Investigation and evaluation of building energy flexibility with energy storage system in hot summer and cold winter zones

The dramatically increasing energy demand of building air-conditioning in hot summer and cold winter zones fluctuates greatly, especially during the period of cooling and heating in summer and winter, which exerts strict operation burden and challenge on power-grid system stability. In order to realize building energy flexibility, this paper proposes a type of energy utilization system including electricity chiller, gas-boiler, electricity heater, cold and thermal energy storage tank (case II), on the basis of electricity chiller and gas-boiler for cooling and heating demand (case I), which is commonly used as cold and heat source in hot summer and cold winter zones. The total cost of the whole life period and annual carbon emission of energy systems are served as objective function is optimized. Furthermore, the system capacity confirmation and load demand management control are analyzed and discussed, the characteristics of energy-flexibility with and without energy storage are presented, the load coefficient is introduced to evaluate the impact of case II on building energy flexibility. Compared with case I, with the deployment of cold and thermal energy storage, the cost-effectiveness of case II is 16.5% and carbon emission is reduced by 30.9% compared with case I .In case II, the load coefficient of electricity chiller and electricity heater is 83.34% and 30.65% respectively, which means that energy storage system enables to promote building energy flexibility improvement and grid-friendliness enhancement. This paper provides methods and theoretical guidance for the planning-operation of building energy system and building energy flexibility in hot summer and cold winter zones.