LONGi announced on 6 December 2024 that its next-generation back contact solar module, the Hi-MO X10, will be available in the UK from March 20251. The launch begins with the Hi-MO X10 Explorer with 72 cells, with 54 and 60-cell product ranges to follow shortly after in 20251. The module is built on the company's HPBC 2.0 back contact technology and its proprietary n-type TaiRay wafer1.
LONGi states the Hi-MO X10 reaches a 670W power output, 24.8% module efficiency and 26.6% cell efficiency, which it describes as the world's highest mass production power output and module efficiency1. The company says it outperforms conventional TOPCon modules by 30W1. On degradation, LONGi gives 1% in the first year and a 0.35% annual linear degradation rate, with a power temperature coefficient of -0.26 per degree Celsius, which it says is a 0.03% improvement over TOPCon modules1.
The company lists several design features behind those figures. A multi-layer anti-reflection film is said to improve short-circuit current by 2.25% and reduce reflection of short-wave light by 12%; bipolar hybrid passivation is said to raise open-circuit voltage by 15mV to 745mV; and a zero-busbar structure is said to cut energy transmission distance by 6.5%, adding 5W to module output1. LONGi also cites a shading optimiser technology that it says reduces loss of power output by 70% compared to TOPCon modules and lowers hotspot temperatures by 28%, and a TaiRay wafer with a 16% increase in break resistance1.
"In the UK the module will be available from March 2025, starting with the Hi-MO X10 Explorer with 72 cells. 54 and 60-cell product ranges will follow shortly after in 2025."
Blair Rankin, LONGi's Product Marketing Manager for the UK and Ireland, said the company sees on average a 1.5% higher efficiency in the Hi-MO X10, resulting in approximately 30W more power output, and that the zero-busbar design maximises production under varied weather conditions including overcast days1. LONGi also states that in May 2024 its heterojunction back contact solar cell reached a conversion efficiency of 27.3%, certified by the Institute for Solar Energy Research Hamelin, and that it holds a 25.4% module efficiency record1.
| Specification | Figure given by LONGi |
|---|---|
| Power output | 670W |
| Module efficiency | 24.8% |
| Cell efficiency | 26.6% |
| First-year degradation | 1% |
| Annual linear degradation | 0.35% |
| Power temperature coefficient | -0.26%/°C |
| Advantage over TOPCon | 30W |
Why it matters for households
Module efficiency determines how much generating capacity fits on a given roof, so a higher-output panel can matter where roof area is fixed and the household wants more kilowatt-peak from the same footprint. LONGi's claim of 30W more output than an equivalent TOPCon module, and of better performance on overcast days, speaks directly to UK conditions, though these are the manufacturer's own figures and have not been independently verified in the material published1. The stated degradation rates and temperature coefficient bear on how much output a system retains over its life, which affects the long-run value of a solar PV installation. Buyers comparing panels can check the LONGi solar panels guide for the Hi-MO range, specifications and warranty terms.
What happens next
The 72-cell Hi-MO X10 Explorer is due in the UK from March 2025, with 54 and 60-cell ranges to follow later in 20251. LONGi says it aims to reach approximately 50GW of production capacity for HPBC 2.0 modules by the end of 20251. UK pricing, installer availability and warranty terms for the UK market have not been reported in the announcement1.