Power-to-methane to integrate renewable generation in urban energy districts

The deployment of distributed energy systems must take place paying attention to the self-consumption of renewable generation. Innovative sector coupling strategies can play that role linking local electricity and gas grids. The present work aims to evaluate the energy and economic feasibility of the Power-to-Methane strategy application in urban energy districts. A residential cluster was considered as a case study. Two PV configurations have been applied to evaluate the Substitute Natural Gas (SNG) production under different renewable excess conditions. Thereafter, the Power-to-Methane strategy was implemented by varying the system's size. Some significant configurations have been compared to each other in terms of energy and economics. Beyond a certain threshold limit, an increase in the photovoltaic size slightly enhances the effectively self-consumed energy. The Power-to-Methane strategy can exploit all the renewable excess once the system is properly sized, almost doubling the potential energy consumption reduction compared to the PV system alone. The SNG production cost is between 100 and 200 EUR/MWh in most configurations, which is competitive with the high natural gas prices on the European market. Therefore, decentralised SNG production can reduce the households' annual expenditures and it can mitigate the energy poverty conditions over the current energy crisis period.