Abstract: A turbine blade particularly useful in a vertical-axis wind turbine, characterized in that the blade includes a central region of a symmetrical airfoil configuration, and opposite end regions of a non-symmetrical airfoil configuration effective to increase the drag forces produced by the wind at the end regions when the turbine blade is used in a vertical-axis wind turbine provide a self-starting capability, and a speed-limiting capability, to the wind turbine. In one described embodiment, the non-symmetry in the sharp trailing edge of the blade is produced by a deep recess extending inwardly past the chord line of the blade to enhance the self-starting and speed-limiting capabilities; whereas in another described embodiment, the non-symmetry is produced by a shallow recess and outwardly-flared ends enhancing the efficiency of the wind turbine during normal wind conditions.