Recently, the China National Photovoltaic Product Quality Inspection Center (CPVT) released the H1 2025 empirical report from the Yantai offshore outdoor empirical project. This report, covering the data collection period from January 4 to June 30, 2025, provides a comprehensive overview of the operational performance of China’s first deep-sea floating PV empirical project. Through the integrated application and comparative analysis of various photovoltaic (PV) technologies, the project has produced systematic and well-supported findings, offering valuable insights for the advancement of offshore PV projects.
Comparative Analysis of PV Technologies: Back Contact vs. TOPCon
The empirical report highlights a comparison between two technological approaches: Back Contact (BC) and TOPCon. The project involved 10 modules of LONGi Hi-MO 9 featuring HPBC 2.0 technology and 10 TOPCon modules, with the following specific parameters:
BC Technology Shows Significant Power Generation Benefits
The empirical data clearly illustrates the exceptional performance of LONGi’s Hi-MO 9 modules across various power generation metrics. From January to June 2025, these modules achieved a 1.94% increase in per-watt power generation compared to the TOPCon modules. This advantage can lead to substantial increases in power generation revenue during actual power plant operations.
Hi-MO 9 modules also excelled under low-light conditions. On an overcast and rainy day, February 4, 2025, they recorded a 0.98% gain in per-watt power generation, showcasing their ability to perform well even with limited irradiance.
Notably, the performance advantage of Hi-MO 9 modules was consistent throughout all times of day and irradiance levels. From early morning at 5:00 to evening at 17:00, and across all irradiance intervals from 0 to 1100 W/㎡, Hi-MO 9 modules consistently outperformed TOPCon modules.
Superior Temperature Characteristics and Overall Power Output
Operating temperature is a crucial factor influencing module performance and lifespan. Throughout the empirical period, the average operating temperature of Hi-MO 9 modules was 1.31°C lower than that of the TOPCon modules. Lower operating temperatures contribute to reduced power degradation and an extended operational lifespan.
In terms of overall power output, considering the actual environmental conditions at the Yantai empirical project in Shandong Province, which had a backside reflectivity of 6.73%, the Hi-MO 9 modules achieved a combined front-and-backside power output of 667.05W. This is significantly higher than the TOPCon modules’ output of 648.11W, demonstrating superior power generation capability in real-world applications.
The empirical findings suggest that LONGi’s HPBC 2.0 technology offers substantial power generation advantages in offshore settings. Its remarkable performance in temperature management, low-light power generation, and operational reliability aligns perfectly with the stringent requirements for offshore PV systems, which demand high reliability, high power generation efficiency, and low maintenance costs.
Source: LONGi
