Experimental Analysis of A Photovoltaic-Thermoelectric Generator (PV-TEG) System: Maximum Temperature Gradient Case Study

Abstract

This study presents an experimental investigation of a photovoltaic-thermoelectric generator (PV-TEG) system under controlled laboratory conditions to establish the upper performance limit under standard irradiance (1000 W/m²). The system was monitored over a 20-minute period, measuring PV surface temperature, TEG hot and cold side temperatures, and electrical output parameters. The results show that the maximum temperature gradient across the TEG module remains limited to 9.6°C, even under optimized conditions. This constraint fundamentally restricts the electrical output, with steady-state maximums of 165.1 mV, 24.1 mA, and 3.98 mW recorded. A strong linear relationship (R² = 0.98) between temperature gradient and output voltage confirms that the TEG operates according to the Seebeck effect. However, the limited T range indicates that the system is thermally constrained rather than conversion-limited. Despite the low electrical output, the TEG provides a measurable thermal management benefit where an average temperature reduction of 3.2°C results in a 1.44% relative improvement in PV efficiency (12.96 mW equivalent gain). This value is approximately 3.3 times greater than the direct electrical output of the TEG, demonstrating that the primary benefit of PV-TEG integration lies in thermal management. Finally, this study provides experimentally validated upper-bound performance data and offers a more realistic framework for evaluating PV-TEG systems.

Keywords

• PV-TEG
• thermoelectric generator
• experimental analysis
• thermal management
• laboratory conditions
• temperature gradient

Bir Fotovoltaik-Termoelektrik Jeneratör (PV-TEG) Sisteminin Deneysel Analizi: Maksimum Sıcaklık Gradyanı Vaka Çalışması

Abstract

Bu çalışma, standart ışınım (1000 W/m²) altında üst performans sınırını belirlemek amacıyla, kontrollü laboratuvar koşullarında bir fotovoltaik-termoelektrik jeneratör (PV-TEG) sisteminin deneysel incelemesini sunmaktadır. Sistem; PV yüzey sıcaklığı, TEG sıcak ve soğuk taraf sıcaklıkları ve elektriksel çıkış parametreleri ölçülerek 20 dakikalık bir süre boyunca izlenmiştir. Sonuçlar, optimize edilmiş koşullar altında bile TEG modülü üzerindeki maksimum sıcaklık gradyanının 9.6°C ile sınırlı kaldığını göstermektedir. Bu kısıtlama, kararlı durumda kaydedilen 165.1 mV, 24.1 mA, ve 3.98 mW maksimum değerleriyle elektriksel çıkışı temelden sınırlandırmaktadır. Sıcaklık gradyanı ile çıkış voltajı arasındaki güçlü lineer ilişki (R² = 0.98), TEG'in Seebeck etkisine göre çalıştığını doğrulamaktadır. Bununla birlikte, sınırlı T aralığı, sistemin dönüşüm sınırlı olmaktan ziyade termal olarak kısıtlı olduğunu göstermektedir. Düşük elektriksel çıkışa rağmen TEG, ortalama 3.2°C 'lik bir sıcaklık düşüşünün PV verimliliğinde %1,44'lük bir bağıl iyileşme 12.96 mW eşdeğer güç kazancı) sağladığı ölçülebilir bir termal yönetim faydası sunmaktadır. Bu değer, TEG'in doğrudan elektriksel çıkışından yaklaşık 3,3 kat daha fazladır ve standart çalışma koşulları altında PV-TEG entegrasyonunun temel faydasının elektriksel güç üretiminden ziyade termal yönetimde yattığını kanıtlamaktadır. Son olarak bu çalışma, deneysel olarak doğrulanmış üst sınır performans verileri sağlamakta ve PV-TEG sistemlerini değerlendirmek için daha gerçekçi bir çerçeve sunmaktadır.

Keywords

• PV-TEG
• termoelektrik jeneratör
• deneysel analiz
• termal yönetim
• laboratuvar koşulları
• sıcaklık gradyanı.

