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Hurricane Maria's power outages are larger than Sandy and Katrina
Puerto Rico was hit by both Hurricane Irma and Maria this summer
Tens of thousands of Puerto Rico residents are fleeing to Florida after Hurricane Maria, leaving behind an island that is still struggling to regain power more than one month after the storm.
In all, Hurricane Maria has caused a loss of 1.25 billion hours of electricity supply for Americans, according to the analysis from the Rhodium Group. That makes it the largest blackout in US history, well ahead of Hurricane Georges in 1998 and Superstorm Sandy in 2012, the group said.
That 1.25 billion number will continue to grow. More than a month after Hurricane Maria knocked out the electric grid on the islands, the vast majority of residents remain without electricity, and the restoration of that power is months away.
The Rhodium Group analysis largely relies on data on electricity loss provided to the Department of Energy, as well as news reports for storms prior to 2000, according to Trevor Houser, a partner at Rhodium who co-wrote the analysis with Peter Marsters.
Houser said the group analyzes the economic impacts of weather and climate events, and they decided to dig in more deeply on the impacts of Maria on the Puerto Rican economy.
“As we started looking at the scale of the blackout and try to put that in historical context, it became clear this was a record-breaking event and worthy of some attention and focus just from an electric standpoint,” Houser said.
9 of top 10 are hurricane-related

Other major storms or incidents have knocked out power for more people, but those were for shorter periods of time.
For example, the 2003 blackouts in the Northeast US affected about 30 million people, but the power was restored within a few days. That incident caused the loss of 592 million customer-hours of electricity, according to Rhodium Group, making it the eighth-largest blackout in US history.
As of Thursday, just 26% of households had power restored, according to the Puerto Rico Electric Power Authority.
The state-owned utility filed for bankruptcy in July, is $9 billion in debt and is struggling to recover from the hurricane outages. Not coincidentally, several of the top 10 blackouts in US history involve Puerto Rico, including Maria and Irma this year and Hurricane Georges in 1998.
Whitefish Energy, a two-year-old utility firm with ties to the Trump administration, was awarded a $300 million contract to help restore the country’s power grid. The huge contract to a small company has drawn questions and criticism.
The Virgin Islands, with a much smaller population, has similarly struggled to restore power since Hurricane Maria. As of October 22, just 14.9% of customers had power, according to the U.S. Virgin Islands Water and Power Authority. That includes about 71% without power on St. Thomas, 98.4% without power on St. Croix and 100% without power on St. John.
Aside from the 2003 blackout, all of the biggest blackouts in US history were due to hurricanes or major storms, including Hurricane Hugo in 1989, Hurricane Ike in 2008, and Hurricane Katrina in 2005.
This year’s hurricane season has been particularly destructive. Hurricane Irma, the Category 5 storm that tore through the Caribbean before hitting Florida in early September, caused the loss of 753 million hours of electricity, making it the fourth-largest blackout in US history.
CNN’s Sam Petulla contributed to this report.