Optimal sizing and assessment of a renewable rich standalone hybrid microgrid considering conventional dispatch methodologies

Abstract

This paper presents an evaluation of the optimized design of an off-grid hybrid microgrid for alternative load dispatch algorithms with the determination of the most optimal sizing of each equipment, analyzing the voltage and frequency outputs and various costs of the proposed microgrids. Kushighat and Rajendro Bazar, two geographical locations in Bangladesh have been taken as test sites. The proposed microgrids incorporating diesel generator, renewable resources, storage device, and 23.31 kW of demand have been optimized for five conventional load dispatch methodologies: HOMER predictive dispatch, Load Following, Generator Order, Cycle Charging, and Combined Dispatch to reduce the system's net present cost, gas discharge and cost of energy. HOMER (Hybrid Optimization of Multiple Electric Renewables) software has been used for the analysis to determine the optimal sizes and costing and the voltage-frequency performances of the microgrids are analyzed using MATLAB/Simulink. From our analysis, load following is determined as the superior approach with a minimum operating cost of 3738 USD, net present cost of 152,023 USD, CO2 discharge of 3375 kg/year and cost of energy of 0.208 USD /kWh along with a steady voltage-frequency output. Combined dispatch is determined as the worst strategy for the proposed microgrids with the highest energy cost of 0.532 USD /kWh, the operational cost of 15,394 USD, net present cost of 415,030 USD, and high CO2 discharge. At the end of this work, a comparative analysis between the proposed design, another hybrid, and traditional generation plant is also presented. The findings of this work will be appropriate for any location with an identical demand profile and meteorological estate.