ABSTRACTThis work experimentally studied the influence of guide vane design to increaseSavonius rotor performance. Guide vane is one of additional device that its function is todirect wind stream onto concave blade and deserves as obstacle of the wind that flowing on toconvex blade. This method increased wind speeds to the rotor, consequently it producedhigher power and the Savonius rotor performed better. Four designs of guide vane werearranged in this study. They were basic design of guide vane and basic design of guide vanethat added a tilt angle on the top and bottom sides by 15°, 30°, and 45°. The result concludedthat guide vane affects the performance of Savonius rotor. The power that generated by therotor with guide vane increases significantly compared with Savonius rotor without guidevane. The maximum improvement was attained up to 65.89%.Keywords: Wind energy, Wind Turbine, Savonius rotor, Guide Vane, Savonius rotorperformance