Poly (ethylene-co-vinyl acetate) (EVA) is the major polymer used for photovoltaic (PV) modules encapsulation. Its degree of cross-linking (related to its gel content) is taken as a major quality reference. Differential Scanning Calorimetry (DSC) has been proven to be fast and effective but is to determine the gel content, however, destructive for the PV module. With the aim to develop a non-destructive quality assessment tool, a detailed discussion on the DSC thermogram of EVA PV encapsulant is presented here. A possible path towards a fast and non-destructive method for determing EVA gel content is proposed based on the DSC analysis.