In addition, falling glass prices have also made them cost-effective. According to the TaiyangNews PV Price Index for Calendar Week 5, the price of 3.2 mm glass was 19.5 RMB/m², while the 2 mm variant was 12 RMB/m², both dropping significantly by about 30% and 50%, respectively, from the start of 2024. The 2 mm glass, typically used for glass-glass structures and a main contender for rear covers, has seen a substantial price reduction. These falling prices have also lured module makers, who are reeling under severe cost pressure with module prices hitting rock bottom. All this has led manufacturers to replace the backsheet with glass as the rear cover. According to the 15th edition of International Technology Roadmap for Photovoltaics (ITRPV), glass-backsheet modules had a share of 60% in 2023, dropping to less than 50% in 2024, expected to be less than 40% by 2026, and finally to decline to 23% in the next 10 years. However, several companies we spoke to estimate that the glass-backsheet configuration accounts for only 15% to 20%. The flip side of using glass-glass modules is that they require longer lamination times, which can reduce the productivity of module fabs, are susceptible to damage during handling, and are notably heavier.
Sharing the Indian context, Alishan and RenewSys emphasize that backsheets are still in demand, though not in the mainstream. According to Khushbu Patel, AGM at Alishan, the company's backsheet capacity is mostly occupied, primarily supplying module makers catering to specialty applications, such as agrivoltaics and building-integrated photovoltaics (BIPV), and a few government projects. RenewSys’ encapsulation and backsheets business wing CEO Rakesh Singh also emphasizes that the company's backsheet capacity is fully utilized, while no new capacity has been added. In February 2025, RenewSys introduced its anti-acid property EVA for high-efficiency PV module manufacturing (see RenewSys: Anti Acid EVA Technology For Reliable PV Module).
Jolywood notes that glass-glass modules, although preferred, face challenges related to thickness and cost reduction. While some manufacturers are experimenting with thinner glass (e.g., 1.8 mm or 1.6 mm), these alternatives are still considered risky due to the increasing size of PV modules, which raises reliability concerns. The size of the module plays a crucial role in determining the required glass thickness. A compromise on thickness could also affect reliability. Nevertheless, the backsheet segment as a whole is going through tough times and has seen a significant decline since 2022.
Summarizing the discussion with leading backsheet suppliers, the majority agrees that the production of glass-backsheet modules accounted for about 160 GW in 2022 using a total of about 800 million m2 of backsheets. For 2023, total backsheet shipments were close to 600 million m2. However, the total backsheet market reduced by nearly 50% in 2024 to about 310 million m2, indicating a glass-backsheet module volume of about 60 GW. It is further expected to decline to between 200 and 300 million m2 in 2025. During SNEC 2025, the Chinese backsheet & module maker Jolywood showcased its transparent meshed & reflective black backsheet and the latest windproof module (see Jolywood Displays Latest Offerings At SNEC 2024).
