Numerical study of a parabolic-trough CPV-T collector with spectral-splitting liquid filters

Abstract

Conventional flat-plate photovoltaic-thermal (PV-T) collectors generate electricity and heat simultaneously; however, the outlet temperature of the latter is typically below 60 °C, limiting their widespread application. The use of optical concentration can enable higher-temperature heat to be generated, but this can also lead to a rise in the operating temperature of the PV cells in the collector and, in turn, to a deterioration in their electrical performance. To overcome this challenge, an optical spectral-splitting filter that absorbs the infrared and transmits the visible portion of the solar spectrum can be used, such that wavelengths below the bandgap are sent to the cells for electricity generation, while those above it are sent to a thermally decoupled absorber for the generation of heat at a temperature that is considerably higher than that of the cells. In this study, a triangular primary PV-T channel, wherein the primary heat transfer fluid (water) flows, is integrated into a parabolic trough concentrator of geometrical concentration ratio ~10, while a secondary liquid filter (water, AgSiO₂-eg or Therminol-66) is introduced for spectral splitting. Optical, electrical and thermal-fluid (sub-)models are developed and coupled to study the performance of this collector. Each sub-model is individually checked against results taken from the literature with maximum deviations under 10%. Subsequently, the optical and electrical models are coupled with a 3-D thermal-fluid CFD model (using COMSOL Multiphysics 6.1) to predict the electrical and thermal performance of the collector. Results show that when water is used as the optical filter, the maximum overall thermal (filter channel plus primary channel) and electrical efficiencies of the collector reach ~45% and 15%, respectively. A comparison between water, AgSiO₂-eg and Therminol-66 reveals that AgSiO₂-eg improves the thermal efficiency of the filter channel by ~25% (absolute) compared to Therminol-66 and water, however, this improvement – which arises from the thermal performance of the filter – comes at an expense of a ~5% electrical efficiency loss.

Graphical abstract

Keywords

concentrator / filter / photovoltaic-thermal / solar energy / spectral splitting

References

[1] Sharif A, Meo M S, Chowdhury M A F. . Role of solar energy in reducing ecological footprints: An empirical analysis. Journal of Cleaner Production, 2021, 292: 126028

[2] Spyridonidou S, Vagiona D G. A systematic review of site-selection procedures of PV and CSP technologies. Energy Reports, 2023, 9: 2947–2979

[3] Duffie J A, Beckman W A, McGowan J. Solar engineering of thermal processes. American Journal of Physics, 1985, 53: 382

[4] Sarangi A, Sarangi A, Sahoo S S. . A review of different working fluids used in the receiver tube of parabolic trough solar collector. Journal of Thermal Analysis and Calorimetry, 2023, 148(10): 3929–3954

[5] Herrando M, Pantaleo A M, Wang K. . Solar combined cooling, heating and power systems based on hybrid PVT, PV or solar-thermal collectors for building applications. Renewable Energy, 2019, 143: 637–647

[6] Freeman J, Markides C N. A solar diffusion-absorption refrigeration system for off-grid cold-chain provision, Part II: System simulation and assessment of performance. Renewable Energy, 2024, 230: 120717

[7] Ray S, Tripathy A K, Sahoo S S. . Effect of inlet temperature of heat transfer fluid and wind velocity on the performance of parabolic trough solar collector receiver: A computational study. International Journal of Heat and Technology, 2019, 37(1): 48–58

[8] Cuce P M, Guclu T, Cuce E. Design, modelling, environmental, economic and performance analysis of parabolic trough solar collector (PTC) based cogeneration systems assisted by thermoelectric generators (TEGs). Sustainable Energy Technologies and Assessments, 2024, 64: 103745

[9] Huang G, Markides C N. Spectral-splitting hybrid PV-thermal (PV-T) solar collectors employing semi-transparent solar cells as optical filters. Energy Conversion and Management, 2021, 248: 114776

