Hokkaido races to secure power supplies before winter grips island

(Repeats story published on Friday with no changes to text)

* Govt eases power saving targets after quake-related blackouts

* But tight power supplies remain in northern Japan island

* Hokkaido Elec needs to build up supplies ahead of chilly winter

By Osamu Tsukimori and Aaron Sheldrick

TOKYO, Sept 14 (Reuters) - Japan is racing to secure power supplies ahead of winter after a devastating quake left 41 people dead and damaged generating stations on the northern island of Hokkaido, where temperatures regularly drop well below zero in colder months.

Although the government has eased an initial 20 percent power-savings target for residential and business customers on the island of 5.3 million, Japan's trade and industry minister Hiroshige Seko has said power supplies on Hokkaido will remain tight and unspecified savings are still needed.

Regional utility Hokkaido Electric Power is rushing to repair broken generators and bring on idle power plants, but those efforts will come up against the brutal reality of winter in Hokkaido, where temperatures can reach as low as minus 41 Celsius (minus 42 Fahrenheit).

Power demand on Hokkaido in winter is typically more than a third higher than in the warmer months before the quake.

"The harsh reality is that we have to ask for power savings every winter in Hokkaido," trade and industry minister Seko told reporters on Friday.

Asked if he was confident there would be enough supply to cope with the rise in demand, Seko said it was too early to say.

Temperatures in urban areas on the island are already dropping below 10 Celsius in early morning hours, while snow was recorded in the mountains of northern Hokkaido on Aug. 17, the earliest snowfall since 1974, local press have reported.

Sufficient power supplies for winter heating may depend on whether Hokkaido Electric can get its biggest coal-fired plant - Tomato-Atsuma - fully operational after the quake damaged all three generators at the station, Seko said.

On Tuesday, Seko said his ministry will investigate Hokkaido Electric's response to the quake, which left an island the size of Austria without power after Tomato-Atsuma was shut down. It was the nation's worst outage since the March 2011 earthquake and tsunami that devastated northeastern Japan.

Fully restarting the Tomato-Atsuma power station, will take more than a month, Seko said earlier this week.

Hokkaido Electric engineers cannot inspect its No. 4 unit, the biggest, because it is still too hot after a fire broke out in its turbine, a company spokesman told Reuters by phone.

Depending on the damage, repairing or replacing turbines can take weeks or months.