According to some embodiments, an airborne body extends horizontally along an axis between a first point and a second point. The body may be, for example, at least partially filled with a gas. Two or more vanes may be provided airborne with the body such that the vanes, when acted upon by a wind force perpendicular to the axis, are operable to cause rotation about the axis. Moreover, one or more tethers may be coupled to anchor the body to a third point, and one or more electrical generators may be airborne with the body to convert rotational energy produced by the rotation about the axis into electrical energy. According to some embodiments, each vane comprises a horizontal blade panel attached to and extending along the body.