Photo/IllutrationBlackouts hit residential areas of Sapporo on the night of Sept. 6, following a powerful earthquake that rocked the region earlier in the day. (Soichiro Yamamoto)

The government is considering implementing rolling blackouts in Hokkaido to deal with electricity shortages caused by the earthquake that cut power across the island on Sept. 6.

Under the plan, Hokkaido would be split into 60 areas, and power would be cut to some of them for two-hour periods when electricity demand is expected to match the full supply capacities of power plants, according to the economy ministry.

The last time the government used rolling blackouts was in March 2011 in the Tokyo metropolitan area following the Great East Japan Earthquake.

“We will proceed with preparations for every measure, including planned blackouts,” Hiroshige Seko, minister of economy, trade and industry, said on Sept. 7.

Immediately after the quake hit southwestern Hokkaido at 3:08 a.m. on Sept. 6, 2.95 million households in Hokkaido lost power.

By 6 a.m. on Sept. 8, electricity was back at 2.93 million households, or 99 percent of the total.

To overcome the difficulties in meeting peak power demand, the government is asking residents and companies to reduce their electricity usage by about 10 percent.

However, electricity conservation could prove insufficient to secure enough power when companies and factories begin to operate on Sept. 10, a weekday.

Problems could also occur at some of the power plants.

In such a situation, the government will implement rolling blackouts.

“We want to avoid planned blackouts, so we hope the people of Hokkaido will cooperate with electricity saving as much as possible,” Seko said.

The quake seriously damaged buildings and facilities in areas close to the quake’s epicenter, including the Tomato-Atsuma thermal power plant run by Hokkaido Electric Power Co. in the town of Atsuma.

A resumption of operations at the Tomato-Atsuma plant, the largest thermal power plant in Hokkaido, is needed to raise the electricity supply to a level that should dispel worries about additional power outages.

Turbines and boilers at the plant, which has a power generation capacity of 1.65 gigawatts, were damaged in the earthquake, and it could take more than a week to resume operations.

The damage to the plant led to a chain reaction that caused all other thermal plants in Hokkaido to shut down after the Sept. 6 earthquake.