Direct application of geothermal energy: 2005 Worldwide review

This paper is a review of worldwide direct applications of geothermal energy. It attempts to update the surveys presented at and after the World Geothermal Congresses of 1995, 2000 and 2005. Seventy-two countries report direct utilization of geothermal energy. In May 2005, the direct-use projects had an estimated installed thermal capacity of 28,268 MWt. The thermal energy usage is 273,372 TJ/year (75,943 GWh/year), a 43% increase over 2000; the annual compound growth rate is 7.5%. The distribution of thermal energy used by category is approximately 32% for geothermal heat pumps, 30% for bathing and swimming (including balneology), 20% for space heating (of which 83% is for district heating), 7.5% for greenhouse and open-ground heating, 4% for industrial process heat, 4% for aquaculture pond and raceway heating, <1% for agricultural drying, <1% for snow melting and cooling, and <0.5% for other uses. The equivalent annual savings in fuel oil amounts to 170 million barrels (25.4 million tonnes) and 24 million tonnes in carbon emissions to the atmosphere. © 2005 CNR. Published by Elsevier Ltd. All rights reserved