Due to fossil fuel shortages and environmental concerns, alternative energy systems have been developed as an economic and environmentally beneficial alternative. The most potential alternative energy source is solar. Before commercialization, solar thermal systems must be more efficient and effective. Increased heat transfer rate and performance parameters are improved with nanofluids. Nanofluids are sophisticated liquid mixtures with nano-sized solid particles suspended. Aluminum Oxide (Al2O3) nanoparticles in water as nanofluids are used to test a Glass Fiber Reinforced Parabolic (GFRP) parabolic solar collector. Particle volume concentrations of 0.02, 0.06, and 0.09% were tested. Thermal conductivity, specific heat, and heat transfer coefficient of nanofluid at varied concentrations are examined. Thermal conductivity increases with concentration, whereas specific heat and heat transfer coefficient decrease. Efficiency is highest at 12.30–13.30 PM. Al2O3 nanofluid at 0.02, 0.06, and 0.09% concentration increased collector instantaneous efficiency by 5.4%, 7.9%, and 14.8% respectively, which enhances the solar energy efficiency for various solar thermal systems. Calculations of temperature distribution at different times of day were made in ANSYS 15.0 and compared to experimental measurements.