Comparative Evaluation of Power Generating Capacity of a Low Head River Using Conventional Small Hydropower and Hydrokinetic Turbines: A Case Study on Ona River, Oyo State, Nigeria

Abstract

The demand for electricity is growing rapidly around the world as economic development spreads to emerging economies. Among hydro, wind, solar, biomass and geothermal energies, hydro power can be considered as the most exciting and sustainable renewable energy resource for electricity generation, providing 19% of the planet’s electricity.  A considerable amount of the global electricity production is obtained from hydropower, but with an insignificant contribution from low head rivers (i.e. ≤ 5m). The interest among researchers towards exploring and harnessing energy from low-head hydro resources is gaining more prominence in recent years. Therefore, this study was designed to investigate the competitiveness of the hydrokinetic turbine (HKT) against conventional hydro turbines for harnessing the hydropower available in low-head rivers. A vertical axis hydrokinetic turbine using NACA 0021 airfoil profile and a cross-flow turbine were the technologies employed for the study. Hydrological data were collected from the Ona River in Ibadan, Nigeria. The data were used as input for a computer simulation.In respect of the two hydropower generation technologies considered in this study. The set of mathematical equations used in the design steps for cross flowcross-flow turbine was used and computed using MATLAB.  The simulation results were used to develop a scorecard for the evaluation of the two technologies. This study revealed that HKT is more suitable for a zero or low head river than a conventional hydro-turbine, such as cross-flow turbine.