A vertical axis multi-phased wind turbine power generating system is disclosed. An adjustable air scoop directs air from a first phase of the prevailing wind into an air turbine for efficient power generation. An exit section, which uses a second phase of the prevailing wind in combination with an optional and adjustable exit section drag curtain or barrier, provides for efficient re-entrainment of this first stage of power generating air back into the downstream prevailing wind. The adjustable air scoop and adjustable exit drag curtain or barrier, where utilized, is automatically rotated in a self correcting manner to be suitably and optimally oriented to the prevailing wind direction. The design provides for a second stage of power generation to be accomplished by additionally utilizing a portion of the second phase of prevailing wind to directly or indirectly drive the turbine in a second stage of power production.