Potential Evaluation of Vertical Axis Hydrokinetic Turbine Implementation in Equatorial River

Abstract

In rural areas, small villages are often disconnected from the electrical grid because of lack of economic resources. Long extensions of the grid, only contributing small rural areas with electricity, are not economically beneficial. The temporary solution for the disconnection is to contribute with diesel-generators. These have become common for remote electricity distribution because of their quick installation and mobility. However, the high expenses of the fuel for the diesel generators, along with the challenging fuel transportation because of the scarce to non-existing infrastructure, are not a sustainable solution for electricity distribution in the rural areas. Hydrokinetic turbine is an attractive option for harnessing energy from natural flow of rivers where no static head exists. However, equatorial river system is subjected to high amount of sediment and flowing objects due to the large quantity of vegetation in the area. This leaves the turbine exposed to a higher degree of erosion on the blades and a higher risk of getting clogged. A field study was conducted to attain the velocity and characteristics of sediment in the Niah River located in Miri of Sarawak state, Malaysia. The collected data was analyzed and used as input values during simulations of a turbine model by the Computational Fluid Dynamics. Areas on the turbine exposed to the water with a high velocity and containing a high concentration of sediment were examined. The investigation states that areas on the blade's outer sides are most exposed to erosion and will be in need of protection in form of a harder surface. Adaptation of hydrokinetic turbine for the conditions prevailing in the equatorial river is essential to improve the efficiency and lifetime of the turbine