The Geothermal Training Programme was established in the shadow of the oil crisis, when nations were looking for new and renewable energy sources in order to reduce dependence on hydrocarbons, in particular oil with its rapidly escalating prices. The current situation is somewhat similar in the sense that the international community is looking towards renewable energy sources as an alternative to fossil fuels in order to reduce emissions of greenhouse gases.

The development of geothermal resources requires a group of highly skilled specialists from a number of disciplines of science and engineering. Because of its diversity, geothermal energy has not been taught as a specific subject at universities. The training of geothermal specialists has mainly taken place on-the-job within companies and institutions. International geothermal schools have contributed significantly in the transfer of geothermal technology, especially for the benefit of lower- to middle-income countries.

The first official statement on establishing a UNU geothermal institute in Iceland was made in 1975 when the United Nations University (UNU) had just been established. After a first proposal in 1976, and an international workshop in 1978, the Government of Iceland decided in October 1978 to ask Orkustofnun (the National Energy Authority - NEA), to sign an Agreement on Association with UNU and establish the United Nations University Geothermal Training Programme (UNU-GTP).  The Programme was a cooperation between the United Nations University (UNU) and the Government of Iceland.

The UNU-GTP operated in Iceland under the UNU brand from its establishment in 1979 until 31 December 2019, when UNU-GTP and UNU decided to part ways.  As of 1 January, 2020 GTP joined hands with the other three training Programmes in Iceland (Fisheries Training Programme, Land Restoration Training Programme, and Gender Equality Studies Training Programme) to form GRÓ: the Centre for Capacity Development – Sustainable Use of Natural Resources and Societal Change in Iceland.  The Geothermal Training Programme was hosted by the National Energy Authority (Orkustofnun) since its establishment until 1. February 2021 when Iceland GeoSurvey - ISOR took over as the host institute.  

The first annual training session of the UNU-GTP started in May 1979 with two UNU Fellows from the Philippines. Since then, a group of scientists and engineers from energy agencies and research organizations as well as universities in lower- to middle-income countries, have come to Iceland every spring to spend six months in highly specialized studies in geological exploration, borehole geology, geophysical exploration, reservoir engineering, borehole geophysics, chemistry of thermal fluids, environmental science, geothermal utilization, drilling technology, and project management and finances.