** Wind contains power from kinetic energy equal to:E = 0.5 * (rho) * V3 * (pi) * R2.RHO= air density. V= wind speed.**

Wind Speed | Horsepower per Exposed Sq Ft | 10 ft. Windmill Exposed Area Sq Ft (approx) | Horsepower Exposed to
| At 30% Efficiency: Usable HP |

10 MPH | .007 | 75 | .5 | .16 |

20 MPH | .06 | 75 | 4.5 | 1.5 |

40 MPH | .42 | 75 | 31.5 | 10.4 |

A 10-mph wind contains about 4 ft-lb/sec.

Or about .007 Horsepower per square foot of wind area.

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A 20-mph wind has about 8 times as much power as a 10-mph wind - .06 HP

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A 40-mph wind has about 64 times as much power - .42 HP

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A 60-mph wind contains about 810 ft-lb/sec.

Or about 1.5 HP per square foot of wind area.

A 10 foot windmill intercepts about 75 square feet of wind area.

And performs, at best, at 30% efficiency.

A 10 mph wind x 75 sq.ft. = about 0.5 horsepower.

At 30% efficiency, about 0.16 horsepower

A 20 mph wind x 75 sq.ft. = about 4.5 horsepower.

At 30% efficiency, about 1.5 horsepower

A 40 mph wind x 75 sq.ft. = about 31.5 horsepower.

At 30% efficiency, about 10.4 horsepower

Fuel Cost -- Per Horsepower -- In Dollars

$0.00!