This document discusses using nanofluids to enhance the efficiency of a parabolic trough solar thermal power plant. Nanofluids are liquids containing nanoparticles that have higher thermal conductivity than ordinary fluids. The document analyzes how nanofluids can be used to help maintain optimal thermal process parameters in a solar thermal plant, whose solar radiation input varies daily and seasonally. It also summarizes different types of solar collectors, including parabolic trough collectors, and reviews heat transfer properties of nanofluids and their potential to increase solar plant efficiency. The conclusion is that a model is developed to accurately calculate thermal efficiency of a parabolic trough collector system based on parameters like inlet fluid temperature and flow rate.