Abstract
This paper studies energy storage sharing in a grid-connected residential microgrid, where a group of households with controllable loads and renewable generations cooperatively shares an energy storage. By exploiting delay tolerance of elastic loads, we develop a joint real time storage sharing and load management system that takes into consideration the operational constraints of the shared energy storage coupled with the time-varying load demands and stochastic renewable generations of all households, with the aim of minimizing the long term time-averaged energy costs of the households without reducing energy consumption. A Lyapunov-based online battery sharing control algorithm is designed to jointly optimize energy consumption, load scheduling and energy charging/discharging actions of individual households only based on current system states. The proposed online sharing algorithm enables the households to optimally utilize the shared battery and reschedule their delay tolerant loads in a distributed but coordinated fashion, while satisfying the time-varying energy consumption preference of each household. Numerical simulation results demonstrate that the low-complexity joint storage sharing and load scheduling algorithm serves the load demands of each household with a lower delay at a relatively low cost while facilitating a fair utilization of the shared energy among the households in terms of their energy contributions.