Ukraine has called on several European countries, including Finland, to help rebuild damaged energy infrastructure. Ukrainian officials on Saturday said over a million Ukrainian households lost electricity after Russian air raids.
Finland's grid operator, Fingrid, however, said it lacked the replacement parts Ukraine needs.
"The Ukrainians have asked European grid operators for spares, and we have also received a request. We naturally strive to help if we have the parts, but it's my understanding that Ukraine's system isn't an exact match with ours," Timo Kaukonen, who manages operational planning at Fingrid, told Finnish news agency STT.
Kaukonen said Ukraine could expect a difficult winter if Russia continued to target the country's energy infrastructure.
He noted that Ukraine had already started conserving electricity ahead of Saturday's drone attacks on power infrastructure.
"They're going to have to ration electricity or there won't be enough to cover the whole country," Kaukonen explained.
Earlier this week Ukrainian President Volodymyr Zelensky said 30 percent of Ukraine's power stations had been destroyed in Russian attacks.
Ukraine maintains that Russia's strategy is to damage critical infrastructure as winter approaches, leaving people without heat or electricity and triggering a mass exodus of Ukrainian refugees into western states.