Thermal performance of a hybrid photovoltaic-thermal collector with a modified absorber

Hybrid collectors offer unique advantages over photovoltaic modules and solar water heaters, however, they have yet to receive comparable mainstream implementation. Two problems hybrids have faced are high cost and the inability to match the thermal performance of solar water heaters. In this study, a hybrid photovoltaic thermal collector with a modified absorber was built and tested in Jamaica. The absorber was modified with the aim of increasing heat transfer from the PV cells to the thermal fluid. A 3D dynamic numerical model was used to conduct parametric analyses for optimization purposes. Based on the results of the model, a prototype was hand built as well as a solar water heater and a PV module. A stand test facility was constructed to facilitate the simultaneous testing of the three collectors. The hybrid collector was able to heat 7.5L of water from 26.4°C to 45°C in ~5.5 hours while the solar water heater was able to do the same from 28.4°C to 47.6°C in ~4.5 hours. The hybrid collector managed an average operating temperature of 51.6°C, 5.5°C cooler than the 57.1°C of the PV module. This cooler operating temperature theoretically corresponded to a longer lifespan and a 2.5% increase in electrical output from the PV cells. The results thus far are promising and hint at the immense possibility for the thermal performance of hybrids to be improved.