Solar Energy, Vol.161, 125-137, 2018
Optimal operation of hybrid PV-battery system considering grid scheduled blackouts and battery lifetime
In many developing countries where the energy supply capacity is less than the demand, energy companies distribute the available power according to a specific time schedule, leading to grid scheduled blackouts (GSBs) for the costumers. A suitable way to solve this problem for residential loads is to install a combined photovoltaic (PV) and battery storage system as a replacement of the grid during the blackout periods. However, it is well-known that the lifetime of battery storage will be considerably shortened, if it is not operated appropriately. This paper explores the potential benefits of applying economic model predictive control (EMPC) to optimize the operation of a hybrid PV-battery system to address the GSB problem. The aim of our control strategy is to cover the load as much as possible and meanwhile minimize the total cost of the energy consumed from the grid. In particular, the battery is operated in such a way that its lifetime will be prolonged. A comparison between different operation strategies for the system considering the seasonal variation in the load and the PV power generation is made. The results show that the proposed approach leads to a significant reduction of the total energy consumed from the grid while decreasing the curtailment of the generated power from the PV-array, and maximizing the battery lifetime.
Keywords:Photovoltaic hybrid system;Battery lifetime cost;Economic model predictive control;Grid blackouts