# Calculation of Wind power and energy

## Principle

A windturbine is composed of rotor often fitted with several blades. The rotor is fixed at a nacelle installed on the top of a vertical mast. A central rotating shaft connects the major components of the drivetrain. The drivetrain includes the blades and rotor hub and a mechanical transmission that converts the angular momentum from the rotating blades into power that is transmitted to the induction generator. The nacelle also houses a yaw control motor that allows the entire nacelle and blade assembly to rotate to face into the wind for maximum power production. Blades transform kinetic energy (motion energy) of the wind in mechanical energy. The generator transform the mechanical energy in electrical energy. Most of generators turn at 1000 to 2000 rotations per minute.

## Calculator

Enter your own values in the white boxes, results are displayed in the green boxes.

### Wind power potential according to wind speed and area swept by the blades

#### Potential of wind power before blades

Rotor diameter :   m
Area of the rotor A=   m²
Wind speed v = m/s
Air density ρ = kg/m3
kinetic power = watt (hypothesis of constant wind)
kW

#### Potential of wind power after blades - Betz limit

Betz limit = 59% (16/27)
Pmax according to Betz limit   kW

### Electric power in output of wind turbines

Yield losses :
For each component fill the appropriate ratio according to your system :

Mechanical losses :
Blades :                      between 0,2 and 0,85
Gear box :                  between 0,7 and 0,98

Electrical losses :
Generator :                between 0,85 and 0,98
Transformer :            between 0,92 and 0,98
Rectifier :                    between 0,9 and 1(1 if no batteries)
Batteries :                   between 0,7 and 1 (1 if no batteries)
Wire losses :               between 0,9 and 0,99
Total losses ratio :
Real power in output of windturbine : kVA  (losses included).

## Excel file to calculate wind turbine power and energy

This excel file will help you to calculate power and electricity production of wind turbines.