The decarbonization targets set by the “European Green Deal – fit for 55” for 2030 are partially modified by the actions formulated in the REPowerEU plan. The plan shifts the share of renewable energy from 40 percent to 45 percent and promotes a strong increase in the production of renewable fuels, particularly biomethane and hydrogen.

To date, the term flexibility is mostly associated with the flexibility of the electricity grid, and studies on operational, management, and market arrangements are largely aimed at developing “flexibility services” for the electricity grid itself. Looking forward, the overall European energy system will be characterized by the integration of different energy networks (electric, thermal, gas), and its resilience will require not only system-specific flexibility, but more general flexibility that includes the possible interactions between different coupled energy systems.

The report summarizes an overview of “Carbon-neutral” gas production technologies (biogas, biomethane, and hydrogen) fueled by nonprogrammable renewable sources, which have the potential to contribute to the implementation of the European REPowerEU plan, as well as to the resilience of the European integrated energy system. Among them, anaerobic digestion of biomass combined with the transformation of biogas into biomethane has become considerably widespread in European countries. In addition, electrolysis is proposed as the best candidate for the production of green hydrogen.

The optimal exploitation of the full potential of the two technologies will enable a broader integration between the electricity and gas sectors. Although the coupling of the two sectors entails operational flexibility for both, there is a need for increased monitoring of the gas grid and profound changes in the way it operates. A configuration of the two green gas production technologies is proposed at the end of the report as representative of the coupling between the electricity and gas sectors.