Electricity supply-demand conditions in the Tokyo area are projected to remain tight this summer after power crunch concerns hit resource-poor Japan last year, according to estimates compiled by the government.

The reserve power supply capacity ratio in the metropolitan area in July could drop to 3 percent, the lowest level for maintaining stable supply, if a once-in-a-decade level of extreme heat grips the region served by Tokyo Electric Power Company Holdings Inc.

Utilities in other areas are expected to see power supply reserves of above 3 percent even if such severe weather conditions prevail, according to estimates released in late March by the Ministry of Economy, Trade and Industry.

People walk under the scorching sun in Tokyo on Aug. 9, 2022. (Kyodo)

The forecast is based on the supply plans of electricity service businesses, compiled at a time when most nuclear power reactors remain offline after the 2011 nuclear disaster and many aged thermal power plants have been shut down.

The reserve capacity rate is projected to improve to 3.9 percent in the Tokyo area in August and stand at 4.6 percent in January 2024 for the region as well as northern parts of Japan including Hokkaido.

Although the reserve rate forecast for last winter fell below 3 percent for the area served by TEPCO, the country avoided a serious power shortage by restarting idle thermal reactors and asking the general public to take power-saving measures.

In July last year, the government requested Japanese households and businesses to conserve electricity to prevent a power crunch for the first time since fiscal 2015, when all of the country's nuclear reactors were offline in the wake of Fukushima nuclear power plant disaster triggered by a massive earthquake and tsunami in 2011.

A similar request was made for this winter through Friday, also for the first time for the season since fiscal 2015, with the government asking users to set the heating at a lower temperature and turn off lights when not needed.

Amid power crunch concerns, Prime Minister Fumio Kishida has instructed his government to speed up efforts to restart nuclear reactors that face stringent safety standards implemented after the 2011 disaster as a way to ensure a stable power supply.

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