In Hainan's hot, humid climate, JA Solar's n-type bifacial PV modules outshone p-type modules by 3.5% in year-long field tests.

Situated within the national photovoltaic PV product outdoor testing base in Qionghai City, Hainan Province, our year-long field test provides compelling evidence of JA Solar's innovative n-type bifacial PV modules thriving in demanding climates. Hainan, known for its tropical monsoon climate, with an average annual temperature of approximately 24°C and yearly precipitation reaching around 2,100 millimeters, the region poses significant challenges for solar technology. Pease refer to Figure 1 illustrating the field testing project.

Project Background

N-type PV modules have gradually become mainstream due to their numerous advantages such as high power, high efficiency, high electricity generation capability, and high reliability. Assessing module performance in various environments is crucial. JA Solar collaborated with TÜV Rheinland to test the power generation performance of n-type modules. Following their successful performance in Yinchuan's arid and hot climate, this comparison project was conducted in the hot and humid environment of Qionghai, Hainan. To ensure accuracy, the project maintained consistent installation methods and system configurations across different module types. Additionally, to gather comprehensive seasonal data, the project analyzed a full year of empirical data from February 2023 to January 2024.

Project Overview

Figure 1 Empirical Project of JA Solar and TÜV Rheinland in Hainan 

The field test installed a set of DeepBlue 4.0 series n-type bifacial modules (with Bycium+ cell based on n-type passivated contact technology, hereinafter referred to as n-type modules) and a set of PERC bifacial modules (hereinafter referred to as p-type modules), each with an installed capacity of about 5 kW (measured power in the on-site laboratory), connected to one 6 kW string inverter each. The project used a fixed mounting structure (tilt angle of 19°), with the long side of the modules fixed on vertical purlins to ensure unobstructed module backsides. The modules were mounted at a height of about 1 meter above ground level. In addition to configuring site-level environmental monitoring stations, the site also included monitoring equipment such as high-precision DC meters, module-level temperature sensors, and high-precision pyranometers.

In terms of system design and analysis of modules' power generation performance, to eliminate the influence of inverters on the power generation performance of different types of modules and ensure more accurate data, DC meter data is directly utilized and subjected to normalization processing. 

Comparison of Power Generation Performance

During the operation period from February 2023 to January 2024, the overall power generation performance of n-type modules and p-type modules at the empirical power station is summarized in Table 1. The comparison of power generation per watt and gain between the two types of modules is illustrated in Figure 2.

Table 1: Comparison of Empirical Module Power Generation

The PV module's power generation capability primarily depends on characteristics such as power degradation rate, high-temperature performance, bifacial rate, and low irradiance performance. In this field test, both n-type modules and p-type modules adopted the same module encapsulation form (half-cut cells, double-glass structure), with the difference in yield gain mainly attributed to distinct cell technologies. 

Figure 2 Comparison Data of Power Generation per Watt between n-type and p-type Modules

Summary

Following the successful one-year field test at the Hainan Qionghai test base, JA Solar's n-type modules have proven their superiority, delivering a remarkable 3.5% increase in power generation per watt over p-type modules. This solidifies the outstanding performance of JA Solar's DeepBlue 4.0 series modules in real-world scenarios. Movingg forward, JA Solar is committed to conducting further extensive field tests across various locations, formats, and environmental conditions. This strategic initiative aims to consistently demonstrate our products' enduring safety, stability, and reliability, ensuring continued value for our global customers.