Russia fired dozens of missiles and 60 drones at Ukraine’s energy infrastructure Friday, damaging three power plants and causing massive blackouts, according to Ukrainian authorities.

President Volodymyr Zelenskyy accused Russia of targeting two hydropower plants and threatening to cause an environmental disaster not only in Ukraine but also in neighboring Moldova.

The attack was the latest in a series of intensified Russian strikes in March. Last week, Russia launched over 190 missiles and 140 Shahed drones against Ukraine, Zelenskyy said. The attacks caused more than $11.5 billion in damage to Ukraine’s energy infrastructure, the country’s Energy Ministry estimated.

It will take months to repair the damage to power plants, Ukraine’s largest private power firm, DTEK, reported. And years will be required to repair the Dnipro hydropower plant, which was hit eight times during last week’s attack, authorities said.

FILE - Energy supply workers restore a high-voltage line destroyed in Russian missile attack, amid Russia's attack on Ukraine, in Kyiv, Feb. 7, 2024.

FILE – Energy supply workers restore a high-voltage line destroyed in Russian missile attack, amid Russia’s attack on Ukraine, in Kyiv, Feb. 7, 2024.

Commenting on the damage, Aura Sabadus of British think tank Independent Commodity Intelligence Services told VOA that the Russians know where to strike to inflict the most damage.

“What is extraordinary is that they knew exactly what to hit, which is an indication that they are working with energy specialists on their own side who know exactly the Ukrainian system and who are presumably helping the military to strike key pieces of infrastructure in Ukraine,” Sabadus said.

Both the Russian and Ukrainian energy systems were built during Soviet times, and each country’s energy experts might know of vulnerabilities of the other’s transmission and energy generating systems, she said.

She also pointed out that Russian energy experts are known to have helped the Russian military in other instances. For instance, Russian energy company Rosatom is operating at the Zaporizhzhia nuclear power plant occupied by the Russian military.

Many observers expected Russia to attack Ukraine’s energy system, as was the case last year. Help from allies allowed Ukraine to be somewhat better prepared for the energy disruptions.

“The situation is much different from last heating season, when there was scarcity of equipment,” said Volodymyr Kudrytskyi, head of Ukrainian power grid operator Ukrenergo, in a video address on Tuesday. The major difficulty this time is the time needed for the repairs, Kudrytskyi said.

Rescuers work at the site of a missile attack in Mykolaivka, Donetsk region, amid the Russian invasion of Ukraine, March 28, 2024. (Ukrainian Emergency Service)

Rescuers work at the site of a missile attack in Mykolaivka, Donetsk region, amid the Russian invasion of Ukraine, March 28, 2024. (Ukrainian Emergency Service)

Ukraine also was able to increase imports of power from Europe. In a move right before the war, Ukraine unplugged from Russia’s power grid and achieved permanent synchronization with European grid in late 2023. This allowed Ukraine to substantially increase imports of electricity from Europe.

Despite these preparations, Ukraine is still vulnerable to attacks. The recent missile barrages have left hundreds of thousands without power, inflicting social costs and prompting the Ukrainian government to renew calls to allies to provide much needed munitions for air defense.

U.S. Ambassador to Ukraine Bridget Brink on X called Russia’s attacks “barbaric,” adding, “Our assistance is needed now.” European Union foreign policy chief Josep Borrell called the attacks “war crimes” and urged the EU to speed up military assistance deliveries to Ukraine.

Russia is known to use energy as a weapon in Europe and continues its tactics now, said University of Pennsylvania senior fellow Benjamin Schmitt, who served as European energy security adviser at the U.S. State Department.

“Putin wants to make it as bad as possible for ordinary citizens” in the hope that Ukrainians become tired and push their government for a cease-fire, even if it means ceding territory to Russia, Schmitt said. He added, however, that this will not break the resilience of Ukrainians.

Through these attacks, Schmitt said, Putin also wants to deplete Ukraine’s air defenses while Ukraine is not being backfilled by U.S. supplies.

“They want to try to get momentum while in particular the United States has been irresponsible … and has not yet approved the next tranche of military funding for Ukraine,” he said.

At the same time, Ukraine has intensified its drone attacks on Russian oil refineries. The strikes have knocked out about 10% to 14% of Russia’s oil-refining capacity, according to various estimates.

Local residents walk next to their house that was damaged during a Russian missile and drone strike, amid Russia's attack on Ukraine, in Kamianske, Dnipropetrovsk region, Ukraine, March 29, 2024.

Local residents walk next to their house that was damaged during a Russian missile and drone strike, amid Russia’s attack on Ukraine, in Kamianske, Dnipropetrovsk region, Ukraine, March 29, 2024.

Last week, the Financial Times reported that the U.S. had asked Ukraine not to hit Russia’s oil refineries. The U.S. has neither confirmed nor denied the report, but State Department spokesperson Matthew Miller said at the press briefing Monday that “it has always been our position since the outset of this war that we do not encourage or support Ukraine taking strikes outside its own territory.”

Attacks on Russian oil refineries might be the way for Ukrainians to compensate for the inefficiencies of the Western sanctions against Russian oil, Schmitt said.

“These are legitimate military targets from the point of view of the Ukrainians, and in particular, it’s a way for Ukraine in their understanding to basically to put a physical sanction on Russian energy where Western sanctions have not had the effect needed,” Schmitt said.