Long-term reliability and high efficiency of panels are two of the most important requirements for rooftop photovoltaic installations. This applies to both family houses and industrial or commercial buildings.
The rear-contact solar cell technology (all-back-contact) represents a significant advancement in both the efficiency and aesthetics of photovoltaic panels.
Significant Advancement While most photovoltaic panel manufacturers opt for TOPcon technology, LONGi, as one of the few, has chosen a different technological path known as rear-contact (BC) and has developed its own HPBC (Hybrid Passivated Back Contact) technology.
In a recent technical discussion at a professional conference in Shanghai, Baoshen Zhong, Chairman of the Board at LONGi, shared a comprehensive perspective on innovations in photovoltaic panels.
According to Zhong, over the next few years, LONGi, one of the world's top 5 solar panel manufacturers, will focus on rear-contact (BC) solar cell technology.
This rear-contact technology, utilized in the Hi-MO series panels by LONGi, was specifically designed and developed for long-lasting rooftop installations in both residential and commercial segments. Even after 25 years, these panels retain 88.9% of their performance and boast a high efficiency exceeding 23%.
Advantages of BC Cell Technology LONGi's patented HPBC solar cell technology features a design without a front-side busbar on the surface of the cells. This rear-contact structure eliminates the shading effect on the front surface of the cells, which significantly enhances the overall efficiency of photovoltaic panels.
The standard HPBC cell achieves a very high efficiency of 25.5%, while the efficiency of the HPBC+ cell exceeds 25.8%. The Hi-MO X6 panel equipped with this technology delivers 6 to 10% more solar energy output compared to conventional panels and technologies, including TOPcon.
Beyond improving performance, the panels by LONGi also boast an aesthetic design. This is a key feature of solar panels, making them suitable for both residential and commercial installations.
Cost-effective mass production
The production of back-contact (BC) cells is known for being costly and yielding low output due to the complexity of the manufacturing process.
However, LONGi has already successfully optimized the production process to be more cost-efficient, significantly increasing the yield in the process.
Innovation and record-breaking efficiency In October 2024, LONGi launched a new line of panels, the Hi-MO X10, which stands out with a high conversion efficiency of up to 24.80%, setting a new world record. The latest solar panel is based on HPBC 2.0 technology, marking a new chapter in LONGi's mass production capabilities.
The Hi-MO X10 is currently the highest-performing mass-produced panel with a power output of up to 670 W, which is over 30 Wp higher than standard TOPCon panels. LONGi’s latest innovation comes with a 15-year product warranty and a 30-year linear performance guarantee. The Hi-MO X10 series panels are designed with a 30-year linear degradation rate of 0.35%, with a first-year limit of 1.0%. Their temperature coefficient is -0.26% per ℃.