Energy storage is one of the key factors to reach EU aims to be climate-neutral by 2050, with a net-zero greenhouse gas (GHG) emissions economy. The decarbonisation and the transition to clean energy sources, together with the improvement of the energy efficiency, will bring to a severe change in the employed energy systems. The potentialities of thermal energy storage (TES) systems, able to provide electricity load shifting by mean of energy conversion and storage, can help in developing flexible energy systems, managing the intrinsically intermittent nature of renewable energy sources. ECHO solutions will be flexible and adaptable to different end-user requests, in terms of charging (and discharging) power, dimension and types of energy sources... ECHO project will provide a key tool for thermal energy storage in the context of sector coupling and provision of flexibility of demand. ECHO system will be adapted to the different energetic scenarios. Additionally, its modularity will..