Identification of Archimedes Screw Turbine for Efficient Conversion of Traditional Water Mills (Gharats) into Micro Hydro-power Stations in Western Himalayan Regions of India: An Experimental Analysis

Abstract

The abundant sources of low headwater streams in the Western Himalayan region create huge potential in terms of micro-hydro power generation capability, and the existing Gharats (Traditional Watermills) that were used previously for grinding flour provides an already built plant for the electricity generation. The Archimedes screw turbine is being explored all around the world as one of the best candidates for efficient electricity generation at low head and low flow rate sites. But there is a lack of research in identifying the best screw configuration for achieving maximum output power and efficiency at such low head and low flow rate sites. The experimental analysis conducted here reveals that the screw angle around and below 25^o along with flow rate below 1.5 L/s can increase the efficiency of the Archimedes Screw Turbine to around 90% provided the RPM is kept at the optimal level to reduce the frictional and overflow losses in the turbine. The analysis also indicates that Archimedes Screw Turbine can produce a humungous amount of power when implemented at all the 500,000 tradition water mills and can easily support the adverse power requirement of the country in a cost-effective manner.