deep geothermal applications
(Deep) geothermal heat from aquifers or reservoirs can be used directly in hydrothermal heating plants to supply heat demand close to the plant or in a district heating network for several different types of heat (see Chapter 8). Due to the high drilling costs deep geothermal energy is mostly feasibly for large applications in combination with heat networks. It is already economic feasible and has been in use for a long time, where aquifers can be found near the surface, e.g. in the Pacific Island or along the Pacific ring of fire. Also in Europe deep geothermal applications are being developed for heating purposes at investment costs from 500€/kWth (shallow) to 3000 €/kWth (deep), with the costs strongly dependent on the drilling depth. As deep geothermal systems require a high technology level, European cost assumptions were transferred to all regions worldwide.