Fluid turbine devices and methods related to fluid turbine devices are disclosed herein. One example method includes deflecting a first portion of a fluid flow from a return path of a vertical blade assembly, while permitting a second portion of the fluid flow to enter a drive path of the vertical blade assembly. Another example method related to a fluid flow device includes orienting a shroud relative to a fluid flow to deflect a first portion of a fluid flow from a return path of a vertical blade assembly and to permit a second portion of the fluid flow to enter a drive path of the vertical blade assembly and activating a generator, based on an operating characteristic of the fluid turbine device, to regulate a rotational speed of the vertical blade assembly.