Energy from deep geothermal resources plays an increasing role in many countries in their efforts to increase the proportion of renewables in their energy portfolio. Deep geothermal heat and electric power have a high load factor, are sustainable and environmentally friendly. Even regions with moderate geothermal gradients are today considered to have a high geothermal potential, however, deep drilling is required to reach temperatures high enough for economic exploitation of the geothermal reservoir. The safe, sustainable, and economic development of deep geothermal resources, also in less favourable regions, faces a number of issues requiring substantial research efforts: (1) The probability of finding an unknown geothermal reservoir has to be improved; (2) Drilling methods have to be better adapted and developed to the specific needs of geothermal development; (3) The assessment of the geothermal potential should provide more reliable and clear guidelines for the development; (4) Stimulation methods for enhanced geothermal systems (EGS) have to be refined to increase the success rate and reduce the risk associated with induced seismicity; (5) Operation and maintenance in aggressive geothermal environments require specific solutions for corrosion and scaling problems; (6) Last but not least, emerging activities to harness energy from supercritical reservoirs would make significant progress with qualified input from research. We want to address scientists that deal with geophysical, geological and geochemical investigations regarding potential geothermal reservoirs, as well as scientists who model geothermally relevant reservoir parameters that influence the potential performance and long-term behaviour of Geothermal power generation. We invite contributions dealing with information systems, technological investigations, improvement of deep drilling methods, numerical and analytical modelling of hydraulic and thermal properties, and contributions that aim at a better understanding of physical, hydraulic and chemical processes during the operation of geothermal power plants.