link to Home Page

icon Overdriven


The power available in the wind is proportional to the speed of the wind cubed. As a particular alternator spins faster it produces more current. I have never seen or heard of a DC wind generator or a giant MOD-1 wind turbine coming to a halt because it's load was too great. I'm sure that many home experimenters have had this problem. It's most likely because they did not have access to the proper formulas and design materials.

The first component to fail in a small wind generator or a massive wind turbine is almost always the generator. Why? Because they are overdriven during high load conditions, they simply burn themselves up! Even in the big wind turbines the alternator, usually a three phase asynchronous motor of varying size, is the most inexpensive component. Throughout the wind turbine industry they are considered to be expendable items, they are easily rewound. Here is the formula for the power that is available in the wind. All wind formulas are in meters.

Power P=.5*d*A*V^3 where,

P = is the power in the wind
d = is the density of the air @ 1.22kg./m3
A = is the swept area of your rotor
V = is the velocity of the wind in m/s, meters per second.

When using these formulas don't try to convert the variables in the formula, it wont work. Convert the answers.

Offered by Jay.

icon