ABSTRACT
Geothermal energy is the internal heat of the earth that has accumulated in hydrothermal systems or in dry rocks within the earth's crust, in amounts which constitute energy resources. Lack of global standardization can be caused also by a different understanding of what are "geothermal energy" and "geothermal resources". Terminology must cover both the fundamentally geological nature of geothermal resources and the practical technological and economic aspects of resource exploitation to remain understandable to the broad community as well as non-specialists. In September 2014, the International Geothermal Association (IGA) and the United Nations Economic Commission for Europe (UNECE) signed a Memorandum of Understanding (MoU) to develop a globally applicable harmonized standard for reporting geothermal resources. Additionally, the IGA Resources and Reserves Committee actively engages in matters related to the global standardization of geothermal terminology, methods of geothermal resources and reserves estimation, and classification systems for geothermal potential.
