http://www.renewable-solar-energy.blogspot.com. Success of the first phase of a homemade Vertical Axis Wind Turbine (VAWT), this homemade helical twisted vertical axis wind turbine (VAWT) is a drag type, it was built and installed on the rooftop of our building in order to harness wind energy and power our building to overcome the continuous electric power rational. The helical twisted prototype of this Vertical Axis Wind Turbine (VAWT) is a Savonius drag type model that was designed for 10KW, 3 phase direct drive and can be modified for lower rating once completed.