Panasonic’s new $4 billion battery factory in De Soto, Kansas, is designed to be a model of sustainability—it’s an all-electric factory with no smokestack. When finished, it will cover the size of 48 football fields, employ 4,000 people, and produce enough advanced batteries to supply half a million electric cars per year.

But there’s a catch, and it’s a big one.

While the factory will run on wind and solar power much of the time, renewables supplied only 34% of the local utility Evergy’s electricity in 2023.

In much of the United States, fossil fuels still play a key role in meeting power demand. In fact, Evergy has asked permission to extend the life of an old coal-fired power plant to meet growing demand, including from the battery factory.

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