Yes, that's always the issue with Charcoal isn't it? All good except you have to make the stuff!
The next burn barrel I light up will have a sealed container containing 5-10 lbs of store bought wood pellets in it. I will inspect the resulting charcoal for quality, toughness, and measure for density.
If it all looks good I will build a pellet mill, I already have a hammer mill, and I will produce pellets from both straw and wood.
For charcoal production, I want to experiment with huge TLUD gasifiers. They're simple enough to build, make great charcoal, don't smoke, and don't go up in a hurricane of roaring fire like some retorts do. They also put out the kind of heat that would be easy to use for space heating: moderate, and long lasting.
I'd love to find a way to choke a TLUD off automatically at the right time. Then I could build 4 or 5 of them, fill 'em, light 'em, and forget 'em .