Quality, Reliability, And Supply-Chain Transparency At STC.I 2026

As the PV manufacturing industry continues to evolve with new cell architectures, advanced materials, and innovative production technologies, maintaining high standards of quality and reliability remains critical alongside gains in efficiency and cost reduction.  

During the Quality and Sustainability Workshop, a parallel session moderated by TaiyangNews Managing Director Michael Schmela on Day 1 of the TaiyangNews Solar Technology Conference India 2026 (STC.I 2026), speakers discussed strategies to ensure consistent quality in cell and module manufacturing. They addressed topics such as material robustness, process-related reliability risks, and field performance expectations while integrating new technologies at scale.  

Debajyoti Sarangi Consultant at SKC explained that solar module quality is critical because modern modules now carry warranties of up to 30 years and must withstand various environmental conditions such as UV radiation, moisture, and temperature changes. Over time, several degradation mechanisms can affect performance, including yellowing of materials, corrosion, peeling of anti-reflection coatings, and failures of components like junction boxes and diodes.  

He noted that developers often prioritize module cost during procurement instead of carefully reviewing the bill of materials (BOM). However, key components such as solar cells and encapsulants have a major impact on reliability and long-term performance, even though some of them represent a smaller share of the total module cost.  

Sarangi also highlighted different degradation mechanisms such as potential induced degradation (PID), light-induced degradation (LID), light- and elevated temperature-induced degradation (LeTID), and UV-induced degradation (UVID). While some of these issues have been reduced with newer technologies like gallium-doped or n-type wafers, emerging technologies such as TOPCon and heterojunction (HJT) bring new reliability concerns that need closer monitoring.   

Recent changes in module design—such as larger module sizes, thinner 2 mm glass, and new encapsulant materials like POE and EPE—can create additional reliability risks, including glass breakage and material compatibility issues. Another concern is the difference between the nameplate power claimed by manufacturers and the actual measured output of modules, which in some cases may vary significantly.  

Sarangi stressed that developers should verify module performance data and testing methods more carefully to ensure long-term system reliability. 

Presenting the industry perspective on quality and sustainability, Navitas Solar Chief Operating Officer Vijay Menon called to raise standards across the board—from manufacturing to installations. Building on the concerns raised about module reliability and materials by Sarangi, Menon expanded the discussion by looking at quality from both the manufacturer’s and the buyer’s perspective.  

He noted that the solar industry has undergone major changes over the past 2 decades, with module prices falling by around 99% and manufacturing capacity expanding significantly.  

At Navitas Solar, he shared, module manufacturing began in 2013 and has now reached about 3 GW of capacity, with plans to expand to 10 GW by 2030 while also adding solar cell production. The company is also exploring energy storage and further vertical integration.  

From a manufacturing standpoint, he said quality control is increasingly moving upstream, with greater focus on preventive measures such as stronger incoming quality checks, supplier qualification, and process-based quality management rather than relying only on final product inspection.  

Automation, digitalization, and data-driven manufacturing systems are also improving consistency, traceability, and production efficiency. In addition, many manufacturers are setting up in-house reliability laboratories to test products regularly rather than depending solely on external certifications.  

However, Menon emphasized that the industry continues to place heavy emphasis on price during procurement. According to him, most buyer discussions still revolve around price rather than long-term performance, even though developers increasingly request 3rd-party validations, certified bill of materials, and independent reliability testing.  

He also pointed out that quality challenges often arise after modules leave the factory. Poor installation practices, improper handling, inadequate cable management, and unsafe maintenance practices can lead to microcracks, damage, and early degradation of modules in the field. In many projects, operation and maintenance decisions are also driven mainly by cost, which can further reduce long-term performance.  

Menon added that gaps remain in data tracking and feedback from field performance to manufacturing improvements. Limited long-term performance data, weak traceability beyond the factory, and insufficient analysis of environmental factors affecting module output make it difficult to fully evaluate degradation trends.  

He concluded that improving solar project outcomes requires a broader industry focus on end-to-end quality—from manufacturing and procurement to installation, operation, and maintenance. Without stronger standards and accountability across the entire value chain, investors and lenders ultimately bear the risk if projects fail to deliver the expected returns. 

Technical bankability was another key topic at the session as Parth Bhatt, Senior Engineer for Solar Technology at DNV, presented a framework to evaluate whether the technical risks of a solar technology are adequately managed for project financing. Developed with colleagues and industry experts, Bhatt said the framework aims to evaluate whether the technical risks of a technology are sufficiently managed for financiers to feel confident investing in projects.  

Bhatt explained that technical bankability depends largely on three factors: reliability testing, manufacturing quality, and accurate energy-performance modeling. Highly accelerated stress tests are used to simulate long-term behavior, though rapidly evolving technologies mean extensive field data is often limited. Manufacturing processes, equipment management, and quality control also remain critical despite increasing automation, while reliable energy-yield modeling helps investors predict project performance and financial returns over time.  

To address gaps in existing assessment approaches, such as technology readiness and performance level frameworks, DNV developed a Technical Bankability Level (TBL) framework based on six pillars, including reliability testing, manufacturing quality systems, safety and toxicity considerations, and energy prediction. The framework rates technologies on a scale from low to high bankability. 

