THERMCAP is a project aimed at the development of modular capsules with phase change materials (PCM) for thermal storage applications in industrial environments. The project is based on an analysis of the state of the art on thermal batteries, encapsulation systems and PCM materials, in order to identify the most appropriate solutions, their limitations and existing opportunities for improvement. From this base, the most appropriate PCM will be selected through a multi-criteria analysis and its properties will be validated by experimental characterization techniques. Subsequently, the project will address the conceptual and detailed design of a modular PCM capsule using 3D modeling, as well as its evaluation through multiphysics, mechanical, and fluid dynamics simulations. The final objective is to obtain an optimized and technically validated design that contributes to the development of thermal batteries with macroencapsulated PCMs, providing an efficient and applicable solution for thermal energy storage.