Quantifying the energy flexibility potential of a centralized air-conditioning system: A field test study of hub airports

Centralized air-conditioning systems are widely considered a major energy consumer with high energy flexibility, contributing to renewable penetration and power system regulation. Nevertheless, a lack of understanding of their system components' abilities limits the utilization of their full potential. Hereby, we took the centralized air-conditioning systems of two hub airports as typical examples and quantified their energy flexibility potential by cooling load reduction potential (qmax), cooling energy storage capacity (Q), based on field test. Cooling plants had the highest potential (qmax = 70–110 Wc/m2; Q = 500∼1500 Whc/m2), followed by terminal devices with building thermal mass (qmax = 2–11 Wc/m2; Q = 10–40 Whc/m2) and transmission & distribution networks (qmax = 50–200 Wc/m2; Q = 10–20 Whc/m2). Various air-conditioning terminal devices utilize building thermal mass to different degrees. During the investigation, the conventional all-air system used 7.8 %∼18.7 % of the building's thermal capacity, whereas that of the radiant floor system significantly increased to 38.9 %∼48.3 %. Consequently, the systems of the hub airports can participate in demand response programs with a cooling load reduction of 2∼15 MWe, for 6–20 h using different operating strategies. These findings shed light on demand-side flexibility characterization and exploitation to support a decarbonized energy system.