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Natural ForceThe purpose of this project is to cover one's need for energy, with the wind as a power source, enough to provide for a normal family home. In this example we have a 2-blade turbine with an advanced aerodynamic shape, a so called fast runner, to convert wind energy to kinetic energy. This type of turbine is ideal to use in combination with electric generators due to it's high rotor speed, which can be chosen so that the motion of the tips of the propeller blades becomes 8-9 times faster than the motion of the wind.
About 15,000 - 30,000 kWh per year is needed to heat a house, depending on where the house is located. This would be as much as having two moped motors going full force, hour after hour, continuously. With a well built turbine one can get 30 - 40 % of the wind's energy. This means that the wind velocity has been decreased by 1/3. Wind velocity is of great importance. The energy that one can gather from the wind increases by the velocity of the wind measured in cubic. The degree of efficiency in this example below gives an effect of 2,198 W.
| Natural force (kpm/s) per square meter | N = P x V |
| Force (kp/square meter) | P = 0 . 064 x V2 |
| Effect (kpm/s) | N = 0 . 064 x V3 |
| Recalculated to w | Nw = 0.64 x V3 |
| Wind velocity 5 meters/second | Nw = 0,64 x 53 = 80 W / M2 |
| Turbine diameter - 10 meters: Wrapped surface 78 square meter Wind force: 5 m/s | Nw = 0.64 x 53 x 78 = 6,320 W |
If you have trouble understanding this kind of math, check the page on how to calculate the output of the natural force of the wind. The larger part of Sweden has a normal wind velocity at 5 m/s or more, at an acceptably reachable height. In Sweden there will be enough wind for a 10 m turbine. The wind also blows more in the winter than in any other season.
Offered by Geson.