[10] Huang G, Wang K, Markides C N. Efficiency limits of concentrating spectral-splitting hybrid photovoltaic-thermal (PV-T) solar collectors and systems. Light, Science & Applications, 2021, 10(1): 28

[11] Herrando M, Markides C N, Hellgardt K. A UK-based assessment of hybrid PV and solar-thermal systems for domestic heating and power: System performance. Applied Energy, 2014, 122: 288–309

[12] Chandan S V, Suresh V, Iqbal S M. . 3-D numerical modelling and experimental investigation of coupled photovoltaic thermal and flat plate collector. Solar Energy, 2021, 224: 195–209

[13] Peacock J, Huang G, Song J. . Techno-economic assessment of integrated spectral-beam-splitting photovoltaic-thermal (PV-T) and organic Rankine cycle (ORC) systems. Energy Conversion and Management, 2022, 269: 116071

[14] Herrando M, Wang K, Huang G. . A review of solar hybrid photovoltaic-thermal (PV-T) collectors and systems. Progress in Energy and Combustion Science, 2023, 97: 101072

[15] Chandan S, Dey Iqbal S. . Numerical modelling and performance assessment of elongated compound parabolic concentrator based LCPVT system. Renewable Energy, 2021, 167: 199–216

[16] Chandan D S, Kumar P S, Reddy K S. . Optical and electrical performance investigation of truncated 3X non-imaging low concentrating photovoltaic-thermal systems. Energy Conversion and Management, 2020, 220(113056): 113056

[17] Chandan B H, Tahir A A, Reddy K S. . Performance improvement of a desiccant based cooling system by mitigation of non-uniform illumination on the coupled low concentrating photovoltaic thermal units. Energy Conversion and Management, 2022, 257: 115438

[18] Acosta-Pazmiño I P, García-Ramos R A, Rivera-Solorio C I. . Development and testing of a low-concentrating photovoltaic-thermal collector. In: Proceedings of SolarPACES 2023, 29th International Conference on Concentrating Solar Power, Thermal, and Chemical Energy Systems, 2024,

[19] Pandey C, Wu M, Yildizhan H. . Modelling of a CPV-T collector for combined heat and power generation. In: Proceedings of Solar World Congress, International Solar Energy Society, 2023,

[20] Daneshazarian R, Cuce E, Cuce P M. . Concentrating photovoltaic thermal (CPVT) collectors and systems: Theory, performance assessment and applications. Renewable & Sustainable Energy Reviews, 2018, 81: 473–492

[21] Li J, Zhang W, Xie L. . A hybrid photovoltaic and water/air based thermal (PVT) solar energy collector with integrated PCM for building application. Renewable Energy, 2022, 199: 662–671

[22] Leonforte F, Miglioli A, Del Pero C. . Design and performance monitoring of a novel photovoltaic-thermal solar-assisted heat pump system for residential applications. Applied Thermal Engineering, 2022, 210: 118304

[23] Kumar L, Hasanuzzaman M, Rahim N A. . Modeling, simulation and outdoor experimental performance analysis of a solar-assisted process heating system for industrial process heat. Renewable Energy, 2021, 164: 656–673

[24] Ju X, Xu C, Liao Z. . A review of concentrated photovoltaic-thermal (CPVT) hybrid solar systems with waste heat recovery (WHR). Science Bulletin, 2017, 62(20): 1388–1426

[25] He W, Huang G, Markides C N. Synergies and potential of hybrid solar photovoltaic-thermal desalination technologies. Desalination, 2023, 552: 116424

[26] Pan X, Ju X, Yuan M. . Energy tracing of solar cells for spectral-beam-splitting photovoltaic/thermal (PVT) systems. Applied Energy, 2023, 345: 121320

[27] Imenes A G, Mills D R. Spectral beam splitting technology for increased conversion efficiency in solar concentrating systems: A review. Solar Energy Materials and Solar Cells, 2004, 84(1–4): 19–69

