2. index: 1.Cover 2.Index 3.History 4.Type of windmills 4.1 Aeromotors 4.2 Big Aeromotors 4.3 Small Aeromotors 5.Big Generators 5.1 Parts 5.2 How they works 6.Aeolian Centres 7.Advantages and disadvantages

3. History: The use of eolic energy, that is to say, taking advantage of the force of the wind is very old. The first application was the use of sails in boats. Later, about 1,500 years ago, in ancient Persia, the fist windmills appeared, which were used to grind cereals and make flour, or to extract water from wells. From Persia, windmills spread all over the world. In Europe they have been used since the Middle Ages, especially in the Mediterranean and in the North. The windmills of La Mancha and Balearic Islands are well known in Spain. During the 20th Century windmills were developed to produce electricity, its principle use at present.

4. types of windmills:TypesCharacteristicsUses Aeromotors Transformation of kinetic energy from the wind into mechanical energy Pumping water from wells Aerogenerators Transformation of kinetic energy from the wind into electrical energy Small Power:Small Power: Country houses, isolated houses, sailboats, etc Big Power:Big Power: They are grouped together to from Aeolian power centres. They produce electricity for the electric power network.

5. Aeromotors: Transform kinetic energy from the wind into rotational mechanical energy. They are used to move other machines normally water pumps to extract water from wells. Most Aeromotors have photographic design, which called, American multiblade windmill. It was developed in the nineteenth century and can be found all over the world.

6. Big Aerogenerators: They transforms kinetic energy from the wind into electricity They are very big They can be installed by themselves, but it is more common to see them in groups, forming what is called an aeolic park, or Aeolian centre. The aeolic energy which is produced is injected into the electrical network and end up in homes and industry

7. Small Aerogenerators : They transform kinetic energy from the wind into electricity. They are of modest size, The rotor measures between one and seven metres in diameter. They are used in country houses, isolated installations and small sailboats.

8. Big Generators: The big Aerogenerators are the machines that are more developed in the last years and have allowed that the wind energy should turn into a competitive energy from the economic point of life.

9. Parts: Blades: They are constructed by light materials and simultaneously resistant, normally plastic as the polyester or the epoxi reinforced with glass fibber. They have a profile similar to that of a wing of a plane. The blades of the big mills are of changeable step, which it wants to say that they can turn on his axis to obtain the major possible power depending on the speed of the wind.

10. Rotor is licked to the set of all the spades. Normally the big Aerogenerators have a rotor of 3 spades, some models, only they have 2. Rotor:

11. Gondola: The gondola is the structure that it supports and protects from the atmospheric agents to the electrical generator and to the elements of control of the generator.

12. Tower: It made of sheets of steel doubled in practically cylindrical form

13. Aerodynamic Brake: If the wind is too slow or too rapid it is necessary to stop the rotor. To do it the aerodynamic brake is in use. The punts of the spades are turned and, in the same way as when we extract the palm of the hand for the window of a car, the air does a great resistance to itself to the advance, which does that the rotor is given birth.

14. Foundations: A great mill this one submitted to forces that tend to knock down it. In the same way as a tree needs roots to be supported, an aerogenerator needs from a few foundations that they allow him to subject firmly to the area.

15. How they works: Generator: Generator: The most important interior component is the generator. By turning quickly the axis of the generator produces electricity. It is responsible for transforming the mechanical energy from the rotation of the windmills into Aeolian energy. Cables: Cables: The electricity produced by the generator is extracted from the aerogenerator by means of cables which are lowered inside the tower.

16. Secondary Axis/ Principal Axis: Secondary Axis/ Principal Axis: The generator is joined to the rotor by means of the principal and secondary axis. These axes transmit the movement of the rotor to the generator. The fist is very thick, it has to support the rotor and bear a great strain. The other is thinner, it is the one which makes the generator turn. Multiplier: Multiplier: The multiplier is a box of cogs which make the axis of the generator turn more quickly. Mechanical Brake: Mechanical Brake: It is a safety brake used to stop the generator when it has to be repaired or when it isn't working properly.

17. Turning Mechanism: Turning Mechanism: When the wind changes it is necessary for the gondola to turn horizontally in order to position the blades facing the wind. In order to do this it has a turning mechanism which is run by a electric motor. Computer: Computer: The element which decides where the windmill should face. Vane: Vane: The vane indicates the direction of the wind at all times.

18. Anemometer: Anemometer: This is the sensor which informs about wind speed. Blades with variable movement: Blades with variable movement: The blades of big Aerogenerators are blades with variable movement, which is to say that the can turn on their axis in order to adapt themselves better to the wind direction, thereby obtaining more energy.

19. Aeolian centres: The big Aerogenerators gather in crowds forming wind head offices, as that of the photo. Normally it is between 30 and 100 mills, though there can be hundreds. To look for an emplacement for a head office is complex since rich places need in wind, but where one does not believe an environmental, spatially visual, too big impact.

20. Advantages: It is a source of safe and renewable energy It doesn’t pollute the atmosphere nor does it generate residues, except for the making of the equipment and the oil for the cops. The area occupied by Aeolian centres can be use for herding animals and other purposes.

21. Disadvantages: Visual impact: Its installation modifies the landscape considerably. Aural Impact: The movement of the blades through the air produces a constant noise the nearest house should be at least at a distance of 200 m. It can only be used in areas with a lot of wind.

22. The end Jeremiah Bohane Mendoza nº3 Alba Blanco Morquecho nº2