Technology

Glass Evolving As Alternate To Backsheets

Growing Demand For Bifacial Technology And Lower Glass Prices Challenge Traditional Backsheets, Leading To Shift Towards Glass-Glass Modules

Shravan Chunduri
  • Glass is emerging as a strong competitor to traditional backsheet materials, driven by its transparency, extended module power warranty and competitive pricing
  • Backsheets on other hand are preferred because of lower module weight and ease of handling, increase in demand for rooftop applications, in which glass is typically preferred, is working in favour of backsheet segment growth
  • The backsheet market has seen growth in 2022 with estimated total shipments ranging from 800 to 900 million m2.

The market size for backsheets was once directly proportional to module production. These polymers were the unanimous choice for the rear cover of the module, and glass was a niche a few years ago. In our first market survey on solar backsheets we hardly mentioned glass-glass module (see Market Survey Backsheets For Solar Modules 2017).

It has not taken long for the situation to turn around. Many of the backsheet market participants TaiyangNews spoke to for our 2022/2023 report characterized glass as the main competitor as opposed to other backsheet suppliers or products based on different structures. Backsheets are facing tough competition from glass, courtesy of bifacial. The share of the bifacial technology, especially in utility applications, is increasing and glass is the predominant choice for a module's rear cover. Although transparent backsheets are also available and indeed preferred in a few specific markets such as the US and India, glass remains the first choice.

On top, in these times of high PVDF prices, some companies have moved directly from PVDF backsheets to glass, away from backsheets altogether (see High Price Of PVDF Is The Hot Topic). Glass prices remained low during thecourse of 2022, acting both as a motivator to make the switch and enough of an incentive for those companies that had made it already. According to consulting firm Gessy, the price of 2 mm glass, the key competitor for the backsheet, remained more or less stable in a range of 20 RMB/m2 to 21.5/ m2 during 2022. The price for the 3.2 mm front glass has ranged from 24 RMB/m2 to 27.5 RMB/m2. Simply put, glass has become extremely competitive. There is little motivation for module makers to opt for transparent backsheets unless the application (weight sensitive) or the market itself demands such a product. Also, using glass has another perk – there is industry-wide acceptance for extending the module power warranty to 30 years when using glass as rear cover, which in glass-polymer modules usually is only offered for bifacial products with transparent backsheets.

All this has led to an increase in the use of the double glass structure. According to Cybrid's international marketing director Eric Yang, while the share of the glass-glass module configuration in China was about 50-50 in 2021, it further increased to 60% in 2022. Out of the remaining 40% for backsheets, transparent backsheets claim a 10% share – an indication that monofacial modules are being favored less and less of late. According to the 2022 edition of ITRPV, the glass-glass structure had a global presence of 25% in 2021 and a little over 30% in 2022, while it would need the next decade to surpass the 50% benchmark. However, a few backsheet makers estimate that the share of glassglass has already reached 40% in 2022 with an uptrend to increase further in coming years.

That said, there are also specific segments of PV such as rooftop, in which monofacial configurations are preferred, that have witnessed considerable growth, especially in Europe and China. Bifacial's increasing share is not a concern for the backsheet market. Several backsheet makers are betting on the transparent backsheet's prospects with its long list of advantages, among which low weight and ease of handling in production are at the top. However, with the trend to larger and much more powerful panels, a few module makers increasingly have introduced glass-glass products for rooftop applications. While still a negligible part, if that segment grows it would create further pressure on polymers.

Overall, despite the headwinds, the backsheet market as a whole has seen some growth in 2022. Several companies we spoke to estimated total backsheet shipments for 2021 to have been between 700 and 750 million m2. For example, Jolywood's marketing director Chad Yuan put the backsheet market size for 2021 at 730 million m2, which he equates approximately to 145 GW. As for 2022, he estimates the total backsheet shipments to be about 870 to 900 million m2 that is approximately 180 GW, 20% YoY. He attributes the growth to an abrupt increase in demand from the monofacial modules from the booming distributed segment in China and Europe. "Rooftop projects requiring single glass module structure pushed the demand for backsheets," he added. When factoring the input from other leading backsheet suppliers, the market size for 2022 was estimated to be between 800 and 900 million m2.

Jolywood's CTO Fute Zhang, in his presentation at TaiyangNews' reliability conference, listed 5 key characteristics of the backsheet segment – China holds more than 90% of the backsheet capacity; more than 80% raw materials are made in China; the segment is growing at a pace of 70% YoY; the global backsheet capacity reached 220 GW; and the CPC structure reached 52% market share (see Jolywood presentation here).

For more details, download the TaiyangNews Market Survey on Backsheets and Encapsulation 2022/23 for free here.