In light winds and if there is no separation because the spring has not wound the prop back, the prop just works against the spring until finally the spring turns the shaft. Sometimes, this becomes a turn/no turn situation until the wind picks up sufficiently to keep the shaft turning continuously.

You may be talking about gizmo (www.thebackshed.com), who uses four blades to get the torque or other contributors use even more blades as the F&P cogs badly. My blades are 1.5m radius or 3m in dia., which with better wooden blades would give you one kW but not with PVC blades. I am hoping for 200-300W at the most, the rule with F&Ps from memory is 1 W for 1 RPM. More with three capacitors paralleled to the three phases.

However, an F&P can have its poles rounded to reduce cogging at the expense of power OR a new rotor can be purchased, which does away with cogging altogether.

Testing so far: A friend gave me a 36V UPS and a stock standard F&P without rewiring gave me only 2 Amps. Since then I have paralleled 14 coils and made them into two parallel seven coils to better fit a 36V battery as per a suggestion by commanda. And that has not been tested yet.

A larger tower is under construction.

Sorry, no quantitative testing so far as the Picaxe-based V, Amp, wind speed and RPM electrickery is still being constructed.