Author/Authors :
John W. Lund، نويسنده , , Derek H. Freeston، نويسنده ,
Abstract :
The worldwide application of geothermal energy for direct utilization is reviewed. This paper
attempts to update the previous survey carried out in 1995 (Freeston, 1995) and presented at the
World Geothermal Congress 1995 in Florence, Italy. For each of these updates since 1975, the
recording of data has been similar, but not exactly the same. As in 1995, an eort was made to
quantify geothermal heat pump data and the investment in geothermal energy development.
Final update papers were received from 60 countries, of which 55 reported some form of geo-
thermal direct utilization. Three additional countries were added to the list based on other
sources of information. An estimate of the installed thermal power at the beginning of 2000
(1995 values in brackets) from the current reports is 15,145 MWt [8664 MWt] utilizing at least
52,746 kg/s [37,050 kg/s] of ¯uid, and the thermal energy used is 190,699 TJ/yr [112,441 TJ/
yr]. The distribution of the thermal energy used by category is approximately 42% for bathing
and swimming pool heating, 23% for space heating, 12% for geothermal heat pumps, 9% for
greenhouse heating, 6% for aquaculture pond and raceway heating, 5% for industrial appli-
cations, 2% for other uses, and less than 1% each for agricultural drying, snow melting, and air
conditioning. The reported data for number of wells drilled was 1028, the work by professionals
over the ®ve-year period was 3363 person-years, and the total investment over the same ®ve
years was 841 million US$, indicating minimum values. # 2001 CNR. Published by Elsevier
Science Ltd. All rights reserved.
Keywords :
low enthalpy , Spas , balneology , Space heating , aquaculture , Crop drying , Greenhouses , Heatpumps , industrial , Snow melting , Direct use