Abstract: Solar Parabolic Trough Systems (PTS) are highly efficient solar thermal technologies for converting concentrated solar radiation into thermal energy. However, their intermittent energy production, primarily due to variations in solar availability, underscores the necessity for effective thermal energy storage (TES) solutions. Phase Change Materials (PCMs) have emerged as a promising means to store and release thermal energy efficiently. This study focuses on the critical task of optimizing PCM properties to enhance thermal energy storage within Solar Parabolic Trough Systems. The selection and fine-tuning of PCM properties are paramount to achieving superior TES performance. Parameters under scrutiny include the melting temperature, latent heat of fusion, thermal conductivity, and cost-effectiveness. Each of these factors plays a pivotal role in the overall efficiency and economic viability of PCM-based TES systems integrated with PTS. Through a thorough review of existing research and recent advancements in the field, this study sheds light on the profound impact of tailored PCM properties. It demonstrates how optimizing these properties can lead to substantial improvements in energy storage capacity, system efficiency, and overall cost-effectiveness. Such optimizations are crucial not only for enhancing the competitiveness of solar thermal technology but also for promoting sustainable energy utilization. The investigation presented herein underscores the significance of PCM property optimization as a strategic pathway toward advancing solar thermal technology. By maximizing energy storage capacity, minimizing thermal losses, and optimizing cost factors, we can unlock the full potential of PTS, making them more reliable and accessible for meeting the world's growing energy demands. This research serves as a valuable resource for engineers, researchers, and stakeholders working towards the integration of PCM-based TES with solar thermal systems. Ultimately, it contributes to the realization of a cleaner, more sustainable energy future, addressing the urgent need to reduce greenhouse gas emissions and our reliance on non-renewable energy sources