Deep underground in southeastern Ukraine, miners work around the clock extracting coal to power the country's war effort and to provide civilians with light and heat.
Coal is central to meeting Ukraine's energy needs following the Russian military's 6-month campaign to destroy power stations and other infrastructure, the chief engineer of a mining company in Dnipropetrovsk province said.
Elevators carry the company's workers underground to the depths of the mine. From there, they operate heavy machinery that digs out the coal and moves the precious resource above ground. It is hard work, the miners said, but essential to keep the country going.
"Today, the country's energy independence is more than a priority," said Oleksandr, the chief engineer, who, like all the coal miners interviewed, spoke on the condition of giving only his first name for security reasons.
Russia's attacks on Ukraine's nuclear, thermal and other power stations continue to disrupt electricity service as the war grinds on for a second year.
Negotiations to demilitarize the Zaporizhzhia Nuclear Power Plant, which the Kremlin's forces captured last year at the start of the full-scale invasion, are at an impasse. Ukrainian President Volodymyr Zelenskyy opposes any proposal that would legitimize Russian control of the plant, which is Europe's largest nuclear energy facility.
At full capacity, the plant can produce 6,000 megawatts of electricity. The Ukrainian operators of the plant shut down the last reactor in September, saying it was too risky to run while Russia bombarded nearby areas.
Shelling has damaged the plant numerous times, raising fears of a possible nuclear meltdown. Russian missiles have also threatened the power lines needed to operate vital cooling equipment at Zaporizhzhia and Ukraine's other nuclear plants.
Before the war, the Ukrainian government planned to reduce the country's reliance on coal-fired power stations, which contribute to global warming, and to increase nuclear energy and natural gas production. But when Russian attacks damaged thermal plants in the middle of winter, it was coal that helped keep Ukrainian homes warm, Oleksandr said.
The work of the coal miners cannot fully compensate for the loss of energy from nuclear power plants, but every megawatt they had a role in generating reduced gaps.
"We come and work with optimism, trying not to think about what is going on outside the mine," a miner named Serhii said. "We work with a smile and forget about it. And when we leave, then another life begins (for us), of survival and everything else."
While many miners from the area joined the armed forces when Russian troops invaded and are now fighting at the front in eastern Ukraine, nearly 150 displaced workers from other coal-producing regions in the east joined the team in Dnipropetrovsk.
A man named Yurii left the embattled Donetsk province town of Vuhledar, where he worked as a coal miner for 20 years. "The war, of course, radically changed my life," he said. "It is now impossible to live there and the mine where I used to work."
"Life begins from scratch," he said.
British military analysts reported Saturday that they think Russia's campaign to degrade Ukraine's energy grid over the winter through intense missile and drone strikes "highly likely failed," and that the invaded country's energy situation would improve as temperatures rise.
The U.K. Defense Ministry said that while the strikes have continued since October, large-scale attacks causing significant infrastructure damage are becoming rare. Ukraine's network operators also managed to source replacement transformers and other "critical" components to keep electricity flowing, the ministry said.