Enhancing sustainability of a mini hydro station through a self-cleaning debris diverter

Mini hydro can be among the most sustainable energy resource, appropriate for Malaysian condition. In its actual sense, ‘availability’ is one of the sustainability indicators, but choked intakes have been the main common issue that keep lowering the availability figure. This works aims to improve sustainability ranking of a mini hydro station by improving its availability through an improvement in its intake cleaning procedure. It takes Sg. Renyok Mini Hydro Station, located at Jeli, Kelantan, as a case study. Here, flow and geometry of the river are simulated using CFD, in order to establish a baseline on the flow profile. Characteristics and behaviour of floating debris at this station were studied giving 28 kg per day as the total amount of floating debris accumulated. 1.64% per hour, as the clogging rate was also established. A peculiar louvered steel diverter is designed, that when installed at a pre-determined angle of 73°, a self-cleaning effect can be realized. A physical model test of this structure has also been performed with a good success in proving the concept, obtaining an efficiency of 85% on diverting the floating debris. A meticulous cost-benefit analysis was performed, giving a favourable result: 1.72 cost-benefit ratio and 2.8 years simple payback period. The results presented herein can improve the station's availability, while at the same time providing an alternative solution from the commonly available measures.