Wind Turbine Rotation Calculator

Calculates the rotational speed of wind turbine blades, the duration for one revolution, the produced electricity and the revenue. The tip-speed ratio depends from the construction type of the turbine, three-bladed vertical turbines have a value of about 5, two-bladed of about 8.
The table can be filled top-down, the units can be chosen at will. The speed of the tips is calculated as wind speed times tip-speed ratio. From tip speed and radius, the revolutions per time and the duration for one rotation are calculated. The amount of electricity is the power multiplied with the duration. Finally from electricity amount and the price paid per kilowatt-hour, the monetary revenue for one rotation and for a certain duration can be calculated.

Example: a three-bladed wind turbine with a tip-speed ratio of 5 has at a wind speed of 12 m/s a tip-speed of 216 km/h. At a blade length (radius) of 80 meters, it makes about 7 revolutions per minute, for one rotation it needs a bit more than 8 seconds. With each rotation, 19.4 kilowatt-hours of electricity are produced, which at a compensation of 5 cents per kilowatt-hour sum up ton almost one euro (or dollar or any other currency). Per hour, these are about 417 euros (dollars, ...), if the wind blows constantly.

The tip-speed is the speed of rotation at the blade ends of the wind turbine. The tip-speed ratio is the ratio of the tip-speed and the wind speed; it has no unit. Slow runners have a low tip-speed ratio (1-3), fast runners have a high ratio (5-12). At a low tip-speed ratio, the rotational speed is lower, but usually more energy is generated with the same radius.

Wind speed:
Tip-speed ratio λ:
Tip-speed:
Radius:
Revolutions per time:
Rotation duration:		s
Air density ρ:		kg/m³
Efficiency factor η:		%
Electricity per rotation:
Electricity tariff:		€/kWh, $/kWh
Revenue per rotation:		€, $
Revenue per :		€, $