EXPERİMENTAL INVESTİGATİON OF THE EFFECT OF OPTİCAL FİLTER TEMPERATURE ON THE ELECTRİCAL PERFORMANCE İN PHOTOVOLTAİC THERMAL SYSTEMS

Abstract

In this study, a photovoltaic-thermal (PVT) system integrated with an optical filter was developed by going beyond the conventional photovoltaic (PV) panel architecture. The electrical and thermal performance of the system, dependent on water temperature, was experimentally analyzed in comparison with a conventional PV system tested simultaneously. The panel was placed inside a specially sealed chamber, and deionized water within the chamber was circulated in a closed loop using a peristaltic pump to control the surface temperature of the panel. Within the scope of the experimental study, the electrical efficiencies of the PV and PVT systems were calculated, and the amount of thermal energy obtained through the circulating fluid in the PVT system was determined. The results showed that the optical filter-integrated PVT system provided higher electrical efficiency than the PV system at low and moderate fluid inlet temperatures, reaching up to 77% total efficiency with an average thermal efficiency of 72.1%. However, when the fluid inlet temperature approached 40 °C, the cooling effect of the PVT system diminished, leading to an increase in PV cell temperature and a sudden drop in current, voltage, and overall performance. When the inlet temperature was reduced to 23 °C, a rapid recovery in electrical parameters was observed. Additionally, while the PV system benefited more from convective cooling due to its direct exposure to the environment, the performance of the PVT system depended primarily on the fluid temperature. The study demonstrates that optical filter-integrated PVT systems are effective in improving total energy efficiency; however, this effectiveness is directly dependent on controlling the fluid inlet temperature.

Keywords

• Photovoltaic thermal (PVT) system
• Optical filter
• Electrical performance
• Fluid temperature
• Experimental analysis

FOTOVOLTAİK TERMAL SİSTEMLERDE KULLANILAN OPTİK FİLTRE SICAKLIĞININ ELEKTRİKSEL PERFORMANSA ETKİSİNİN DENEYSEL İNCELENMESİ

Abstract

Bu çalışmada, geleneksel fotovoltaik (PV) panel mimarisinin ötesine geçilerek optik filtre entegreli bir fotovoltaik-termal (PVT) sistemi tasarlanmış ve sistemin su sıcaklığına bağlı elektriksel ve termal performansı, eş zamanlı olarak test edilen klasik bir PV sistemle karşılaştırmalı olarak analiz edilmiştir. Panel, özel olarak sızdırmaz şekilde kapatılmış bir hazne içerisine yerleştirilmiş, bu hazne içerisindeki saf su, peristaltik bir pompa yardımıyla kapalı çevrim hâlinde dolaştırılarak panelin yüzey sıcaklığı kontrol altında tutulmuştur. Deneysel çalışma kapsamında, PV ve PVT sistemlerin elektriksel verimleri hesaplanmış, PVT sistemde dolaşan akışkan sayesinde elde edilen termal enerji miktarı belirlenmiştir. Sonuçlar, optik filtreli PVT sistemin düşük ve orta sıcaklıklarda PV sistemine göre daha yüksek elektriksel verim sağladığını ve ortalama %72,1’lik termal verimiyle toplam verimin %77’ye ulaştığını ortaya koymuştur. Ancak, akışkan giriş sıcaklığı 40 °C’ye yaklaştığında PVT sistemin soğutma etkisi azalmış; bu da PV hücre sıcaklığının artmasına ve kısa sürede akım, gerilim ve verimde ani düşüşlere neden olmuştur. Giriş sıcaklığı 23 °C’ye düşürüldüğünde ise elektriksel parametrelerde hızlı bir toparlanma gözlemlenmiştir. Ayrıca, PV sistemi dış ortamla doğrudan temas ettiğinden rüzgârdan kaynaklanan taşınımla daha iyi soğuma sağlarken, PVT sistemin performansı esas olarak akışkan sıcaklığına bağlı kalmıştır. Çalışma, optik filtreli PVT sistemlerin toplam enerji verimliliğini artırmada etkili olduğunu, ancak bu etkinin akışkan sıcaklığının kontrolüne doğrudan bağlı olduğunu göstermektedir.

