The factor was effective to cut in wind speed of CR-VAWT is a tangential force acting the pulley or
load (XF). Fig. 3 shows the variation of rotational speed of CR-VAWT with XF, the divided tangential
force acting the pulley by cross section area of the swept of the wind turbine, N/m2, of the various setting
wind speed of 1.5 – 4.0 m/s. Rotational speeds reach zero with a maximum value of the corresponding
tangential force ratio. A rotational speed of CR-VAWT was becoming lower in curve line, but for n-
VAWT the rotational speeds were become lower in a straight line. The rotational speed of CR-VAWT
was softly become lower when XF increase. It is a good property for keeping the mechanical system.