Power outages from Hurricane Irma in Florida and nearby states declined to about 6.9 million customers on Tuesday from a peak over 7.4 million late Monday as utilities organised one of the biggest restoration efforts in US history.
Eric Silagy, the CEO of Florida Power & Light, said Irma caused the most widespread damage in the company's history.
Irma hit southwestern Florida on Sunday morning as a risky Category 4 storm, the second-highest level on the five-notch Saffir-Simpson scale.
After Hurricane Wilma knocked out power to millions of Floridians, FPL spent $3 billion over the past decade to bolster the power grid.
Georgia reported more than 570,000 homes and businesses without electricity, and there were 80,000 in SC.
FPL said on Friday that Irma could affect around 4.1 million customers, but that was before the storm track shifted away from the eastern side of the state.
Meanwhile, Duke Energy reported Monday morning that more than 860,000 of the homes and businesses it serves in Florida were without power.
Gainesville and Miami had the highest number of stations out of fuel on Tuesday afternoon, with 62 percent and 49 percent respectively, according to GasBuddy.
They plan to spend the next two weeks working to restore power to millions affected by Hurricane Irma.
Workers left last Thursday and arrived in Florida on Saturday.
Some Florida utilities, including FPL, had warned customers it could take weeks to restore power in the hardest hit areas. Both reactors at its Turkey Point facility, about 30 miles (48 km) south of Miami, remained shut early Tuesday, while both reactors at its St. Lucie plant, about 120 miles (190 km) north of Miami, were operating at full power. On Sunday, Gould said its nuclear plants were safe.
In a worst case scenario, the spent fuel in the pool could release radiation if exposed to the air, but a federal nuclear official said that was extremely unlikely.