The first generating unit of the Yangjiang nuclear power plant in south China's Guangdong Province has begun commercial operation, authorities announced Wednesday.

The No. 1 unit finished 168 hours of trial operation on Tuesday, according to the Yangjiang Nuclear Power Co., Ltd. under China General Nuclear Power Group (CGN).

Construction started in mid-December 2008, and has cost some 73.2 billion yuan (11.8 billion U. S. dollars). The unit began trial operation on Dec. 31 last year.

CGN spokesman Hu Guangyao said the No. 2 unit of Yangjiang nuclear power plant is being tested, the No. 3 unit is having equipment installed and tested, and the No. 4, 5, 6 units are still being constructed.

The six units will generate 48 billion kwh of electricity a year after going into commercial operations around January 2019, according to Yangjiang nuclear power company.

So far, China has six operating nuclear power plants. Eighteen generating units have began commercial operations with a total installed capacity of 15.86 million kw.