We have had some experience with small scale wind turbines, the ABSOLUTE minimum size that
should be considered is 3kW, but paybacks get better the bigger the turbine you can use.
We are asked to consider different sites for turbines, and for turbines up to 50kW, our
advice is, if you are on top of a hill, or are on raised ground overlooking the sea then
a turbine makes a lot of sense. Otherwise it could end up costing more money than it generates.
We like the turbines from Windro, which uses an "Axial Flux Permanent Magnet (AFPM) Generator" which
elimates field windings and hence makes the tubine better in low wind speeds and increases the generator efficiency.