A decision support system for optimal design of hydroelectric projects in Uttara Kannada

Abstract

The first hydropower plant in Karnataka state, India, was set up at Shivanasamudram in 1902. Gradually, the capacities of hydropower plants became very large due to increased electricity demand. Large-scale hydroelectric plants now contribute significantly to meeting the state's and the nation's demand for electricity. Most of Karnataka's hydroelectric plants are located in Uttara Kannada district. Construction of large reservoirs is restricted due to environmental constraints and necessitates the development of ecologically sound alternatives to cater for the needs of the region. The planning of water resources depends on type and size of projects, the ecological factors involved, etc. Emphasis is placed on presenting an overview of water resources through meteorological, hydrological, ecological and economic data. Economic data includes all costs and benefits, specifically hitherto underestimated, environmental social costs and benefits. This study was carried out in Bedthi and Aghnashini rivers in Uttara Kannada district of the Western Ghats region, Karnataka state, India. An estimated 720 and 510 million kWh of electricity can be generated in Bedthi and Aghnashini river basins if all the streams are harnessed. Focusing on land submergence impact, a model is proposed to minimize submergence and maximize net energy in a region, with seasonal power generation, reservoir storage capacity (so as to meet the region's demand during all seasons) and installed generation capacity as the decision variables. Net energy analyses incorporating biomass energy lost in submergence show that maximization in net energy at a site is possible, if the hydroelectric generation capacity is adjusted according to the seasonal variations in the river's water discharge. A decision support system (DSS) used in water resource planning for electricity generation is discussed in this paper.