An Advanced Maturity of Parabolic Solar Collector Passive Enhancement Techniques

Document Type : Review Article

Authors

Chemical Engineering Department, Al-Nahrain University, Baghdad, Iraq

10.22059/jser.2025.395560.1568

Abstract

Renewable energy sources are seen as a viable alternative to traditional energy sources, which are quickly depleting and have negative environmental impacts from their excessive usage. Free thermal energy for medium to high-temperature production comes from solar power, a renewable energy source. Based on the effective solar power optical concentration, thermal or electrical energy may be extracted. Sunlight thermal energy has been the focus of more and more research. The parabolic trough collector is a globally accessible, time-tested technique for generating thermal energy. The factors affecting the enhancement techniques are represented by a perfect absorber design made from the best conductive material with perfect coating properties, and high-reflection performance mirror properties. This paper outlined the most promising investigations that have been conducted on parabolic-trough collectors and enhancement techniques. The design of the fluid's heat transmission mechanism, the Parabolic-Trough Collector (PTC), a reflector, a receiver, and thermal storage devices are all part of this. This article discusses parabolic trough collectors and the various uses they have. The PTC is now one of the most significant solar-powered heating applications available, widely used for both industrial and domestic applications under various operating conditions.

Keywords

[1]. Twidell, J. (2021). Renewable energy resources. Routledge.‏ https://doi.org/10.4324/9780429452161.
[2]. Herzog, A. V., Lipman, T. E., & Kammen, D. M. (2001). Renewable energy sources. Encyclopedia of Life Support Systems (EOLSS). Forerunner Volume-Perspectives and overview of life support systems and sustainable development, 76.
[3]. Ahmed, O. K., & Ahmed, A. H. (2011). Principle of Renewable energies. Foundation of Technical Education.
[4]. Giostri, A., Binotti, M., Astolfi, M., Silva, P., Macchi, E., & Manzolini, G. (2012). Comparison of different solar plants based on parabolic trough technology. Solar Energy, 86(5), 1208-1221.‏ https://doi.org/10.1016/j.solener.2012.01.014.
[5]. Hashim, W. M., Shomran, A. T., Jurmut, H. A., Gaaz, T. S., Kadhum, A. A. H., & Al-Amiery, A. A. (2018). Case study on solar water heating for flat plate collector. Case studies in thermal engineering, 12, 666-671.‏ https://doi.org/10.1016/j.csite.2018.09.002.
[6]. Pandey, K. M., & Chaurasiya, R. (2017). A review on analysis and development of solar flat plate collector. Renewable and Sustainable Energy Reviews, 67, 641-650.‏ https://doi.org/10.1016/j.rser.2016.09.078.
[7]. Struckmann, F. (2008). Analysis of a flat-plate solar collector. Heat and Mass Transport, Project Report, 2008MVK160.
[8]. Udoy, S. A., Bhuiya, K. M. S., Das, P., Azad, A. M., Haque, M. A., Oishi, Z. T., ... & Jahan, M. (2025). Advancements in Solar Still Water Desalination: A Comprehensive Review of Design Enhancements and Performance Optimization. Journal of Solar Energy Research.
https://doi.org/10.22059/jser.2025.382301.1464.
[9]. Duffie, J. A., Beckman, W. A., & Blair, N. (2020). Solar engineering of thermal processes, photovoltaics and wind. John Wiley & Sons.
[10]. Jebasingh, V. K., & Herbert, G. J. (2016). A review of solar parabolic trough collector. Renewable and Sustainable Energy Reviews, 54, 1085-1091.‏ https://doi.org/10.1016/j.rser.2015.10.043.
[11]. Mallik, A., Al Nahian, S. R., & Rashid, F. (2018). PV/T Systems for Renewable Energy Storage: A Review. Journal of Solar Energy Research, 3(1), 35-42.
[12]. Gupta, N., & Tiwari, G. N. (2017). Energy matrices of building integrated photovoltaic thermal systems: case study. Journal of Architectural Engineering, 23(4), 05017006. https://doi.org/10.1061/(ASCE)AE.1943-5568.0000270.
[13]. Naik, H., Baredar, P., & Kumar, A. (2017). Medium temperature application of concentrated solar thermal technology: Indian perspective. Renewable and Sustainable Energy Reviews, 76, 369-378.‏ https://doi.org/10.1016/j.rser.2017.03.014.
