As part of a wind turbine design project, I have come to selecting the most appropriate coil and permanent magnet configuration. The aim is to design a turbine capable of 3kW (max), and approximately 300rpm. It will use mechanical furling to regulate speed. So far, I have only seen plans/ideas on generators up to about 1.5kW, using turbines up to about 3m in diameter. They seem to use 9 coils of #14 gauge wire, wound 36 times for each coil. This is typically used with 12 permanent magnets 2"x1"x1/2", and at a mounting diameter of about 250mm. These are wired by connecting groups of 3 coils in series, the wiring up in 'Star'. It is then rectified and converted to 12vDC for storage. By going to a 5m turbine, I am hoping to generate enough power to be self sufficient (but still tied to grid), and use the excess for other ideas I have down the track. It will need to be mounted high enough (12-16m) to be in a high velocity wind zone. I am trying to understand from first principles (almost), how I would go about determining the following variables: Coils - quantity, wire size, number of windings, coil shape, mounting radius. Magnets - Quantity, strength, material, physical dimensions. Does anyone have any information or calculations to help me understand better, the relationship between these factors and what components I should be selecting?