As Russian forces advance in the Donetsk region of Ukraine at the fastest rate since the early days of their wide-scale invasion, they have moved to the city of Kurakhove and are about two kilometres from one of the country's oldest thermal power plants.

Not long after the Kurakhove coal-fired power station opened in 1941, workers were forced to hurriedly disassemble part of it, in a bid to move critical infrastructure to the east before the Nazis swept in and occupied the area.

This past spring and summer, as Russia's military edged closer, hundreds of workers gathered at the site again to take what they could and transport the equipment to thermal plants in the west that were in desperate need of spare parts after waves of Russian attacks.

"Basically we cannibalized Kurakhove," said Pavlo Bilodid, who works in international communications at DTEK, Ukraine's largest private provider of power.

"It was a solution to save the equipment from further attacks and to deliver it to other thermal power plants in Ukraine."

Waves of attacks

Since March of this year, Ukraine's energy grid has endured 11 major attacks by Russia. The most recent was early Thursday morning, when nearly 200 drones and missiles targeted sites across the country, leaving more than a million people without power in the immediate aftermath.

With temperatures plunging as winter sets in, there is the threat of widespread power outages if long cold snaps are accompanied by more waves of major attacks.

Throughout the war, which began when Russia invaded its neighbour in February 2022, nearly half of Ukraine's power-generating capacity has been destroyed, forcing energy workers to make repairs and continue operations under constant threat.

In July 2023, three workers at the Kurakhove plant were killed when a roof collapsed, which Ukrainian authorities blamed on months of Russian attacks.

For the more than 600 workers employed at the facility, the ever-present danger ramped up again dramatically in December 2023, when the plant's director at the time, Anatoliy Borichevskiy, said that it came under heavy Russian shelling nearly every day.

"When Russians saw the smoke from the chimney, which meant the plant started working, they started to shell immediately," he said. "The situation was quite tense."

The decision to dismantle

During a Zoom interview with CBC News, Borichevskiy consulted his black notebook and said that between Dec. 5, 2023 and Jan. 17, 2024, the plant came under shelling 38 times.

When sirens rang out, some workers would race to the shelter, but others had to stay and keep running the control room.

For more than a month, he said, it was a dismal cycle as crews tried to quickly make repairs, only to see the plant hit again.

That changed in March, when the Russian military destroyed a railway bridge that made it impossible to transport coal to the power plant. With invading troops about seven kilometres away, it was too dangerous and made no sense to try to repair the line.

At that point, the discussion was no longer about fixing the plant but about salvaging what they could.

Borichevskiy said he vividly recalled the day he met with managers at the site and told them everyone was now going to be tasked with disassembling part of the plant. They would be removing critical equipment, including generators and transformers that were badly needed elsewhere — including the five other thermal power plants run by DTEK, which had come under Russian attacks.

"It was hard," said Borichevskiy, who worked at the plant since 1992, when he was first hired as an electrician.

"Everyone understood that we would not be able to work anymore. The front line was approaching. It would not settle quietly."

As extra crews were brought in to get to work, the looming issue became how to move the equipment — which in some cases weighed a few hundreds tonnes — without being able to use the rail line.

Everything would have to be hoisted on trucks, which meant bridges needed to be surveyed to make sure they could bear the weight, and then strengthened if they couldn't.

Trucks and tractors were brought in to move out the equipment, as arrangements were made to evacuate the workers and employ them at other energy sites in Ukraine.

Russian forces close in

The city of Kurakhove, which grew in the shadow of the Soviet-era plant, had 18,000 residents before February 2022. Over recent weeks as the Russians grew closer, those who remained in the city left and were evacuated.

Borichevskiy relocated in August, but as many as 100 workers remained at the facility until November.

Last week, Ukrainian officials said the plant came under shelling again, causing destruction to its cooling towers.

Military analysts and Russian pro-war bloggers say that troops are now in Kurakhove. Russia's Defence Ministry says it has taken control of the settlement of Nova Illinka, which is one kilometre away, on the opposite bank of the reservoir from Kurakhove.

"The place is half-ruined," said Borichevskiy, who was born and raised in the city.

"Everything there is very sad. I don't know what will happen next. How will people be able to live there, when everything is half crumbled?"

The race to repair

The focus for DTEK now, along with the rest of Ukraine's energy operators, is to protect the remaining energy grid and try to minimize the amount of time that large swaths of the country are plunged into darkness.

As of July, 90 per cent of DTEK's generating capacity was destroyed. Since then, crews worked to rebuild 60 per cent of it, but then came an attack on Nov. 17, which killed at  least 11 people and inflicted more damage to the grid.

The U.S. government and European Commission recently announced they would be giving $112 million US to the private company to purchase equipment, including transformers, to help restore capacity.

The managing director of the Kyiv-based Energy Industry Research Center, Oleksandr Kharchenko, said throughout the war, efforts have been made to fortify energy facilities, particularly substations that frequently come under attack.

Work is underway to erect structures made of concrete and steel around them in an effort to protect against drones and missiles.

While Ukrainian cities are undergoing power outages because there isn't enough capacity or reserves, Kharchenko said, overall the system has responded to Russia's attacks and will manage through the winter ahead.

"The Ukrainian energy system has huge challenges, but it is fighting them," he said in an interview with CBC News. "I don't feel that we will have something like an apocalypse or a huge technological disaster."

While communities routinely have planned power outages, many residents say they have adapted by running generators and stocking up on battery packs to charge devices.

What is unpredictable, Kharchenko said, is how cold it will get this winter: If temperatures plunge to –10 or –15 C for more than a week, it looks like across Ukraine, there would need to be power outages on average for at least eight hours a day.