The performance of a PV (photovoltaic) module relies heavily on the operating temperature. The aim of the current study was to improve PV performance by passive cooling with nano-coated aluminum fins attached to the backside of the photovoltaic panels. Four identical PV panels were installed side by side for simultaneous measurements. The first one (B) is a basic PV that was used for comparison purposes, the second one (N) PV, which is coated with water-based Al2O3 nano-fluid, the third is finned PV (F), with fins being attached to its backside and the Al2O3 nano-fluid coated fins are attached to the backside of the fourth PV (FN). The hourly electrical generated power by each PV, I-V, and I_V curves for each PV were recorded and stored using I-V Checker. In addition, the backside temperature of each PV and the ambient temperature were measured on an hourly basis using K-type thermocouples; the measured temperature values were stored in a data logger. It was found that the (FN) PV gave the best performance compared to the base unit, with an increase in the generated power by 5.77%, followed by the nano-coated (N) PV with an increase of 2.14% and finally the finned (F) PV with an increase of 0.74%. Furthermore, the PV with the nano-coated fins exhibits the lower temperature 31°C, followed by the nano-coated PV, and finally the fined PV, with the backside average temperature of the basic unit being 39°C.