A well system includes a wellhead positionable at a surface of a wellbore. The well system also includes a ball valve for coupling to the wellhead. The ball valve is movable between an open position and a closed position. Further, the well system includes a hollow core electric motor positionable adjacent to the ball valve to move the ball valve between the open position and the closed position. Furthermore, the well system includes a power source that provides electric power to the hollow core electric motor.