"WIND TURBINE"

The present inventioa is a wind turbine having a set of curved blades mounted oa a central rotatable hub. An en¬closure surrounds and is attached to the tips of the blades. The enclosure is arranged to rotate with the hub and the blades. The blades have a fixed pitch such that a pitch angle of each of the blades at the tip end is from 50 degrees and 75 degrees to a rota¬tional (central) axis of the hub. A pitch angle of each of the blades at a hub end is defined by a product of a ratio, of a hub radius divided by a turbine radius, multiplied by a pilch angle at the tip. The blade is provided with a compound curve that causes the blade to fall away from an angle of apparent wind (the angle of the wind seen by the moving blade) impinging upon the blade at a wmd entry location of the blade. The turbine is further provided with an apparatus that controls speed of rotation of the turbine so that the angle of the apparent wind to the blades can be adjusted relative to the pitch angle of the blades To obtain at least 50% of maximum energy that can be extracted using the turbine.