LONGi’s HPBC 2.0 modules the first to receive TÜV SÜD certification for PID-p resistance

LONGi’s HPBC 2.0 back contact modules, Hi-MO 9 for utility-scenarios and Hi-MO X10 for residential and C&I scenarios, have become the first in the industry to receive TÜV SÜD’s certification for resistance to Potential Induced Degradation - Polarization (PID-p), in accordance with PPP 58234A:2025 and IEC TS 62804-1 Ed2 (DTS) standards.

Addressing a critical reliability risk

PID-p represents an emerging reliability concern in advanced photovoltaic modules. It occurs when the electric field generated by system voltage causes polarization effects in the passivation layer of silicon cells, leading to reversible power losses. Unlike conventional PID-s (Potential Induced Degradation – Shunting), which results in more permanent damage, PID-p develops more rapidly but allows for performance recovery through light exposure, particularly ultraviolet radiation. The growing relevance of PID-p has drawn increasing attention from technical standard bodies such as the IEC and research institutions like NREL.

Successful testing of module durability under polarization stress

TÜV SÜD’s testing process simulates real-world stress conditions by combining voltage, temperature, and light exposure to assess module durability under polarization stress. Both Hi-MO 9 and Hi-MO X10 passed these tests with excellent results, confirming their robust resistance to PID-p in demanding operational environments.

Demonstrating technological leadership and maturity of back contact architecture

By securing TÜV SÜD’s PID-p certification, LONGi underscores its leadership in addressing long-term degradation mechanisms in high-efficiency modules. The achievement reflects the maturity of its HPBC 2.0 architecture and its commitment to reliability alongside efficiency gains.

Commitment to standards and industry progress

LONGi continues to work closely with third-party certification bodies such as TÜV SÜD to elevate global photovoltaic standards. Through ongoing R&D and testing collaboration, the company aims to support the sustainable development of solar technology and contribute to the global energy transition.