| Abstract |
Geothermal energy has been used for electric power production, starting experimentally in Italy in 1904, and with the first commercial plant in 1913 at Larderello. This followed with plants in Mexico, New Zealand and at The Geysers in the United States. At present there are about 8,000 MWe installed in 22 countries, producing about 50,000 GWh/yr. Direct heat utilization has a much longer history, with early uses of hot springs at least 10,000 years ago. Early documentation of direct-use has not been consistent, and often left out key countries. The first reliable report on this use appeared in the 1970s. Today there are reported uses in at least 58 countries, with an estimated installed capacity of 15,200 MWt and annual production of 53,000 GWh. The capacity increase over the past 30 years has been 8.6% for electricity production and 9.7% for direct-use, compounded annually. The energy savings amounts to and equivalent 26.7 million tonnes of fuel oil and 23.8 million tonnes of carbon annually. Recommendations for the 2008 Summer Olympics in Beijing include utilization of the potential high temperature geothermal resource for binary power generation and direct cooling; the intermediate temperature geothermal resource for heating domestic hot water (showers, kitchen use, tap water) and swimming pools; and the low temperature resources for heating and cooling with geothermal heat pumps. |