Geothermal Energy Systems The book encounters basic knowledge about geothermal technology for the utilization of geothermal resources. The book helps to understand the basic geology needed for the utilization of geothermal energy, shows up the practice to make access to geothermal reservoirs by drilling and the engineering of the reservoir by enhancing methods. The book describes the technology to make use of the Earth?s heat for direct use, power, and/or chill and gives boundary conditions for its economic and environmental utilization. A special focus is made on enhanced or engineered geothermal systems (EGS) which are based on concepts which bring a priori less productive reservoirs to an economic use. From the contents: Reservoir Definition Exploration Methods Drilling into Geothermal Reservoirs Enhancing Geothermal Reservoirs Geothermal Reservoir Simulation Energetic Use of EGS Reservoirs Economic Performance and Environmental Assessment Deployment of Enhanced Geothermal Systems plants and CO2-mitigation