The idea to study in deep PCM materials, their behavior and possible applications was born between in 2015 during the evaluation of an action to improve energy efficiency at an industrial company, which have a large dispersion of heat difficult not recoverable with traditional solutions. This research has led the PCM to be known as a means of thermal energy accumulation and from that moment on it began a deeper study of these materials and their possible applications. After a year of work and awareness of the benefits that PCMs can bring to thermal storage, as confirmed by the global trend in this area, i-TES has come to life.