Employees work as Japan's biggest power generator JERA prepares for restart of some aged units while building new units at its Anegasaki gas-fired power station in Chiba, near Tokyo, Japan June 22, 2022.
Employees work as Japan's biggest power generator JERA prepares for restart of some aged units while building new units at its Anegasaki gas-fired power station in Chiba, near Tokyo, Japan June 22, 2022. Reuters / YUKA OBAYASHI

JERA, Japan's biggest power generator, has started preparation work to restart another aged power generation unit at its Anegasaki thermal power station, near Tokyo, to help the region avoid any power crunch during the peak winter demand season.

Japan's energy supply problems relate to various domestic issues, including the suspension of some plants after March earthquakes in Fukushima, a drop in the number of thermal plants and delays to the restart of nuclear plants because of tighter regulation following the Fukushima disaster in 2011.

JERA is already set to restart the 45-year-old 600 megawatts (MW) No.5 gas-fired unit in Anegasaki between July 1 and Aug. 31, as it has won an auction to provide extra electricity during the summer to make up for any shortfall.

The company has begun equipment inspection work of the 600 MW No.6 gas-fired unit, with a view to resuming operation in the winter, when the electricity supply situation is expected to be even more severe than in the summer, Hiroaki Kamei, general manager at Anegasaki power station, told reporters on Wednesday.

Japan is predicted to face tight power supply this

summer, with three out of a total of 10 regions expecting excess generation capacity to fall in July towards the 3% threshold that makes shortages and blackouts more likely.

Electricity supply is expected to become even tighter in the winter, with estimated excess capacity declining below 3% in seven out of 10 regions in January and February, including the Tokyo area, where it is expected to slide below 0%.

"We are checking all equipment of No.6 unit to determine whether it can be restarted and what parts need repair," Kamei said during a media tour of the facilities.

It will take about six months to inspect equipment and order necessary parts for repair as the 43-year-old unit has been mothballed since spring last year, he said.

It would be desirable to have a nation-wide electricity supply plan determined at the earliest possible time, he said.

JERA had retired Anegasaki's four old units last December to make way for three new, less polluting gas-fired units it is building with the aim to start commercial operation next year.