Optimizing energy cost via battery sizing in residential PV/battery systems

Application of renewable sources of energy is vital for the mankind due to global warming. Residential buildings consume major portion of electricity. Therefore, a grid-connected photovoltaic system of domestic level with battery storage backup (PV/storage system) is addressed in this article. This system has a significant effect on decreasing energy costs and contributes to meet the requirements of a nearly net-zero energy building. In this article, Mixed Integer Linear Programming (MILP) is applied to optimize the energy cost of a single-family house with battery energy storage for four different scenarios of installing solar panels. Optimization is performed on monthly scale for a house in Helsinki, Finland. The numerical results indicate that it is reasonable to integrate a storage in grid-connected PV systems in residential applications and represent the impact of battery size on household´s monthly energy cost.