Factories in Shanghai have been ordered to switch to nighttime production amid a severe power shortage, while shopping malls are being told to turn down winter heating, the city government said.
The city hoped to avoid the need for the power cuts that have hit other parts of the country.
Shanghai needed an extra two million kilowatts during the peak hours above the 9.6 million kilowatts it was able to provide.
Last summer, when faced with a similar power crisis, the government ordered about 4,000 enterprises in Shanghai to reschedule production to non-peak hours and many factories had to close for several days.