Energy management strategies for base stations in a smart grid environment

In this paper, we propose an optimal energy management strategy that minimises the energy bill incurred by cellular base stations (CBSs) in a smart grid environment. The CBS can harvest renewable energy for local use and is equipped with a limited-capacity battery that is subject to charging and discharging losses. Because the proposed optimal strategy requires non-causal information and hence cannot be implemented online, we propose an estimation-based strategy that only requires causal knowledge of the renewable energy generation and the energy consumption at the CBS. Through simulations, we show that the proposed online estimation-based strategy has only a small performance gap from the optimal offline strategy. Additionally, we derive and verify three analytical results: an upper bound for the optimal cost, the critical battery capacity, above which no further cost reduction can be achieved, and the conditions on the energy price profile, which ensure that the savings can outweigh both the operational and the per-cycle battery costs. These analytical results can be used as guidelines in designing energy storage systems for CBSs in a smart grid environment. Copyright (c) 2014 John Wiley & Sons, Ltd.