of Zurich are treated, with a total biogas production of 1400 Nm 3 /h. The biogas plant already produces biomethane by upgrading and currently vents the CO2 waste stream . In the designed process, this CO2 stream is directed to a storage tank, which operates as a seasonal storage, allowing the utilisation of CO2 at the times when renewable H2 is available. A photovoltaic system is designed to provide over the year sufficient H2 to convert the entire CO2 stream (560 Nm 3 /h in average). The H2 production section includes a battery and a H2 tank with peak shaving purposes (capacity defined to ensure the electrolyser continuous operation in summer). In the case study, both methanol and methane are assessed as energy carrier molecules. These molecules are transported to the centralised storage site and kept in liquid form or as compressed gas, respectively. The final products, electricity or H2, are then produced at the centralised location, as already discussed in the previous paragraphs. The case study allows understanding the required CAPEX and OPEX, as well as the dimensioning of the various units in relevant conditions. Additionally, the reference to a real scale plant helps in the determination of the cost of generating negative emissions by coupling waste management system and mobility.