Keywords

• Fotovoltaik termal (PVT) sistem
• Optik filtre
• Elektriksel performans
• Akışkan sıcaklığı
• Deneysel analiz

References

1. Barthwal M, Rakshit D. (2024). Selective transmission and absorption in oxide-based nanofluid optical filters for PVT collectors. Sol Energy Adv, 4:100078. https://doi.org/10.1016/J.SEJA.2024.100078
2. Boes EC, Hall IJ, Prairie RR, Stromberg RP, Anderson HE. (1976). Distribution of direct and total solar radiation availabilities for the USA.
3. Duffie JA, Beckman WA. (2013). Solar Engineering of Thermal Processes. Fourth Edition, https://doi.org/10.1002/9781118671603.
4. Duffie JA, Beckman WA, Winston R, Kreith F. (19769). Solar‐Energy Thermal Processes. Phys Today, https://doi.org/10.1063/1.3023429
5. Hale, G.M. & Querry, M.R. (1973). Optical constants of water in the 200 nm to 200 µm wavelength region. Applied Optics, 12(3), 555–563. https://doi.org/10.1364/AO.12.000555
6. Hsu PC, Huang BJ, Lin WC, Chang YJ, Chang CJ, Li K, et al. (2016). Effect of switching scheme on the performance of a hybrid solar PV system. Renew Energy,(96),520–530. https://doi.org/10.1016/j.renene.2016.05.004
7. Huang G, Markides CN.(2021). Spectral-splitting hybrid PV-thermal (PV-T) solar collectors employing semi-transparent solar cells as optical filters. Energy Convers Manag, 248(1), 114776. https://doi.org/10.1016/j.enconman.
8. Huang G, Wang K, Curt SR, Franchetti B, Pesmazoglou I, Markides CN. (2021). On the performance of concentrating fluid-based spectral-splitting hybrid PV-thermal (PV-T) solar collectors. Renew Energy, 174(7), 590–605. https://doi.org/10.1016/J.RENENE.2021.04.070

9. Kandilli, C. (2016). Exergoeconomic analysis of a novel concentrated solar energy for lighting-power generation combined system based on spectral beam splitting. International Journal of Exergy, 20(3), 239–260. https://doi.org/10.1504/IJEX.2016.078927
10. Kandilli, C. & Külahlı, G. (2017). Performance analysis of a concentrated solar energy for lighting-power generation combined system based on spectral beam splitting. Renewable Energy, 111, 357–366. https://doi.org/10.1016/j.renene.2016.09.032
11. Lee JW, Song MS, Jung HS, Kang YT. (2023). Development of solar radiation spectrum-controlled emulsion filter for a photovoltaic-thermal (PVT) system. Energy Convers Manag, 287(5),117087. https://doi.org/10.1016/J.ENCONMAN.2023.117087
12. Safan, Y. M., Abdelrazik, A. S., Elmohlawy, A. E., Abdel-Moneim, S. A. & Salem, M. R. (2024). Investigating the performance of photovoltaic panels using optical water spectral splitting filter: An experimental and computational analysis. Journal of Renewable and Sustainable Energy, 16(4), 043503. https://doi.org/10.1063/5.0215914
13. Segelstein, D.J. (1981). The Complex Refractive Index of Water. Master’s Thesis, University of Missouri, Kansas City.
14. Taylor RA, Otanicar T, Rosengarten G. (2012). Nanofluid-based optical filter optimization for PV/T systems. Light Sci Appl, 1( 34),1–7. https://doi.org/10.1038/lsa.2012.34
15. Tiwari GN, Dubey S. (2009). Fundamentals of Photovoltaic Modules and Their Applications. Royal Society of Chemistry, https://doi.org/10.1039/9781849730952
16. Tu L, Ma Y, Han X, Zhu M. (2023). Numerical analysis of a modified combined volumetric filtered concentrating PV/T system using MCRT and FVM coupled method. J Clean Prod, 410:137296. https://doi.org/10.1016/J.JCLEPRO.2023.137296
17. Wang G, Wang B, Yuan X, Lin J, Chen Z. (2021). Novel design and analysis of a solar PVT system using LFR concentrator and nano-fluids optical filter. Case Stud Therm Eng, 27(5),101328. https://doi.org/10.1016/J.CSITE.2021.101328
18. Wieliczka, D.M., Weng, S. & Querry, M.R. (1989). Wedge shaped cell for highly absorbent liquids: infrared optical constants of water. Applied Optics, 28(9), 1714–1719. https://doi.org/10.1364/AO.28.001714
19. Zengin, N. & Yamaçlı, R. (2024). İklim Değişikliği Konulu Lisansüstü Çalışmaların Bibliyometrik Analizi Tt- Bıblıometrıc Analysıs Of Graduate Studıes On Clımate Change. Bartın Univ Int J Nat Appl Sci, 7(2), 27–40. https://doi.org/10.55930/jonas.1387511