Barcelona receives advice on how to improve its biowaste collection system to produce biomethane

The 3rd Peer Review Session of the Biocircularcities project was held on 23-24 May 2023. It follows the 3rd round of Local Living Labs that brought together AMB’s local stakeholders last March. This third Peer Review session took place in presential mode for the first time, bringing together 6 external experts. In particular, the experts discussed the environmental impact assessment and policy recommendations for the potential implementation of an improved collection system in the Metropolitan Area of Barcelona in order to produce biomethane.

Experts discussed the opportunity to focus the life-cycle assessment on one tonne of biowaste generated, rather than on the separately collected waste, so that the benefit of diverting biowaste from disposal could be taken into consideration. They also explained the importance to take into consideration the potential increase of cost incurred when switching from a bring to a door-to-door system, due to longer, more human resource-intensive collection routes. Experts highlighted the relevancy of biogas and biomethane to generate revenues, when compost requires to be of high quality to have economic value. Upgrading biogas to biomethane can also lead to a 40% increase of revenues. However, these figures also largely depends on the selling price and possible subsidies for biomethane, that are generally set at national level. The economic balance is also heavily dependent on the selected biogas upgrading technology and capacity.

The discussions of the session additionally focused on the policy recommendations identified by ENT to support the transition from the current situation to the improved municipal biowaste value-chain. Among the key drivers and recommendations, the following ones were mentioned: financial support for investment, the need to secure a good quality substrate for the next 20 years (the time for the plant to be amortised), and the price of biomethane in comparison with the price of electricity needed to produce it, as well as the access to the gas grid. One key barrier is the fact that bioenergy production is still too high compared to fossil fuel. Therefore, incentives to decrease the cost of bioenergy or to increase the cost of fossil-based energy are necessary. Carbon footprint valuation as supported by the International Sustainability and Carbon Certification could also contribute to the transition.