 
[14]. Jamshidian, F. J., Gorjian, S., & Far, M. S. (2018). An overview of solar thermal power generation systems.‏
 
[15]. Kalogirou, S. A. (2004). Solar thermal collectors and applications. Progress in energy and combustion science, 30(3), 231-295.‏ https://doi.org/10.1016/j.pecs.2004.02.001.
[16]. Kalogirou, S. (2003). The potential of solar industrial process heat applications. Applied Energy, 76(4), 337-361.‏ https://doi.org/10.1016/S0306-2619(02)00176-9.
[17]. Bazen, E. F., & Brown, M. A. (2009). Feasibility of solar technology (photovoltaic) adoption: A case study on Tennessee's poultry industry. Renewable Energy, 34(3), 748-754.‏ https://doi.org/10.1016/j.renene.2008.04.003.
[18]. Huang, J., Li, R., He, P., & Dai, Y. (2018). Status and prospect of solar heat for industrial processes in China. Renewable and Sustainable Energy Reviews, 90, 475-489.‏ https://doi.org/10.1016/j.rser.2018.03.077.
[19]. Upadhyay, B. H., Patel, A. J., & Ramana, P. V. (2022). A detailed review on solar parabolic trough collector. International Journal of Ambient Energy, 43(1), 176-196.‏ https://doi.org/10.1080/01430750.2019.1636869.
[20]. Suman, S., Khan, M. K., & Pathak, M. (2015). Performance enhancement of solar collectors—A review. Renewable and Sustainable Energy Reviews, 49, 192-210 https://doi.org/10.1016/j.rser.2015.04.087.
[21]. Kumar, L., Hasanuzzaman, M., & Rahim, N. A. (2019). Global advancement of solar thermal energy technologies for industrial process heat and its future prospects: A review. Energy conversion and management, 195, 885-908.‏ https://doi.org/10.1016/j.enconman.2019.05.081.
[22]. eddine Boukelia, T., & Mecibah, M. S. (2013). Parabolic trough solar thermal power plant: Potential, and projects development in Algeria. Renewable and Sustainable Energy Reviews, 21, 288-297.‏ https://doi.org/10.1016/j.rser.2012.11.074.
[23]. Senthilkumar, R., Sithivinanayagam, N., & Shankar, N. (2014). Experimental investigation of solar water heater using phase change material. International Journal of Research in Invent Technology, 2(7), 1110-1117.
[24]. Bellos, E., & Tzivanidis, C. (2019). Alternative designs of parabolic trough solar collectors. Progress in Energy and Combustion Science, 71, 81-117.‏ https://doi.org/10.1016/j.pecs.2018.11.001.
[25]. Cabrera, F. J., Fernández-García, A., Silva, R. M. P., & Pérez-García, M. (2013). Use of parabolic trough solar collectors for solar refrigeration and air-conditioning applications. Renewable and sustainable energy reviews, 20, 103-118.‏ https://doi.org/10.1016/j.rser.2012.11.081.
[26]. Montes, I. E. P., Benitez, A. M., Chavez, O. M., & Herrera, A. E. L. (2014). Design and construction of a parabolic trough solar collector for process heat production. Energy Procedia, 57, 2149-2158.‏ https://doi.org/10.1016/j.egypro.2014.10.181.
[27]. Fuqiang, W., Ziming, C., Jianyu, T., Yuan, Y., Yong, S., & Linhua, L. (2017). Progress in concentrated solar power technology with parabolic trough collector system: A comprehensive review. Renewable and Sustainable Energy Reviews, 79, 1314-1328.‏ https://doi.org/10.1016/j.rser.2017.05.174.
[28]. Lu, J., Ding, J., Yang, J., & Yang, X. (2013). Nonuniform heat transfer model and performance of parabolic trough solar receiver. Energy, 59, 666-675. https://doi.org/10.1016/j.energy.2013.07.052.
[29]. Razmmand, F., Mehdipour, R., & Mousavi, S. M. (2019). A numerical investigation on the effect of nanofluids on heat transfer of the solar parabolic trough collectors. Applied Thermal Engineering, 152, 624-633.‏ https://doi.org/10.1016/j.applthermaleng.2019.02.118.
