⚡ Quick Read
- What happened: Fraunhofer CSP researchers found that certain commercial PV cleaning agents can degrade anti-reflective coatings (ARC), causing performance losses of up to 5.6%.
- Why it matters: Using improper chemicals during O&M can lead to permanent, irreversible damage to module glass, directly impacting long-term energy yield and project ROI.
- Watch: Developers should demand compatibility certifications from cleaning product suppliers and prioritize DI water or proven non-abrasive solutions.
Background and Context
The maintenance of utility-scale solar projects in India often involves frequent cleaning to mitigate the impact of dust and soiling, which can significantly reduce energy output. While many operators utilize automated or manual cleaning solutions, the chemical composition of these agents is rarely scrutinized. The Fraunhofer Center for Silicon Photovoltaics (CSP) recently conducted a study to evaluate the impact of five market-leading, commercially available PV cleaning products on module glass surfaces, specifically focusing on the integrity of anti-reflective coatings (ARC).
Key Details
The research team exposed module glass samples to various cleaning agents for 24 hours at a temperature of 55 C to simulate the cumulative wetting time and thermal stress experienced by modules over their operational lifetime. The study utilized pure deionized (DI) water as a control reference. The results revealed a significant variance in product safety: while two of the cleaners performed similarly to DI water, three agents caused measurable degradation of the ARC.
Microscopy analysis confirmed that the damaging cleaners physically stripped or altered the ARC, resulting in non-uniform surfaces often visible to the human eye as “rainbow” discoloration. In the most severe instances, this degradation translated into a power loss of up to 5.6% compared to modules with intact coatings. Researchers emphasized that this loss is permanent, as the anti-reflective functionality is compromised once the coating is damaged.
What This Means for EPCs and Developers
For Indian EPC contractors and O&M service providers, these findings serve as a critical warning regarding procurement practices. Many cleaning agents are marketed as “all-purpose” or “PV-safe,” yet the study suggests that such claims may not always be backed by rigorous testing. Using an aggressive cleaner can lead to a direct, irreversible reduction in the performance ratio (PR) of a solar plant. Developers must move beyond price-based procurement of cleaning chemicals and begin requesting technical validation or compatibility certificates from manufacturers to ensure that their chosen cleaning regimen does not jeopardize the long-term asset value of the project.
What Happens Next
The industry is expected to see a shift toward more stringent O&M protocols. Asset owners are advised to conduct independent screening tests or verify that cleaning agents have been specifically certified for use on ARC-coated glass. As the Indian solar market matures, the focus is shifting from simple capacity installation to long-term performance optimization, making the selection of maintenance consumables a high-priority operational concern.
