Gas molecules encapsulated in a water matrix, i.e., gas hydrates, are found in confined pressurized environments, such as on the sea floor of Earth or the interiors of icy bodies surrounding our Solar system. They are suitable for the storage of light energy carriers such as methane or hydrogen. Especially, hydrogen hydrates offer carbon-free high energy content per unit mass (~14 MJ·kg-1). They are promising functional materials for clean energy storage and offer alternative to the current cryo-compressed hydrogen storage technology. In this proposal, we aim to explore the phase diagram and, therefore, determine the melting curves of C2 (H2O·H2) and recently discovered C3 (H2O·2H2) hydrogen-filled ices along with their stability ranges with respect to decomposition into H2O and H2.