Analytical Model and Experimental Validation of Optical-Thermal-Electrical Performance of Bifacial Photovoltaic Systems

doi:10.12096/j.2096-4528.pgt.24239

Abstract

Abstract:

Objectives Bifacial photovoltaic (BPV) can provide rear-side gain and has promising development prospects. However, how to accurately analyze the performance of BPV systems under coupled environmental conditions has become one of the urgent issues to be addressed. To this end, an optical-thermal-electrical-environmental coupling (OTEEC) model is proposed to explore the optical-thermal-electrical performance of BPV panels in real environments. Methods Firstly, the propagation path of light in the BPV system is simulated based on the Monte Carlo ray tracing method to obtain the non-uniform irradiation distribution on the front and rear sides of the BPV panel. Then, the system's thermal-electrical performance is calculated using the finite volume method and the discrete integral method, respectively. Finally, the model is validated through experiments and compared with the existing optical-thermal-electrical coupling (OTEC) model. Results On both cloudy and sunny days, the maximum relative errors between the irradiation distribution on the front and rear sides of the BPV panel obtained from the OTEEC model and the experimental data are less than 13%. On windless cloudy days and windy sunny days, the maximum relative errors between temperature data and instantaneous electric power obtained from the OTEEC model and the experimental results are less than 11%. Moreover, the calculation accuracy of the OTEEC model is higher than that of the existing OTEC model under both windy and windless conditions. Conclusions The OTEEC model has good universality and reliability, provides a scientific basis for the performance enhancement, operation scheduling, and management of BPV systems.

Key words: bifacial photovoltaic (BPV) system, optical-thermal-electrical coupling (OTEC) model, optical-thermal-electrical- environmental coupling (OTEEC) model, Monte Carlo ray tracing method, performance analysis, environmental conditions, optical-thermal-electrical performance, experimental validation

CLC Number:

TK 51

Jianyong LI, Zemeng LANG, Chongyang WANG, Hailiang ZHAO, Chengwei JIANG, Ruiling XU, Xi HU, Qingmao MENG, Huaisen LI, Shijie XU, Shuangying WU. Analytical Model and Experimental Validation of Optical-Thermal-Electrical Performance of Bifacial Photovoltaic Systems[J]. Power Generation Technology, 2025, 46(5): 939-949.

Figures/Tables 15

Fig. 1 Physical model of BPV system

Fig. 2 Cross-section of BPV panel

Tab. 1 Structural parameters of BPV panel and performance parameters under standard test conditions

参数	取值
电池单元数量/个	156
电池单元长度Δl/mm	158.75
电池单元宽度Δw/mm	79.375
电池单元间距/mm	2.1(左右)；1.53(前后)
玻璃盖板厚度/mm	4.2
EVA厚度/mm	0.5
晶硅电池厚度/mm	0.4
铝边框厚度/mm	4和9
开路电压/V	53.37
短路电流/A	10.52
最大功率/W	445
最大工作电压/V	43.93
最大工作电流/A	10.13
双面因子/%	65
正面发电效率η_ref.f/%	20.59
背面发电效率η_ref.r/%	13.38
温度影响系数δ/%	0.35

Tab. 2 Physical properties of BPV panel

参数	正面玻璃	EVA	晶硅电池	背面玻璃	铝边框(铝)
热导率/[W/(m⋅K)]	0.93	0.35	150	0.93	204
密度/(kg/m³)	2 530	960	2 328	2 530	2 710
比热容/[J/(kg⋅K)]	850	2 090	677	850	910
吸收率	—	—	0.93	—	—
发射率	0.85	—	—	0.85	0.5
透射率	0.935	1	—	0.915	—

Fig. 3 Optical properties

Fig. 4 Performance test platform of BPV system

Fig. 5 Irradiance measurement points on front and rear sides of BPV panel

Fig. 6 Temperature measurement points on front and rear sides of BPV panel

Tab. 3 Testing instrument parameters

仪器型号	量程	精度
TBQ-2C型辐照表	0~2 000 W/m²	<5%
华盛昌DT-1037型辐照表	0~2 000 W/m²	<5%
K型热电偶	0~600 ℃	—
Agilent 34970A型数据采集仪	0.000 2~1 000 V，0~1 A	—
PROVA210型I-V曲线测试仪	0~60 V，0.01~12 A	±1%
SN-3000-FSJT-GPRS型风速仪	0~70 m/s	±0.1 m/s
SN-3000-FXJT-N01型风向仪	8个指示方向	—

