Some googling they still make charcoal the old way in parts of Switzerland. To convert 60 ster (3.6 per cord) of wood to charcoal takes 2 men 3 weeks to build the kiln and 2 weeks to burn it. So 17 cords in 5 weeks. Some of that is the piling wood up part but more or less 3 cords of wood a week. So a slight productivity gain and a lot more convenient since you can do one batch on a free day.
https://www.reuters.com/article/us-s...29563720080903