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/