Power cables have been connected to all six reactors at Japan's damaged nuclear plant, a significant step in bringing the complex under control.
In making the announcement after days of anxious waiting by the public, the Tokyo Electric Power Company (Tepco) warned that much needed to be done before the electricity can be turned on.
Workers were checking all additional equipment for damage to make sure cooling systems can be safely operated.
In another advance, emergency teams dumped tons of seawater into a nearly boiling storage pool holding spent nuclear fuel, cooling it to 50C, Japan's nuclear safety agency said. Steam, possibly carrying radioactive elements, had been rising for two days from the reactor building, and the move lessens the chances that more radiation will seep into the air.
Added up, the power and concerted dousing bring authorities closer to ending a nuclear crisis that has complicated the government's response to the catastrophic earthquake and tsunami that devastated Japan's north-east coast 11 days ago.
The Fukushima Dai-ichi nuclear complex has leaked radiation that has found its way into vegetables, raw milk, the water supply and even sea water across a band of Japan.
The resulting fears of radiation mean the impact has reverberated well beyond the disaster area and the families of the hundreds of thousands of displaced and of the estimated 18,000 dead.
"We must overcome this crisis that we have never experienced in the past, and it's time to make a nationwide effort," Chief Cabinet Secretary Yukio Edano, said in his latest remarks meant to soothe public anxieties.
In another repercussion, three of Japan's big companies - Sony, Toyota and Honda - announced temporary halts or extensions of closures at plants in Japan because of a shortage of parts caused by ruined factories in the disaster area.
The edginess was palpable in the town of Kawamata, just outside the city of Fukushima. Hundreds of people moved from their homes near the nuclear plant 50 miles away crowded into an school gym to hear about the impact of radiation on health from a doctor from Nagasaki, the city destroyed by an atomic bomb to end the Second World War.
"I want to tell you that you are safe. You don't need to worry. The levels of radiation here are clearly not high enough to cause damage to your health," Noboru Takamura told them. "Outside the 30-kilometre (19-mile) zone, there is no need to hang your laundry indoors or wear surgical masks - unless you have hay fever."
Virtually everyone in the hall was wearing a mask.
While Fukushima's and many other schools, gymnasiums and other community buildings remain packed with displaced people, in the 11 days since the disasters the numbers of people staying in shelters has halved to 268,510, as many move in with relatives and friends.
In the first five days after the disasters struck, the Fukushima complex saw explosions and fires in four of the plant's six reactors, and the leaking of radioactive steam into the air. Since then, progress continued intermittently as efforts to splash seawater on the reactors and rewire the complex were disrupted by rises in radiation, elevated pressure in reactors and overheated storage pools.
With the power lines connected, Tepco and experts said, days or even weeks would be needed to replace damaged equipment and vent any volatile gas to make sure electricity does not spark an explosion.
Much of the broader public's concern has centred on radiation contamination of food and water. The government has already ordered a ban on spinach, canola and raw milk from the prefectures around Fukushima. The sea off the nuclear plant is showing elevated levels of radioactive iodine and caesium, prompting the government to test seafood.
Government officials and health experts say the doses are low and not a threat to human health unless the tainted products are consumed in abnormally excessive quantities.
The Vienna-based International Atomic Energy Agency said that radiation seeping into the environment is a concern and needs to be monitored.
The levels drop dramatically with distance from the nuclear complex. In Tokyo, about 140 miles south of the plant, levels in recent days have been higher than normal for the city but still only a third of the global average for naturally occurring background radiation.