A major coal-fired power plant on Japan's northernmost main island of Hokkaido went fully back online on Wednesday, about a month after a deadly earthquake caused a prefecture-wide blackout.

The No. 2 unit of the Tomatoatsuma thermal power plant, which suffered damage after the Sept. 6 quake, resumed full operation at 6 a.m., adding 600,000 kilowatts in output, according to its operator Hokkaido Electric Power Co. The other two units of the plant in the town of Atsuma went back online last month.

The plant, capable of producing 1.65 million kw of electricity, was supplying roughly half of Hokkaido's power at the time of the quake. Its suspension temporarily left about 2.95 million households without power.

With the restart, the utility can now provide 5.2 million kw of electricity in the prefecture. It is just in time for the arrival of the region's severe winter weather that boosts electricity demand to over 5 million kw every year for heating and other purposes.

The company had been working to restore power supply to normal while a third-party panel was investigating why the extensive blackout took place. Residents of Hokkaido were asked to limit their energy use in the days following the magnitude 6.7 quake, which claimed the lives of 41 and injured hundreds of others.

A separate thermal power plant in Hokkaido's Tomakomai, capable of generating 250,000 kw, is expected to resume operation at the end of October.

Hokkaido Electric had to replace 12 boiler tubes at the No. 2 unit that had caused steam leaks and it resumed operation on a trial basis on Sept. 21.

The operator sought to bring operation back to normal in stages while checking the status of equipment used to break coal used as fuel after its temperature control failed to work properly.

One of the two units of the Tomatoatsuma plant, whose boiler tubes also suffered damage, resumed operation on Sept. 19 and the other one on Sept. 25 after it went offline due to a fire.

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