GUANGZHOU, June 5 (Xinhua) -- An 18-megawatt semi-direct drive offshore wind turbine was successfully installed in a coastal test base in the city of Shantou, south China's Guangdong province Wednesday.

It is the world's largest installed offshore wind turbine, according to its developer, Dongfang Electric Corporation.

The rotor diameter of the wind turbine is 260 meters, and the swept area is more than 53,000 square meters, which is equivalent to the size of 7.4 standard football fields.

Its average annual power generation is up to 72 million KWH, enough to meet the electricity demand of about 36,000 households for a year while saving more than 22,000 tonnes of standard coal and reducing carbon dioxide emissions by more than 59,000 tonnes per year, according to the company.