Shanghai will hold a massive exercise to test the reliability of its power grid in case of disaster such as typhoons, power overloads and man-made damage.

The exercise, required by the State Council, China's Cabinet, will take place on Wednesday under the supervision of the state electricity regulator.

Two district governments, four power firms and another 28 companies will take part, involving more than 10 departments and industries ranging from finance, transport, hospitals, shopping malls and telecommunications.

"Disastrous weather like typhoons and other external damages are casting a bigger influence on the city's power grid in recent years," said the Shanghai Economic Commission in a statement.

"The safe and stable operation of the local grid is facing a severe test," said the statement.

As China's electricity grids expand and become more complicated in structure amid rapid economic development, chances of massive blackouts are also increasing.

In March, a blizzard in Dalian in northeastern China's Liaoning Province short-circuited a number of cables and left hundreds of thousands of homes without power or heat in subfreezing temperatures.

Another massive blackout hit the central province of Henan last summer, when the Central China Grid lost nearly four million kilowatts' supply.

Shanghai's most serious recent blackout was in August 2004, when a tornado blasted suburban Jiading District, injuring nine people and shutting a major electricity artery. Thousands of homes and businesses across wide areas of the city were without power for up to five hours.

The city is also facing power blackouts this summer in areas with an underdeveloped network, as operators may have to pull the plug if an overload occurs.

(Shanghai Daily June 18, 2007)