Backpass Passivation Process

For more than a decade, the Backpass Passivation Process (PERC) was the first major process change implemented in the c-Si battery industry. Equipment suppliers used in battery production lines are industry tested. For many c-Si battery l profile manufacturers active in 2015-2019, this is the first time they have implemented and are the first to change their processes. For new attendees during this period, the default new line is the PERC line (assuming a single crystal line is installed).

The rapid success of PERC (and the significant efficiency gains compared to Al-BSF) has given Chinese battery manufacturers the confidence to take some other steps to increase the watt peak data in the datasheet. Improvements to be implemented on the front and back of the battery are also emerging.

We also need to consider the transition to double-sided products, Grabbing opening line, half-cut battery designs, and battery/component changes, including multi-grid lines, in addition to many other things. Currently, any practice to increase component power is a fair game.

The result left a deep impression. As early as 2013, there were 60 pieces of battery p-type components in 240W around the world. This mainstream supply channel was used in both roof projects and outdoor experiments. Currently popular are p-type and n-type design products of 400-450W and above.

Of course, the focus is on the STC’s Watt-DC power. In most cases, the extra power of power is not derived from true battery efficiency gains, but simply because of the increased component size (larger silicon or more cells). Therefore, the actual economic benefits are not so obvious, and in many cases the cost is simply transferred to the balance system.

In fact, these changes will also affect the role of the tracker company, as tracker companies need to be prepared for component changes and the impact this change has on the company’s unique supply chain.

Manufacturing changes have brought a unique set of challenges – manufacturers must add new equipment every few months. Not only that, but the impact of manufacturing changes on the bill of materials used, the manufacturer’s control over subcontractors and OEMs is also evident. For almost all leading c-Si manufacturers today, these factors are critical to component shipment targets.

Currently, bill of materials, specifications, and supplier changes for c-Si PV modules appear to be more frequent than changes in handset products. However, the warranty period for mobile phones is only 2-3 years, and the warranty period for PV modules (especially for utilities) must be more than 25 years. In this way, people will immediately find that change is not always a good thing, especially when the customer has not prepared for it, or that the change will only cause problems for the customer.

Driven by silicon, the industry is changing, and this change mechanism may make things more complicated (the craze for larger silicon wafers), in addition to the development of half-cut battery design (cut 6-inch battery The two halves are then assembled into 144 pieces of half size), which results in no standard size parameters for the package components.

From the standpoint of the (roof or ground project) installer, this is certainly not good news. If the component size starts to get bigger, what if I need to replace the faulty product after 3-5 years? Structural suppliers are also affected, and they face the chore of needing to adapt to different non-standard component sizes and multiple interfaces on a regular basis.

Product availability has thus become a limiting factor in the warranty period, and its importance even exceeds the risks associated with component suppliers’ ability to survive for more than a decade. It is impossible for PV module suppliers to stock the various types of PV modules that were supplied in the previous 3-5 years and meet the warranty period. The ultimate responsibility is the project owner and third-party stakeholders who need to maintain the agreed capacity level of the project.

This is the current state of the battle for silicon size. For more background information, please see the recent issue of PV-Tech. Why is the size of monocrystalline silicon wafers larger? Large silicon wafers will eventually force component suppliers to increase component size. With a half-cut battery, you can also install more batteries (over 144) on one component and change the component size again. The standard 72-cell battery pack does seem to have become a thing of the past.

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