Enhanced energy efficiency technologies in healthcare buildings: a case study of waste heat recovery from an optimized battery-integrated cogeneration system

Healthcare buildings face signi icant challenges in enhancing energy ef iciency. Combined, heat and power (CHP) plants integrated with battery energy storage systems (BESS) offer a promising solution by meeting electric, thermal and cooling demands using a single fossil primary energy source. Starting from an optimized battery-integrated cogeneration plant, a comparative analysis of two waste heat recovery technologies in a hospital building context has been conducted in this study. Speci ically, an ammonia-water absorption, power, and cooling (APC) system and an organic Rankine cycle (ORC) plant are examined, both powered by the waste heat recovered from exhaust gases of the natural gas internal combustion engine, operating in a cogenerative con iguration. A control strategy is implemented to enhance the ef iciency of the integrated systems, prioritizing either cooling or electric power production based on hourly demand within the hospital. The results highlight the integration of waste heat recovery technologies inside the optimized battery-integrated cogeneration is capable to reach a 20.1% and 18.82% in fossil primary energy saving (PES), respectively with the ORC and APC systems. However, the higher investment cost brings the simple payback (SPB) period of the con iguration with the ORC plant to 3.5 years, compared to 3.3 years of the solution with the APC plant. The study shows the bene its of incorporating waste heat recovery technologies into cogeneration systems with energy storage system, providing valuable guidance for developing economically viable and eco-friendly solutions for managing energy in healthcare buildings.