Fig. 7 Test results of environmental and performance parameters under different weather conditions

Fig. 8 Comparison of irradiance distribution at different measurement points on BPV panel on July 22, 2024

Fig. 9 Thermal-electrical performance of BPV panel from simulation and experiment on July 22, 2024

Fig. 10 Flow and heat transfer characteristics of BPV system at 12:00 on July 22, 2024

Fig. 11 Comparison of irradiance distribution at different measurement points on BPV panel on August 27, 2024

Fig. 12 Thermal-electrical performance of BPV panel based on two models and experiments on August 27, 2024

References 30

[1]	肖瑶，钮文泽，魏高升，等．太阳能光伏/光热技术研究现状与发展趋势综述[J]．发电技术，2022，43(3)：392-404． doi:10.12096/j.2096-4528.pgt.21145
	XIAO Y， NIU W Z， WEI G S，et al ．Review on research status and developing tendency of solar photovoltaic/thermal technology[J]．Power Generation Technology，2022，43(3)：392-404． doi:10.12096/j.2096-4528.pgt.21145
[2]	李英峰，张涛，张衡，等．太阳能光伏光热高效综合利用技术[J]．发电技术，2022，43(3)：373-391． doi:10.12096/j.2096-4528.pgt.22052
	LI Y F， ZHANG T， ZHANG H，et al ．Efficient and comprehensive photovoltaic/photothermal utilization technologies for solar energy[J]．Power Generation Technology，2022，43(3)：373-391． doi:10.12096/j.2096-4528.pgt.22052
[3]	刘洋，章子潇，赵贤根，等．进气流量对滑动电弧放电分解CO₂的瞬态电-光-热特性和转化性能的影响[J]．电工技术学报，2024，39(23)：7616-7627．
	LIU Y， ZHANG Z X， ZHAO X G，et al ．The effect of inlet flow rate on the transient electrical-optical-thermal characteristics and conversion performance of CO₂ decomposition in gliding arc discharges[J]．Transactions of China Electrotechnical Society，2024，39(23)：7616-7627．
[4]	PATEL M T， KHAN M R， SUN X S，et al ．A worldwide cost-based design and optimization of tilted bifacial solar farms[J]．Applied Energy，2019，247：467-479． doi:10.1016/j.apenergy.2019.03.150
[5]	GU W B， MA T， AHMED S，et al ．A comprehensive review and outlook of bifacial photovoltaic (BPV) technology[J]．Energy Conversion and Management，2020，223：113283． doi:10.1016/j.enconman.2020.113283
[6]	KATSAOUNIS T， KOTSOVOS K， GEREIGE I，et al ．Performance assessment of bifacial c-Si PV modules through device simulations and outdoor measurements[J]．Renewable Energy，2019，143：1285-1298． doi:10.1016/j.renene.2019.05.057
[7]	ABOU AKROUCH M， CHAHINE K， FARAJ J，et al ．Advancements in cooling techniques for enhanced efficiency of solar photovoltaic panels：a detailed comprehensive review and innovative classification[J]．Energy and Built Environment，2025，6(2)：248-276． doi:10.1016/j.enbenv.2023.11.002
[8]	SAHU P K， ROY J N， CHAKRABORTY C ．Performance assessment of a bifacial PV system using a new energy estimation model[J]．Solar Energy，2023，262：111818． doi:10.1016/j.solener.2023.111818
[9]	MANISCALCO M P， LONGO S， MICCICHÈ G，et al ．A critical review of the environmental performance of bifacial photovoltaic panels[J]．Energies，2024，17(1)：226． doi:10.3390/en17010226
[10]	MANUEL LONGARES J， GARCÍA-JIMÉNEZ A， GARCÍA-POLANCO N ．Multiphysics simulation of bifacial photovoltaic modules and software comparison[J]．Solar Energy，2023，257：155-163． doi:10.1016/j.solener.2023.04.005
[11]	ERNST M， CONECHADO G E J， ASSELINEAU C A ．Accelerating the simulation of annual bifacial illumination of real photovoltaic systems with ray tracing[J]．iScience，2022，25(1)：103698． doi:10.1016/j.isci.2021.103698
[12]	ZHAO C R， XIAO J W， YU Y J，et al ．Accurate shading factor and mismatch loss analysis of bifacial HSAT systems through ray-tracing modeling[J]．Solar Energy Advances，2021，1：100004． doi:10.1016/j.seja.2021.100004
