BIPV (Building Integrated PVs) refers to the combination of PV power generation on the outer surface of a building structure. It is the perfect body of the integration of the future urbanized building form and distributed PV energy system under the intensive concept. It can maximize the self-circulation of energy in the building and minimize the dependence on the external power system, so the building integrates the PV power generation system (BIPV) will become the mainstream form of green smart buildings.

　　System integration of green smart power generation systems in new buildings has become the consensus of all countries. On May 9, 2018, the California Energy Commission (CEC) unanimously passed the nation’s first building standard to apply solar energy systems. This standard requires that all three-floor and within new residential buildings in California, including single-family houses and apartments, must be installed with solar panels. The new standard will be implemented in 2020.

　　However, the application of traditional PV module products and technologies to buildings has major shortcomings, making the development speed of the BIPV market far slower than ground-based PV power plants.

　　Since the 1990s, BIPV has mostly adopted thin-film battery technology. Thin film batteries have good advantages in PV curtain walls. The disadvantage is that the power generation efficiency is low, and basically it can only be used in new buildings.

　　At present, crystalline silicon products mainly use double glass module products in the BIPV market, which are mostly used in the roof of the sun room. Very few demonstration projects are used in the glass curtain wall. However, due to poor aesthetics, except for some early demonstration projects, no large-scale commercial applications have been seen.

　　In the past few years, the European market has adopted the flat tile and sealing ring model, and successfully realized the component installation on the large slope roof of the household. Due to the extensive use of micro-inverter technology, the roof component flat tile has better water conductivity and single-sided heat dissipation. Each PV component operates independently and adopts low-voltage direct current (less than 60V), which better realizes the integrated structure of building and PV.

　　Glazed tile-style BIPV products are impeccable in appearance. They take into account both power generation and architectural aesthetics. The disadvantages are low capacity per unit area, high prices, and high-voltage DC systems are still used.

　　The market calls for PV products that can truly integrate with buildings. It should first have the necessary functions of building materials (waterproof, moisture-proof, fireproof, weather-resistant, and durable), and then PV power generation functions.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect replacement for lead-acid batteries, and they are the first choice for grid-connected peak shaving, off-grid energy storage, PV energy storage, UPS, data center and other industries.

　　Solar power generation system with lithium battery energy storage system is a very promising clean energy.