Physics and math

Here's a very good website that has a lot of information on the physics and math part of the project:

http://www.educypedia.be/education/windturbines.htm

An important thing in building a wind turbine is aerodynamic drag. There is a whole bunch of other terms to be used by engineers, but the main idea is that the work of our turbine would depend on:
capture area of the wind;
wind speed;
of course, shape of the blades;
efficiency of the generator;
roughness of the surface;
the drag coefficient;
Reynolds number (viscosity of the air and density of the air).

To calculate the efficiency, power product, etc. we can just use the ready formulas.
We just need to make sure that our turbine is strong enough not to break under pressure of strong winds, and not too heavy for the low winds.