The deliverable at hand reports on the SONNET city lab in Mannheim which focused on novel governance arrangements to enhance social innovation in energy (SIE) in the district of Neckarstadt-West. The aim of the lab was to develop, test and instigate an organisational governance process, which includes a stakeholder interaction as well as an inner-administrative dialogue and the use of innovative methods to foster dialogue and participation. As part of the lab, different activities were conducted such as design thinking workshops, activities in public and digital spaces to allow for new ways of interaction between local stakeholders as well as for citizen participation in the local energy transition.