Almost universally, coal is cheap only because it’s subsidized under dubious energy security et al. schemes: besides explicit monetary subsidies, government also helps evict people from the site of your open-cast mine, government makes sure you can sell your energy profitably, government turns a blind eye when you don’t meet environmental guidelines, government believes in “Clean Coal” and gives you money for research, …

Many of the same things are true of other types of energy generation as well, of course.