Waste Heat Recovery Technologies on Optimized CHP-BESS Plant: A Performance Comparison Between Organic Rankine Cycle and H2O-NH3 Absorption Plant

Combined, heat, and power (CHP) plants, integrated with battery energy storage systems (BESS), represent a feasible solution to meet electric and thermal demand with a single fossil primary energy source. In this work, a comparative analysis of two waste heat recovery technologies for a hospital was performed. An ammonia-water absorption, power, and cooling (APC) system and an organic Rankine cycle (ORC) plant were combined within an optimized fossil primary energy saving (PES) oriented batteryintegrated cogeneration system, characterized by natural gas internal combustion engines, which waste heat is recovered inside the APC and ORC plants. A control strategy was implemented to optimize the efficiency of the system, prioritizing cooling or electric power production based on hourly Hospital’s demand. The APC-based trigeneration configuration reaches a 20% of PES and a 24% reduction in CO2 emissions, while the ORC-based trigeneration system performs a 19% improvement in PES and a 23% reduction in CO2 emissions, compared to the hospital separate production of the same amount of energy. The simple payback (SPB) period for both configurations increases slightly, moving from 3.23 years for the optimized CHP-BESS plant to 3.3 years for the APC-based configuration and 3.4 years for the ORC-based plant.