Applying the framework to current cell technologies, Bhatt noted that PERC remains highly bankable due to its mature manufacturing ecosystem, though larger module designs raise mechanical reliability questions. TOPCon shows strong potential but still requires more field data and refined energy-yield modeling. Heterojunction (HJT) technologies face additional challenges, including tighter manufacturing tolerances and reliability concerns such as TCO degradation. 

Bhatt also highlighted the need for stronger quality enforcement and independent oversight, particularly in markets like India, where financiers and third-party technical advisors are less involved in enforcing module quality compared with regions such as North America. He emphasized that developers should closely examine bill-of-materials changes, manufacturing quality systems, equipment maintenance, and independently validated energy-yield models when selecting modules for projects. 

Building on Bhatt’s remarks on bankability frameworks, Purushothama A., the Senior Technical Manager at TÜV Rheinland (India) Pvt. Ltd., outlined the key standards and testing approaches used to evaluate the reliability of solar PV modules.  

Globally, the solar industry follows the core certification standards, including International Electrotechnical Commission (IEC) standards IEC 61215 and IEC 61730. These define comprehensive testing protocols to ensure photovoltaic modules meet safety, durability, and performance standards. These cover a range of test categories, including environmental stress, mechanical load, electrical safety, and fire hazards. These certifications typically require at least 26 module samples and around 3.5 months to complete testing.  

Beyond these baseline requirements, he highlighted additional reliability and performance tests such as IEC 61853 performance evaluation, salt mist and ammonia corrosion testing, potential induced degradation (PID), UV-induced degradation, transportation testing, and sand and dust resistance.  

Taking into account some emerging reliability challenges—particularly UV-induced degradation and light- and elevated-temperature-induced degradation (LETID)— led TÜV to develop supplementary testing standards to address gaps not yet fully covered by IEC specifications. It also introduced an extended bankability test program that builds on IEC technical specifications but adds extra test sequences relevant to newer cell technologies such as TOPCon and heterojunction (HJT).  

Purushothama also presented reliability data from tests, including thermal cycling, damp heat exposure, PID, LETID, and UV degradation. The results showed that TOPCon and back-contact technologies generally exhibited lower degradation compared to PERC modules in several stress tests. Module construction also influenced performance, with glass-glass structures demonstrating lower degradation than glass-backsheet designs in damp heat testing.  

Common module failures observed in the field are also a result of poor connector installation, corrosion, arcing-related fire risks, and hotspots detected through thermal imaging. 

He concluded that TOPCon modules show strong reliability, with low degradation in the PC200 test and lower degradation in damp heat, PID, LETID, and UVID tests. After completing the 2PFC29 certification program, modules can receive TÜV Rheinland certificates with A, AA, or AAA ratings based on degradation levels. TÜV’s testing laboratory is accredited under ISO 17025 and recognized under the CB scheme, OSHA accreditation, and BAS. The presentation also showed examples of field issues such as improper cable glanding, poorly fixed connectors, connector corrosion, fire caused by arcing, and hotspots visible in thermal images due to partial electrical contact. 

While there have long been technical reliability tests in the market, Margaux Plurien, Global Membership Manager at the Solar Stewardship Initiative (SSI), highlighted that quality in the solar industry increasingly extends beyond product performance to include supply-chain transparency and responsible manufacturing practices.  

Giving a background on the SSI, which was launched in 2023, Plurien described it as a global certification and assurance initiative focused on strengthening credibility across the solar value chain. The initiative brings together manufacturers, buyers, financial institutions, and civil society organizations to support compliance with growing international regulations and to build trusted partnerships within the industry. Its members include major manufacturers and buyers representing a significant share of global solar manufacturing capacity.  

She noted that as solar deployment expands globally, investors and regulators are placing greater emphasis on traceability, due diligence, and responsible sourcing. Regulations in markets such as Europe, the US, and the UK increasingly require companies to demonstrate transparency across their supply chains, including labor practices, environmental management, and material sourcing.  

In this context, self-declarations are becoming insufficient, with greater reliance on independent verification. To address these requirements, SSI has introduced certification standards covering environmental, social, and governance (ESG) criteria as well as supply-chain traceability. Through third-party audits and graded certifications, the program evaluates manufacturing sites, production processes, and supply-chain transparency.  

The initiative currently covers a growing share of global PV manufacturing capacity and aims to help manufacturers and buyers demonstrate compliance while facilitating market access and investor confidence. Plurien emphasized that, as the solar industry scales rapidly, long-term competitiveness will depend not only on module performance and cost, but also on transparent supply chains, credible verification systems, and responsible production practices that support sustainable market growth. 

This article is part of TaiyangNews’ multi-part coverage of the TaiyangNews Solar Technology Conference India 2026 (STC.I 2026). Other sessions on Day 1 of the STC.I 2026, apart from the inaugural session, included one on module manufacturing equipment, on module performance and reliability, a policy panel, and an executive panel. Day 2 also covered a market overview. 

TaiyangNews will be back with this year’s 1st Virtual Conference on Smarter Solar for Homes & Businesses on March 25, 2026. Registrations are open here.