Effect of flow channel dimensions on the performance of a box-frame photovoltaic/thermal collector

The hybrid photovoltaic/thermal (PV/T) collector technology is a new trend in solar energy application. For the thermal absorber, a box-frame water-channel design is able to enhance better heat transfer between the solar cells and the liquid coolant, thereby improving the combined electrical and thermal performance of the collector. This article reports the findings of the effect of water-flow channel dimensions on the energy performance of a box-frame PV/T collector design. A mathematical model of this PV/T collector system was first developed. Dynamic simulation results the authors obtained show that both the number and the height of the water-flow channels can significantly affect the collector performance. With a reduction in the channel height and an increase in the number of channels per unit width, better convective heat transfer between the working fluid and the channel wall can be achieved. This improves both the thermal and the electrical efficiencies of the collector. However, this also leads to an increase in the friction loss at the water circuit and, therefore, more pumping power is required. The optimal designs are discussed.