Hi Theresa,
I think the ick factor does play into it. I mean, why don't we see a more widescale adoption of home scale composting toilets and use of said
compost on ornamental garden beds and perennials?
I believe we have a cultural fecophobia, and I think it's addressed as a topic in many of the humanure books available. Our aversion to our own feces and that of others and of animals does stem from, I believe, some instinct that informed our ancestors of the need to be discrete with human and animal wastes due to their potential to spread disease. While not accurate, the idea that ill health was conveyed or produced by bad smells (bad heumers) is consistent with some rudimentary ideas about sanitation and even composting (if it smells bad, you're doing something wrong).
But I digress. I would love to see a scalable home biogas system, especially one that aesthetically could pass for a regular water-based flush toilet system. I think that emulating the interface we already know, the big porcelain bowl with water in it that you flush when you're finished, is the best way to idiot-proof any system. I am not suggesting anyone's imperfections, simply stating that if you have a system that requires no extra steps or methodology to use properly, you don't have to worry about an uninitiated visitor doing anything wrong to a more complicated system and creating a big, smelly mess.
I only bring this up because it complicates, in some scenarios, the adoption of home biogas systems. Not in that it makes it really difficult or impossible, but that you need to account for it.
Do you know of any Home Biogas Systems on the market or are you looking to design and build one? There is a wealth of materials dating as far back as the 70s from Mother Earth News, talking about methane digesters in India for cooking and heating. A great many of the scaled-down versions I saw were made using commonly available materials, even freely obtained from the local waste stream, in some cases.
Are you looking at this hypothetically, or are you looking to build a home biogas system? How big are you looking? Where are you, and what's available?
-CK
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein