Insights into the acceptance of a deep geothermal energy project in Germany through the co-design of scenarios

Unlike solar and wind energy, which have grown significantly over the past decade, the use of deep geothermal energy (DGE) has stagnated in Germany and worldwide. This is despite DGE's significant potential as a reliable, weather-independent source of decarbonised electricity and heat, and despite its political support. However, the high upfront costs, exploration risks, complex permitting processes, environmental concerns, and lack of social acceptance, particularly with regard to the risk of induced seismicity, have hindered its development. This study addresses the prerequisites for the acceptance of DGE by analysing the needs, concerns and expectations of stakeholders regarding its use, based on the principles of procedural and distributive justice. To this end, we developed a co-design method to analyse stakeholders' evaluation criteria and, based on these, design scenarios to identify conditions for success. The results revealed several key findings that are prerequisites for accepting a DGE project. These include the importance of trustworthiness and regional roots of project developers, as well as reliable seismic risk mitigation strategies and energy sharing with local municipalities, for example, through the decarbonisation of district heating. The findings emphasise the importance of procedural and distributive justice, a shared vision and co-designed scenarios for the use of DGE resources and open communication on the feasibility of deep geothermal energy sharing. These findings, along with the co-design method, can be applied beyond the context of Germany's energy transition to other regulatory and cultural frameworks. The authors recommend that developers of DGE projects tailor their projects to the needs, concerns, and expectations of municipalities and their stakeholders and integrate them into the local energy transition context to improve the conditions for acceptance.