Optimal planning and operation of heterogeneous autonomous and grid-connected microgrids based on multi-criteria techno-economic, environmental, and social indices

Sustainable energy transition involves the execution of recent technologies as a means of ensuring energy access and security. However, the increasing adoption of such technologies, particularly in the presence of diverse constraints, poses significant challenges from a planning perspective. In this context, the multi-objective analysis offers valuable insights for decision-making that balances mutual benefits, as relying solely on a single objective may increase the risk level for stakeholders engaged in coordinated decisions. Based on the real dataset, this study presents a comparative multi-criteria techno-economic, environmental, and social evaluation of site-specific unified standalone and grid-connected hybrid microgrids. The study employs a modified Last Cluster Mean Carried Forward approach for data processing, incorporating the Proprietary Derivative-free Algorithm and Original Grid-Search Algorithm to ensure a standardized comparison. Results reveal the substantial advantages of grid-connected systems over standalone counterparts, with reductions of 12.54 % to 63.73 % and 68.93 % to 89.13 % in terms of Net Present Cost and Levelized Cost of Energy, respectively. Grid-connected systems exhibit superior adaptability, recovering 52.3 % to 98.1 % surplus energy with a Renewable Fraction averaging 77.1 % to 87.9 %. However, these systems were hindered by frequent interruptions and required a minimum capacity shortage of 2.5 % to 3.5 %. Furthermore, grid-connected systems have proved feasible when carbon emissions, forests required to absorb the emissions, and the Social Cost of Carbon Emissions are considered in the range of 4.65–67.13 kiloton (metric), 423.32–6108.53 ha, and $0.24-$3.42 million, respectively. Social analysis and sensitivity analyses are performed to justify the robustness and adaptability. Lastly, the findings are followed by policy recommendations and results validation by comparing prevailing government tariffs and other studies.