In a significant advancement for the concentrated solar power (CSP) sector, researchers have unveiled a groundbreaking method for remotely measuring the reflectivity of heliostats—large mirrors that direct sunlight to a central receiver. This innovative approach, termed the “backward gazing procedure,” promises to enhance the efficiency of solar power plants while addressing critical operational challenges.
François Hénault from Université Grenoble Alpes led this research, which was recently presented at the SolarPACES Conference Proceedings. The ability to assess the reflectivity of heliostats during operation is crucial, as it directly influences the energy output and efficiency of solar power systems. Hénault emphasized the importance of this advancement, stating, “Our method allows for real-time monitoring of heliostat performance without interrupting energy production. This is a game changer for maintaining optimal efficiency in solar power plants.”
The backward gazing method operates by capturing four simultaneous images of a heliostat from various vantage points near the thermal receiver. These images are then analyzed using a sophisticated minimization algorithm that determines the reflectance and slope errors of the mirrors. This technique not only provides quantitative reflectivity maps but also accounts for environmental factors such as thermal cycles, soiling, and aging effects that can degrade mirror performance over time.
Preliminary results from tests conducted at the Themis solar tower power plant in Targasonne, France, reveal that this method can achieve reflectivity measurements with a repeatability of about ± 5% Peak-to-Valley (PTV) and 1% RMS. Hénault noted, “These results indicate that we can reliably assess the condition of heliostat surfaces, which is vital for ensuring long-term efficiency and performance in CSP systems.”
The commercial implications of this research are substantial. As the demand for renewable energy sources continues to rise, improving the operational efficiency of solar power plants becomes increasingly important. By enabling operators to monitor and maintain heliostat performance remotely, this method could lead to significant cost savings and enhanced energy production. It also opens the door for more resilient solar infrastructure, capable of adapting to varying environmental conditions.
As the energy sector increasingly pivots toward sustainability, innovations like the backward gazing procedure will play a pivotal role in optimizing solar technologies. This research not only enhances the understanding of heliostat performance but also sets the stage for future developments in the field of concentrated solar power, potentially transforming the landscape of renewable energy generation.
