Any method for doing anything that cannot be sustained for 100 billion years minimum is unsustainable. Nothing is sustainable in the long term. So why not just focus on getting by with an eye towards future requirements?

And let me add that the things people were doing 200 years ago were unsustainable. And 200 years hence?

My definition of sustainable? Can we keep it up for about 100 years? Which is time enough to figure out what to do next.

Which was brought up by a discussion of the Bloom Box fuel cell and water heater.

Now if you want to get more into the technology of the Bloom Box here are a couple of very pricey books that may help:

Biofuels for Fuel Cells (Integrated Environmental Technology)

That came out in 2006. I wonder if The Bloom Boys got some ideas there? Here is one of the latest books in the field:

Solid Oxide Fuel Cell Technology: Principles, Performance and Operations

I haven't read either of them so I can't give any recommendations.

Cross Posted at Power and Control