Testing and Validation of Innovative on-Site Solar Field Measurement Techniques to Increase Power Tower Plant Performance: The LEIA Project

The LEIA project aims to contribute to the development of the next generation of central receiver power plants focusing on validating a combination and integration of pre-commercial solar field control and O&M solutions for the central tower receiver technology using molten salts, as the most promising cost-effective solution with the highest market penetration potential. To effectively remove the existing technical and industrial barriers to optimize central receiver and heliostat field operation & maintenance and thus to improve overall CSP performance, the following innovations are being developed: 1) Smart heliostat field control, 2) Smart control systems, 3) Solar Field Operation and Maintenance control strategies. These developments will be tested and demonstrated in three flagship operational environments: a) Cerro Dominador (Chile), b) CIEMAT-PSA (Spain), and c) CENER-Tudela (Spain)

Nowcasting System Based on Sky Camera Images to Predict the Solar Flux on the Receiver of a Concentrated Solar Plant

As part of the research for techniques to control the final energy reaching the receivers of central solar power plants, this work combines two contrasting methods in a novel way as a first step towards integrating such systems in solar plants. To determine the effective power reaching the receiver, the direct normal irradiance was predicted at ground level using a total sky camera, TSI-880 model. Subsequently, these DNI values were used as the inputs for a heliostat model (Fiat-Lux) to trace the sunlight’s path according to the mirror features. The predicted valuex of flux, obtained from these simulations, differ of less than 20% from the real values. This represents a significant advance in integrating different technologies to quantify the losses produced in the path from the heliostats to the central receiver, which are normally caused by the presence of atmospheric attenuation factors

Intercomparison of opto-thermal spectral measurements for concentrating solar thermal receiver materials from room temperature up to 800 °C

International audienceAn intercomparison of opto-thermal spectral measurements has been performed for some relevant receiver materials in concentrating solar thermal applications, from room temperature up to 800°C. Five European laboratories performed spectral measurements at room temperature, while two laboratories performed infrared spectral measurements at operating temperature up to 800 °C. Relevant materials include Haynes 230 (oxidized, Pyromark 2500 and industrial black coating) and silicon carbide. Two key figures of merit were analyzed: i) solar absorptance αsol at room temperature, over the spectral range [0.3 – 2.5] μm, ii) thermal emittance εth(T), over the common spectral range [2-14] μm, derived from spectral measurements performed from room temperature up to 800 °C.Oxidized H230 reached an αsol value of 90.9±1.0%. Pyromark 2500 reached an αsol value of 96.3±0.5%, while the industrial black coating achieved an αsol value of 97.0±0.4%. Silicon carbide reached an αsol value of 93.5±1.1%. Low standard deviations in αsol indicate reproducible measurements at room temperature.For oxidized H230, the εth,calc(T) value varied from 55% at room temperature up to 81% at 800 °C. For Pyromark 2500 and the industrial black coating, εth,calc(T) fluctuated between 90% and 95%, with a weak temperature dependence. For silicon carbide, εth,calc(T) varied from 70% at room temperature up to 86% at 800 °C. The typical standard deviation among participating laboratories is about 3%. εth,meas(T) values derived from spectral measurements at operating temperature were consistent within a few percentage points in comparison to εth,calc(T) values derived from spectral measurements at room temperature