Tokyo Electric Power Co. warned that a blackout could hit the greater Tokyo metropolitan area on March 22 after pleas for electricity conservation failed to save enough power.

The utility had urged consumers to save energy because of the unusually cold weather combined with crippled thermal power plants caused by the March 16 earthquake.

However, the level of energy conservation was only about a third of what company officials were hoping for.

At a hastily called news conference on March 22, Koichi Hagiuda, the economy minister, urged greater conservation efforts because the initial goals were not being met.

He suggested that if energy use was not cut by another 2 gigawatts between 3 p.m. and 8 p.m., the possibility of power outages over a wide area was very likely.

Hagiuda referred to the forced power outages that went into effect soon after the March 16 earthquake to avoid a blackout caused by an imbalance in the supply and demand of electricity. At that time, power was temporarily stopped to about 2.23 million households in 14 prefectures.

TEPCO officials later said there was a possibility that between 2 million and 3 million households would be without electricity after 8 p.m. because hydroelectric generation facilities will have used up all the stored water on hand.

Company officials urged continued energy conservation steps after 8 p.m. to avoid power outages.

TEPCO’s website said about 103 percent of the electricity supply was being used as of 11 a.m.

The figure has previously exceeded 100 percent without a blackout occurring because of emergency generators used by companies. This electricity is not included on TEPCO's supply register.

The government on the evening of March 21 for the first time issued a warning about the expected crunch on electricity supply and urged individuals and companies to take measures to conserve energy.

TEPCO’s call to conserve energy will be in place from 8 a.m. until 11 p.m. on March 22 and cover the nine prefectures it supplies electricity to: Tokyo, Kanagawa, Saitama, Chiba, Gunma, Tochigi, Ibaraki, Yamanashi and eastern Shizuoka.

The temperature in Tokyo as of 9 a.m. on March 22 was 3.9 degrees, a level normally found in mid- winter rather than the day after the vernal equinox.

The Japan Meteorological Agency forecast the temperature to remain below 5 degrees throughout the day.

Rain, snow and cloudy skies meant solar power could not be counted on to provide the normal level of electricity.

Hagiuda said at an earlier news conference on March 22 that the government’s decision to issue the warning was made after carefully analyzing the expected supply and demand of electricity with the weather forecast.

Government officials were seeking a conservation rate of about 10 percent.

The magnitude-7.4 earthquake that hit Miyagi and Fukushima prefectures on March 16 damaged a number of thermal plants, and six generators have yet to go back online.

TEPCO also announced that it was scheduled to receive up to 1.41 gigawatts of electricity from seven other utilities between 7 a.m. and 4 p.m. on March 22.

The system of issuing warnings about electricity supply was introduced in 2012 after the Great East Japan Earthquake and tsunami devastated the Tohoku region the previous year. If customers conserve enough energy in emergencies, the government and utilities can avoid having to implement rolling blackouts.

Companies with emergency generators were switching over to reduce the burden on TEPCO’s supply.

Local residents were urged to set their air-conditioning thermostats to 20 degrees and to turn off lights in rooms not being used.

But one 79-year-old homemaker in Tokyo said, “While it may not be a problem for younger people, it will not be easy for us to set the thermostat at 20 degrees.”

The woman said the thermostat at her home was normally set at 25 degrees.

Tokyo Governor Yuriko Koike said at a March 22 news conference that the thermostats at metropolitan government buildings would be set at 19 degrees and that lights would be turned off as much as possible.

Education ministry officials said they were moving quickly to instruct prefectural education boards and schools to take measures to conserve energy.

The ministry was told at 7:46 p.m. on March 21 about the economy ministry’s request to conserve energy.

Railway companies were not affected by TEPCO’s request, and none planned to reduce the number of trains operating on March 22.

Tohoku Electric Power Co. was also asking its customers to conserve energy as its supply outlook was also being pressed.

More than 100 percent of the utility’s electricity was being used after 9 a.m., with the figure still hovering at the 99-percent level after 10 a.m.