Shanghai is facing power blackouts this summer. Some parts of the city have an underdeveloped power-distribution network and grid operators may be forced to pull the plug on electricity supplies if an overload occurs.

The intentional cut-off, which is rare in the city even during the power shortages of the past few years, was tried out this week when a major transformer in Pudong was overloaded by a sudden increased demand.

"Such measures will be inevitable this summer, or we will have an even bigger problem," said Li Xinzhang, a spokesman for the Shidong Power Supply Co, which is in charge of areas east of the Huangpu River. The company turned off supply to more than 1,000 families and businesses in Pudong's Beicai, Yuqiao and Liuli areas on Wednesday without giving any notice in advance as "they had no time."

Damage to households, such as home-appliance breakdowns, and factories, is still unknown, although Li said they haven't received any complaints.

These areas, according to Li, are suffering "a power-distribution bottleneck," which means there's not enough transmission capacity for them to arrange additional supplies. Bottlenecks also exist elsewhere in the city, such as the Chunshen area of Minhang District, an industrial park zone, according to Zhou Leiyong of the Shinan Power Supply Co.

One thing in common between these places is that demand has soared over the past few years due to rapid economic development and massive use of air-conditioners and heaters, while the electricity infrastructure lags behind, said Li Rongmin, a director of the Shanghai Power Grid Load Management Center.

"We have worked hard to achieve a basic balance of supply and demand this year, and now the power-distribution problem has made things even worse," he said.

All the experts agree that the root cause is the difficulty to get land to install equipment in a city that is so densely populated.

Their projects sometimes require relocation of homes and businesses, which needs coordination of district governments.

Then there can be protests about radiation from the transformers and power lines, which apartment owners or real estate developers are worried will devalue their property.

Shanghai has budgeted 20 billion yuan (US$2.56 billion) in grid construction and upgrades this year, with the major goal to prevent a massive blackout as the city's electricity demand is forecast to increase 10 percent from last year to 21 million kilowatts in peak times.

However, of the 17 projects scheduled to be finished before summer this year, only 11 have been completed.

(Shanghai Daily June 1, 2007)