For the future renewable based power systems dealing with the fluctuations and uncertainty of renewable production in a costefficient and secure way will be a big challenge. To address this challenge the integration of electricity, heat, cooling and gas systems has become more important in providing the required flexibility. Among all enabling technologies, power-to-gas (P2G) technology is very promising. It produces hydrogen by using excessive electrical energy from renewable energy sources (RESs) in an electrolyser, whileoptionally combining the hydrogen produced with carbon dioxide to produce methane or other hydrocarbons. Hydrogen will play a key role in facilitating the transition to the future low-carbon (or no-carbon) energy systems. This Special Section on P2G for future renewable based energy systems contains 13 high-quality papers that are relevant to this topic, including modelling, operation, planning and power electronics of integrated energy systems (IES) with P2G.