Enagás, GRTgaz, Teréga and REN Transmission System Operators have signed the initiative Green2TSO, aimed to transform the gas grid into H2 grid through open innovation. The Green2TSO project is aligned with the European Commission’s initiatives Green Deal, fit for 55 and REPowerEU, underlining the role of European TSOs to become carriers of H2 as an efficient, safe and clean energy vector, using its large-scale infrastructure.