They can save the money that they were going to spend on charcoal and they can produce excess and sell it in the market to people who aren't making their own.
می توانند پولی که قرار بود روی  خرید زغال صرف شود را ذخیره کنند. و می توانند تولید اضافه شان را بفروشند به کسانی که سوخت خودشان را تولید نمی کنند.