How much Power is in the wind?
It is easy to see how wind provides enough force to become energy but the big mystery is figuring out how that process happens.
Wind power is converted to electricity by a wind turbine, like GALE™. In a typical, modern, large-scale wind turbine, the kinetic energy in the wind (the energy of moving air molecules) is converted to rotational motion by the rotor – typically a three-bladed assembly at the front of the wind turbine. The rotor turns a shaft which transfers the motion into the nacelle (the large housing at the top of a wind turbine tower). Inside the nacelle, the slowly rotating shaft enters a gearbox that greatly increases the rotational shaft speed. The output (high-speed) shaft is connected to a generator that converts the rotational movement into electricity at medium voltage (a few hundred volts).
The electricity flows down heavy electric cables inside the tower to a transformer, which increases the voltage of the electric power to the distribution voltage (a few thousand volts). (Higher voltage electricity flows more easily through electric lines, generating less heat and fewer power losses.) The distribution-voltage power can flow through underground lines to a collection point where the power may be combined with other turbines.
The following chart shows exactly how much potential the wind holds as an energy source since wind power increases exponentially as wind speed increases.
| Example 1 | Example 2 |
|---|---|
| Turbine runs for 1 year | Same turbine runs for 1 year |
| Half the time the wind is 10m/s (22mph). Half the time there is no wind at all. | The wind blows at 5m/s (11mph) all year. |
| Therefore, the average wind speed is 5m/s (11mph) | Therefore, the average wind speed is also 5m/s (11mph) |
| Power generated is 1,752 kWh |
Power generated is 613 kWh |
Both examples have the same average wind speed but Example 1 produces 2.85 times as much power as Example 2.