Question

Why Coal is used in thermal Power Plant and Not charcoal...even though is good fuel in comparison to Coal?

Answer 1

Coal is naturally occurring substance while charcoal is made by the following process
Charcoal has been made throughout the world for thousands of years. The usual process is to pile long pieces of wood in the shape of a large cone. Bury the wood with dirt, leaving a chimney hole at the top and a few air hole at the bottom. Light the wood from the bottom and let burn for several days. This is a long and slow process, but to yield charcoal and not ash you need to burn the wood very slowly and thoroughly. As you might guess this is an art form. Once the wood is burned to a good charcoal state, cover all the holes and let it cool. If you do it right you should get about 20% of the wood back as charcoal. Sound hard and unrewarding? Well it is, but before coal mining became a industrialized and practical process, it was about all people had to work with.

burning coal produces much more energy than charcoal as it is an almost pure form of carbon while charcoal is carbon with a lot of dirt so there are impurities which don't let the carbon to burn at its full potential
hence in big power plants coal is used as it gives more returns.