioned as alternative sources, but doesn't oil have as many, if not more negative effects? 

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