The Zhitong Finance App learned that CITIC Construction Investment released a research report saying that in order to meet the demand for larger and lighter modules, glass thinning is one of the ideas. Currently, 1.6mm small-sized double glass modules have already begun to be released in rooftop photovoltaic power plants. In the first three quarters of 2023, the share of module production has reached about 1%, and the penetration rate is expected to gradually increase. However, considering the current level of glass tempering technology+component cost control requirements, there is still a difference between 1.6mm glass strength and 2.0mm glass at this stage. Currently, it is mainly used in small-format components+roof distribution scenarios with load requirements or high installation difficulties, so it is expected that 2mm will remain mainstream for a long time to come.

The main views of CITIC Construction Investment are as follows:

The reliability advantages of glass packaging and the lightweight requirements of components are the basic logic driving the thinning of photovoltaic glass, so thinning is one of the directions of glass technology iteration.

1) Double-sided batteries require a more reliable packaging method on the back of the component. Compared to single-sided batteries, on the one hand, double-sided batteries require a more reliable packaging method because the aluminum back field is replaced with a partial aluminum back field (aluminum wire), so the field passivation effect is more likely to be damaged and the PID effect occurs. On the other hand, in electrodes printed with silver-aluminum paste on the back, since aluminum easily reacts with water and acid, the grid line is corroded, so double-sided batteries require a more reliable packaging method.

2) Compared with backplates, the reliability of glass packaging is superior, mainly reflected in water resistance, wear resistance, insulation, waterproofness, and carrying capacity, so the vast majority of double-sided components on the market are encapsulated with double glass;

3) However, increasing module size and rooftop photovoltaics adaptation scenarios also put forward requirements for lightweight modules, and thinning glass is one of the current ideas.

With the increase in demand for rooftop photovoltaics, 1.6mm glass began to be introduced this year, and the share of module production in the first three quarters of 2023 has reached about 1%. Referring to Amaton's cumulative 1.6mm glass shipments in the first three quarters, 1.6mm double glass modules currently account for about 1% of module production, and companies such as Follett and Xinyi Solar also have 1.6mm glass technology reserves.

However, we expect 2.0mm glass to remain the mainstream double glass packaging solution for a long time to come. Currently, the main reason that impedes rapid release of 1.6mm glass is the balance between strength and economy:

1) To achieve the same strength as 2.0mm glass, 1.6 mm glass requires higher tempering technology and cost. At the same time, 1.6 mm glass is relatively more likely to deform, causing problems such as component damage and battery deformation. However, the larger and thinner the glass area, the greater the degree of deformation, and the higher the risk of fracture.

2) Currently, the lightweight and cost requirements of photovoltaics are comprehensively considered. Currently, 1.6mm glass on the market mainly uses a semi-tempered process. There is a gap in strength compared to 2.0 and 3.2 mm glass. At the same time, in order to reduce the risk of component breakage and battery cracking due to deformation. Currently, it is mainly used in small-sized components. It is not safe to use 1.6mm glass for component packaging in large sizes and in scenarios where the external environment is harsh.

Investment advice:

In order to meet the demand for larger and lighter modules, glass thinning is one of the ideas. Currently, 1.6mm small-sized double glass modules have already begun to be released in rooftop photovoltaic power plants. In 2023, their share of module production has reached 1%, and the penetration rate is expected to gradually increase. However, considering the current level of glass tempering technology+component cost control requirements, there is still a difference between 1.6mm glass strength and 2.0mm glass at this stage. Currently, it is mainly used in small-sized components+roof distribution scenarios with load requirements or high installation difficulties, so it is expected that 2mm will remain mainstream for a long time to come.