Tokyo Electric Power Co. (TEPCO) on Monday began implementing its planned rolling power cuts in some areas near Tokyo to avoid massive blackout in its service area following Friday's colossal earthquake.
A TEPCO official said that the planned power outage first applied to Ibaraki and Shizuoka prefectures.
The energy-saving move to cope with a serious power shortage in eastern Japan is expected to last at least through the end of April.
Earlier in the day TEPCO suspended a second round of planned power outages in the greater Tokyo and surrounding areas, as actual electricity shortages in the wake of Friday's earthquake were not as severe as initially estimated.
A TEPCO official told a news conference that the firm would decide whether to go ahead with the third, fourth and fifth rounds of power cuts after further assessing supply and demand.
The original plan announced by TEPCO was that there would be planned 3-hour power cuts at 5 predetermined time slots, in a rotating order, in Tokyo and its neighboring prefectures.
The planned power outage is expected to affect most of the 45 million people in TEPCO's service area covering Tokyo, Chiba, Gunma, Ibaraki, Kanagawa, Saitama, Tochigi, Yamanashi and part of Shizuoka prefectures.