Get 50 people chained up in front of the gates, and stop workers and coal coming in.
Maintain this human blockade until the last coal power plant is shut down. Ignore arrests and ignore the police.
Screw the impact on the 'investment'. The grid will handle the loss of electricity anyway.
That's about 12,000 people across the USA who could actively shape the future of humanity.
No, it won't. And if you do it in the midst of a hot summer, or a cold winter, people will die because you killed them.
There are responsible ways to close those plants without killing people.
What you suggest has only ever worked through history when protesting slowly enlightened people and the majority of people chose to support the protestors over time.
I think the US is so divided and fed up from BLM and the election chaos at the moment, so enacting change that way is a hopeless cause.