Shanghai residents face the prospect of power shortages this summer as the city's supply cannot keep pace with soaring demand, the energy supplier warned yesterday.

Demand is predicted to reach 28.5 million kilowatts during peak hours - up 7 percent on last year. Factories closed and construction projects halted during the World Expo last year have since resumed operations, contributing to demand.

"There could be power shortages," the Shanghai Electric Power Co said in a statement yesterday.

The current capacity of the city is only 18.7 million kilowatts, the company said.

With the support of the National Grid, 8.9 million kilowatts has been promised from Anhui, Fujian, Sichuan and Hubei provinces and Chongqing. Shanghai can afford a 27.6 million kilowatt power load, leaving a possible 0.9 million kilowatt shortfall.