Low-light conditions below 400 W/m² can contribute around a quarter of total energy generation
Reduced leakage current and improved red-light response support higher output under weak irradiance
Data shows yield depends on extended generation hours, not just peak power ratings
Low-light performance is an important parameter in evaluating solar module output beyond standard test conditions. While module ratings are defined at 1,000 W/m² irradiance, actual operating conditions rarely sustain such levels throughout the day. Energy generation is not limited to peak sunlight hours. A significant share comes from low-irradiance periods such as early morning and late afternoon.
In a recent press release, JinkoSolar reported that irradiance below 400 W/m² can account for nearly a quarter of the total energy yield. This highlights the importance of consistent performance across varying light conditions, beyond peak power metrics.
At high irradiance, leakage pathways have a limited impact on overall current. Under low-light conditions, reduced current levels increase their relative effect. According to JinkoSolar, improved junction isolation in TOPCon cells helps limit leakage current, thereby preserving a higher share of generated carriers under weak illumination. This is typically associated with higher shunt resistance (Rsh), which reduces internal current losses under weak irradiance.
Spectral response also plays a role, as low irradiance conditions typically involve a higher proportion of longer-wavelength light due to atmospheric scattering. The company states that TOPCon cells demonstrate improved response in the red and near-infrared regions, enabling higher energy capture during these periods.
JinkoSolar cited field data indicating that the Tiger Neo 3.0 module retains approximately 96-97% of its efficiency at an irradiance of 200 W/m². In comparative assessments, the company reports higher energy yield under low-light conditions than back-contact (BC) modules, with gains of up to 10.79% under irradiance below 400 W/m² and around 8.27% over longer test periods. These figures are based on company-reported and third-party field tests.
From a system perspective, improved low-light performance can extend generation hours. Modules that operate over longer daily windows can deliver higher energy output. This becomes important in regions with lower and more variable irradiance. Applications such as rooftop PV, agrivoltaics, and distributed generation stand to benefit.
The impact is not limited to energy output. In markets with time-of-use tariffs, additional generation during early or late hours can contribute disproportionately to revenue. The company cites scenarios where modest gains in low-light output, for example, around 2-3% during morning and evening periods, translate into measurable financial benefits over the system lifetime.
In the April edition of the TaiyangNews TOP SOLAR MODULES listing, JinkoSolar’s TOPCon module reached 23.9% efficiency, placing it among the top-performing products in the segment, just behind the current leader. The company’s Tiger Neo module is ranked 4th, with a rated power output of 645 W.