This letter reviews the related research on Building Integrated Photovoltaics (BIPV) for efficient utilization of solar energy, and further clarifies the concept of networked batteries. Taking Lithium-ion batteries as an example, maximizing the energy storage is the target, which is achieved by managing the charging and discharging of the individual batteries within a network. With the optimal management of the networked batteries, buildings constructed by using PV-capable materials are expected to be energy self-sufficient, which leads to zero-carbon energy supply. It is pointed out that the real-time estimation on the State-of-Charge (SoC) of Lithium-ion battery is crucial for secure management of the networked batteries.