[13]	MA T， KAZEMIAN A， HABIBOLLAHZADE A，et al ．A comparative study on bifacial photovoltaic/thermal modules with various cooling methods[J]．Energy Conversion and Management，2022，263：115555． doi:10.1016/j.enconman.2022.115555
[14]	LORENZO E ．On the historical origins of bifacial PV modelling[J]．Solar Energy，2021，218：587-595． doi:10.1016/j.solener.2021.03.006
[15]	GARROD A， GHOSH A ．A review of bifacial solar photovoltaic applications[J]．Frontiers in Energy，2023，17(6)：704-726． doi:10.1007/s11708-023-0903-7
[16]	LIU B Y H， JORDAN R C ．The long-term average performance of flat-plate solar-energy collectors：with design data for the U.S.，its outlying possessions and Canada[J]．Solar Energy，1963，7(2)：53-74． doi:10.1016/0038-092x(63)90006-9
[17]	DUFFIE J A， BECKMAN W A ．Solar engineering of thermal processes[M]．3rd ed．New Jersey：Wiley-Interscience Publication，2006．
[18]	PEREZ R， STEWART R， ARBOGAST C，et al ．An anisotropic hourly diffuse radiation model for sloping surfaces：description，performance validation，site dependency evaluation[J]．Solar Energy，1986，36(6)：481-497． doi:10.1016/0038-092x(86)90013-7
[19]	GU W， MA T， LI M，et al ．A coupled optical-electrical-thermal model of the bifacial photovoltaic module[J]．Applied Energy，2020，258：114075． doi:10.1016/j.apenergy.2019.114075
[20]	ANDRES C， RUBEN C， DAVID G，et al ．Time-varying，ray tracing irradiance simulation approach for photovoltaic systems in complex scenarios with decoupled geometry，optical properties and illumination conditions[J]．Progress in Photovoltaics：Research and Applications，2023，31(2)：134-148． doi:10.1002/pip.3614
[21]	MARION B， MACALPINE S， DELINE C，et al ．A practical irradiance model for bifacial PV modules[C]//2017 IEEE 44th Photovoltaic Specialist Conference (PVSC)．Washington，DC：IEEE，2017：1-8． doi:10.1109/pvsc.2017.8366263
[22]	SHOUKRY I， LIBAL J， KOPECEK R，et al ．Modelling of bifacial gain for stand-alone and in-field installed bifacial PV modules[J]．Energy Procedia，2016，92：600-608. doi:10.1016/j.egypro.2016.07.025
[23]	Sandia national laboratories ．Sandia cell temperature model[EB/OL]．(2016-06-01)[2024-10-20]．．
[24]	FAIMAN D ．Assessing the outdoor operating temperature of photovoltaic modules[J]．Progress in Photovoltaics：Research and Applications，2008，16(4)：307-315． doi:10.1002/pip.813
[25]	STINE WB GM ．Power from the sun[EB/OL]. (2014-04-03)[2024-10-20]．．
[26]	REDDY K S， BALAJI S， SUNDARARAJAN T ．Estimation of heat losses due to wind ef fects from linear parabolic secondary reflector-receiver of solar LFR module[J]．Energy，2018，150：410-433． doi:10.1016/j.energy.2018.02.125
[27]	GARG A，RAY B， JAIN S ．Development of Nusselt number correlation for solar CPC with a tubular receiver[J]．Thermal Science and Engineering Progress，2023，37：101553． doi:10.1016/j.tsep.2022.101553
[28]	REDDY K S， PARTHIBAN A， MALLICK T K ．Numerical modeling of heat losses in a line focusing solar compound parabolic concentrator with planar absorber[J]．Applied Thermal Engineering，2020，181：115938． doi:10.1016/j.applthermaleng.2020.115938
[29]	XU S J， WU S Y， XIAO L，et al ．Performance assessment of compound parabolic concentrating photovoltaic system based on optical-thermal-electrical-environmental coupling[J]．Energy，2023，284：129241． doi:10.1016/j.energy.2023.129241
[30]	HOLMAN J P ．Experimental methods for engineers[M]．6th ed．New York：McGraw-Hill，1994． doi:10.1093/oso/9780198163404.001.0001