Experimental Study to Investigate Effect of Blde, Chord Length and Turbine Diameter on Performce of Vertical Axis Wind Turbine (VAWT) Type Lenz-2

Indonesia has been committed to use 23% of Renewable energy by the year of 2025. One of energy source in renewable energy is wind energy with its potential energy as high as 60 GW with wind speed ranging from 3 to 6 m/s. One of suitable choice for low-speed wind turbine is Vertical Axis Wind Turbine (VAWT) type Lenz 2. Since there are few research about Lenz 2-type wind turbine, recent research is intended to study effect of wind speed (U), chord length (C) and turbine diameter (D) on performance of the wind turbine. The experiment uses number of blade (N) 3 blades, blade height (H) 400 mm and turbine diameter (D) of 300, 400, and 500 mm. Cord length of turbine is varied into 140, 160 and 180 mm. The turbine will be operated in wind speed of 4, 5, dan 6 m/s. Tip speed ratio, ratio between linear speed of turbine tip/end and wind speed, will decrease as turbine is connected with electrical generator. Produced power and moment will strongly affected by tip speed ratio. Result of experiment shows that highest Coefficient of Power (CoP) as high as 0,063 is obtained at tip speed ratio (λ) = 0,41, wind speed 4 m/s and chord length 180 mm. Same configuration will produce Maximum Coefficient of Moment (CM) as high as 0,19 is obtained at tip speed ratio (λ) = 0. Variation in chord length gives maximum Coefficient of Static Torque (CTs) at Chord length (C) 180 mm and angular position of θ = 180⁰. Variation in turbine diameter gives maximum Coefficient of Power maximum as high as 0,0889 at turbine diameter (D) = 300 mm, wind speed 4 m/s and tip speed ratio (λ) = 0,4. It can be concluded that optimum operation for Lenz2-type turbine is at wind speed 4 m/s, Chord length (C) 180 mm and turbine diameter (D) = 300 mm. The experiment agrees with fundamental concept that Lenz 2-type wind turbine has the best performance at low wind speed. The turbine is more suitable in Indonesia since most of region in Indonesia has low wind speed.