An apparatus for obtaining of mechanical work and/or generating power from fluid flows with increased effectiveness comprising of a vertical arrangement of a blade and a counterweight pivoting on a pivot joint, wherein the pivot joint of the blade is coupled with the counterweight via an arm of the counterweight, while the arm of the counterweight is coupled with the following control mechanisms: - a mechanism with an incorporated flywheel, a first articulated mounting, a first rod and a first pivot joint for taking torque or tensile / compressive force, wherein an electric generator or machinery is attached to the flywheel; - a mechanism comprising a second articulated mounting, a second rod, a second pivot joint and an angle lever for continuously and periodically changing an alpha angle of the blade between 0° and max. ± 90° throughout the oscillation to the direction of the flow of fluid; - a mechanism for continuously rotating a surface of the blade into a direction of the fluid's flow containing a length-adjustable member incorporated into the second rod; characterized in that the apparatus further comprises the following control mechanisms: - a first mechanism for changing the amplitude of the oscillation of the blade with respect to the fluid's flow velocity containing a first linear actuator coupled to the first articulated mounting, and/or a second mechanism for changing the amplitude of the oscillation of the blade with respect to the fluid's flow velocity containing a second linear actuator coupled to the first pivot joint; and - a first mechanism for changing the amplitude of the angle of the blade with respect to the fluid's flow velocity containing a third linear actuator coupled to the second articulated mounting, and/or a second mechanism for changing the amplitude of the angle of the blade with respect to the fluid's flow velocity containing a fifth linear actuator coupled to an angle lever. - a mechanism with an incorporated flywheel, a first articulated mounting, a first rod and a first pivot joint for taking torque or tensile / compressive force, wherein an electric generator or machinery is attached to the flywheel; - a mechanism comprising a second articulated mounting, a second rod, a second pivot joint and an angle lever for continuously and periodically changing an alpha angle of the blade between 0° and max. ± 90° throughout the oscillation to the direction of the flow of fluid; - a mechanism for continuously rotating a surface of the blade into a direction of the fluid's flow containing a length-adjustable member incorporated into the second rod; - a first mechanism for changing the amplitude of the oscillation of the blade with respect to the fluid's flow velocity containing a first linear actuator coupled to the first articulated mounting, and/or a second mechanism for changing the amplitude of the oscillation of the blade with respect to the fluid's flow velocity containing a second linear actuator coupled to the first pivot joint; and - a first mechanism for changing the amplitude of the angle of the blade with respect to the fluid's flow velocity containing a third linear actuator coupled to the second articulated mounting, and/or a second mechanism for changing the amplitude of the angle of the blade with respect to the fluid's flow velocity containing a fifth linear actuator coupled to an angle lever.