The purpose of this work is to give a general overview of the main regulatory mechanisms and of the key support schemes adopted by EU Member States to sustain the transition of the energy system towards a zero-emission economy. In this work, the focus is on energy systems integration and the role of the relative technologies in the achievement of the environmental targets. We analysed the regulatory and policy context of three EU Member States: Belgium, Denmark and the Netherlands, trying to provide a general view of the main characteristics influencing the investments by network operators and by other energy players.