i am really happy that the "green" energy production is in such a price war. It's Solar vs. Wind not Solar vs. Coal. I don't care what's cheaper as long as it's not Coal!
Remember that the untaxed price of coal isn't a real price for it. Without a tax the market does not take the externality of its environmental effect into an account.
Economically speaking, a high tax on coal/other fossil fuels is simply forcing the market to consider its full and actual price.
I don't know, but there is soon to be a new president who says he wants to support the coal industry.
P.S. I agree about the comment regarding negative externalities not being accounted for unless something like this is in place.