Last week, millions of Egyptians suffered frequent blackouts. The phenomenon intensified on Wednesday with people in some areas reporting two-hour outages.
The electricity ministry said a shortage of natural gas, necessary to operate power plants, caused the blackouts.
Ministry spokesperson Aktham Abul-Ela told Ahram Online that output was reduced by 1000 Megawatts on Wednesday.
Egypt's high season for electricity consumption is in the summer due to the increased use of air conditioning and ventilators.
Yearly Peak Load jumped from 25.700 Megawatts in 2011/12 to 27.000 last year. Currently it stands at 22.000 Megawatts, far below the peak.
Power cuts have become more frequent since August 2008 but have been mostly limited to summer. The phenomenon extended into winter in December last year.
The government has blamed fuel shortages, high temperatures in summer, local protests at power plants, and the security vacuum.
However, experts believe the problem is deeper because annual power consumption has exceeded expectations for a number of years and will require considerable investment to solve.
Others blame poor maintenance of the national power grid and power plants.
Abul-Ela rejected claims consumption had decreased this year due to an economic slowdown, a months-long nighttime curfew and political instability.
Energy shortages helped spark protests against president Mohamed Morsi on 30 June.