Parametric influence and efficiency assessment of water-cooled photovoltaic thermal PV/T absorber designs

The present study investigates photovoltaic thermal absorber designs by developing a computational model. A novel spiral circular photovoltaic absorber and spiral rectangular photovoltaic absorbers were designed with water as a heat transfer medium and compared with traditional PV systems without an absorber. The developed models aimed to study the influence of solar radiations, absorber geometry, flow pattern, water and flow rates on parameters such as PV panel temperature, outlet water temperature, the electrical, thermal and overall performance of the PVT system. The test was conducted under constant inlet water temperature and water flow rate ranging from 0.03 kg/s to 0.06 kg/s and 3-level radiation of 600 W/m2, 800 W/m2, and 1000 W/m2 on a multi-crystal photovoltaic module. It was seen that water cooling proved beneficial over traditional PV systems to achieve lower PV temperature and better electrical efficiency. The comparative result shows that spiral rectangular photovoltaic absorber design exhibits better electrical and thermal performance than spiral circular design. The maximum electrical efficiency of 14.32 % was noted at a ceiling water flow of 0.06 kg/s, whereas it was 12.80 % and 12.30 % for circular spiral design and no absorber PV system. The highest recovery of heat from the flipside of PV module was achieved from spiral rectangular and reached to 63.56 % while it was limited to 56.82 % for the circular spiral design. Hence study concluded that spiral rectangular photovoltaic absorber design demonstrated better desirable absorber characteristics. The experimental work is performed with superior absorber and the results are validated with numerical results. It was found that numerical and experimental results are in good harmony and relative error is limited to less than 10 %.