Mitigating Hotspot RiskThe Hi-MO X10 module, featuring HPBC 2.0 back-contact cell technology with positive and negative contacts on the backside, incorporates advanced soft breakdown technology to mitigate hotspot risks. This innovation leverages the internal diode characteristics of each cell and the unique back-contact cell structure to bypass individual cells rather than an entire substring under shading conditions. According to LONGi Solar, this approach reduces power losses by over 70% in cases of single-cell shading compared to conventional TOPCon modules.Additionally, the soft breakdown feature effectively prevents fire hazards caused by localized overheating by allowing blocked current to bypass the shaded area. It also reduces localized temperatures by more than 28% compared to conventional cells, resulting in a significantly lower maximum hotspot temperature of under 110°C compared to the standard 170°C. This enhancement ensures improved module reliability.LONGi Solar has also incorporated an anti-dust frame design to further enhance module performance. By eliminating shorter-length frames, the uniform height of the frame and glass minimizes dust sedimentation, reducing maintenance needs and preserving efficiency.Withstanding PID and UVIDAfter addressing hotspot risks, LONGi Solar highlighted the Hi-MO X10 module’s advanced HPBC 2.0 cell technology, which is designed to withstand potential degradation modes such as PID and UVID.The HPBC 2.0 cell features advanced front-side passivation with more than 2% uniformity compared to conventional TOPCon cells, which rely on high-temperature boron diffusion without advanced passivation. This improvement significantly enhances the module’s resistance to UVID. On the rear side, the back-contact cell structure employs uniform bipolar hybrid passivation, reducing current losses at both positive and negative electrodes and boosting open-circuit voltage (Voc) by over 15 mV, outperforming the unipolar rear-side passivation of TOPCon cells.In addition to cell technology, LONGi Solar emphasized the importance of high-quality packaging materials. The use of a high-density POE-type encapsulant, which resists acetic acid formation, effectively reduces moisture ingress into the module lamination. The adoption of aluminum-free pure silver paste for both positive and negative electrodes further mitigates corrosion risks. Moreover, the module operates at a temperature 0.5°C lower than conventional designs, improving the long-term aging rate of module materials and films.LONGi Solar has validated these reliability-enhancing features through in-house extended reliability tests, including damp heat (DH3000), UV (UV180), and thermal cycling (TC800), demonstrating the durability and performance of the Hi-MO X10 module under extreme conditions.
