Friday’s total blackout came after the Antonio Guiteras power plant in Matanzas – the island’s largest – shut down around 11:00 a.m. local time.
President Miguel Diaz-Canel Bermudez said the situation was his “absolute priority.”
“There will be no rest until the power is restored,” he wrote on X.
The communist president blamed the decades-long US embargo for preventing much-needed supplies and spare parts from reaching Cuba.
Cuban Foreign Minister Bruno Rodríguez later echoed his words, saying the damage from just 18 days of the embargo was equivalent to the annual cost of maintaining the national electricity grid.
“If the embargo is lifted, there will be no blackouts. In this way, the US government could support the Cuban people… if it wanted to,” the minister wrote in a message on X.
Cuba has also suffered this year from a drop in vital fuel supplies from Venezuela.
On Friday, Cuban officials announced that all schools and non-essential activities, including nightclubs, must be closed until Monday.
Non-essential workers were urged to stay at home to ensure power supply, and non-essential government services were suspended.
“It’s crazy,” Eloy Fon, an 80-year-old retiree who lives in central Havana, told AFP.
“This shows the fragility of our energy system… We have no reserves, nothing to support the country, we live by the day.”
Barbara Lopez, 47, a digital content creator, said she had “barely been able to work for two days.”
“It’s the worst I’ve seen in 47 years,” she said. “They’ve really screwed up now… We have no power, no mobile data.”
