Ukraine's power grid operator issued a new appeal to civilians to save electricity on Friday as temperatures fell and energy consumption rose, threatening new strains on a network devastated by Russian air strikes.
Russian missile and drone attacks on energy infrastructure since October have caused widespread damage that has led to winter blackouts and shortages of heating and water.
After hovering at around 10 degrees Celsius (50°F) during an unseasonably warm spell since New Year, temperatures are now falling. Forecasters say they could soon plunge to -11°C in Kyiv and to -18°C in eastern Ukraine.
"In the near future, a significant drop in temperature is expected, which will lead to a rapid increase in consumption," state-run energy company and grid operator Ukrenergo said in a statement on the Telegram messaging app.
"The energy system is currently unable to fully cover it due to the damage and the enemy's occupation of a number of power plants that produce electricity, in particular, and the most powerful - the Zaporizhzhia NPP (nuclear power plant)."
It added: "Please use electricity wisely, alternate the use of energy-intensive appliances. It helps reduce the load on the power system and reduce the need to limit consumption."
Prime Minister Denys Shmyhal told a government meeting on Friday that Ukraine should expect Russian attacks and emergency outages.
Russia, which invaded Ukraine last February, says it regards energy facilities as legitimate military targets. Ukraine and its allies say attacks on civilian infrastructure could be war crimes.
Cities across Ukraine, including Kyiv, are undergoing scheduled blackouts to reduce the strain on the electrical grid during peak usage hours.
Ukrenergo said it was working with electricity producers and distributors to restore damaged facilities but that the repairs took up a lot of resources and time because of the complexity and scale of the damage.
Ukraine's Soviet-era power system cannot be fixed easily as energy operators need vast quantities of equipment.
Businesses and residents have bought tens of thousands of generators to ensure electricity supplies. Yaroslav Zheleznyak, a parliamentary deputy, said on Telegram that 669,400 generators were imported into Ukraine in 2022, with deliveries peaking at 309,400 units in December.
(Additional reporting by Dan Peleschuk, Editing by Timothy Heritage)