Real-world performance data signals a leap forward for utility-scale solar
Chinese PV giant Longi has released comprehensive global field data for its Hi-MO 9 back-contact modules, offering one of the most detailed performance validations yet for next-generation BC technology. According to the company’s latest report, the flagship Hi-MO 9 consistently outperforms mainstream TOPCon modules in long-term energy yield, cost efficiency, and operational safety across diverse climates.
Global testing confirms consistent efficiency gains
Longi’s testing program spanned temperate continental, tropical, arid, and coastal high-humidity environments, providing a robust dataset far beyond controlled lab conditions. The findings show watt-for-watt power generation gains ranging from 1.21% to 3.92% over TOPCon technology.
- Spain: At a 47 MW single-axis tracker site in Seville, Hi-MO 9 delivered 2,209 equivalent full-load hours in its first year, generating 2.4%–3.4% more energy than TOPCon modules and reducing LCOE by up to 4.47% (Solar Builder).
- France & Denmark: Tests led by IPVF found average generation gains of 1.84% and LCOE reductions between 2.43%–3.32%.
- Sanya, China: The module achieved a 1.54% generation gain, operated 1.21°C cooler, and showed a 0.19% lower degradation rate over six months.
HPBC 2.0 and zero busbar design: Why the gains matter
The Hi-MO 9’s performance edge is rooted in HPBC 2.0 cell architecture, which uses n-type TaiRay wafers, zero busbar (0BB) technology, and full-surface passivation. This combination maximizes light capture, minimizes resistive losses, and boosts bifaciality up to 80%. The result: higher output per installed watt and lower levelized cost of electricity, both critical for utility-scale developers seeking strong ROI under tightening margins.
Safety and reliability under partial shading
One standout finding in the new data is the Hi-MO 9’s ability to suppress hot spots—a common risk when modules face partial shading from vegetation, bird droppings, or structural shadows. Reduced hot spot temperatures directly lower the risk of material aging, accelerated degradation, and even fire hazards. For asset managers and plant operators, this translates into lower maintenance costs and extended asset lifespans.
Implications for large-scale solar deployment
This dataset reinforces the argument that BC technology could overtake TOPCon as the mainstream choice in the next five years. With proven gains across varied climates, developers can deploy Hi-MO 9 with greater confidence in predictable yield improvements. As utility-scale projects face increasing scrutiny over performance guarantees, such empirical evidence is invaluable for securing financing and long-term power purchase agreements.
Key takeaways for project developers
- Expect measurable energy yield gains (1.2%–3.9%) over TOPCon in multiple geographies.
- Lower LCOE can significantly improve project economics and competitiveness in tenders.
- Enhanced safety profile reduces operational risk and potential liability.
- BC modules’ cooling advantage supports performance stability in hot climates.
Looking ahead
According to Photon International, the Hi-MO 9’s efficiency record of 24.8% is already pushing the boundaries of commercial silicon PV. With this new field data, Longi has moved beyond theoretical promise to demonstrable, bankable performance. The next frontier will be scaling BC technology at competitive manufacturing costs, potentially redefining module selection standards for the next generation of solar farms.