[28] Huang G, Wang K, Curt S R. . On the performance of concentrating fluid-based spectral-splitting hybrid PV-thermal (PV-T) solar collectors. Renewable Energy, 2021, 174: 590–605

[29] Han X, Tu L, Sun Y. A spectrally splitting concentrating PV/T system using combined absorption optical filter and linear Fresnel reflector concentrator. Solar Energy, 2021, 223: 168–181

[30] Han X, Chen X, Wang Q. . Investigation of CoSO₄-based Ag nanofluids as spectral beam splitters for hybrid PV/T applications. Solar Energy, 2019, 177: 387–394

[31] Barthwal M, Rakshit D. Holistic opto-thermo-electrical analysis of a novel spectral beam splitting-based concentrating photovoltaic thermal system. Journal of Cleaner Production, 2022, 379: 134545

[32] Liu Y, Hu P, Zhang Q. . Thermodynamic and optical analysis for a CPV/T hybrid system with beam splitter and fully tracked linear Fresnel reflector concentrator utilizing sloped panels. Solar Energy, 2014, 103: 191–199

[33] Looser R, Vivar M, Everett V. Spectral characterisation and long-term performance analysis of various commercial heat transfer fluids (HTF) as direct-absorption filters for CPV-T beam-splitting applications. Applied Energy, 2014, 113: 1496–1511

[34] Mojiri A, Stanley C, Rosengarten G. A high temperature hybrid photovoltaic-thermal receiver employing spectral beam splitting for linear solar concentrators. In: Proceedings Volume 9559, High and Low Concentrator Systems for Solar Energy Applications X, SPIE, 2015,

[35] Mojiri A, Stanley C, Taylor R A. . A spectrally splitting photovoltaic-thermal hybrid receiver utilising direct absorption and wave interference light filtering. Solar Energy Materials and Solar Cells, 2015, 139: 71–80

[36] Stanley C, Mojiri A, Rahat M. . Performance testing of a spectral beam splitting hybrid PVT solar receiver for linear concentrators. Applied Energy, 2016, 168: 303–313

[37] Widyolar B, Jiang L, Winston R. Spectral beam splitting in hybrid PV/T parabolic trough systems for power generation. Applied Energy, 2018, 209: 236–250

[38] Joshi S S, Dhoble A S. Analytical approach for performance estimation of BSPVT system with liquid spectrum filters. Energy, 2018, 157: 778–791

[39] Han X, Xue D, Zheng J. . Spectral characterization of spectrally selective liquid absorption filters and exploring their effects on concentrator solar cells. Renewable Energy, 2019, 131: 938–945

[40] Li H, He Y, Wang C. . Tunable thermal and electricity generation enabled by spectrally selective absorption nanoparticles for photovoltaic/thermal applications. Applied Energy, 2019, 236: 117–126

[41] Wingert R, O’Hern H, Orosz M. . Spectral beam splitting retrofit for hybrid PV/T using existing parabolic trough power plants for enhanced power output. Solar Energy, 2020, 202: 1–9

[42] Yazdanifard F, Ameri M, Taylor R A. Numerical modeling of a concentrated photovoltaic/thermal system which utilizes a PCM and nanofluid spectral splitting. Energy Conversion and Management, 2020, 215: 112927

[43] Ling Y, Li W, Jin J. . A spectral-splitting photovoltaic-thermochemical system for energy storage and solar power generation. Applied Energy, 2020, 260: 113631

[44] Alnajideen M, Min G. Hybrid photovoltaic-thermoelectric system using a novel spectral splitting solar concentrator. Energy Conversion and Management, 2022, 251: 114981

[45] Wang G, Zhang Z, Jiang T. . Thermodynamic and optical analyses of a novel solar CPVT system based on parabolic trough concentrator and nanofluid spectral filter. Case Studies in Thermal Engineering, 2022, 33: 101948

