What is Wind Power Plant || Wind Energy

In a power system, there are different types of power plant like hydropower, thermal, diesel etc. One of them is wind power plant.

What is Wind Energy? Its operation

Wind energy is the energy which is provided by converting mechanical energy into electrical energy by the blades on the tower.  Wind energy is energy which is generated by the use of wind to provide the mechanical power through wind turbines(blades) to turn electric generators. Traditionally, it is also used to do other work, like milling or pumping. Wind power is a sustainable and renewable energy, and it has a much smaller impact on the environment as compared to burning fossils fuels. Wind farm or plant consist of many individual wind turbines, which are connected to the electric generator after that connected to electric power transmission system. Generally, wind power is located in hilly region or height places so it is far from the national grid system. So it need high cost to connect to grid system. Although, its operating cost is low as compared to thermal power plant and it is renewable energy source so we need to focus on wind power plant.

calculation of wind power

Let's discuss about its formula for calculating the power production.

Consider a packet of air with mass 'm' kg is moving with velocity 'v' m/s. For that mass and speed, we can calculate the kinetic energy by,

 

K.E. = mv² / 2

We know, power is the energy per unit time, so we can calculate the power for that air with mass m and velocity v,

Power = energy / time

            = mv² / (2 x time)

            = (v² / 2 ) x (m / time)

We know, density = mass / volume

                                   = mass / (area x height)

                    or, m = ρ x A x height

Here, ρ = density

          A = area

For small mass of air dm is moving for small time dt then,

dm / dt = d(ρ x A x height) / dt

              = ρ x A x d(height) / dt

              = ρ x A x v

             

we know distance per unit time is velocity.

so, power = v² x ρ x A x v / 2

               = (ρ x A x v³) / 2

Here, P is power in watts

          ρ is the density of air kg/m³ (at 15⁰C and 1atm,  ρ = 1.225 kg/m³

          A is the cross-sectional area through which the wind passes, unit m²

This value is theoretical or ideal value which is not applicable while calculating actual power produced by wind power plant. Actually, wind power plant has efficiency of about 0.59 and there is also losses in generator, turbine, gear etc. For that case, we can multiply this with a coefficient which will gives actual power. This coefficient is called power coefficient and denoted by Cp. So actual power generation is given by, 

    power = (ρ x A x v³ x Cp) / 2          

From Area (A) we can calculate blade length. For this, we have formula of A,

A = ⊓r²

r = √(A/⊓) 

where r is the radius of blade or blade length.

Advantages of wind Energy

Advantages of wind energy is as follows:-

• It is reliable and infinite renewable energy resource
• No air pollution and no usage of water
• It reduces carbon emissions as compared with burning fossil fuels
• It is cost-effective and energy price is dropping.
• Few running costs as the turbines are running without any cost.
• Since it is domestic source of energy.

Challenges/disadvantage of wind Energy

Disadvantage of wind energy is as follows:-

• It must still compete with conventional generation sources on a cost basis.
• Good land-based for wind sites are often located in the remote locations, far from cities where the electricity is needed.
• Its development might not be the most profitable use of the land.
• Rotating turbines might cause noise and aesthetic pollution
• This plants can impact local wildlife