Optimization of pico-scale Turgo turbines for rural electrification: Design, performance, and applications in decentralized energy systems

• Turgo turbine with 23 cm runner and 4 cm blades achieves 19.95% peak efficiency. • New polynomial model predicts efficiency trends with 0.23% error margin. • Experimental testing reveals diminishing returns with larger turbine components. • Study challenges traditional design ratios for small-scale hydropower systems. • Findings support sustainable energy solutions for remote communities. Indonesia’s energy transition necessitates decentralized solutions to address the electrification gap and reduce fossil fuel dependence. This study optimizes a pico-scale Turgo turbine for low-head hydropower generation by revising the traditional design ratio derived from Pelton turbine. Experimental testing of a 3D-printed prototype under controlled conditions (3 m head, 44 L per minute flow) combines velocity triangle analysis with response surface methodology to evaluate runner and blade geometries. Results derived from that adjusting the conventional size ratio improves efficiency, with a 23 cm runner and 4 cm blade achieving a peak efficiency of 19.95% at optimal rotation. A predictive polynomial model shows diminishing returns with larger components. This optimized design offers a practical solution for remote communities, potentially replacing diesel generators while reducing costs and environmental impact. Although material and scalability limitations require further investigation, this study provides actionable guidance for small-scale hydropower systems, supporting Indonesia's renewable energy goals and global sustainable electrification efforts.