[30]. Conrado, L. S., Rodriguez-Pulido, A., & Calderón, G. (2017). Thermal performance of parabolic trough solar collectors. Renewable and Sustainable Energy Reviews, 67, 1345-1359.‏ https://doi.org/10.1016/j.rser.2016.09.071.
[31]. Fuqiang, W., Jianyu, T., Lanxin, M., & Chengchao, W. (2015). Effects of glass cover on heat flux distribution for tube receiver with parabolic trough collector system. Energy Conversion and Management, 90, 47-52.‏ https://doi.org/10.1016/j.enconman.2014.11.004.
[32]. Gugulothu, R., Reddy, K. V. K., Somanchi, N. S., & Adithya, E. L. (2017). A review on enhancement of heat transfer techniques. Materials Today: Proceedings, 4(2), 1051-1056.‏ https://doi.org/10.1016/j.matpr.2017.01.119.
[33]. Prasad, B. N., Kumar, A., & Singh, K. D. P. (2015). Optimization of thermo hydraulic performance in three sides artificially roughened solar air heaters. Solar Energy, 111, 313-319.‏ https://doi.org/10.1016/j.solener.2014.10.030.
[34]. Prasad, B. N. (2013). Thermal performance of artificially roughened solar air heaters. Solar Energy, 91, 59-67.‏ https://doi.org/10.1016/j.solener.2013.01.014.
[35]. Karwa, R., Maheshwari, B. K., & Karwa, N. (2005). Experimental study of heat transfer enhancement in an asymmetrically heated rectangular duct with perforated baffles. International Communications in Heat and Mass Transfer, 32(1-2), 275-284.‏ https://doi.org/10.1016/j.icheatmasstransfer.2004.10.002.
[36]. Karwa, R., & Maheshwari, B. K. (2009). Heat transfer and friction in an asymmetrically heated rectangular duct with half and fully perforated baffles at different pitches. International Communications in Heat and Mass Transfer, 36(3), 264-268.‏ https://doi.org/10.1016/j.icheatmasstransfer.2008.11.005.
[37]. Mahmood, A. J., Aldabbagh, L. B. Y., & Egelioglu, F. (2015). Investigation of single and double pass solar air heater with transverse fins and a package wire mesh layer. Energy Conversion and Management, 89, 599-607.‏ https://doi.org/10.1016/j.enconman.2014.10.028.
[38]. Kumar, R., &
Rosen, M. A. (2011). Performance evaluation of a double pass PV/T solar air heater with and without fins. Applied Thermal Engineering, 31(8-9), 1402-1410.‏ https://doi.org/10.1016/j.applthermaleng.2010.12.037.
[39]. Omojaro, A. P., & Aldabbagh, L. B. Y. (2010). Experimental performance of single and double pass solar air heater with fins and steel wire mesh as absorber. Applied energy, 87(12), 3759-3765.‏ https://doi.org/10.1016/j.apenergy.2010.06.020.
[40]. Hans, V. S., Saini, R. P., & Saini, J. S. (2010). Heat transfer and friction factor correlations for a solar air heater duct roughened artificially with multiple v-ribs. Solar energy, 84(6), 898-911.‏ https://doi.org/10.1016/j.solener.2010.02.004.
[41]. Kumar, A., Saini, R. P., & Saini, J. S. (2013). Development of correlations for Nusselt number and friction factor for solar air heater with roughened duct having multi v-shaped with gap rib as artificial roughness. Renewable Energy, 58, 151-163.‏ https://doi.org/10.1016/j.renene.2013.03.013.
[42]. Akpinar, E. K., & Koçyiğit, F. (2010). Energy and exergy analysis of a new flat-plate solar air heater having different obstacles on absorber plates. Applied energy, 87(11), 3438-3450.‏ https://doi.org/10.1016/j.apenergy.2010.05.017.
[43]. Kulkarni, K., Afzal, A., & Kim, K. Y. (2015). Multi-objective optimization of solar air heater with obstacles on absorber plate. Solar Energy, 114, 364-377.‏ https://doi.org/10.1016/j.solener.2015.02.008.
[44]. Bekele, A., Mishra, M., & Dutta, S. (2014). Performance characteristics of solar air heater with surface mounted obstacles. Energy conversion and management, 85, 603-611.‏ https://doi.org/10.1016/j.enconman.2014.04.079.
