The world's most powerful offshore wind turbine with an 18-megawatt capacity rolled off the assembly line in Fuqing, southeast China's Fujian province last Friday.

The offshore direct-drive wind turbine has the largest unit capacity and the largest impeller by far in the world.

Consisting of over 30,000 components, the wind turbine has 126-meter-long blades that can sweep an area of 53,000 square meters, an equivalent of 7.5 standard soccer fields. The diameter of the inside of its rotor hub can be as long as 160 meters. The turbine was developed for sea areas with wind speeds of over 10 meters per second. It can also resist typhoons with a wind speed of 80 meters per second.

"As the direct-drive turbines are easy to operate, maintenance-free and capable of large power production, we will use it widely in the far sea," said Ge Hongbing, general manager of Dongfang Electric Wind Power Co.

A single turbine unit can reach 18 megawatts in an environment where the annual average wind speed is 10 meters per second. It generates 38 kilowatt-hours (kWh) of electricity from just one rotation and produces 72 million kWh of clean electricity annually, meeting the annual demand of 40,000 households.

The clean energy it generates annually can save over 20,000 tonnes of standard coal and reduce carbon dioxide emissions by 55,000 tonnes.

The 18-megawatt wind turbine is expected to be mass-produced within the year and installed in coastal areas in China's southeastern coastal areas.

The key components of the turbine, such as blades, rotors, generators, converters and transformers, are developed domestically.

The offshore wind turbines require a higher standard and have higher research and development costs than those used on land. The newly developed wind turbine, built with new technology, can be more stable in a complex offshore environment than the previous design, with a longer service life.

By far, China is the world's largest producer of wind turbine equipment, accounting for half of the global production. The country has established over 20 offshore wind power farms with wind turbine unit capacity ranging from 6 to 18 megawatts.