Hybrid energy system for St. Martin Island, Bangladesh: An optimized model

St. Martin's island is a small island in the Bay of Bengal about 9 km south of the main land of Bangladesh. Nearly 6000 inhabitants live there and fishing is their primary livelihood. Since the island is far away from the main land grid connection is almost impossible in terms of cost and geographic location. However, the electricity demand is partly fulfilled by stand alone diesel generators. In this study, an attempt has been made to model a hybrid electricity generation system for a small community of the island. This system incorporates a combination of solar PV, wind turbine, battery and diesel generator. HOMER software is used to analyze and find out the optimum configuration among a set of systems for electricity requirement for 100 households and 10 shops. The system must satisfy the requirements of 78 kWh/day primary load with 20 kW peak load. Sensitivity analysis is also done to see the impact of solar insolation, PV investment cost, wind speed and diesel fuel price on the optimum result. Solar PV (8 kWp), 2 wind turbines (3 kW) each, diesel generator (15 kW) and 25 batteries (800Ah each) hybrid system is found to be the best among all the configuration in terms of cost of electricity (COE).This configuration gives lowest COE Tk 26.54 / kWh (US$ 0.345/kWh) and total net present cost (NPC) of Tk 10,620,388 (USD$ 137,927) with a renewable fraction of 31%. This system can reduce CO2 emission by about14 tons per year compared to diesel generator only.