References

1. Ahadi, A., Sheikholeslami, M., & Mohammed, H. A. (2025). Phase change materials for next generation renewable thermal energy systems in existence of thermoelectric generator. In Elsevier eBooks (p. 251). Elsevier BV. https://doi.org/10.1016/b978-0-443-33184-8.00022-6
2. Altinkök, S., & ALTINAY, M. (2026). The Effect of Electrical Load on Photovoltaic Module Surface Temperature: An Experimental Investigation. Journal of Solar Energy Engineering, 148(4), 1. https://doi.org/10.1115/1.4071437
3. Altınkök, S., & Altınay, M. (2025). Investigation of Thermal Distribution and Thermoelectric Cooling Performance in A Photovoltaic Panel. Journal of Naval Sciences and Engineering, 21(1), 51-71.
4. Altınkök, S. (2026). Experimental validation of high-performance commercial thermal interface materials in PV-TEG hybrid systems. Next Energy, 11, 100604. https://doi.org/10.1016/j.nxener.2026.100604
5. Altınkök, S., & Altinkök, A. (2024). Photovoltaic Thermal PV/T Solar Panels and Practical Applications. Karadeniz Fen Bilimleri Dergisi, 14(2), 683. https://doi.org/10.31466/kfbd.1425077
6. Amelia, A. R., Irwan, Y. M., Leow, W. Z., Irwanto, M., Safwati, I., & Zhafarina, M. (2016). Investigation of the effect temperature on photovoltaic (PV) panel output performance. Int. J. Adv. Sci. Eng. Inf. Technol, 6(5), 682-688.https://doi.org/10.18517/ijaseit.6.5.938
7. ASTM International. (2012). Standard specification and temperature‐electromotive force (emf) tables for standardized thermocouples.
8. Balaji, C., Srinivasan, B., & Gedupudi, S. (2020). Heat transfer engineering: fundamentals and techniques. Academic Press.

