Better than 2, no, it depends of speed wind, turbine speed, mill size and request speed on turbine shaft. If wind speed is between several values and we want moderate speed on shaft turbine is most effective 3 blades, but if wind speed increases, the windmill performance decreases, and we must put 2 blades, because this arrangement lets best performance.
Normally, 2 bladed turbine is used at small high speed mills, because a largue mill can´t withstand high speeds, it will be destroy .
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