much power can a wind turbine generate?
The ability of a turbine to
generate electric power is measured in Watts (The rate of energy transfer
equivalent to 1 Ampere of electric current flowing under a pressure of 1 Volt
at unity power factor). Watts being a small unit of power, kilowatts (kW = 1000
Watts) and Mega Watts (MW = 1 million Watts) are the most commonly used units
to describe the generating capacity of wind turbines and any power generating
unit in general.
Electricity production and
consumption are most commonly measured in kilowatt-hours (kWh). A kilowatt-hour
means one kilowatt (1,000 Watts) of electricity produced or utilized in an hour
(To light up a 100 Watts bulb for 10 hours requires 1 Kilowatt-hour of
Watt-hour is the electrical
energy unit of measure equal to 1 Watt of power supplied to, or taken from, an
electric circuit steadily for 1 hour.
The power produced by a
wind turbine depends on the turbine's size and the wind speed through the
rotor. In India, we have the commercial large wind turbines from 225 kW to 2.5
MW. In the global market, 6 MW wind turbines are operating and turbines of 10
MW are in laboratory stage.
Wind speed and a wind
turbine size are the factors that determine the power generation capacity of a
wind turbine installation. Usually, wind resource assessment is done prior to a
wind system's construction.
The power (energy/second)
available in the wind will be given by the formula Power = 0.5 x rotor swept
area (m2) x density (kg/m3) x velocity3 (m/s)
It can be noted
that the power generated is cube of the wind velocity and because of this, even
a small difference in wind speed will bring about a large difference in
available energy and in electricity produced and therefore, a large difference
in the cost of electricity generated.