[45]. Layek, A. (2010, October). Performance evaluation of solar air heater having chamfered rib groove roughness on absorber plate. In AIP Conference Proceedings (Vol. 1298, No. 1, pp. 282-287). American Institute of Physics.‏ https://doi.org/10.1063/1.3516316.
[46]. Alam, T., Meena, C. S., Balam, N. B., Kumar, A., & Cozzolino, R. (2021). Thermo-hydraulic performance characteristics and optimization of protrusion rib roughness in solar air heater. Energies, 14(11), 3159. https://doi.org/10.3390/en14113159.‏
[47]. Promvonge, P., & Eiamsa-Ard, S. (2007). Heat transfer behaviors in a tube with combined conical-ring and twisted-tape insert. International Communications in Heat and Mass Transfer, 34(7), 849-859.‏ https://doi.org/10.1016/j.icheatmasstransfer.2007.03.019.
[48]. Yadav, A. S. (2009). Effect of half-length twisted-tape turbulators on heat transfer and pressure drop characteristics inside a double pipe u-bend heat exchanger. JJMIE, 3(1), 17-22.
[49]. Lau, S. C., McMillin, R. D., & Han, J. C. (1991). Turbulent heat transfer and friction in a square channel with discrete rib turbulators.‏ https://doi.org/10.1115/1.2927884.
[50]. Han, J. C. (1988). Heat transfer and friction characteristics in rectangular channels with rib turbulators.‏ https://doi.org/10.1115/1.3250487.
[51]. Alam, T., Saini, R. P., & Saini, J. S. (2014). Effect of circularity of perforation holes in V-shaped blockages on heat transfer and friction characteristics of rectangular solar air heater duct. Energy Conversion and Management, 86, 952-963.‏ https://doi.org/10.1016/j.enconman.2014.06.050.
[52]. Alam, T., Saini, R. P., & Saini, J. S. (2014). Experimental investigation of thermohydraulic performance of a rectangular solar air heater duct equipped with V-shaped perforated blocks. Advances in Mechanical Engineering, 6, 948313.‏ https://doi.org/10.1155/2014/948313.
[53]. Promvonge, P., Khanoknaiyakarn, C., Kwankaomeng, S., & Thianpong, C. (2011). Thermal behavior in solar air heater channel fitted with combined rib and delta-winglet. International Communications in Heat and Mass Transfer, 38(6), 749-756.‏ https://doi.org/10.1016/j.icheatmasstransfer.2011.03.014.
[54]. Chokphoemphun, S., Pimsarn, M., Thianpong, C., & Promvonge, P. (2015). Heat transfer augmentation in a circular tube with winglet vortex generators. Chinese Journal of Chemical Engineering, 23(4), 605-614.‏ https://doi.org/10.1016/j.cjche.2014.04.002
[55]. Akhavan-Behabadi, M. A., Kumar, R., Salimpour, M. R., & Azimi, R. (2010). Pressure drop and heat transfer augmentation due to coiled wire inserts during laminar flow of oil inside a horizontal tube. International Journal of Thermal Sciences, 49(2), 373-379.‏ https://doi.org/10.1016/j.ijthermalsci.2009.06.004.
[56]. Gunes, S., Ozceyhan, V., & Buyukalaca, O. (2010). The experimental investigation of heat transfer and pressure drop in a tube with coiled wire inserts placed separately from the tube wall. Applied Thermal Engineering, 30(13), 1719-1725.‏ https://doi.org/10.1016/j.applthermaleng.2010.04.001.
[57]. Min, C., Qi, C., Kong, X., & Dong, J. (2010). Experimental study of rectangular channel with modified rectangular longitudinal vortex generators. International Journal of Heat and Mass Transfer, 53(15-16), 3023-3029.‏ https://doi.org/10.1016/j.ijheatmasstransfer.2010.03.026.
[58]. Yakut, K., Sahin, B., Celik, C., Alemdaroglu, N., & Kurnuc, A. (2005). Effects of tapes with double-sided delta-winglets on heat and vortex characteristics. Applied energy, 80(1), 77-95.‏ https://doi.org/10.1016/j.apenergy.2004.03.003.
[59]. Ozgen, F., Esen, M., & Esen, H. (2009). Experimental investigation of thermal performance of a double-flow solar air heater having aluminium cans. Renewable Energy, 34(11), 2391-2398.‏ https://doi.org/10.1016/j.renene.2009.03.029.
