**Wind energy formula**

Wind energy is a kind of solar energy. Wind energy describes the process by which wind is used to produce electricity. The wind turbines convert the kinetic energy present in the wind to mechanical power.

Wind energy is a renewable source of energy that determines the total power in the wind. The wind turbines which convert kinetic energy to mechanical power, where in the mechanical power is converted into electricity which acts as a useful source.

**The wind energy formula is given by,**

**P = ****1 / 2** **ρ**** A V****3**

**Where,**

P = power,

ρ = air density,

A = swept area of blades given by A = π r2 where r is the radius of the blades,

V = velocity of the wind.

**Example 1**

Determine the power in the wind if the wind speed is 20 m/s and blade length is 50 m.

**Solution:**

Given:

Wind speed v = 20 m/s,

Blade length l = 50 m,

Air density ρ = 1.23 kg/m.

The area is given by, A = π r2

A = π × 2500

= 7850 m

The wind power formula is given as,

P = 1 ρ A V

= 1 x 1.23 x 7850 x 8000

**P = 38.62 MW**

**Example 2**

A wind turbine travels with the speed is 10 m/s and has a blade length of 20 m. Determine the wind power.

**Solution:**

Given:

Wind speed v =10 m/s,

Blade length l = 20 m,

air density ρ = 1.23 kg/m3,

area A = πr2

= π × 400

= 1256 m2

The wind power formula is given as,

P = 1 / 2 ρ A V3

= 1 / 2× 1.23 × 1256 × 1000

** P = 77.2 MW.**