Sure, but if you have to burn wood to made coal, then you cannot use coal on the scale required to have a whole steam-powered economy. I am fine with coal for smelting metals and the like, just as I am fine with oil lamps or similar things. I might even be fine with clocks and other fine machineries. The important point is that it must be impossible to arrive at the widespread use of energy-intensive technology which would ruin the flavour of fantasy for my world.