This winter is likely to be Japan’s first without numerical power-saving targets since 2011, sources say.

The March 2011 core meltdowns in Fukushima triggered power-saving efforts through most of the country after all 50 of the nation’s viable atomic plants were shut down for safety inspections. This resulted in rolling blackouts in some cities for several months because about 30 percent of the nation’s electricity had come from nuclear power.

But now that the world’s third-largest economy has returned to thermal power, sources say the government might not set any electricity-saving targets this winter, when demand tends to soar.

Nevertheless, the nine regional utilities with idle nuclear plants will still be expected to maintain a power reserve of 3 percent over anticipated demand this winter, the sources said. The tenth utility is in Okinawa but does not have use nuclear power.

All of the nation’s atomic plants are idle and none are expected to be running this winter.

As it did this summer, the government will likely urge consumers and companies in regions served by the nine utilities to save power by following the practices adopted when the nuclear crisis began at the Fukushima No. 1 power plant.

The ability to avoid power shortages despite the total loss of atomic power can be credited to the utilities’ return to thermal generation and to public conservation efforts.

According to the sources, based on estimates for this winter given to the government by the nine nuclear utilities, Hokkaido Electric Power Co. is projected to have a power surplus of 6.9 percent next February, when its service area is still expected to be stuck in winter.

Tohoku Electric Power Co. meanwhile is projected to have a surplus of 8.6 percent, with beleaguered Tokyo Electric Power Co. expected to have a surplus of 10.2 percent. Tepco serves nearly a third of the nation’s population and most of its largest companies.

Chugoku Electric Power Co. will have a surplus of 8.4 percent, Shikoku Electric Power Co. 7.1 percent, Chubu Electric Power Co. 6.3 percent, and Hokuriku Electric Power Co. 6 percent, according to their estimates.

The surplus power at the two remaining utilities — Kansai Electric Power Co. and Kyushu Electric Power Co. — is projected to stay at only 3 percent, but major power shortages are unlikely because additional power will be available from other utilities.