KYIV, Ukraine — The head of Ukraine’s national electric utility was standing on the street outside headquarters in central Kyiv two weeks ago when he heard a low rumble in the sky and saw a Russian attack drone for the first time. The power of the blast moments later was still evident on Friday in the blown-out windows and debris that littered the complex.
“Unfortunately, they hit hard,” Volodymyr Kudrytskyi, the chief executive of Ukrenergo, said in an interview in his office.
The drone that hit Ukrenergo’s headquarters was one of dozens of aerial attacks on Oct. 10 that destroyed or severely damaged 30 percent of the national power grid’s infrastructure. In the weeks since, Ukrainian electrical workers have been racing to make repairs, but, it is a monumental challenge.
“Virtually every day, they hit some target run by Ukrenergo,” he said. Unlike a hurricane or other natural disaster, the strikes on Oct. 10 were not a singular occurrence, but the start of a sustained campaign that Russian officials have said is meant to cause civilian suffering and force Ukraine to submit to the Kremlin’s will.
Dmitri A. Medvedev, a former Russian president and prime minister and current deputy head of Russia’s Security Council, said in statement on Friday that Ukraine would regain energy stability only when it recognizes Russia’s demands as legitimate.
President Volodymyr Zelensky of Ukraine, spoke to the nation from the darkened streets of Kyiv late Thursday. “We are not afraid of the dark,” he said. “The darkest times for us are not without light, but without freedom.”
Mr. Zelensky, speaking on Friday night, said that some four million Ukrainians are now living with restrictions on power use. People in cities across the country are struggling with rolling power outages, the only way the country’s energy provider can prevent a “complete blackout.”
More than 5,500 electrical maintenance workers are struggling to make repairs as quickly as they can under harrowing conditions, Mr. Kudrytskyi said.
“Imagine, you are an employee maintaining a substation,” Mr. Kudrytskyi said. “You know it is a target.”
The workers never know what they will find when they emerge from their bunkers.
An alarm sounds and from the bunker workers can hear the roar of the explosion, he said, the power of the missile or drone compounded by the release of energy from the electrical equipment. A strange odor, which he compared to the smell of burned plastic, fills the air when the all clear is finally given.
Across the power plant, which he said can feel like its own small town, fires fueled by oil used in the machinery burn for hours. Alarms blare two or three times a day. And just as workers gather what is needed for repairs: boom, another explosion. Mr. Kudrytskyi said that at one plant, the building where the equipment for repairs was kept was hit.
“Everything gone,” he said. “It is really hard to imagine if you are not inside this horrible movie.”
The Russian targeting has been so precise that Mr. Kudrytskyi and other Ukrainian energy officials said that Moscow must be assisted by energy experts.
“I cannot imagine that military experts would know what combination of things needs to be hit to cause the most damage,” he said.
Ukraine has a robust energy system, Mr. Kudrytskyi said. Despite losing the power generated by the country’s largest nuclear power plant in Zaporizhzhia and the destruction to the grid in parts of the country where fighting is heavy, Ukraine was still exporting power a month ago. The missiles and drone strikes — which Mr. Kudrytskyi said started on Sept. 11 after the Russians were driven out of the Kharkiv region — ended that.
If the Russian attacks stopped today, he said, electrical workers could have power largely restored in under a month. But there is no sign they will end.
Five utility workers have been killed in strikes and dozens more wounded. Mr. Kudrytskyi said he remains amazed at the dedication of crews working to keep the lights on.