Primary healthcare centres (Puskesmas) in North Sulawesi’s coastal and island regions operate under severe energy constraints driven by extreme thermal conditions. This investigation applies a systems-oriented assessment combining meteorological analysis, psychrometric evaluation, and energy system profiling to characterise operational performance. Analysis of Bunaken Island’s healthcare facility reveals that ambient conditions met ASHRAE Standard 55 thermal comfort criteria for only 9 hours annually. The dehumidification processes alone could achieve acceptable conditions for approximately 3,409 hours (39% of operational time). The adaptive comfort model incorporating natural ventilation extends comfort hours to 4,447 hours, though 5,341 hours still require active cooling systems. Electrical system analysis confirms infrastructure vulnerabilities despite the 350 kW solar-diesel hybrid microgrid, with peak facility demand of 7.6 kW creating timing mismatches with solar generation patterns. The facility’s 14.56 kWp photovoltaic array and 57.6 kWh lithium iron phosphate battery storage provide limited energy autonomy, highlighting the critical importance of electricity storage systems. Results demonstrate that hybrid environmental control strategies combining passive cooling with mechanical systems offer the most practical approach for reducing energy consumption whilst maintaining essential clinical functionality. The findings establish a technical foundation for climate-responsive healthcare facility design in tropical maritime contexts, contributing to the understanding of energy performance in off-grid environments and supporting Indonesia’s net-zero emissions commitment by 2060.

Keywords

HVAC loads, Thermal performance, PV systems, Passive design, Energy resilience.