In the humble backyard of a destroyed house, a 13-year-old chops firewood to get ready for winter. His mother, Tetiana Yarema, has been preparing for months as she remembers last winter's Russian strikes on the energy infrastructure that plunged Ukraine into darkness.

"Those were dark days. I didn't want anything. I just wanted to pack my things and go abroad," said Yarema, 48, who says she ended up staying because of her son's insistence.

For the Yarema family, like millions of other Ukrainians touched by Russia's war on Ukraine, winter is an especially challenging time.

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The mother and son live in trailers that were set up in their backyard after fighting in the early days of the war destroyed their house in Moshchun, a village about 25 kilometers (15 miles) northwest of Kyiv.

"I have a feeling that when the cold sets in, they'll start bombing again," the woman said, echoing the sentiments of many Ukrainians.

This time, however, they say they are better prepared.

Sales of generators exploded toward the end of summer. Some, who can afford it, have invested in solar panels. Others, like Yarema, have been purchasing candles, batteries, flashlights, and portable lanterns and stocking up on compact gas canisters, making the most of discounted prices.

"It's a bit challenging … but I already know what to do," she said.

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Last winter was declared the most challenging in the history of Ukraine's energy system, with over 1,200 missiles and drones fired by Russians at power plants, according to Ukrainian state-owned grid operator, Ukrenergo.

The strikes impacted almost a half of Ukraine's energy capacity. People were forced to endure hours without electricity and water during the coldest months in what Ukrainian officials described as "energy terror."

Millions of people across Ukraine had to learn to work, live, and cover their basic needs without relying on electricity.

After a lull of six months, Ukraine's energy system sustained its first attack of the season on Sept. 21, resulting in damage to facilities in the central and western regions, Ukrenergo said.

Ukrainian President Volodymyr Zelenskyy has committed to substantially enhancing air defense systems, which already have demonstrated greater effectiveness than the previous year.

"Everyone must play their part in defensive efforts to ensure that Russian aggression does not halt Ukraine this winter. Just as on the battlefield, in all areas, we must be resilient and strong," Zelenskyy said in a recent address to the nation.

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Ukrainian Prime Minister Denys Shmyhal recently announced that the United States has allocated $522 million for energy equipment and the protection of Ukraine's infrastructure.

"We stand on the threshold of a difficult winter. Thanks to the assistance of our allies, we successfully weathered the last, which was the most challenging winter season in our history," Shmyhal said.

Major retailer Epicenter said sales of generators increased 80% in August compared to the same time last year, and sales of portable charging stations increased by 25 times.

Yurii Musienko, 45, another resident of Moshchun, also plans to rely heavily on firewood, and has a wood-burning stove in his compact wooden trailer that has been provided to him for two years, and which sits next to his ruined home.

"I've already adapted," he said with a smile. The gates of his home still bear the holes from exploded ammunition that serve as a reminder of when Russian forces tried to seize the Ukrainian capital.

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"May no one ever have to endure such conditions," said his mother, Valentyna Kiriian, who lives in a separate plastic trailer installed in the same courtyard.

She's dressed in a hat and a coat, with multiple layers of clothing to stay warm. She notes that the cold has already set in, forcing her to sleep fully clothed, much like the previous winter.

During the power outages last winter, the mother and son relied on canned food. Occasionally, Valentyna would visit her neighbor, whose house remained intact and had a gas stove for boiling water.

"It's difficult for me to talk about. It pains my soul, and my heart weeps," she said.

Private Ukrainian energy producer DTEK has spent the last seven months restoring its damaged infrastructure and fortifying the protection of its equipment for the approaching winter.

The company invested about 20 billion Ukrainian hryvnias ($550 million) to prepare for the upcoming season, and it lost billions of hryvnias because of last year's disruptions caused by Russian attacks, according to CEO Maxim Timchenko.

"We learned our lessons," Timchenko said.

Andrii Horchynskyi, 49. who lives in the village of Maliutianka about 25 kilometers (15 miles) southwest of Kyiv, has invested over $30,000 in recent years to ensure his house is self-sufficient, and ramped up those efforts since Russia's invasion.

Last year, he spent $12,000 to install solar panels to help power his spacious house, where other members of his extended family came to stay for the winter — eight of them surviving comfortably.

"We had a whole ant heap here," Horchynskyi recalled.

He is convinced the Russians will try to damage Ukraine's infrastructure for gas, which he thinks will become expensive or even unavailable. So, he has installed a boiler that burns pine pellets. He also stores one and half cubic meters of water in his backyard.

"They will bombard even more this winter than the last," Horchynskyi said.