Effects and performance of a demand response strategy for active and passive building cold storage

Demand response (DR) is a set of demand-side activities to reduce or shift electricity use to improve the electric grid reliability. Existing demand response programmes and tariffs that utilities or independent system operators (ISO) often provide great incentives to consider the use of sophisticated building operation and control strategies that reduce electricity use during occasional or emergency events. This paper presents the investigations on the power demand alternation potential in commercial buildings with cold storage systems aiming to provide effective power information for grid operation and optimization. A control strategy is developed to estimate the demand-shifting and demand-shedding potentials of buildings with comprehensive utilization of passive and active storages on the premise of certain capacity of chillers shut down at the beginning of emergency event. Compared with conventional exclusive passive or active storage control strategies, the developed strategy can provide a rapid response to electrical grid and an accurate estimation of power demand reduction in advance. Besides, it can also relieve ability degradation of handling latent load through reducing temperature of supply chilled water when chillers overriding. In addition, to reduce negative effects on the electric grid, rebound avoidance is considered in implementation of this strategy that allows HVAC system to slowly ramp up to limit power usage rise after DR event. The required rebound duration is also calculated as part of effective information sent to a grid.