Design and Performance Optimization of Future Concentrated Solar Power Plants for Long-Duration Thermal Energy Storage: A Case Study

Abstract

The development of long-duration thermal energy storage materials has become crucial for improving the performance of Concentrated Solar Power (CSP) plants. Therefore, identifying suitable materials that meet various criteria—such as their properties, their impact on overall plant performance, and their influence on the levelized cost of energy—is essential. In this study, we focused on optimizing the performance of a 50 MW, two-tank, Parabolic Trough Concentrating CSP plant, using the same parameters as the ANDASOL-1 plant. Nine different materials were tested as heat transfer fluids and storage mediums, aiming to achieve ultra-low energy capacity costs of less than 10 Cent$/kWh and a long-duration thermal energy system (10 hours or more). We examined the system's performance in the Tamanrasset region of Algeria under current geographical conditions, considering two criteria: radiative cooling systems and power purchase agreement prices. The results of this study indicate that, when the charging and discharging duration reaches 13 hours, the levelized cost of energy drops to 9.91 Cent$/kWh with the direct two-tank TES mode using Caloria HT43 molten salt as the material.