There is a absolute limit on the cost of coal: What it costs to get it out of the ground and into the powerplant. Even if the price of coal per unit weight goes

There is a absolute limit on the cost of coal: What it costs to get it out of the ground and into the powerplant. Even if the price of coal per unit weight goes down to 0 it will still have a cost to transport it. I think that in the medium term that is what coal is up against; a solar alternative that is cheaper in the long run.