[60]. Kalogirou, S. A. (2004). Solar thermal collectors and applications. Progress in energy and combustion science, 30(3), 231-295.‏ https://doi.org/10.1016/j.pecs.2004.02.001.
[61]. Tagle-Salazar, P. D., Nigam, K. D., & Rivera-Solorio, C. I. (2020). Parabolic trough solar collectors: A general overview of technology, industrial applications, energy market, modeling, and standards. Green Processing and Synthesis, 9(1), 595-649.‏ https://doi.org/10.1515/gps-2020-0059.
[62].Hashemian, N., & Noorpoor, A. (2019). Assessment and multi-criteria optimization of a solar and biomass-based multi-generation system: Thermodynamic, exergoeconomic and exergoenvironmental aspects. Energy conversion and management, 195, 788-797. https://doi.org/10.1016/j.enconman.2019.05.039.
[63]. Chafie, M., Aissa, M. F. B., Bouadila, S., Balghouthi, M., Farhat, A., & Guizani, A. (2016). Experimental investigation of parabolic trough collector system under Tunisian climate: Design, manufacturing and performance assessment. Applied thermal engineering, 101, 273-283.‏ https://doi.org/10.1016/j.applthermaleng.2016.02.073.
[64]. Zou, B., Dong, J., Yao, Y., & Jiang, Y. (2016). An experimental investigation on a small-sized parabolic trough solar collector for water heating in cold areas. applied energy, 163, 396-407. https://doi.org/10.1016/j.apenergy.2015.10.186.
[65]. Hameed, V. M., & Ibrahim, M. (2021, February). An experimental study on new multistage solar parabolic trough collector. In IOP Conference Series: Materials Science and Engineering (Vol. 1094, No. 1, p. 012103). IOP Publishing. doi10.1088/1757-899X/1094/1/012103.
[66]. Bellos, E., Tzivanidis, C., & Antonopoulos, K. A. (2017). A detailed working fluid investigation for solar parabolic trough collectors. Applied Thermal Engineering, 114, 374-386.‏ https://doi.org/10.1016/j.applthermaleng.2016.11.201.
[67]. Diwan, K., & Soni, M. S. (2015). Heat transfer enhancement in absorber tube of parabolic trough concentrators using wire-coils inserts. Universal Journal of Mechanical Engineering, 3(3), 107-112. doi: 10.13189/ujme.2015.030305.
[68]. Jaramillo, O. A., Borunda, M., Velazquez-Lucho, K. M., & Robles, M. (2016). Parabolic trough solar collector for low enthalpy processes: An analysis of the efficiency enhancement by using twisted tape inserts. Renewable energy, 93, 125-141. https://doi.org/10.1016/j.renene.2016.02.046.
[69]. Gong, X., Wang, F., Wang, H., Tan, J., Lai, Q., & Han, H. (2017). Heat transfer enhancement analysis of tube receiver for parabolic trough solar collector with pin fin arrays inserting. Solar Energy, 144, 185-202. https://doi.org/10.1016/j.solener.2017.01.020.
[70]. Jamal-Abad, M. T., Saedodin, S., & Aminy, M. (2017). Experimental investigation on a solar parabolic trough collector for absorber tube filled with porous media. Renewable Energy, 107, 156-163.‏ https://doi.org/10.1016/j.renene.2017.02.004.
[71]. Nasir, K. F., Ali, M., & Mamoori, A. H. A. (2018). Thermal Characteristics of Phase Change Material Used As Thermal Storage System By Using Solar Energy. Kufa Journal of Engineering, 9(1), 1-22.‏ http://dx.doi.org/10.30572/2018/kje/090101.
[72]. Esapour, M., Hamzehnezhad, A., Darzi, A. A. R., & Jourabian, M. (2018). Melting and solidification of PCM embedded in porous metal foam in horizontal multi-tube heat storage system. Energy conversion and management, 171, 398-410. https://doi.org/10.1016/j.enconman.2018.05.086.
[73]. Agbanigo, A. O., & Ajayi, I. S. (2017). Performance Evaluation of Solar Water Heating System with PCM Thermal Storage. Journal of Multidisciplinary Engineering Science and Technology (JMEST), 4(10).
[74]. Venkatesaperumal, R., Syed Jafar, K., Elumalai, P. V., Abbas, M., Cuce, E., Shaik, S., & Saleel, C. A. (2022). Heat transfer studies on solar parabolic trough collector using corrugated tube receiver with conical strip inserts. Sustainability, 15(1), 378.‏ https://doi.org/10.3390/su15010378.
