The present study analyzed the power and heat supply of a small-scale greenhouse by a photovoltaic thermal (PV/T) system while using three greenhouse coverings (glass, plastic and polycarbonate) and four water mass flow rates (0.016, 0.025, 0.033 kg/s and no-flow), with or without a solar tracker. The electrical efficiency results for PV (without mass flow) and PV/T (0.016, 0.025 and 0.033 kg/s) states indicated that the application of the PV/T system enhanced electrical efficiency by 21.5, 28.4 and 36.84% for the glass glazing, by 15.28, 25 and 34.79% for the plastic covering, and by 19.82, 26.67 and 40.25% for the polycarbonate covering, compared to the PV state. The highest overall efficiency was at 0.033 kg/s with 59.9% (glass), 54.56% (plastic) and 47.58% (polycarbonate), and the lowest overall efficiency was at 0.016 kg/s with 41.75% (glass), 32.94% (plastic) and 31.22% (polycarbonate). In general, due to the electrical and thermal energy requirements of greenhouses, it can be said that, in addition to producing electricity by PV/T systems, their significant thermal energy production compared to PV panels can also promote the use of such systems in the future.