Biochar production (pyrolysis of woody waste)

Charring woody waste in a low-oxygen process yields a stable, long-lived carbon material; production is in scope now even though its main use (soil amendment) waits on food production.

Cost

Low

Upkeep

Occasional

Skill to build

Intermediate

Lifespan

Not applicable, a production process; the kiln/retort structure itself lasts 10-20 years depending on construction

Embodied carbon

Low

Space / material use

Medium

Output timing

Continuous process

Skill to repair

Intermediate

Note: Cost, carbon and footprint are rated against the other options for this same need, not in absolute terms.

Inputs

• Organic Waste

Outputs

• Biochar

Tutorials

• https://wiki.lowtechlab.org/wiki/Four_à_Biochar
• https://wiki.lowtechlab.org/wiki/L'amendement_au_Biocharbon

What this page does not tell you

No sizing or quantities: how much a technique yields, and how much a household needs, both depend on the build and the people, so the catalogue compares options rather than dimensioning them. It carries no bill of materials and no build sequence, and it is written for an oceanic, clay-soil climate (Normandy, France). Regulatory notes are indicative and need confirming locally.