Large-Area Si-Cell Encapsulation for Concentrator Systems: Review of Critical Points and New Proposal for the Third Generation of Euclides

Solar concentrators based in large-area Si-cells have been always dealing with the same difficulty: how to encapsulate cells into receivers. Concentration cells have to be cooled in order to avoid high operating temperatures, but in the case of large-area cells additional problems exits due to their weaker mechanical properties. A new solution for the third generation of EUCLIDES is proposed: using an alumina insulator glued to the cell and aluminium substrate that provides a high thermal performance and reduces the thermal drop between materials. Receivers of two levels of concentration have been developed for cells up to 116times102 mm², 40X and 20X, achieving efficiencies of 17.4% and 16.6% and series resistance values of 5.23 mOmega (40X) and 5.91 mOmega (20X). EUCLIDES III is being installed in the context of the IDEOCONTE project and will be finish by September 2006