Residents of the capital Tehran could face up to four hours of blackouts each day, officials said according to media reports.
"If consumers do not cut down consumption by 10 percent, we will have blackouts until the end of the summer," Deputy Energy Minister Mohammad Ahmadian told Fars news agency.
Newspapers published a table by the state electricity company dividing the sprawling capital of 12 million into 11 zones, with each area to face from two-hour-long power cuts twice a day from Saturday.
Ahmadian told state television that the table was provisional, and that blackouts were most likely to hit the zones where consumers have failed to save energy.
Energy Minister Parviz Fattah warned in May that Iran will face severe electricity shortages and power cuts this summer due to "the drought and the lack of water" in dams.
Energy officials have predicted that daily consumption would reach 37,000 megawatts in July while production would stand at only 35,000 megawatts.
In the past weeks Tehran and other cities have already been hit by cuts of up to three hours in certain areas as the authorities seek to make-up the shortfall.
Blackouts were common in Iran during the 1980-1988 war with Iraq but in 1990's Iran made significant investments in power generation to meet ever-increasing consumption.
