Geothermal power, heat energy below the earth's surface, is an indispensable source of power to the Tibet Autonomous Region in Southwest China.

Located at the foot of Nyenchen Tanglha Mountain near Lhasa, Yangbajing power station, China's largest geothermal electricity generator, has been supplying power to the Tibetan capital and its surrounding areas for three decades.

Steam is released from a geothermal well in Yangbajing geothermal power plant near Lhasa, Southwest China's Tibet Autonomous Region, August 23, 2007. [chinadaily.com.cn]

Experts in water resources and electricity generation first discovered the rich geothermal resource in Yangbajing in 1975, and concluded that the hot energy could be tapped 300 meters underground. Then an exploration team from the Chinese Academy of Sciences dug the first well and successfully generated electricity.

Since 1977, a number of Chinese and foreign geothermal experts have come to Yangbajing and installed more powerful generators.

The United Nations Development Programme (UNDP) and the Italian government sent technicians and financial resources to Yangbajing power station since July 1982, and with their help, the station was equipped with power generators with installed capacity of 10,000 kilowatts in total in 1985. The Chinese central government has also invested 230 million yuan into Yangbajing until 1990, building it into a station that provides as much as one third of electricity that Lhasa needs.

Lhasa relies on the Yangbajing geothermal station mostly during the winter when hydroelectricity stations don't work.

In 2000 the Japan International Cooperation Agency, a government body, also helped fund the power plant and worked out a plan to exploit geothermal energy deeper into the earth, which enables the power station to work for another 30 years.

Director of the Yangbajing thermal power station Jiao Zhengyi said the Tibet Autonomous Region is rich in geothermal resources but has difficulties in exploiting the power as they are in a remote location compared to other energy stations in China.

During the past five years, it has had an annual electricity output of more than 100 million kw/h. Today Yangbajing is still the largest geothermal power station in the world, with the installed capacity of 24,180 kilowatts.