Karaoke bars, nightclubs and office buildings might be forced to shut down their air conditioning during the hottest hours of the day this summer in order to reduce power demand, Shanghai's government officials said yesterday.

Controls on air conditioning are one measure being considered in the city's battle against a power supply shortfall. Without such controls, the city's power grid could collapse, according to officials with the Shanghai Economic Commission.

"Air conditioning is the major reason for the big demand that produces seasonal power shortages," said commission Vice Director Le Jingpeng.

This summer, the city is expected to have 16 to 20 extremely hot days, meaning those when temperatures top 35 degrees Celsius.

The peak demand is expected to hit a record high of 19 million kilowatts this summer, up by 1.8 million from last year, which will produce a shortage of up to 3.3 million kilowatts of electricity.

Air conditioners will account for a large amount of that demand, 7.5 to 8 million kilowatts, according to the Shanghai Electric Power Co.

Office buildings, hypermarkets and big department stores will be encouraged to turn on their central cooling system at night or in the morning to ensure there is enough cold water flowing in the system that they can turn down the air conditioners during the afternoon. Alternatively, they will be asked to shut down air conditioners during peak load times, generally the hottest hours of the day.

Entertainment venues, such as karaoke bars and nightclubs, will probably only be allowed to turn on their air conditioners in the evening, as they were last year.

All buildings will be asked to set the central air conditioners no lower than 26 degrees Celsius.

Power shortages could also force hundreds of factories to shut down production in the hottest hours of the day, and shift production to night hours.

Currently 1,500 enterprises have been listed for possible daytime shutdowns.

That list will probably be expanded once officials have a better idea of how much power is being used this summer.

(Shanghai Daily May 9, 2005)