Multi-objective optimization of a multiregional electricity system in an archipelagic state: The role of renewable energy in energy system sustainability

Indonesia, the world's largest archipelagic state, has sizeable fossil and substantial renewable energy resources; however, high disparity in population density, infrastructure, economic level, and distance between energy sources and consumers inflict a discrepancy in electricity system performance among regions. In the present study, a multi-objective optimization model was developed to support decision makers in selecting the most sustainable scenario for Indonesian power generation planning through 2050. To capture regional characteristics more accurately, the model was developed with a multiregional approach by dividing Indonesia into six regions, and a single-regional approach is set as a reference for comparison. Five development scenarios based on economic–environmental trade-off were proposed, and four policy options were incorporated to evaluate the scenario preferences within various priority sets. Generation mixes obtained from the optimization model were input into a sustainability assessment model consisting of eleven indicators, representing three sustainability aspects: economic, social, and environmental. The results show that for most policy options, the most sustainable electricity system can be achieved by the highest orientation on environmental protection, which results in significant advantages regarding most indicators of sustainability; however, this scenario shows high economic disadvantages relative to the social and environmental benefits. The results indicate that optimization with a multiregional approach can capture regional characteristics of an archipelagic state better than that of a single-regional approach, thereby providing more realistic scenarios for the archipelagic state.