It depends on how much coal costs along with how much the alternative fuels cost or how much of the natural forces that are used by some alternatives can be extracted.

In general if coal is cheap nothing will be able to compete with it in the short term (though a fully paid off nuclear power plant that is decades old can usually undersell coal due to having very low operating costs but in the short term the lower cost to build a coal power plant will often win out).

Of course if the coal power plants had to actually pay to deal with the problems they cause coal would end up the most expensive power source by a long shot.

There are some nice charts in George Monbiot’s ‘Heat’ which compare the costs of the various energy sources. I’ll try to remember and find it for you tonight.