IN-POWER European project (GA 720749) aims at developing and integrating new innovative material solutions into concentrated solar technology to increase the efficiency while simultaneously decreasing the energy production cost. These advanced material solutions consist of (1) High reflectance, tailored shapes, self-healing and anti-soiling coated, light glass-free smart mirrors, (2) Optimized and lighter mirror support structure, (3) High-operational-temperature absorber coating in new vacuum-free-designed receiver. (4) Novel modular solar field architecture and design achievable by these new components. Having the identical low associated environmental impact, this promising technology is expected to decrease the land use by four-time. (5) high-operating-temperature thermal storage materials (TES) that will guarantee up to three-time increase in thermal capacity respect to standard TES, depending on Heat Transfer Fluid (HTF), also leading to the reduction of thermal storage system size. IN-POWER will validate these novel functional materials and new manufacturing processes will guarantee decrease in Levelised Cost of Electricity below 0.10 €/KWh beyond 2020 by validating these technologies in Lineal Fresnel Collector and Parabolic through Collector pilot plants under 2100-2700 kWh/(m²a). IN-POWER consortium is composed by 10 partners from different EU countries and type of organizations guarantying the covering of all the developments, from lab scale to validation in demosites. Currently the most widely used reflective coatings are silver and aluminum in polymer films, which in the case of the glass substrate are adhered on the back side, using several additional layers to protect the film. One of the main problems of this configuration is the penetration of moisture on the sides, thus oxidizing the silver layer progressively. In the case of metal substrates, the polymer sheets or films are adhered by the front face, so that they deteriorate quickly, due to the poor weather resistance, thus losing reflectivity in short- term.
The reflective coating to be used in IN-POWER is based on the direct application of the reflective metal on the front face of the reflecting substrate. Through PVD application, the mirror will achieve a high reflectivity property with first silver reflective surface with high homogeneity. The application of previous and posterior treatments (based on chemical bonding and PECVD) to the application of reflective metal, buffers the differences on thermal expansion coefficients, will ensure the durability (preventing delamination) and the high reflectivity values.
The technical KPI expected to achieve with PVD coating:
- Hemispherical reflectivity at 660 nm: 0.96
- Hemispherical reflectivity average in the range of 450 to 1350nm: 0.95
- Specular reflectivity at 660 nm: 0.95