Power-to-methane (PtM) is a potential solution for the storage of excess renewable power and it is a source of low carbon gaseous fuel . The interest in PtM is supported by the fact that the product, methane (CH 4 ), can be utilized in the existing natural gas infrastructure. For example, the EU has a network of approx. 2 million km of transmission and distribution with 800 TWh of underground storage for natural gas . PtM can be applied for the conversion of industrial and/or biogenic CO 2 to CH 4 . Overall, application of PtM can integrate the renewable power grid with biomethane/nautral gas grid, which will offer flexibility to the electricity grid while aiding decarbonization of other sectors . It is estimated that by 2050 about 150 TWh (14 bcm natural gas equivalent) of PtM could be produced in the EU using biogenic CO 2 captured from biogas plants combined with locally produced H 2 using electricity from solar and wind power . The application of PtM at a biogas plant is also a substitute for the conventional biogas upgrading process, where CO 2 is removed from the biogas to increase its heating value. Whereas, using PtM the CO 2 is utilized to produce CH 4 that increases the heating value and the overall CH 4 output from biogas plant.