Planning and Analysis of Optimum Operation of Upper Tamakoshi Hydroelectric Project

Abstract

Electricity demand in Nepal is on an increasing trend and with the increasing growth rate of electricity consumers, power and energy demand is also increasing accordingly. Even though peak power demand and energy demand have continuously increased, the increase in electricity generation is not in par with demand. A large chunk of demand is met with imported energy from India. Since most of the hydropower plants are of the Run of River (ROR) type, power generation during dry season is low due to low discharge in river. This research studies the optimum operation of Upper Tamakoshi Hydroelectric Project (UTKHEP), a Peaking Run of River (PROR) plant. The study focuses on optimization of unit performance by distribution of discharge among units for maximization of power generation. Optimal power generation that could be achieved with any given total discharge and any value of gross head was determined. The comparison of optimal discharge distribution with equal distribution of discharge among units shows that generation gain of 4% from the same discharge is possible. The optimization of reservoir was performed to meet daily load demand of Integrated Nepal Power System (INPS). Optimization was performed for dry season in the month of January and March to compare different modes of operation – ROR, PROR and import optimization. Import optimization was performed in such a way that constant minimum power is to be imported from India throughout the day with additional power to be met by UTKHEP in a proper way. In wet season once UTKHEP is connected to INPS, it would result in total available supply power to be greater than demand that needs to be effectively managed. Shifting from LPG to electricity for cooking can pave a way for the utilization of surplus energy. Peak surplus energy after UTKHEP commissioning can substitute around 12,451 Mton of LPG. The additional import of energy during dry season to substitute LPG can help in the reduction of trade deficit.