Your comments on the charcoal issue is right. This information is for the people who would be interested in charcoal making.
Not properly dried wood will never yield more than 20% charcoal and most of the pieces will be broken. Charcoal which is not broken in pieces, burn longer and gives more energy. In the market what is called Grade A charcoal, brings 30 to 40% more price than lump charcoal. What is most important today is try to make charcoal as clean as possible environmentally, even in traditional kilns.