Operation optimization strategy of a BIPV-battery storage hybrid system

Abstract

Building integrated photovoltaic (BIPV) system attracts increasing attention of researchers due to environmentally friendly and saving land resource. Combining storage battery with BIPV can improve the flexibility of the entire system, which is promising for distributed renewable energy application. However, how to optimally dispatch the hourly energy flow of PV panel, storage battery and power grid based on a building load is crucial and less investigated. In the paper, a multi-restricted condition nonlinear optimization model is established for a BIPV-battery storage hybrid system under different building loads at a clear day. The optimization model was solved by fmincon function through MATLAB code. In the optimization, overall minimum daily cost including facility cost of the hybrid system, electric price and carbon price were considered as objective function to obtain optimal operation strategy of hourly power distributions of PV, battery and grid for daily building consumption. The key finding indicates that the system has high dependence on power gird when the office building load is heavy, while reduces the depending of power grid as the electrical demand is decreased. Under full-load resident building scenario, when the system with battery cost of 800 Yuan/kW·h or higher, the redundant green power generated by photovoltaic (PV) is sold to power grid in real time to earn extra profit, while the green power is accumulated in the storage batteries as storage battery cost is declined. Moreover, the resident building with BIPV-battery storage hybrid system has less dependence on power gird during day time, realizing self-sufficiency. Under all the scenarios, high storage battery cost limits the capacity of storage battery. And the CO2 emission is reduced as the BIPV-battery storage hybrid system is adopted.