KazNU Scientists Develop New Cooling System to Boost the Efficiency of Bifacial Solar Cells

As the population of Kazakhstan and the world continues to grow, so does the demand for electricity, making the development of renewable energy sources such as solar panels increasingly important. While solar concentrators improve output performance, they cause significant heating of solar cells, accelerating their degradation. This issue is especially relevant for bifacial solar cells (BSCs), which can boost electricity generation by up to 22.6%, since their light-sensitive rear side complicates the use of conventional cooling methods.

BSCs held a 50% market share in 2023 and are projected to reach 73% by 2034, yet research into systems that maintain their temperature at an optimal level remains limited. The project aims to close this gap by creating a stable optical-thermodynamic solution that combines parabolic mirrors, a Fresnel lens, and a cooling system based on honeycomb polycarbonate. The research focuses on studying the output characteristics and thermodynamic properties of BSCs under low concentration levels, varying cooling parameters, and different environmental conditions, enabling the design of optimal systems to extend cell lifespan and enhance performance.

The project comprises nine stages: studying optical systems based on mirrors and lenses through computer modeling; examining thermodynamic processes in a cooling system built on honeycomb polycarbonate and silicone tubing; experimentally studying the heating dynamics of silicon BSCs under varying initial temperatures and environmental conditions; investigating cooling dynamics at concentrations of 100-1600 W/m²; building an empirical model based on the data obtained; studying the effect of uneven solar radiation distribution on output characteristics; creating a stable physical model; testing BSC output characteristics under various external conditions; and finally constructing a comprehensive empirical model.

The research employs the Optics, Ray Optics, Heat Transfer, and Non-Isothermal Flow modules of the Comsol Multiphysics software package. BSC parameters — diode factor, reverse saturation current, photocurrent, series and parallel resistance, temperature coefficient, bifaciality coefficient, and specific heat capacity — are studied using an SMU 2461 source-meter, a Keithley 2380-500-30 electronic load, a pyranometer, a Veinasa-FSL albedometer, and Fluke TiS20+ MAX and HIKMICRO M20W thermal imaging cameras. The system will be installed on the roof of a KazNU building for year-round monitoring.

The project's results will be published in at least 2 articles in journals ranked Q1-Q2 in Web of Science or with a CiteScore percentile of at least 70 in Scopus, along with 2 articles in journals recommended by KOKSON; at least 1 PhD candidate will be trained. A solar power plant with a capacity of 4.77 MW using bifacial panels is already operating in the Karaganda region, covering 16-18% of the electricity needs of Konrad Copper Company LLP. Given Kazakhstan's 2050 strategy, which aims to raise the share of renewable energy sources to 15% by 2030 and 50% by 2050, the project's results will help accelerate the adoption of renewable energy technologies in the country's energy sector, reduce electricity costs, and decrease dependence on conventional hydrocarbon resources.

Spanning 36 months (2025-2027), the project will generate new knowledge at the intersection of photovoltaics, thermodynamics, fluid dynamics, optics, and computer modeling, strengthening the international standing of domestic science.