9. Bergman, T. L. (2011). Fundamentals of heat and mass transfer. John Wiley & Sons.
10. Bjørk, R., & Nielsen, K. (2015). The performance of a combined solar photovoltaic (PV) and thermoelectric generator (TEG) system. Solar Energy, 120, 187. https://doi.org/10.1016/j.solener.2015.07.035
11. Chávez‐Urbiola, E. A., Vorobiev, Yu. V., & Bulat, L. P. (2011). Solar hybrid systems with thermoelectric generators. Solar Energy, 86(1), 369. https://doi.org/10.1016/j.solener.2011.10.020
12. Cotfas, D. T., Cotfas, P. A., Mahmoudinezhad, S., & Louzazni, M. (2022). Critical factors and parameters for hybrid Photovoltaic-Thermoelectric systems; review. Applied Thermal Engineering, 215, 118977. https://doi.org/10.1016/j.applthermaleng.2022.118977
13. Dimri, N., Tiwari, A., & Tiwari, G. N. (2017). Thermal modelling of semitransparent photovoltaic thermal (PVT) with thermoelectric cooler (TEC) collector. Energy Conversion and Management, 146, 68. https://doi.org/10.1016/j.enconman.2017.05.017
14. Faddouli, A., Hajji, M., Fadili, S., Hartiti, B., Labrim, H., & Habchi, A. (2024). A comprehensive review of solar, thermal, photovoltaic, and thermoelectric hybrid systems for heating and power generation. International Journal of Green Energy, 21(2), 413.
15. Hajji, M., Labrim, H., Benaı̈ssa, M., Laazizi, A., Ez‐Zahraouy, H., Ntsoenzok, E., Meot, J., & Benyoussef, A. (2017). Photovoltaic and thermoelectric indirect coupling for maximum solar energy exploitation. Energy Conversion and Management, 136, 184. https://doi.org/10.1016/j.enconman.2016.12.088
16. Huen, P., & Daoud, W. A. (2016). Advances in hybrid solar photovoltaic and thermoelectric generators. Renewable and Sustainable Energy Reviews, 72, 1295. https://doi.org/10.1016/j.rser.2016.10.042
17. JCGM (Joint Committee for Guides in Metrology). (2008). Evaluation of Measurement Data — Guide to the Expression of Uncertainty in Measurement. JCGM 100:2008, 50, 134.
18. Kossyvakis, D. N., Voutsinas, G. D., & Hristoforou, E. (2016). Experimental analysis and performance evaluation of a tandem photovoltaic–thermoelectric hybrid system. Energy Conversion and Management, 117, 490. https://doi.org/10.1016/j.enconman.2016.03.023
19. Li, G., Shittu, S., Diallo, T., Yu, M., Zhao, X., & Ji, J. (2018). A review of solar photovoltaic-thermoelectric hybrid system for electricity generation. Energy, 158, 41. https://doi.org/10.1016/j.energy.2018.06.021
20. Oliveira, A. V. da S., Avrit, A., & Gradeck, M. (2021). Thermocouple response time estimation and temperature signal correction for an accurate heat flux calculation in inverse heat conduction problems. International Journal of Heat and Mass Transfer, 185, 122398. https://doi.org/10.1016/j.ijheatmasstransfer.2021.122398
21. Şahin, A. Z., Ismaila, K. G., Yilbaş, B. S., & Al‐Sharafi, A. (2020). A review on the performance of photovoltaic/thermoelectric hybrid generators. International Journal of Energy Research, 44(5), 3365. https://doi.org/10.1002/er.5139
22. Shittu, S., Li, G., Zhao, X., & Ma, X. (2019). Series of detail comparison and optimization of thermoelectric element geometry considering the PV effect. Renewable Energy, 130, 930. https://doi.org/10.1016/j.renene.2018.07.002
23. Skoplaki, E., & Palyvos, J. A. (2008). On the temperature dependence of photovoltaic module electrical performance: A review of efficiency/power correlations. Solar Energy, 83(5), 614. https://doi.org/10.1016/j.solener.2008.10.008
24. Soltani, S., Kasaeian, A., Sarrafha, H., & Wen, D. (2017). An experimental investigation of a hybrid photovoltaic/thermoelectric system with nanofluid application. Solar Energy, 155, 1033. https://doi.org/10.1016/j.solener.2017.06.069
25. Sun, C., Zou, Y., Qin, C., Zhang, B., & Wu, X. (2022). Temperature effect of photovoltaic cells: a review. Advanced Composites and Hybrid Materials, 5(4), 2675. https://doi.org/10.1007/s42114-022-00533-z
26. Tang, J., Ni, H., Peng, R.-L., Wang, N., & Zuo, L. (2023). A review on energy conversion using hybrid photovoltaic and thermoelectric systems. Journal of Power Sources, 562, 232785. https://doi.org/10.1016/j.jpowsour.2023.232785
27. Van Sark, W. G. J. H. M. (2011). Feasibility of photovoltaic–thermoelectric hybrid modules. Applied Energy, 88(8), 2785-2790. https://doi.org/10.1016/j.apenergy.2011.02.008
28. Yin, E., & Li, Q. (2022). Achieving extensive lossless coupling of photovoltaic and thermoelectric devices through parallel connection. Renewable Energy, 193, 565. https://doi.org/10.1016/j.renene.2022.05.054
29. Yin, E., Li, Q., & Xuan, Y. (2017). Thermal resistance analysis and optimization of photovoltaic-thermoelectric hybrid system. Energy Conversion and Management, 143, 188. https://doi.org/10.1016/j.enconman.2017.04.004
30. Yousif, H. S., & Jalil, S. M. (2024). A Comprehensive Review of Hybrid Photovoltaic-Thermoelectric Systems for Enhanced Solar Energy Utilization. Anbar Journal for Engineering Sciences/Mağallaẗ al-Anbār Li-l-ʻulūm al-Handasiyyaẗ, 15(2), 46. https://doi.org/10.37649/aengs.2024.151670.1090
31. Zhang, J., Xuan, Y., & Yang, L. (2014). Performance estimation of photovoltaic–thermoelectric hybrid systems. Energy, 78, 895. https://doi.org/10.1016/j.energy.2014.10.087