Vertical axis wind turbine
A vertical axis wind turbine (VAWT) with improved and optimized wind-directing, wind-shaping, and wind-power conversion features is disclosed. The shapes of these features directly affect the ability of the VAWT to use the power of moving air, such as wind, to spin a rotor and create torque on a rotor shaft to generate electricity. The wind-power-conversion mechanical efficiency of the invention is significantly improved over previous efforts, to the point that the invention can convert wind energy into electrical power at a price-to-performance ratio that competes with or surpasses existing alternative energy technologies.
1. A vertical axis wind turbine, comprising:
at least one rotor blade adapted to turn a shaft;
a rotationally symmetric stator skirt, wherein at least a portion of a wind-facing surface of the stator skirt is parabolic, and wherein the stator skirt has a horizontal cross-section of an ellipse; and
at least one stator fin, each stator fin being attached at a bottom of the stator fin to the stator skirt and comprising a fin flip, the fin flip being disposed at an angle of β relative to a longitudinal axis of the stator fin and adapted to compress wind and direct the wind to the at least one rotor blade in a predetermined direction,
wherein a height-to-width ratio of the vertical axis wind turbine is between 0.1 and 3.0.
2. The vertical axis wind turbine of claim 1 , wherein the predetermined direction is counterclockwise.
3. The vertical axis wind turbine of claim 1 , wherein the at least one rotor blade comprises three rotor blades.
4. The vertical axis wind turbine of claim 1 , wherein at least one of a leading vertical face and a trailing vertical face of each rotor blade is arcuate or parabolic.
5. The vertical axis wind turbine of claim 1 , wherein the at least one stator fin comprises three stator fins.
6. The vertical axis wind turbine of claim 1 , wherein the wind-facing surface of the stator skirt comprises a lower conical portion and an upper parabolic portion.
7. The vertical axis wind turbine of claim 1 , wherein an angle α between the wind-facing surface of the stator skirt and a horizontal axis, as measured by an average or at any point of the stator skirt, is less than 45° or more than 55°.
8. The vertical axis wind turbine of claim 7 , wherein angle α is between 35° and 10° or between 55° and 65°.
9. The vertical axis wind turbine of claim 1 , wherein the ellipse is a circle.
10. A vertical axis wind turbine, comprising:
at least one rotor blade adapted to turn a shaft;
a rotationally symmetric stator skirt, wherein at least a portion of a wind-facing surface of the stator skirt is parabolic, and wherein the stator skirt has a horizontal cross-section of an ellipse;
a rotationally symmetric amplifier skirt, wherein at least a portion of a wind-facing surface of the amplifier skirt is parabolic, and wherein the amplifier skirt has a horizontal cross-section of an ellipse; and
at least one stator fin, each stator fin being attached at a bottom of the stator fin to the stator skirt and comprising a fin flip, the fin flip being disposed at an angle of β relative to a longitudinal axis of the stator fin and adapted to compress wind and direct the wind to the at least one rotor blade in a predetermined direction,
wherein a height-to-width ratio of the vertical axis wind turbine is between 0.1 and 3.0.
11. The vertical axis wind turbine of claim 10 , wherein at least one of a leading vertical face and a trailing vertical face of each rotor blade is arcuate or parabolic.
12. The vertical axis wind turbine of claim 10 , wherein the wind-facing surface of the amplifier skirt comprises an upper conical section and a lower parabolic section.
13. The vertical axis wind turbine of claim 10 , wherein at least one of the ellipse of the stator skirt and the ellipse of the amplifier skirt is a circle.
14. A vertical axis wind turbine, comprising:
at least one rotor blade adapted to turn a shaft;
at least one rotor plate attached to the at least one rotor blade at one or both of a top and a bottom of the at least one rotor blade;
a rotationally symmetric stator skirt, supporting the at least one rotor plate and comprising N identical trapezoidal panels, each trapezoidal panel forming an angle α with respect to a horizontal axis, the stator skirt having a horizontal cross-section of a regular polygon having N sides;
at least one stator fin, each stator fin being attached at a bottom of the stator fin to the stator skirt and comprising a fin flip, the fin flip being disposed at an angle of β relative to a longitudinal axis of the stator fin and adapted to compress wind and direct the wind to the at least one rotor blade in a predetermined direction; and
a top frame, attached to a top of each stator fin,
wherein angle α is less than 45° or more than 55°.
15. The vertical axis wind turbine of claim 14 , wherein the predetermined direction is counterclockwise.
16. The vertical axis wind turbine of claim 14 , wherein the at least one rotor blade comprises three rotor blades.
17. The vertical axis wind turbine of claim 14 , wherein each of a leading vertical face and a trailing vertical face of each rotor blade is semielliptical.
18. The vertical axis wind turbine of claim 14 , wherein angle α is one of (i) more than 12° and less than 45° and (ii) more than 55° and less than 80°.