Aggregated flexibility from multiple power-to-gas units in integrated electricity-gas-hydrogen distribution systems

This work proposes a multi-energy vector framework to quantify the aggregated flexibility envelope from distributed energy resources (DER) including multiple power-to-gas (P2G) units. Aggregated flexibility (with respect to a reference node) is evaluated via the nodal operating envelope (NOE). The proposed framework deploys an optimization approach while modeling electricity and gas networks constraints and their interdependency via P2G units. The gas network model is equipped with hydrogen tracking to quantify the changes in the molar composition resulting from hydrogen injection at multiple nodes. The methodology is applied to a real distribution system and results demonstrate that overlooking gas network constraints leads to P2G units' flexibility contribution overestimation. Furthermore, simultaneous operation of P2G units might be feasible from electricity network perspective but infeasible when considering the maximum hydrogen concentration to meet gas quality standards. This could be achieved if P2G units' location is properly chosen and/or gas quality standards are amended.