Wind

 

The Italian expertise

The Italian manufacturers offer from small to large scale wind energy products such as wind turbine generators, towers, transformers and control systems, including the full range of slew and wheel drive applications and gearboxes for wind turbine pitch and yaw drive systems. 

The Italian expertise in the wind sector ensures the products manufactured have excellent technical characteristics, guaranteeing high performances that are recognized in Italy as worldwide.

 

Wind power plants

A wind power plant transforms wind energy in electric energy. The words "wind power" come from the character of the Greek mithology Aeolus, the God of Wind.

A wind power plant or wind farm generally consists of one or multiple wind turbines, which convert the kinetic energy from wind into electricity. Wind drives a rotor, usually equipped with three blades (generally in fiberglass) and connected to a horizontal-axis shaft. The rotation is then transferred via a gearbox or directly to an electrical generator.

The voltage of the generated electricity is transformed into higher voltage and injected into the power grid. The nacelle is the structure housing the transforming systems - chiefly, the gearbox and the electrical generator - and the controls of the machine.

Wind turbines are mounted on towers at suitable height, to capture more wind energy and prevent turbulences caused by geographical features or obstructions. Indeed, wind power plants' electric production is proportional to the cube of wind speed, and small variations in the site's anemometer features can be transfomed in relevant differences truly deliverable. Furthermore, both a horizontal and a vertical-axis wind turbine require a minimum wind speed (cut-in speed) of 3-5 m/s and generates the design capacity at a wind speed of 12-14 m/s. At high speeds (20-25 m/s, cut-off speed), the wind turbine is blocked by a braking system for safety reasons.

Wind turbine capacity classes are:

  • Small-sized (1-200 kW): rotor diameter: 1- 20 m; tower height: 10 – 30 m
  • Medium-sized (200 – 800 kW): rotor diameter: 20 – 50 m; tower height: 30 – 50 m
  • Large-sized (above 1,000 kW): rotor diameter: 55 – 80 m; tower height: 60 – 120 m

Small wind turbines may be used to generate electricity for individual final users or groups of final users, whether connected to the low-voltage grid or isolated from the power grid. Medium and large wind turbines are mostly used in wind farms, connected to the medium or high-voltage grid.

Wind power plants are divided into two categories: on-shore plants (on dry land) and off-shore plants (in the sea).

The hydroelectric plant transforms potential water energy in mechanic energy of turbine rotation, directly converted, through the generator, into electric energy. The plant is composed of civil and hydraulic works and electronmechanical machinery. 


Number and capacity of wind power plants in Italy

​2011 ​2012 % 2012/2011 ​
​Power classes (MW) ​no. MW no. MW no. MW
​C≤1 MW ​479 74,4​ ​712 154,1​ ​48,6 ​107,0
​1 MW<C≤10 MW ​114 ​522,4 ​98 ​469,6 ​-14,0 ​-10,1
​C>10 MW ​214 ​6.339,3 ​244 ​7.495,7 ​14,0 ​18,2
​Total ​807 6.936,1 1.054 8.119,4 30,6 17,1
 

At the end of 2012, wind power plants were 1.054 with a gross maximum capacity of 8.119 MW.

From 2011 to 2012, the capacity installed in wind power plants was up to 1.183 MW (+ 17,1%), thanx to the large-sized plants (above 10 MW).

With respect to 2011, this class rose by 18,2% and represented 1.156 of the  total increase 1.183 MW, thanx to the new installations and to the plants' riclassification. This riclassification caused the reduction of the class with plants from 1 MW and 10 MW (-10,1%).

In the class with the capacity of less than 1 MW, the installed capacity was up to + 107,0% .
In 2012, as it was in 2011, the installed capacity of wind power plants represented 17% of all the renewable plants.