Techno-Economic Analysis and Resilience Enhancement of a Hospital Microgrid Under Grid Outage Scenarios

Abstract Hospitals are critical infrastructures where power continuity is paramount. This study presents a techno-economic and resilience analysis of a grid-connected hybrid microgrid for a medium-sized hospital, comprising solar photovoltaics (PV), a battery energy storage system (BESS), and a diesel generator. Using a mixed-integer linear programming (MILP) model via NREL's REopt® platform, we optimized the system design to minimize the net present cost (NPC) while ensuring an uninterrupted power supply to critical loads during grid outages. The analysis evaluated a wide range of outage scenarios, varying in duration (7–24 hours), timing, season, and critical load level (50–100%). The results demonstrate that a resilience-oriented microgrid design is not only technically feasible but also economically advantageous. Compared to a business-as-usual case of 100% grid reliance, the optimized microgrid achieves NPC savings of 9% to 14.2% across all scenarios. A key finding is that systems designed for summer outages yield higher savings due to greater solar availability, and a strategic deep-discharge protocol for the battery during emergencies is crucial for cost-effectiveness. This work provides an actionable framework for hospital administrators to enhance energy resilience without incurring a financial penalty, and in many cases, while realizing significant long-term cost savings.