[46] Meraje W C, Huang C C, Barman J. . Design and experimental study of a Fresnel lens-based concentrated photovoltaic thermal system integrated with nanofluid spectral splitter. Energy Conversion and Management, 2022, 258: 115455

[47] Li J, Yang Z, Wang Y. . A novel non-confocal two-stage dish concentrating photovoltaic/thermal hybrid system utilizing spectral beam splitting technology: Optical and thermal performance investigations. Renewable Energy, 2023, 206: 609–622

[48] Zhang Z, Zhang F, Zhang W. . Spectral-splitting concentrator agrivoltaics for higher hybrid solar energy conversion efficiency. Energy Conversion and Management, 2023, 276: 116567

[49] Chougule S S, Srivastava A, Bolegave G G. . Next-generation solar technologies: Unlocking the potential of Ag-ZnO hybrid nanofluids for enhanced spectral-splitting photovoltaic-thermal systems. Renewable Energy, 2024, 236: 121405

[50] COMSOL Inc. COMSOL Multiphysics Reference Manual, version: 6.1. 2025-03-24. , ,

[51] The MathWorks. MATLAB Version: (R2022a). 2025-03-24. , ,

[52] Inventive Power. Solar energy for industry. 2024-09-17. , ,

[53] Hou Y, Yu X, Yang B. . Optical performance investigation on flat receiver for parabolic trough solar collector based on the MCRT method. Renewable Energy, 2023, 202: 525–536

[54] Al Shehri A, Parrott B, Carrasco P. . Impact of dust deposition and brush-based dry cleaning on glass transmittance for PV modules applications. Solar Energy, 2016, 135: 317–324

[55] Han X, Guo Y, Wang Q. . Optical characterization and durability of immersion cooling liquids for high concentration III–V photovoltaic systems. Solar Energy Materials and Solar Cells, 2018, 174: 124–131

[56] Ma Y, Han X, Chen Z. . Performance analysis of a nanofluid spectral splitting concentrating PV/T system with triangular receiver based on MCRT-FVM coupled method. Applied Thermal Engineering, 2024, 239: 122096

[57] Huang G, Curt S R, Wang K. . Challenges and opportunities for nanomaterials in spectral splitting for high-performance hybrid solar photovoltaic-thermal applications: A review. Nano Materials Science, 2020, 2(3): 183–203

[58] SunPower Ltd. C60 monocrystalline silicon solar cell. 2024-09-22. , ,

[59] Incropera F P, Dewitt D P, Bergman T L. . Fundamentals of Heat and Mass Transfer. New York: John Wiley & Sons Inc, 2001,

[60] Rajan A, Reddy K S. Integrated optical and thermal model to investigate the performance of a solar parabolic dish collector coupled with a cavity receiver. Renewable Energy, 2023, 219: 119376

[61] Radwan A, Ahmed M, Ookawara S. Performance enhancement of concentrated photovoltaic systems using a microchannel heat sink with nanofluids. Energy Conversion and Management, 2016, 119: 289–303

[62] Yousef M S, Abdel Rahman A K, Ookawara S. Performance investigation of low-concentration photovoltaic systems under hot and arid conditions: Experimental and numerical results. Energy Conversion and Management, 2016, 128: 82–94

[63] Ju X, Abd El-Samie M M, Xu C. . A fully coupled numerical simulation of a hybrid concentrated photovoltaic/thermal system that employs a therminol VP-1 based nanofluid as a spectral beam filter. Applied Energy, 2020, 264: 114701

[64] Cui Y, Zhu Q. Study of photovoltaic/thermal systems with MgO-water nanofluids flowing over silicon solar cells. In: 2011 Asia-Pacific Power and Energy Engineering Conference, Shanghai, China, 2012,

RIGHTS & PERMISSIONS

The Author(s). This article is published with open access at link.springer.com and journal.hep.com.cn