A shrouded wind turbine system has a number of potential advantages over the conventional wind turbine. A novel power-augmentation-guide-vane (PAGV) that surrounds a Sistan wind turbine was designed to improve the wind rotor performance by increasing the on-coming wind speed and guiding it to an optimum flow angle before it interacts with the rotor blades. The integration of the PAGV into the 3-in-1 wind, solar and rain water harvester on high-rise buildings has been illustrated. A particular concern related to public safety is minimized when the wind turbine is contained inside the PAGV and noise pollution can be reduced due to the enclosure. Besides, the design of the PAGV that blends into the building architecture can be aesthetic as well. Moreover, a mesh can be mounted around the PAGV to prevent the bird-strike problem. From the wind tunnel testing measurements where the wind turbine is under free-running condition (only rotor inertia and bearing friction were applied), the wind rotor rotational speed (with the PAGV) was increased by 75.16%. Meanwhile, a computational fluid dynamics (Cm) simulation shows that the rotor torque was increased by 2.88 times with the introduction of the PAGV. Through a semi-empirical method, the power output increment of the rotor with the PAGV was 5.8 times at the wind speed of 3 m/s. Also, the flow vector visualization (CFD) shows that a larger area of upstream flow was induced through the rotor with the PAGV. (C) 2012 Elsevier Ltd. All rights reserved.