Abstract
The power system using the clean decentralized renewable horizontal axis river current turbine can be an alternative option in delivering locally and sustainably the energies for the communities inaccessible to the electricity connection. One of the important aspects in the technology design is the selection of the blade number. This aspects can raise several consequences including the performance, the manufacturing cost and the construction constrain. The performance must be on the top of the priority in the technology design as the river velocity is typically low which effortlessly brings the technology uneconomically attractive. This study deals with the investigation of effect of the blade number on the performance of the horizontal axis river turbine for low speed condition. The investigation is conducted by a parametric study with the mathematical model of the Blade Element Momentum. The results indicate that turbines with high blade number deliver a better performance than those with the lower blade number. However, the consequences will be the low rotation for the high bladed turbines thus requiring a high gearing ratio for the mechanical transmission. This study also discusses the reason for the results of the investigation and presents a recommendation for designing of the river turbine for such low speed condition in relation to the decision of the blade number