The Expo Garden is among the first areas in Shanghai to benefit from the clean energy transmitted from the Donghai Bridge Wind Farm, which held its launching ceremony on Tuesday.

The Donghai Bridge Wind Farm, located in offshore Shanghai, was approved by the central government in May 2008 and started construction four months later.

A whopping 2.365 billion yuan ($348 million) has been invested in the project, which consists of 34 3-megawatt wind-driven generators that can fuel more than 200,000 households in the city.

The total capacity of the wind farm is only 102 megawatts, making up only 1 percent of Shanghai's current power capacity of about 18,200 megawatts, which is supplied by traditional fuel electric plants.

According to the authorities, the city could save about 86,000 tons of coal and reduce carbon dioxide by more than 234,700 tons each year with the help of the wind farm.

The wind farm was actually connected to the city's grid on June 8, said Zhu Kaiqing, a Shanghai Electric Power Co Ltd official in charge of the Donghai project.

"So far, the performance of the wind farm has been up to our expectations. A total of 26 megawatts of electricity has been supplied to the city, including the Expo Garden," said Zhu.

"But we will have to wait and see if the wind farm can weather the typhoon season," Zhu added. "Although we have studied the side effects of extreme weather conditions on the design, we still have to see how the wind farm works in reality."

According to the Hydropower Planning Research Institute, which is responsible for the planning and design of China's hydropower and wind power projects, the country's offshore wind-power capacity may reach 5gW in 2015 and 30gW by 2020, with more projects to be rolled out soon in Jiangsu, Shandong, Zhejiang and Fujian provinces as well as Shanghai.

Meanwhile, visitors to the Expo Garden can get a rough idea of how wind energy works.

A number of small-scale wind power generation sets have been installed on the top of the State Grid Pavilion to make up the electricity supply and recycle energy.

The air vents in the 22 "wind hats" on top of the London Case Pavilion also use the indoor-outdoor difference of temperature and wind to blow fresh air into every room in the pavilion.