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.