Geothermal energy is reliable, sustainable and environmentally friendly with less greenhouse emission, and therefore is drawing increasing attention recently due to its role in serving as a complement to fossil fuels and in mitigating global warming. This book presents a diversity of topical case studies in geothermal energy, technology and geology. The collection of topics aims to present recent advances in research and application of geothermal energy systems, including ground source heat pump systems and the environmental pollution control; geological occurrence of the thermal aquifers in north-eastern Slovenia; relationships between fracture zones, flow pathways and mineral precipitation corresponding to an enhanced geothermal system in France; and geological and tectonic framework favouring the occurrence of geothermal systems in Western Anatolia, Turkey.