doi:10.1016/j.renene.2023.03.125engHerrando, MaríaFantoni, GuillermoCubero, AnaSimón-Allué, RaquelGuedea, IsabelFueyo, NorbertoNumerical analysis of the fluid flow and heat transfer of a hybrid PV-thermal collector and performance assessmentART-2023-133844In recent years, new materials and absorber configurations have been proposed to improve the performance of hybrid photovoltaic-thermal (PV-T) collectors. This work analyses the fluid flow and the energy performance of an uncovered water-based PV-T collector with a roll-bond thermal absorber. A detailed CFD model was developed and the results were compared with the experimental performance features provided by the PV-T manufacturer. The fluid flow results show uneven flow distribution among the roll-bond microchannels which leads to areas with larger PV cell temperatures and thus a lower electricity generation. The PV-T collector layers were also modelled using the energy transfer equations layer-by-layer. The model was run for several water inlet temperatures and water flow-rates to obtain the thermal performance curve. The results show that the electrical efficiency of the PV-T collector is 14.5–10.3% larger than for a PV-only system for water inlet temperatures of 20–30 °C, respectively. The developed CFD model reproduces accurately the thermal performance of the PV-T collector, with a maximum error of 6.5% for inlet water temperatures of 20–60 °C. Therefore, this model can be used with confidence to propose alternative designs that achieve a homogeneous temperature distribution in the PV layer and improve the overall PV-T collector performance.2023http://zaguan.unizar.es/record/12646810.1016/j.renene.2023.03.125http://zaguan.unizar.es/record/126468oai:zaguan.unizar.es:126468info:eu-repo/grantAgreement/ES/MCIU-FEDER/RTC-2017-6026-3info:eu-repo/grantAgreement/ES/MCIU/IJC-2020-043717-IRenewable Energy 209 (2023), 122-132byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess