Micro hydro crossflow turbine manufacturing cost analysis using optimization technique

Abstract Micro hydro crossflow turbines are machines used for the conversion of the kinetic and potential energy of falling water into mechanical energy. It is mainly used for small scale hydro applications of less than 100 kW. It is widely used in community-based power applications owing to its robustness, practicability, acceptable efficiency, and manufacturability. The electro-mechanical component of a micro hydro system gives a significant cost contribution, specifically the turbine component. Due to the simplicity of the crossflow turbine, many micro hydro developers opt to have local shops manufacture these turbines. The paper aims to analyze the manufacturing process of a typical crossflow turbine to accurately predict its cost. The analysis includes different manufacturing techniques and their cost and performance implications for the different parts of the turbine. A parametric three-dimensional model created using computer-aided design application was used to determine the dimensions, cutting length, and welding length of the turbine. The analysis was conducted considering different site-specific scenarios such as low head, medium head, and high head given constant power output. The results show that the cost of the crossflow turbine is significantly affected due to the water flow rate. At a higher water flow rate the crossflow turbine width widens, which significantly affects the machining time. Design changes and machining techniques also affect the cost and the performance of the turbine. An optimization technique was employed to minimize cost by selecting design characteristics that yielded an acceptable performance. The optimized results have shown a cost reduction of at least 20%.