How do wind power plants work?

Rather like windmills (a name they are sometimes given), wind turbines use the power of the wind, which they transform into electricity. The speed of the wind rotates the blades of a rotor (between 10 and 25 rpm), producing kinetic energy. The rotor then drives a generator that converts the mechanical energy into electricity. A weathervane and a robot orient the nacelle so that the blades are positioned optimally with regard to the wind. Each wind turbine is made up of a mast, which can be between 20 and 100 meters tall, depending on the power of the machine, which supports the rotor, generally consisting of three blades, and the nacelle, which houses the generator and the electrical and mechanical gear. The wind turbines are connected to the power grid via a transformer housed at the base of the mast. The electricity generated is generally raised to the grid voltage (20 kV). It is then transferred via a substation before being injected into the distribution or transmission networks.

The power of modern onshore wind turbines is in excess of 3 MW. Wind turbines are designed for wind speeds of between 14 and 90 kph. When the wind speed is faster, a braking mechanism automatically stops the wind turbine, ensuring the safety of the installation and minimizing wear. Modern wind turbines produce their rated output at wind speeds of around 50 kph.

 The operation of a wind turbine

The acoustic dimension in wind farm projects

Acoustic dimension in wind farm

Noise perception generated by the wind turbines (comparison). For a household at the minimum authorized distances of 500m, a wind turbine emits the same noise as a washing machine (40dB).

 

Sound emitted by a turbine spreads in every direction. Topography, cloud cover or the nature of the air masses, may play a part in its spread. ENGIE applies the acoustic standards applicable to onshore wind power plants, within the framework of the system for installations classified for environmental protection (ICPE).

 

Doubling the number of wind turbines

 

Doubling the number of wind turbines does not double the volume of sound. From a distance of one kilometre, it only adds 3 dB. The total sound level of a wind farm is limited to 70 dB(A) during the day and 60 dB(A) at night over a distance of 200 metres).

 

 

 

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