Renewable energy systems represent a milestone of third millennium applied scientific research. As a viable, economic and environmentally friendly alternative to the solid electrolytes currently used in dyesensitized solar cells (DSSCs), here we propose a biopolymer derived from seaweeds, which undergoes a process of selective carboxylation to improve its transport properties. Subsequently, a chemometric approach is used to tune the amount of salts and additives, and the highest ever measured ionic conductivity for a biopolymeric solid electrolyte has been reached (5.53 . 10(-2) S cm(-1)). To make this material suitable for DSSC application, an innovative sublimation process has been developed to allow a molecule-by-molecule activation of the electrolyte, and an efficiency of 2.06% (stable in aging tests) was measured in a first device prototype. Green chemistry, low cost materials, multivariate-based preparation methods and activation via spontaneous sublimation make this investigation a concrete starting point for the new generation of solid electrolytes for DSSCs. (C) 2014 Elsevier Ltd. All rights reserved.