Development of a Methodology for Quantifying Thermal Losses in Solar Thermal Parabolic Trough Power Plants

Abstract

This thesis presents the development of a data-driven methodology to improve the quantification of thermal losses in parabolic trough solar thermal power plants (PTSTPPs), which constitute the most commercially mature technology within the concentrating solar power (CSP) sector. Accurate modeling of thermal and optical losses remains a critical challenge in CSP simulation tools, which often rely on oversimplified loss models and fixed correction factors. These lead to systematic deviations between simulated and real-world plant behavior, particularly under varying environmental and operational conditions. The methodology introduced in this work focuses on the empirical correction of thermal loss estimations by leveraging operational data from the Andasol 3 CSP plant in southern Spain. A separation strategy is employed to isolate thermal losses from optical influences by analyzing nighttime operation, where no solar input is present. This enables the derivation of a temperature-dependent polynomial correction term, which is fitted to the discrepancy between measured and simulated thermal losses. The resulting correction model is integrated into an existing modular simulation framework and validated across multiple days. The application of the correction significantly improves the agreement between model predictions and measured loss behavior and exhibits temporal robustness. The approach offers a pathway for embedding empirical correction terms into digital monitoring environments, facilitating enhanced anomaly detection, condition assessment, and performance optimization. By bridging the gap between theoretical loss modeling and empirical plant data, this work contributes to more transparent, and physically grounded CSP simulations. Furthermore, it provides a blueprint for future extensions to the loss correction and potential integration into real-time digital twin applications, thereby supporting improved planning, maintenance, and operational strategies in solar thermal power generation.