GRID INTEGRATION ANALYSIS FOR COGENERATION AND CAPTIVE PLANT IN SUGAR INDUSTRY: A CASE STUDY OF INDUSHANKAR SUGAR INDUSTRY PVT. LTD., SARLAHI, NEPAL

Abstract

The electricity sector in Nepal is currently facing the formidable challenges of an insufficient installed capacity, a sub-optimal infrastructure, circular debt and revenue shortage. All of the problems hamper socioeconomic activities. The demand of energy has been consistently increasing annually and the peak demand growth rate of around 10% per year requires addition of generation as well. Nepal, today, experiences a peak power shortage of 12% and an energy shortage of about 8%. To fulfill the gap of demand and supply, integration of industrial cogeneration and captive plant play significant roles. Numerous countries across the globe are consuming bagasse to generate electricity, but regrettably in our country, this valued renewable resource has mostly been thrown away as a mere trash. Analysis of exportable power from sugar industries is an important aspect of the disclosure on grid integration of captive cogeneration plant and resulting environmental impact. This study aimed at investigating exportable power from Indushankar Sugar Industry Pvt Ltd. and analyze the impact of surplus power fed on distribution grid.The GHGs emission is also estimated for bagasse-based cogeneration. The study shows Indushankar Sugar Industry can export upto7.61 and 5.4 MW during crushing and non-crushing seasons with addition of backpressure condensing turbine in existing cogeneration facility. The simulation study shows losses on feeder lines, busses and transformer as well as percentage voltage drop on the network decreases with the increase in power export. The terminal voltage at different load point also get improved. The short circuit analysis shows the fault level increases with the addition of generating units on distribution grid.The total GHG emission ranges from 1010.88 - 3489.11tons CO₂eq, against the power generation of 15.55-53.68 GWh, which is expected to avoid the emission of 3250.08 - 38135.99 tons CO₂eq, if the power exported from sugar industry replace the power generated from diesel plant in the industrial area or NEA’s diesel plant.