Some air generators

Instructions – Questions on this test are taken from the two texts below. Read them carefully and then choose the correct alternatives that answer the questions or complete the statements placed immediately after each of them.

TEXT ONE

                                            Wind Power

Wind power exploits the kinetic energy of wind in wind turbines to generate other forms of power, especially mechanical power and electricity. It is considered one of the most used forms of renewable energies: the term wind power describes the power generated from no-fossil sources, whose use has a very significant environmental importance by assuring both minor air pollution and reduction of gas carbon emission rate. Another positive aspect related to its use is the exceptional cost/production ratio.

Wind and Aeolic Generators

Air generators, the technical name for pinwheel, divide into various categories according to: the Aeolian generator that can be either on horizontal or on vertical axis, the number of shovels (from one to three) and the lengths of shovels (from fifty centimetres to thirty meters).

Air generators are constituted by: a rotor (a pivot on which are inserted shovels), a stopping system for shovels block; a turns’ multiplier to increase shovels’ speed, a generator that enables to convert mechanical power into electricity; and a control system that manages the pinwheel functionality (and that, in overloaded or malfunctioning eventuality, blocks it); some air generators, generally the bigger ones, have also a system that provides a constant alignment between the rotor axis and the wind direction.

Wind Farms

The “Wind Farms” are real power stations: they originate from the connection of several air generators located within a fixed distance from each other in order to avoid dangerous interferences among them.

Some Wind Farms, named Off-Shore, are located into the sea, near coasts and lakes; they are a valuable option also in densely populated countries.

The history of wind plants in Italy is almost recent; the first air generator, installed in Sardinia, dates back to 1989; up to now we can say that the wind power use is considerably increased: the number of wind plants is raised up to around forty. 

Air Generators

Anyway, it is of note that this form of energy has some negative aspects: from an environmental point of view, even if they reduce the gas emissions rates, they have a negative landscape/visual impact. In addition, because air generators are fairly noisy, the noise pollution can annoy persons and animals that take also other risks: birds can be killed while flying across shoves, even if this rarely happens; there is also the problem of interferences, and of the magnetic fields creation, but this can be avoided by using small expedients.

To finish with, it is worth saying that wind power considerably reduces both gas and polluters emissions, which is on the contrary avoidable from normal power stations.

                                                                                  http://www.rheonetic.com/wind-power/wind-power/