An Integrated Techno-Economic Framework for Optimal Microgrid Design: An Australian Case Study

Reliable and affordable electricity supply remains a challenge for remote and regional communities, motivating the deployment of renewable-based microgrids supported by flexible storage and advanced planning methods. This paper proposes an integrated techno-economic framework for optimal microgrid design and robustness assessment, and applies it to a 1000-household residential community in Rockhampton, Queensland (Australia). The framework links time-series simulation, dispatch-based operation, and lifecycle costing to evaluate hybrid configurations comprising photovoltaic and wind generation, battery storage, diesel backup, grid exchange, and an optional hydrogen subsystem (electrolyzer–hydrogen storage–fuel cell). Key indicators include net present cost (NPC), cost of energy (COE), renewable penetration, energy purchased/sold, and emissions-related outcomes. To avoid conclusions that depend on a single set of assumptions, the study performs systematic sensitivity analysis across financial, technical and policy drivers: discount rate, technology capital costs, fuel price, load uncertainty, renewable resource variability, carbon pricing/emissions cost, and grid outage duration, supplemented by a no-hydrogen attribution case. The results demonstrate that several sensitivity dimensions induce nonlinear shifts in the optimal design, including breakpoints where capital-intensive renewable–storage expansion becomes economically preferable. The proposed framework enables transparent comparison of hydrogen-enabled and battery-centric solutions and provides planning guidance for resilient, low-emission community microgrids under Australian operating conditions.