[75]. Yan, P., Fan, W., Yang, Y., Ding, H., Arshad, A., & Wen, C. (2022). Performance enhancement of phase change materials in triplex-tube latent heat energy storage system using novel fin configurations. Applied Energy, 327,120064. https://doi.org/10.1016/j.apenergy.2022.120064.
[76]. Hasan, H. A., & Suffer, K. H. (2023). Thermal performance enhancement of energy storage system using spiral-wired tube heat exchanger. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 45(3), 7280-7293. https://doi.org/10.1080/15567036.2023.2220676.
[77]. Saleh, E. M., & Hameed, V. M. (2024). Innovative new solar parabolic trough collector enhanced by corrugated receiver surface with PCM and turbulator inside. Journal of Energy Storage, 86, 111403.‏ https://doi.org/10.1016/j.est.2024.111403.
[78]. Moravej, M., Noghrehabadi, A., Esmaeilinasab, A. L. I., & Khajehpour, E. (2020). The effect of SiO2 nanoparticle on the performance of photovoltaic thermal system: Experimental and Theoretical approach. Journal of Heat and Mass Transfer Research, 7(1), 11-24.‏ https://doi.org/10.22075/jhmtr.2020.18904.1254.
[79]. Moravej, M. (2021). An experimental study of the performance of a solar flat plate collector with triangular geometry. Journal of Solar Energy Research, 6(4), 923-936.‏ https://doi.org/10.22059/jser.2020.311364.1178.
[80]. Kolahkaj, S., Moravej, M., & Ghafouri, A. (2024). Thermal performance of a flat-plate solar collector using elliptical riser tubes and magnesium oxide nanofluid. International Journal of Ambient Energy, 45(1), 2323642.‏ https://doi.org/10.1080/01430750.2024.2323642.
[81]. Moravej, M., & Soozanyar, A. (2017). An experimental investigation of the efficiency of a stationary helical solar water heater. Current World Environment, 12(2), 250.
[82]. Li, X., Wilson, C. T., Zhang, L., Bhatia, B., Zhao, L., Leroy, A., ... & Wang, E. N. (2022). Design and modeling of a multiscale porous ceramic heat exchanger for high temperature applications with ultrahigh power density. International Journal of Heat and Mass Transfer, 194, 122996.‏ https://doi.org/10.1016/j.ijheatmasstransfer.2022.122996.
[83]. Egerer, U., Dana, S., Jager, D., Stanislawski, B. J., Xia, G., & Yellapantula, S. (2024). Field measurements reveal insights into the impact of turbulent wind on loads experienced by parabolic trough solar collectors. Solar Energy, 280, 112860.‏ https://doi.org/10.1016/j.solener.2024.112860.
[84]. Ritter, K. A., Prilliman, M. J., Chambers, T. L., & Raush, J. R. (2018). Maintenance of a small-scale parabolic trough concentrating solar power plant in Louisiana. International Journal of Sustainable and Green Energy, 6(6), 104.‏ doi: 10.11648/j.ijrse.20170606.12.
[85]. Talayero, A. P., Llombart, A., Casado, A., & Melero, J. J. (2018). Operation and maintenance in solar plants: eight study cases (No. ART-2018-113439).
[86]. Schramek, P., & Mills, D. R. (2003). Multi-tower solar array. Solar Energy, 75(3), 249-260.‏ https://doi.org/10.1016/j.solener.2003.07.004.
[87]. Hepbasli, A. (2008). A key review on exegetic analysis and assessment of renewable energy resources for a sustainable future. Renewable and sustainable energy reviews, 12(3), 593-661.‏ https://doi.org/10.1016/j.rser.2006.10.001.
[88]. Garcia-Vallvé, D., et al. (2023). “Environmental life cycle assessment of parabolic trough CSP plants.” Cleaner Energy Systems, 3, 100045. http://dx.doi.org/10.1021/es1033266.
[89]. Moss, R., Shire, S., Henshall, P., Arya, F., Eames, P., & Hyde, T. (2018). Performance of evacuated flat plate solar thermal collectors. Thermal Science and Engineering Progress, 8, 296-306.‏ https://doi.org/10.1016/j.tsep.2018.09.003.