Exploring the best hybrid energy system for the off-grid rural energy scheme in Bangladesh using a comprehensive decision framework

Abstract

ABSTRACT The dilemma of whether to expand the existing oil-based grid or to promote clean energy in off-grid areas has been challenging for developing countries. In response, the Hybrid Energy System (HES) has been reported to be a balanced solution. However, the traditional decision tool for HES cannot effectively address the associated socio-economic complexity and needs to be further enhanced. Therefore, this study proposed an innovative decision framework that incorporates HOMER (Hybrid Optimization Model for Electric Renewable) and MCDM (Multi-Criteria Decision Making), namely BWM-MCODAS (Best-Worst-Method and Modified Combinative Distance-based Assessment), to select the best HES design based on a case study in Bangladesh. Sixteen various criteria covering technical, economic, environmental, and social aspects were evaluated by three panels of energy experts in various fields. The results show that the best design is the Photovoltaic (PV)-Diesel Generator-Battery HES with the optimal capacity of 36.3 kW, 10 kW, 80.1kWh, which scored 0.11, 0.13, and 0.20, respectively, according to three expert panels. The cost of energy (COE) of the optimal design is 0.32 USD/kWh, which is more affordable than the national grid (0.34 USD/kWh) and cheaper than Solar Home Systems (0.72 USD/kWh). Additionally, the proposed system can reduce CO2 emissions by 64.80% compared to a diesel only system, which keeps the environment cleaner. Two types of sensitivity analyses were further adopted to verify the consistency and robustness of the results. The first one proves that the score remains stable when varying the proposed MCODAS used in the framework. Second, sensitivity analysis shows that ‘capital cost’ is the most sensitive criterion and further confirms the stability of the results. Hence, the proposed method enhances the information value to achieve a balanced solution, and offers a useful tool to ease the dilemmas faced in the rural energy schemes of developing countries.