China's economic hub of Shanghai plans to shut down another three sets of coal-fired generating units with a total capacity of 500,000 kilowatts to meet its annual energy-saving target, sources with the local government said on Sunday.

In the next two months, two generating units at the Wujing power plant in the city's Minhang district and a fuel unit in the Jinshan petrochemical construction company will stop operation.

Last month, the city shut down all three generators at the 110-year-old Nanshi power plant along the Huangpu River, and sets to transform the site into an exhibition area for the 2010 World Expo.

Shanghai has been echoing a national call to close small but energy-guzzling coal-fired generating units.

According to the city's 11th Five-year Plan for the 2006-2010 period, it will close about 2.1 million kilowatts of generating units in seven power plants, which will save about 1.1 million tons of coals and cut sulphur dioxide emissions by 80,000 tons ever year.

Meanwhile, the city has started building wind power stations and installing desulphurization facilities in the city's 11 power plants.

China's national target is to close all small generators with an aggregate capacity of 50 million kilowatts by 2010, and build more large-capacity power plants to save energy and reduce emissions.

The large-scale shutdown will enable the country to save 14.5 million tons of coal, and reduce sulfur dioxide emissions by 247,000 tons and carbon dioxide emissions by 29 million tons a year.