I had a low productivity weekend, due to work, and spent too many hours in front of YouTube doing research, from a spark of inspiration, seeking more inspiration.

Ed's Biochar Tech – System Overview and Demonstration

https://www.youtube.com/watch?v=HsATDiIoqhg

Rocket Stove – Biochar, heater, and what not to do with water heating:
https://www.youtube.com/watch?v=vW7SeIfYmk0

Rocket Stove Build:

https://www.youtube.com/watch?v=gGY-GLcfd-A

Rocket Stove, Off-Grid Water Heater:

https://www.youtube.com/watch?v=jygYDu4nCCg

Rocket Stove, Build of Off-Grid Water Heater:

https://www.youtube.com/watch?v=VLjif2v2UBs

Endless hot water without electricity:

https://www.youtube.com/watch?v=5IRLVCJ1olA

https://www.permaculturenews.org/2013/05/20/how-to-build-a-rocket-stove-mass-water-heater/

www.billybon3s.com