The German government requires states to set aside at least 2% of their land for renewable energy. Despite public support, the specific location of renewable energy installations is often debated. The study presents a new approach to resolving land use competition in the context of energy system transformation. Ground-mounted photovoltaics (GM PV) in a German municipality serves as a case study. Its methodology goes beyond standard socio-scientific methods. The innovation is the model-based spatial assessment of GM PV scenarios with different constraints and suitability criteria based on stakeholder values. The scenarios are a tool for dialogue between renewable energy producers, farmers and environmentalists. To the surprise of stakeholders, even in scenarios with strict constraints, GM PV has considerable potential within the municipal administrative boundaries. There was a consensus that GM PV should be used to achieve the energy transition, preferably after the potential of roofs and sealed surfaces has been exploited, except for a few farmers. The innovative participatory modelling approach, the results and the recommendations allow for a systematic, transparent and fair assessment of the GM PV projects at the community level. It enables responsible land-use planning and improves public acceptance by incorporating stakeholder values into the siting of GM PV projects. The new approach helps to defuse emotionally charged debates and promotes positive public attitudes towards genetically modified crops. It has already attracted considerable interest in other municipalities.