Geothermal sustainability in Europe and worldwide

This paper presents and discusses the current state of developments in harnessing geothermal power for medium and large-scale generation of electricity and for space heating worldwide. Potential and current developments and probable and possible developments both in developed and developing countries in near future and long term are reviewed. Topics discussed include enhanced power cycles for enhancing geothermal sustainability, deep drilling projects in Iceland - exploration of deep unconventional geothermal resources, the phases of development of a 400 MWe generation capacity geothermal scheme in NE Iceland, geothermal development in reducing CO₂ emissions, and perspectives on the future of geothermal energy in the United States. Technology of harnessing geothermal power now and future is also discussed. The economics, availability, and reliability of geothermal plants are reviewed.