BEIJING, June 26 (AFP) - Tibet's first major hydroelectric plant, bitterly opposed by the local population, has been officially opened, officials said Thursday.

The facility will use water from the Yamdrok Tso lake, one of Tibet's four sacred lakes.

The four Austrian-made generators will provide 100,000 kilowatts to Lhasa, about 100 kilometres (60 miles) to the north, an official of Tibet's industry and energy department told AFP.

The first generator went on-line Wednesday after 72 hours of tests and the other three will be connected "between now and September," he said.

Tibet suffers severe electricity shortages, and the facility represents Beijing's greatest effort yet to reach its goal of doubling electricity production in the Himalayan region by 2000.

Although necessary, the project angered many ethnic Tibetans who considered it sacrilege. The Yamdrok Tso is believed to shelther Buddhist spirits.

Critics fear the project on the lake, surrounded by high mountains, will be completely drained in a matter of decades by the pumping.

The project is also believed to have drawn bad kharma when construction was halted for months after the deaths of several labourers in an accident in 1995.

According to sources in Lhasa, the official in charge of works is in prison after being found guilty of dealing in materials destined for the project.

To relieve local concerns, the power station management has introduced a system where the station pumps water from the nearby Brahmapoutre river into the lake during the night to maintain its level, the official said.