Vertical Axis Wind Turbine for Low Wind Speed Environment: Effect of Scoop Harmony Blade

Abstract

The wind condition in Malaysia is in the low-speed category with an average speed of 1 ms-1 to 4 ms-1. Effect of ground level relies significantly on the wind speed distribution. Despite these conditions, it is less suitable for the development of horizontal wind turbine as an energy source. The obvious weakness is the lack ability to self-start and predict the wind direction thus affects the energy efficiency output. To overcome this problem, improvement of the vertical axis wind turbine design is observed to be the solution in replacing horizontal axis wind turbine. Hence, this study is to investigate a suitable type of vertical axis wind turbine blade design for the best performance RPM output in a low-speed wind environment. The investigation was conducted in a Longwin LW-9300R subsonic wind tunnel at 0 ms-1 to 10 ms-1 wind speed condition from three wind turbine blades specified as Solid Harmony, Scoop Harmony and Conventional Savonius blade with angle of 90º, 135º and 180º to determine the highest RPM productivity. Result shows that Scoop Harmony blade delivers the highest RPM blade output while Savonius 180º is seen to have the highest self-start blade achieved at 64 rpm at 1 ms-1 wind speed. However, Solid Harmony shows an acceptable range TSR of 0.5 with difference of 23% lower than Scoop Harmony. This shows that both Scoop Harmony has a higher performance RPM but Solid Harmony still has the potential design to be applied at low-speed condition due to its low TSR output.